2017 AHA/ACC/HRS Guideline for Management of Patients With Ventricular Arrhythmias and the Prevention of Sudden Cardiac Death: A Report of the American College of Cardiology/American Heart Association Task Force on Clinical Practice Guidelines and the Heart Rhythm Society

The association between GRACE score at admission for myocardial infarction and the incidence of sudden cardiac arrests in long-term follow-up - the MADDEC study

Background. Sudden cardiac arrest (SCA), often also leading to sudden cardiac death (SCD), is a common complication in coronary artery disease. Despite the effort there is a lack of applicable prediction tools to identify those at high risk. We tested the association between the validated GRACE score and the incidence of SCA after myocardial infarction. Material and methods. A retrospective analysis of 1,985 patients treated for myocardial infarction (MI) between January 1st 2015 and December 31st 2018 and followed until the 31st of December of 2021. The main exposure variable was patients' GRACE score at the point of admission and main outcome variable was incident SCA after hospitalization. Their association was analyzed by subdistribution hazard (SDH) model analysis. The secondary endpoints included SCA in patients with no indication to implantable cardioverter-defibrillator (ICD) device and incident SCD. Results. A total of 1985 patients were treated for MI. Mean GRACE score at baseline was 118.7 (SD 32.0). During a median follow-up time of 5.3 years (IQR 3.8-6.1 years) 78 SCA events and 52 SCDs occurred. In unadjusted analyses one SD increase in GRACE score associated with over 50% higher risk of SCA (SDH 1.55, 95% CI 1.29-1.85, p < 0.0001) and over 40% higher risk for SCD (1.42, 1.12-1.79, p = 0.0033). The associations between SCA and GRACE remained statistically significant even with patients without indication for ICD device (1.57, 1.30-1.90, p < 0.0001) as well as when adjusting with patients LVEF and omitting the age from the GRACE score to better represent the severity of the cardiac event. The association of GRACE and SCD turned statistically insignificant when adjusting with LVEF. Conclusions. GRACE score measured at admission for MI associates with long-term risk for SCA.

Hemodynamic gain index and risk of ventricular arrhythmias: a prospective cohort study

Objectives: Hemodynamic gain index (HGI), a novel hemodynamic index obtained from cardiopulmonary exercise testing (CPX), is associated with adverse cardiovascular outcomes. However, its specific relationship with ventricular arrhythmias (VAs) is unknown. We aimed to assess the association of HGI with risk of VAs in a prospective study. Design: Hemodynamic gain index was estimated using heart rate and systolic blood pressure (SBP) responses ascertained in 1945 men aged 42-61 years during CPX from rest to maximum exercise, using the formula: [(Heart ratemax x SBPmax) - (Heart raterest x SBPrest)]/(Heart raterest x SBPrest). Cardiorespiratory fitness (CRF) was measured using respiratory gas exchange analysis. Hazard ratios (HRs) (95% confidence intervals, CIs) were estimated for VAs. Results: Over a median follow-up duration of 28.2 years, 75 cases of VA were recorded. In analysis adjusted for established risk factors, a unit (bpm/mmHg) higher HGI was associated with a decreased risk of VA (HR 0.72, 95% CI: 0.55-0.95). The results remained consistent on adjustment for lifestyle factors and comorbidities (HR 0.72, 95% CI: 0.55-0.93). Comparing the top versus bottom tertiles of HGI, the corresponding adjusted HRs (95% CIs) were 0.51 (0.27-0.96) and 0.52 (0.28-0.94), respectively. The associations were attenuated on addition of CRF to the model. HGI improved risk discrimination beyond established risk factors but not CRF. Conclusions: Higher HGI is associated with a reduced risk of VAs in middle-aged and older Caucasian men, but dependent on CRF levels. Furthermore, HGI improves the prediction of the long-term risk for VAs beyond established risk factors but not CRF.

A novel tool for arrhythmic risk stratification in desmoplakin gene variant carriers

BACKGROUND AND AIMS

Pathogenic desmoplakin (DSP) gene variants are associated with the development of a distinct form of arrhythmogenic cardiomyopathy known as DSP cardiomyopathy. Patients harbouring these variants are at high risk for sustained ventricular arrhythmia (VA), but existing tools for individualized arrhythmic risk assessment have proven unreliable in this population.

METHODS

Patients from the multi-national DSP-ERADOS (Desmoplakin SPecific Effort for a RAre Disease Outcome Study) Network patient registry who had pathogenic or likely pathogenic DSP variants and no sustained VA prior to enrolment were followed longitudinally for the development of first sustained VA event. Clinically guided, step-wise Cox regression analysis was used to develop a novel clinical tool predicting the development of incident VA. Model performance was assessed by c-statistic in both the model development cohort (n = 385) and in an external validation cohort (n = 86).

RESULTS

In total, 471 DSP patients [mean age 37.8 years, 65.6% women, 38.6% probands, 26% with left ventricular ejection fraction (LVEF) < 50%] were followed for a median of 4.0 (interquartile range: 1.6-7.3) years; 71 experienced first sustained VA events {2.6% [95% confidence interval (CI): 2.0, 3.5] events/year}. Within the development cohort, five readily available clinical parameters were identified as independent predictors of VA and included in a novel DSP risk score: female sex [hazard ratio (HR) 1.9 (95% CI: 1.1-3.4)], history of non-sustained ventricular tachycardia [HR 1.7 (95% CI: 1.1-2.8)], natural logarithm of 24-h premature ventricular contraction burden [HR 1.3 (95% CI: 1.1-1.4)], LVEF < 50% [HR 1.5 (95% CI: .95-2.5)], and presence of moderate to severe right ventricular systolic dysfunction [HR 6.0 (95% CI: 2.9-12.5)]. The model demonstrated good risk discrimination within both the development [c-statistic .782 (95% CI: .77-.80)] and external validation [c-statistic .791 (95% CI: .75-.83)] cohorts. The negative predictive value for DSP patients in the external validation cohort deemed to be at low risk for VA (<5% at 5 years; n = 26) was 100%.

CONCLUSIONS

The DSP risk score is a novel model that leverages readily available clinical parameters to provide individualized VA risk assessment for DSP patients. This tool may help guide decision-making for primary prevention implantable cardioverter-defibrillator placement in this high-risk population and supports a gene-first risk stratification approach.

Magnesium for disease treatment and prevention: emerging mechanisms and opportunities

Magnesium (Mg2+) is a commonly used dietary supplement for the prevention and treatment of diseases. However, the efficacy and mechanisms of action of Mg2+ in most diseases have been controversial because of conflicting findings in earlier studies. Recent clinical and preclinical studies provide novel insights into the use of Mg2+ for the treatment and prevention of diseases affecting different organ systems. In this review, we provide an overview of recent clinical evidence for, and controversies over, the medical benefits of Mg2+. In addition, we critically discuss recent advances in understanding the mechanisms of action of Mg2+, which could enable the development of novel targeted therapies.

Clinical Outcomes with Cardiac Resynchronization Therapy in Patients with Cardiac Sarcoidosis: A Systematic Review and Proportional Meta-analysis

BACKGROUND

Cardiac sarcoidosis (CS) is an inflammatory condition that can present with heart failure (HF). Cardiac resynchronization therapy (CRT) is known to improve clinical outcomes for patients with left bundle branch block in the general HF population. However, data about the outcomes of CRT in CS is limited.

METHODS

A systematic literature search was conducted using PubMed/Medline, Embase, and the Cochrane Library from inception to February 2024 to identify studies that reported clinical outcomes following the use of CRT in patients with CS. Data for outcomes was extracted, pooled, and analyzed. OpenMetaAnalyst was used for pooling untransformed proportions along with the corresponding 95% confidence intervals (CIs).

RESULTS

Five studies with a total of 176 CS patients who received CRT were included. The pooled incidence for all-cause mortality was 7.6% (95% CI: -3% to 18%), for HF-related hospitalizations 23.2% (95% CI: 2% to 43%), and for major adverse cerebral and cardiovascular events 27% (95% CI: 8% to 45%) after a mean follow-up of 60.1 (±48.7) months. The pooled left ventricular ejection fraction (LVEF) was 34.28% (95% CI: 29.88% to 38.68%) demonstrating an improvement of 3.75% in LVEF from baseline LVEF of 30.58% (95% CI: 24.68% to 36.48%). The mean New York Heart Association (NYHA) functional class was 2.16 (95% CI: 1.47 to 2.84) after CRT as compared to the baseline mean NYHA of 2.58 (95% CI: 2.29 to 2.86).

CONCLUSION

Although improvements were observed in LVEF and mean NYHA, mortality was high in CS patients with CRT.

Mortality in Recipients of Durable Left Ventricular Assist Devices Undergoing Ventricular Tachycardia Ablation

BACKGROUND

Left ventricular assist device (LVAD) recipients have a higher incidence of ventricular tachycardia (VT). However, the role of VT ablation in this population is not well-established.

OBJECTIVES

This single-center retrospective cohort study sought to examine the impact of post-LVAD implant VT ablation on survival.

METHODS

This retrospective study examined a cohort of patients that underwent LVAD implantation at Baylor St. Luke's Medical Center and Texas Heart Institute between January 2011 and January 2021. All-cause estimated mortality was compared across LVAD recipients based on the incidence of VT, timing of VT onset, and the occurrence and timing of VT ablation utilizing Kaplan-Meier survival analysis and Cox proportional hazards models.

RESULTS

Post-implant VT occurred in 53% of 575 LVAD recipients. Higher mortality was seen among patients with post-implant VT within a year of implantation (HR: 1.62 [95% CI: 1.15-2.27]). Among this cohort, patients who were treated with a catheter ablation had superior survival compared with patients treated with medical therapy alone for the 45 months following VT onset (HR: 0.48 [95% CI: 0.26-0.89]). Moreover, performance of an ablation in this population aligned mortality rates with those who did not experience post-implant VT (HR: 1.18 [95% CI: 0.71-1.98]).

CONCLUSIONS

VT occurrence within 1 year of LVAD implantation was associated with worse survival. However, performance of VT ablation in this population was correlated with improved survival compared with medical management alone. Among patients with refractory VT, catheter ablation aligned survival with other LVAD participants without post-implant VT. Catheter ablation of VT is associated with improved survival in LVAD recipients, but further prospective randomized studies are needed to compare VT ablation to medical management in LVAD recipients.

The burden of sudden cardiac arrest in the setting of acute coronary syndrome

BACKGROUND

The incidence of sudden cardiac arrest (SCA) during acute coronary syndrome is somewhat unclear, since often subjects dying before the first healthcare contact are not included in the estimates. We aimed to investigate the complete incidence of SCA during ACS.

METHODS

The study population consists of two cohorts. The first cohort includes 472 ACS patients from Northern Ostrobothnia, Finland from year 2016 and the second cohort 162 autopsy-verified SCD subjects (extrapolated) from the same region and year, whose death was attributable to coronary artery disease (CAD) and ACS. An extrapolation of SCA incidence during ACS was done by utilizing autopsy data and data from prior autopsy study on this sample.

RESULTS

The overall incidence of SCA in the setting of ACS was 17.5%. The incidence of SCA was 20.6% in all ACS subjects without prior CAD diagnosis, and 25.4% in STEMI subjects without prior CAD diagnosis. In subjects with previously diagnosed CAD, the incidence of SCA was 10.9% in all ACS subjects and 16.1% in STEMI subjects. There was a statistically significant difference in the incidence of SCA between subjects with and without prior CAD diagnosis (p = 0.0052).

CONCLUSION

The inclusion of ACS-SCA subjects dying before the first emergency medical service (EMS) contact results in a higher and likely more accurate estimation of SCA during ACS. The incidence of SCA was higher among subjects without prior CAD diagnosis. The high mortality rate highlights the importance of early ACS detection to reduce the burden of CAD-related premature deaths.

Scar-Related Monomorphic Ventricular Tachycardia After Treated Right Ventricular Metastatic Diffuse Large B-Cell Lymphoma

A patient with ventricular tachycardia (VT) and right ventricular (RV) metastatic diffuse large B-cell lymphoma had persistent RV gadolinium enhancement following chemotherapy and disease remission. Electrophysiology study demonstrated inducible sustained monomorphic VT requiring subcutaneous implantable cardioverter-defibrillator implantation. This highlights the arrhythmogenic potential of residual scar after resolution of cardiac masses.

2024 AHA/ACC/AMSSM/HRS/PACES/SCMR Guideline for the Management of Hypertrophic Cardiomyopathy: A Report of the American Heart Association/American College of Cardiology Joint Committee on Clinical Practice Guidelines

AIM

The "2024 AHA/ACC/AMSSM/HRS/PACES/SCMR Guideline for the Management of Hypertrophic Cardiomyopathy" provides recommendations to guide clinicians in the management of patients with hypertrophic cardiomyopathy.

METHODS

A comprehensive literature search was conducted from September 14, 2022, to November 22, 2022, encompassing studies, reviews, and other evidence on human subjects that were published in English from PubMed, EMBASE, the Cochrane Library, the Agency for Healthcare Research and Quality, and other selected databases relevant to this guideline. Additional relevant studies, published through May 23, 2023, during the guideline writing process, were also considered by the writing committee and added to the evidence tables, where appropriate.

STRUCTURE

Hypertrophic cardiomyopathy remains a common genetic heart disease reported in populations globally. Recommendations from the "2020 AHA/ACC Guideline for the Diagnosis and Treatment of Patients With Hypertrophic Cardiomyopathy" have been updated with new evidence to guide clinicians.

Missense and Non-Missense Lamin A/C Gene Mutations Are Similarly Associated with Major Arrhythmic Cardiac Events: A 20-Year Single-Centre Experience

Arrhythmic risk stratification in patients with Lamin A/C gene (LMNA)-related cardiomyopathy influences clinical decisions. An implantable cardioverter defibrillator (ICD) should be considered in patients with an estimated 5-year risk of malignant ventricular arrhythmia (MVA) of ≥10%. The risk prediction score for MVA includes non-missense LMNA mutations, despite their role as an established risk factor for sudden cardiac death (SCD) has been questioned in several studies. The purpose of this study is to investigate cardiac features and find gene-phenotype correlations that would contribute to the evidence on the prognostic implications of non-missense vs. missense mutations in a cohort of LMNA mutant patients. An observational, prospective study was conducted in which 54 patients positive for a Lamin A/C mutation were enrolled, and 20 probands (37%) were included. The median age at first clinical manifestation was 41 (IQR 19) years. The median follow-up was 8 years (IQR 8). The type of LMNA gene mutation was distributed as follows: missense in 26 patients (48%), non-frameshift insertions in 16 (30%), frameshift deletions in 5 (9%), and nonsense in 7 (13%). Among the missense mutation carriers, two (8%) died and four (15%) were admitted onto the heart transplant list or underwent transplantation, with a major adverse cardiovascular event (MACE) rate of 35%. No statistically significant differences in MACE prevalence were identified according to the missense and non-missense mutation groups (p value = 0.847). Our data shift the spotlight on this considerable topic and could suggest that some missense mutations may deserve attention regarding SCD risk stratification in real-world clinical settings.

Sodium glucose cotransporter 2 inhibitors with cardiac arrhythmias in patients with type 2 diabetes mellitus: a systematic review and meta-analysis of randomized placebo-controlled trials

BACKGROUND

Type 2 diabetes mellitus (T2DM) is associated with an increased risk of cardiac arrhythmias, which increases serious morbidity and mortality. Novel hypoglycemic drug sodium glucose cotransporter 2 (SGLT2) inhibitor has shown sufficient cardiovascular benefits in cardiovascular outcome trials.

OBJECTIVE

This systematic review and meta-analysis aimed to investigate the relationship between SGLT2 inhibitors and cardiac arrhythmias in patients with T2DM.

METHODS

We searched on PubMed and ClinicalTrials.gov for at least 24 weeks of randomized double-blind placebo-controlled trials involving T2DM subjects assigned to SGLT2 inhibitors or placebo as of May 5, 2023. Risk ratio (RR) with 95% confidence interval (CI) were used for binary variables. Primary outcomes included atrial arrhythmias, ventricular arrhythmias, bradyarrhythmias, cardiac arrest, and atrial fibrillation/atrial flutter. Secondary outcomes comprised atrial fibrillation, atrial flutter, ventricular fibrillation, ventricular tachycardia, atrioventricular block, and sinus node dysfunction.

RESULTS

We included 32 trials covering 60,594 T2DM patients (SGLT2 inhibitor 35,432; placebo 25,162; mean age 53.9 to 68.5 years). SGLT2 inhibitors significantly reduced the risk of atrial arrhythmias (RR 0.86; 95%CI 0.74-0.99; P = 0.04) or atrial fibrillation/flutter (RR 0.85; 95%CI 0.74-0.99; P = 0.03) compared to placebo; in subgroup analysis, SGLT2 inhibitors achieved a consistent effect with overall results in T2DM with high cardiovascular risk or follow-up > 1 year populations. There was no substantial evidence to suggest that SGLT2 inhibitors reduced the risk of ventricular arrhythmias (RR 0.94; 95%CI 0.71-1.26; P = 0.69) and cardiac arrest (RR 0.88; 95%CI 0.66-1.18; P = 0.39). A neutral effect of SGLT2 inhibitors on bradyarrhythmias was observed (RR 1.02; 95%CI 0.79-1.33; P = 0.85). SGLT2 inhibitors had no significant impact on all secondary outcomes compared to placebo, while it had borderline effect for atrial fibrillation.

CONCLUSION

SGLT2 inhibitors were associated with a reduced risk of atrial arrhythmias in patients with T2DM. Our results support the use of SGLT2 inhibitors in T2DM with high cardiovascular risk populations. We also recommend the long-term use of SGLT2 inhibitors to achieve further benefits.

Ventricular Tachycardia and Hospital Readmission in Patients Discharged From the Hospital After an Acute Myocardial Infarction

Background

Although ventricular tachycardia (VT) occurring during hospitalization for an acute myocardial infarction (AMI) increases mortality risk, its relationship with 30-day postdischarge rehospitalization has not been examined.

Methods

Using data from the Worcester Heart Attack Study, we examined the association between early (during the first 48 hours of admission) and late (after 48 hours from admission) VT with 30-day postdischarge all-cause and cardiovascular disease (CVD)-related rehospitalization while analytically controlling for several demographic and clinical factors.

Results

The study population consisted of 3534 patients who were hospitalized with an AMI between 2005 and 2015 (average age, 67.2 years; 40.7% women); VT occurred in 452 patients (13.7%), with the majority of instances (81.2%) occurring within 48 hours of admission. The 30-day all-cause rehospitalization rate was 17.3%, with 70.9% of the hospitalizations related to CVD. The odds of rehospitalization were 1.63 times (95% confidence interval [CI] = 0.99-2.69) and 1.12 times (95% CI = 0.83-1.51) higher for patients with AMI who developed late VT and early VT, respectively, compared to patients who did not develop VT. The risk of rehospitalization among patients with late VT was higher (odds ratio = 2.22 (95% CI = 0.79-6.26) in those with ST-segment-elevation AMI, compared to those with non-ST-segment-elevation AMI (odds ratio = 1.45 (95% CI = 0.81-2.57); early VT was not associated with rehospitalization in patients with either AMI subtype. No significant association was present between the occurrence of VT and CVD-related rehospitalization.

Conclusions

Patients who develop late VT may experience a higher risk of 30-day rehospitalization following hospital discharge for AMI, especially among those with ST-segment-elevation AMI. Larger studies are needed to confirm our findings.

Feasibility of remote monitoring for fatal coronary heart disease using Apple Watch ECGs

Background

Fatal coronary heart disease (FCHD) is often described as sudden cardiac death (affects >4 million people/year), where coronary artery disease is the only identified condition. Electrocardiographic artificial intelligence (ECG-AI) models for FCHD risk prediction using ECG data from wearable devices could enable wider screening/monitoring efforts.

Objectives

To develop a single-lead ECG-based deep learning model for FCHD risk prediction and assess concordance between clinical and Apple Watch ECGs.

Methods

An FCHD single-lead ("lead I" from 12-lead ECGs) ECG-AI model was developed using 167,662 ECGs (50,132 patients) from the University of Tennessee Health Sciences Center. Eighty percent of the data (5-fold cross-validation) was used for training and 20% as a holdout. Cox proportional hazards (CPH) models incorporating ECG-AI predictions with age, sex, and race were also developed. The models were tested on paired clinical single-lead and Apple Watch ECGs from 243 St. Jude Lifetime Cohort Study participants. The correlation and concordance of the predictions were assessed using Pearson correlation (R), Spearman correlation (ρ), and Cohen's kappa.

Results

The ECG-AI and CPH models resulted in AUC = 0.76 and 0.79, respectively, on the 20% holdout and AUC = 0.85 and 0.87 on the Atrium Health Wake Forest Baptist external validation data. There was moderate-strong positive correlation between predictions (R = 0.74, ρ = 0.67, and κ = 0.58) when tested on the 243 paired ECGs. The clinical (lead I) and Apple Watch predictions led to the same low/high-risk FCHD classification for 99% of the participants. CPH prediction correlation resulted in an R = 0.81, ρ = 0.76, and κ = 0.78.

Conclusion

Risk of FCHD can be predicted from single-lead ECGs obtained from wearable devices and are statistically concordant with lead I of a 12-lead ECG.

Incidence and Predictors for Recurrence of Ventricular Arrhythmia Presenting During Acute Myocarditis: A Multicenter Study

BACKGROUND

Management of acute myocarditis (AM) patients experiencing ventricular arrhythmia (VA) during acute illness is controversial, especially regarding early implantable cardioverter-defibrillator (ICD) implantation.

OBJECTIVES

The purpose of this study was to evaluate the prevalence of and find predictors for long-term sustained VA recurrence and overall mortality among AM patients with VA.

METHODS

This was a multicenter retrospective analysis of AM patients (verified by cardiac magnetic resonance imaging or myocardial biopsy) with documented VA during the acute illness ("initial VA"). Patients with history of myocardial infarction, heart failure, or VA were excluded. The study endpoint was a composite of sustained VA and overall mortality during follow-up.

RESULTS

The study included 69 AM patients with initial VA: sustained monomorphic ventricular tachycardia (MMVT) (n = 25), sustained polymorphic ventricular tachycardia (VT)/ventricular fibrillation (n = 13), and nonsustained VT (n = 31). Age was 44 ± 13 years, and 23 of 69 (33.3%) were women. During median follow-up of 5.5 years, 27 of 69 (39%) patients reached the composite endpoint including sustained VA (n = 24) and death (n = 11). Initial MMVT, predischarge left ventricular dysfunction (left ventricular ejection fraction <50%), and anteroseptal delayed enhancement on cardiac magnetic resonance imaging were significantly associated with the composite endpoint. On multivariable analysis, initial MMVT (HR: 5.17; 95% CI: 1.81-14.6; P = 0.001) and predischarge LV dysfunction (HR: 4.57; 95% CI: 1.83-11.5; P = 0.005) were independently associated with the composite endpoint. Using these 2 predictors, we could delineate subgroups with low (∼4%), medium (∼42%), and high (∼82%) 10-year incidence of composite endpoint.

CONCLUSIONS

AM patients presenting with VA have high incidence of sustained VA recurrence and mortality posthospitalization. Initial MMVT and predischarge LV dysfunction are independently associated with VA recurrence and mortality. Implantable cardioverter-defibrillator implantation may be considered in such high-risk patients.

Clinical characteristics and follow-up of complex arrhythmias associated with RYR2 gene mutations in children

Objective

The aim of this study was to analyze the diagnosis, treatment, and follow-up of six cases of complex arrhythmias associated with RYR2 gene mutations in children.

Method

A retrospective analysis was conducted on six children diagnosed with complex arrhythmias associated with RYR2 gene mutations. The study included an analysis of the age of onset, initial symptoms, electrocardiographic characteristics, genetic results, treatment course, and follow-up outcomes.

Results

Among the six cases included in the study, there were four males and two females, with an average age of 3.5 ± 0.5 years. The average time from initial symptoms to diagnosis was 2.7 ± 1.3 years. The most common clinical manifestation was syncope, with exercise and emotions being the main triggers. All six children had de novo missense mutations in the RYR2 gene identified through whole-exome sequencing. In Holter electrocardiogram, atrial arrhythmias and sinoatrial node dysfunction were commonly observed in younger children. Four patients underwent exercise stress testing, with two experiencing bidirectional ventricular premature contractions and two experiencing bidirectional ventricular tachycardia and polymorphic ventricular tachycardia. Initial treatment involved oral propranolol or metoprolol. If arrhythmias persisted, flecainide or propafenone was added as adjunctive therapy. Two patients received permanent cardiac pacemaker treatment (single chamber ventricular pacemaker, VVI). All patients survived, with three experiencing occasional syncope during treatment. The follow-up period ranged from 12 to 37 months, with an average follow-up time of 24.3 ± 3.7 months.

Conclusion

Complex arrhythmias associated with RYR2 gene mutations in children can present with various clinical manifestations. Atrial arrhythmias combined with sinoatrial node dysfunction are commonly observed in younger children, and the combination of pharmacological therapy and cardiac pacemaker treatment yields favourable treatment outcomes.

A Modular Communicative Leadless Pacing-Defibrillator System

BACKGROUND

The subcutaneous implantable cardioverter-defibrillator (ICD) is associated with fewer lead-related complications than a transvenous ICD; however, the subcutaneous ICD cannot provide bradycardia and antitachycardia pacing. Whether a modular pacing-defibrillator system comprising a leadless pacemaker in wireless communication with a subcutaneous ICD to provide antitachycardia and bradycardia pacing is safe remains unknown.

METHODS

We conducted a multinational, single-group study that enrolled patients at risk for sudden death from ventricular arrhythmias and followed them for 6 months after implantation of a modular pacemaker-defibrillator system. The safety end point was freedom from leadless pacemaker-related major complications, evaluated against a performance goal of 86%. The two primary performance end points were successful communication between the pacemaker and the ICD (performance goal, 88%) and a pacing threshold of up to 2.0 V at a 0.4-msec pulse width (performance goal, 80%).

RESULTS

We enrolled 293 patients, 162 of whom were in the 6-month end-point cohort and 151 of whom completed the 6-month follow-up period. The mean age of the patients was 60 years, 16.7% were women, and the mean (±SD) left ventricular ejection fraction was 33.1±12.6%. The percentage of patients who were free from leadless pacemaker-related major complications was 97.5%, which exceeded the prespecified performance goal. Wireless-device communication was successful in 98.8% of communication tests, which exceeded the prespecified goal. Of 151 patients, 147 (97.4%) had pacing thresholds of 2.0 V or less, which exceeded the prespecified goal. The percentage of episodes of arrhythmia that were successfully terminated by antitachycardia pacing was 61.3%, and there were no episodes for which antitachycardia pacing was not delivered owing to communication failure. Of 162 patients, 8 died (4.9%); none of the deaths were deemed to be related to arrhythmias or the implantation procedure.

CONCLUSIONS

The leadless pacemaker in wireless communication with a subcutaneous ICD exceeded performance goals for freedom from major complications related to the leadless pacemaker, for communication between the leadless pacemaker and subcutaneous ICD, and for the percentage of patients with a pacing threshold up to 2.0 V at a 0.4-msec pulse width at 6 months. (Funded by Boston Scientific; MODULAR ATP ClinicalTrials.gov NCT04798768.).

Soluble suppression of tumorigenicity 2 associated with major adverse cardiac events in children with myocarditis

Objective

Soluble suppression of tumorigenicity 2 (sST2) is associated with the prognosis of some cardiac diseases, but studies on sST2 and the prognosis of patients with myocarditis are rare. This study investigated the relationship between major adverse cardiovascular events (MACEs) and sST2 during hospitalization in pediatric patients with myocarditis.

Methods

This was a single-center retrospective cohort study. A total of 252 patients aged ≤14 years diagnosed with myocarditis were enrolled. Events during the hospitalization were defined as MACEs (all-cause death > new heart failure > ventricular arrhythmia).

Results

A total of 25 people had MACEs during their hospital stay. The mortality during hospitalization was 6/23 (26%) in patients with heart failure and 3/10 (30%) in patients with ventricular arrhythmias. After including these risk factors in a multivariate logistic regression analysis, NT-proBNP (OR 4.323; 95% CI, 2.433-7.679; p < 0.001) and sST2 (OR 1.020; 95% CI, 1.003-1.037; p = 0.022) remained statistically significant and were independent risk factors for MACEs during hospitalization in pediatric myocarditis patients.

Conclusions

Elevated levels of NT-proBNP and sST2 were independently associated with major adverse cardiovascular events during hospitalization in children with myocarditis, and both showed good predictive efficacy.

Use of three-dimensional electroanatomic mapping for epicardial access: needle tracking, electrographic characteristics, and clinical application

AIMS

Pericardiocentesis is usually completed under fluoroscopy. The electroanatomic mapping (EAM) system allows visualizing puncture needle tip (NT) while displaying the electrogram recorded from NT, making it possible to obtain epicardial access (EA) independent of fluoroscopy. This study was designed to establish and validate a technique by which EA is obtained under guidance of three-dimensional (3D) EAM combined with NT electrogram.

METHODS AND RESULTS

3D shell of the heart was generated, and the NT was made trackable in the EAM system. Unipolar NT electrogram was continuously monitored. Penetration into pericardial sac was determined by an increase in NT potential amplitude and an injury current. A long guidewire of which the tip was also visible in the EAM system was advanced to confirm EA. Epicardial access was successfully obtained without complication in 13 pigs and 22 patients. In the animals, NT potential amplitude was 3.2 ± 1.0 mV when it was located in mediastinum, 5.2 ± 1.6 mV when in contact with fibrous pericardium, and 9.8 ± 2.8 mV after penetrating into pericardial sac (all P ≤ 0.001). In human subjects, it measured 1.54 ± 0.40 mV, 3.61 ± 1.08 mV, and 7.15 ± 2.88 mV, respectively (all P < 0.001). Fluoroscopy time decreased in every 4-5 cases (64 ± 15, 23 ± 17, and 0 s for animals 1-4, 5-8, 9-13, respectively, P = 0.01; 44 ± 23, 31 ± 18, 4±7 s for patients 1-7, 8-14, 15-22, respectively, P < 0.001). In five pigs and seven patients, EA was obtained without X-ray exposure.

CONCLUSION

By tracking NT in the 3D EAM system and continuously monitoring the NT electrogram, it is feasible and safe to obtain EA with minimum or no fluoroscopic guidance.

A Novel Nomogram for Predicting Early Rebleeding After Endoscopic Treatment of Esophagogastric Variceal Hemorrhage

BACKGROUND

Early rebleeding is a significant complication of endoscopic treatment for esophagogastric variceal hemorrhage (EGVH). However, a reliable predictive model is currently lacking.

AIMS

To identify risk factors for rebleeding within 6 weeks and establish a nomogram for predicting early rebleeding after endoscopic treatment of EVGH.

METHODS

Demographic information, comorbidities, preoperative evaluation, endoscopic features, and laboratory tests were collected from 119 patients who were first endoscopic treatment for EGVH. Independent risk factors for early rebleeding were determined through least absolute shrinkage and selection operator logistic regression. The discrimination, calibration, and clinical utility of the nomogram were assessed and compared with the model for end-stage liver disease (MELD), Child-Pugh, and albumin-bilirubin (ALBI) scores using receiver-operating characteristic (ROC) curves, calibration plots, and decision curve analyses (DCA).

RESULTS

Early rebleeding occurred in 39 patients (32.8%) within 6 weeks after endoscopic treatment. Independent early rebleeding factors included gastric variceal hemorrhage (GVH), concomitant hepatocellular carcinoma (HCC), international normalized ratio (INR), and creatinine. The nomogram demonstrated exceptional calibration and discrimination capability. The area under the curve for the nomogram was 0.758 (95% CI 0.668-0.848), and it was validated at 0.71 through cross-validation and bootstrapping validation. The DCA and ROC curves demonstrated that the nomogram outperformed the MELD, Child-Pugh, and ALBI scores.

CONCLUSIONS

Compared with existing prediction scores, the nomogram demonstrated superior discrimination, calibration, and clinical applicability for predicting rebleeding in patients with EGVH after endoscopic treatment. Therefore, it may assist clinicians in the early implementation of aggressive treatment and follow-up.

Class 1C Antiarrhythmics for Premature Ventricular Complex Suppression in Nonischemic Cardiomyopathy With Implantable Cardioverter-Defibrillators

BACKGROUND

Premature ventricular complexes (PVCs) are common and associated with worse outcomes in patients with heart failure. Class 1C antiarrhythmic drugs (AADs) effectively suppress PVCs, but guidelines currently restrict their use in structural heart disease.

OBJECTIVES

This study aimed to assess the safety and efficacy of class 1C AADs in patients with nonischemic cardiomyopathy (NICM) and implantable cardioverter-defibrillators (ICDs).

METHODS

All patients with NICM and an ICD treated with flecainide or propafenone at the Hospital of the University of Pennsylvania between 2014 and 2022 were identified. PVC burden, left ventricular ejection fraction (LVEF), and biventricular pacing percentage were compared before and during class 1C AAD treatment. Safety outcomes included sustained atrial and ventricular arrhythmias, heart failure admissions, and death.

RESULTS

We identified 34 patients, 23 receiving flecainide and 11 propafenone. Most patients (62%) had failed other AADs or catheter ablation (68%) prior to class 1C AAD initiation. PVC burden decreased from 20% ± 13% to 6% ± 7% (P < 0.001), LVEF increased from 33% ± 9% to 37% ± 10% (P = 0.01), and biventricular pacing percentage increased from 85% ± 9% to 93% ± 7% (P = 0.01). Sustained ventricular tachycardia (2 vs 9 patients) and admissions for decompensated heart failure (2 vs 3 patients) decreased compared with the 12 months prior to class 1C AAD initiation.

CONCLUSIONS

Class 1C AADs effectively suppressed PVCs in patients with NICM and ICDs, leading to increases in LVEF and biventricular pacing percentage. In this limited sample, their use was safe. Larger studies are needed to confirm the safety of this approach.

Conduction system disease in cardiac amyloidosis

Cardiac amyloidosis (CA) has diverse and deleterious effects on the conductive system. Atrial fibrillation is by far the most common electrophysiological manifestation of CA and is associated with more mortality, morbidity, and hospitalizations. While AF increases the risk of thrombosis regardless of the CHA2DS2-VASc score, the risk of thromboembolism seems to be high even in CA patients without AF. AV Nodal disease is prevalent and may precede the diagnosis of CA. The incidence of ventricular arrhythmias remains disputed, and the role of implantable cardioverter defibrillator devices in CA patients is controversial. Newer therapies targeted against specific types of CA have been developed, but their effects on conductive system disease are not well studied.

Mortality Benefit Among Primary Prevention Implantable Cardioverter-Defibrillator Recipients on Contemporary Heart Failure Treatment

BACKGROUND

Past clinical trials have shown the benefit of implantable cardioverter-defibrillators (ICDs) for reducing sudden cardiac death in at-risk patients. However, heart failure management and ICD technology have changed since these trials were first published. An updated assessment of ICD mortality benefit is needed.

OBJECTIVES

The purpose of this study was to compare mortality rates between patients with a primary prevention (PP) indication for an ICD who did or did not receive an ICD using a contemporary, real-world data set.

METHODS

Data was obtained from a large electronic health record data set covering patients in the United States from 2012 through 2020 who had a PP indication for an ICD and survived at least 1-year postindication.

RESULTS

A total of 25,296 patients were identified as having a PP indication for ICD implantation, of which 2,118 (8.4%) were treated with an ICD within a year. Treated patients were younger than nontreated patients (age 63.4 years vs 66.1 years) with a smaller proportion of women (25.0% vs 36.7%). After 4-to-1 propensity matching, treated patients had similar clinical characteristics to nontreated patients. A Cox proportional hazard model estimated a 24.3% lower risk of all-cause mortality in patients when treated vs not treated with an ICD (HR: 0.757; 95% CI: 0.678-0.835; P <0.001). There was no detectable difference in ICD benefit between patients with ischemic and nonischemic heart disease (P = 0.50).

CONCLUSIONS

ICD treatment of patients with a PP indication is associated with improved mortality even in the context of evolving adjunctive HF treatment, consistent with earlier landmark trials.

Ventricular Arrhythmias After Primary Percutaneous Coronary Intervention for STEMI

Importance

Currently, mortality risk for patients with ST-segment elevation myocardial infarction (STEMI) treated with primary percutaneous coronary intervention (PCI) with an uncomplicated postprocedure course is low. Less is known regarding the risk of in-hospital ventricular tachycardia (VT) and ventricular fibrillation (VF).

Objective

To evaluate the risk of late VT and VF after primary PCI for STEMI.

Design, Setting, and Participants

This cohort study included adults aged 18 years or older with STEMI treated with primary PCI between January 1, 2015, and December 31, 2018, identified in the US National Cardiovascular Data Registry Chest Pain-MI Registry. Data were analyzed from April to December 2020.

Main Outcomes and Measures

Multivariable logistic regression was used to evaluate the risk of late VT (≥7 beat run of VT during STEMI hospitalization ≥1 day after PCI) or VF (any episode of VF≥1 day after PCI) associated with cardiac arrest and associations between late VT or VF and in-hospital mortality in the overall cohort and a cohort with uncomplicated STEMI without prior myocardial infarction or heart failure, systolic blood pressure less than 90 mm Hg, cardiogenic shock, cardiac arrest, reinfarction, or left ventricular ejection fraction (LVEF) less than 40%.

Results

A total of 174 126 eligible patients with STEMI were treated with primary PCI at 814 sites in the study; 15 460 (8.9%) had VT or VF after primary PCI, and 4156 (2.4%) had late VT or VF. Among the eligible patients, 99 905 (57.4%) at 807 sites had uncomplicated STEMI. The median age for patients with late VT or VF overall was 63 years (IQR, 55-73 years), and 75.5% were men; the median age for patients with late VT or VF with uncomplicated STEMI was 60 years (IQR, 53-69 years), and 77.7% were men. The median length of stay was 3 days (IQR, 2-7 days) for the overall cohort with late VT or VF and 3 days (IQR, 2-4 days) for the cohort with uncomplicated STEMI with late VT or VF. The risk of late VT or VF was 2.4% (overall) and 1.7% (uncomplicated STEMI). Late VT or VF with cardiac arrest occurred in 674 patients overall (0.4%) and in 117 with uncomplicated STEMI (0.1%). LVEF was the most significant factor associated with late VT or VF with cardiac arrest (adjusted odds ratio [AOR] for every 5-unit decrease ≤40%: 1.67; 95% CI, 1.54-1.85). Late VT or VF events were associated with increased odds of in-hospital mortality in the overall cohort (AOR, 6.40; 95% CI, 5.63-7.29) and the cohort with uncomplicated STEMI (AOR, 8.74; 95% CI, 6.53-11.70).

Conclusions and Relevance

In this study, a small proportion of patients with STEMI treated with primary PCI had late VT or VF. However, late VT or VF with cardiac arrest was rare, particularly in the cohort with uncomplicated STEMI. This information may be useful when determining the optimal timing for hospital discharge after STEMI.

The importance of variant reinterpretation in inherited cardiovascular diseases: Establishing the optimal timeframe

Inherited cardiovascular diseases are rare diseases that are difficult to diagnose by non-expert professionals. Genetic analyses play a key role in the diagnosis of these diseases, in which the identification of a pathogenic genetic variant is often a diagnostic criterion. Therefore, genetic variant classification and routine reinterpretation as data become available represent one of the main challenges associated with genetic analyses. Using the genetic variants identified in an inherited cardiovascular diseases unit during a 10-year period, the objectives of this study were: 1) to evaluate the impact of genetic variant reinterpretation, 2) to compare the reclassification rates between different cohorts of cardiac channelopathies and cardiomyopathies, and 3) to establish the most appropriate periodicity for genetic variant reinterpretation. All the evaluated cohorts (full cohort of inherited cardiovascular diseases, cardiomyopathies, cardiac channelopathies, hypertrophic cardiomyopathy, dilated cardiomyopathy, arrhythmogenic cardiomyopathy, Brugada syndrome, long QT syndrome and catecholaminergic polymorphic ventricular tachycardia) showed reclassification rates above 25%, showing even higher reclassification rates when there is definitive evidence of the association between the gene and the disease in the cardiac channelopathies. Evaluation of genetic variant reclassification rates based on the year of the initial classification showed that the most appropriate frequency for the reinterpretation would be 2 years, with the possibility of a more frequent reinterpretation if deemed convenient. To keep genetic variant classifications up to date, genetic counsellors play a critical role in the reinterpretation process, providing clinical evidence that genetic diagnostic laboratories often do not have at their disposal and communicating changes in classification and the potential implications of these reclassifications to patients and relatives.

Left ventricular entropy is a novel predictor of major adverse cardiac events (MACE) in patients with coronary atherosclerosis: a multi-center study

OBJECTIVES

To investigate the incremental prognostic value of left ventricular (LV) entropy in a large multi-center population with coronary atherosclerotic heart disease (CAD).

BACKGROUND

Current risk stratification of patients with CAD is imprecise and not accurate enough.

METHODS

A total of 314 CAD patients who underwent cardiovascular magnetic resonance (CMR) late gadolinium enhancement (LGE) at two medical centers in China between October 2015 and July 2022 were included in this study. Additionally, the 193 patients under 3.0-T field also underwent CMR T1 mapping. LV entropy and extracellular volume (ECV) were calculated from the LGE image of LV myocardium, and major adverse cardiac events (MACEs) were analyzed.

RESULTS

Among 314 patients, 110 experienced MACE during a median follow-up of 13 months. The risk of MACE was significantly increased in the high entropy group (log-rank p < 0.001). Entropy maintained an independent association with MACE in a multivariable model including left ventricular ejection fraction (LVEF) and LGE (HR = 1.78; p = 0.001). In addition, the primary endpoint events prognostic value was significantly improved by adding LV entropy to the baseline multivariable model (C-statistic improvement: 0.785-0.818, Delong test: p = 0.001). Similarly, among 193 3.0-T field patients, adding LV entropy to the multivariable baseline model significantly improved the prognostic value of the model for MACE (C-statistic improvement: 0.820-0.898, Delong test: p = 0.004).

CONCLUSION

CMR-assessed LV entropy is a powerful independent predictor of MACE in patients with CAD, incremental to common clinical and CMR risk factors, including LVEF, LGE, Native T1, and ECV.

CLINICAL RELEVANCE STATEMENT

Left ventricular entropy is a powerful independent predictor of major adverse cardiac events in patients with coronary atherosclerotic heart disease, incremental to common clinical and cardiac magnetic resonance risk factors.

KEY POINTS

• Left ventricular entropy, a novel cardiac magnetic resonance parameter of myocardial heterogeneity, demonstrated a robust prognostic association with major adverse cardiac events beyond guideline-based, clinical risk markers. • Entropy can have an important role in the primary prevention of major adverse cardiac events in patients with coronary atherosclerotic heart disease. • Compared with late gadolinium enhancement, extracellular volume, and native T1, entropy could be used to more comprehensively characterize the heterogeneity of left ventricular myocardium.

Role of Nuclear Imaging in Cardiac Stereotactic Body Radiotherapy for Ablation of Ventricular Tachycardia

Ventricular tachycardia (VT) is a life-threatening arrhythmia common in patients with structural heart disease or nonischemic cardiomyopathy. Many VTs originate from regions of fibrotic scar tissue, where delayed electrical signals exit scar and re-enter viable myocardium. Cardiac stereotactic body radiotherapy (SBRT) has emerged as a completely noninvasive alternative to catheter ablation for the treatment of recurrent or refractory ventricular tachycardia. While there is no common consensus on the ideal imaging workflow, therapy planning for cardiac SBRT often combines information from a plurality of imaging modalities including MRI, CT, electroanatomic mapping and nuclear imaging. MRI and CT provide detailed anatomic information, and late enhancement contrast imaging can indicate regions of fibrosis. Electroanatomic maps indicate regions of heterogenous conduction voltage or early activation which are indicative of arrhythmogenic tissue. Some early clinical adopters performing cardiac SBRT report the use of myocardial perfusion and viability nuclear imaging to identify regions of scar. Nuclear imaging of hibernating myocardium, inflammation and sympathetic innervation have been studied for ventricular arrhythmia prognosis and in research relating to catheter ablation of VT but have yet to be studied in their potential applications for cardiac SBRT. The integration of information from these many imaging modalities to identify a target for ablation can be challenging. Multimodality image registration and dedicated therapy planning tools may enable higher target accuracy, accelerate therapy planning workflows and improve patient outcomes. Understanding the pathophysiology of ventricular arrhythmias, and localizing the arrhythmogenic tissues, is vital for successful ablation with cardiac SBRT. Nuclear imaging provides an arsenal of imaging strategies to identify regional scar, hibernation, inflammation, and sympathetic denervation with some advantages over alternative imaging strategies.

Impacts of gene variants on drug effects-the foundation of genotype-guided pharmacologic therapy for long QT syndrome and short QT syndrome

The clinical significance of optimal pharmacotherapy for inherited arrhythmias such as short QT syndrome (SQTS) and long QT syndrome (LQTS) has been increasingly recognised. The advancement of gene technology has opened up new possibilities for identifying genetic variations and investigating the pathophysiological roles and mechanisms of genetic arrhythmias. Numerous variants in various genes have been proven to be causative in genetic arrhythmias. Studies have demonstrated that the effectiveness of certain drugs is specific to the patient or genotype, indicating the important role of gene-variants in drug response. This review aims to summarize the reported data on the impact of different gene-variants on drug response in SQTS and LQTS, as well as discuss the potential mechanisms by which gene-variants alter drug response. These findings may provide valuable information for future studies on the influence of gene variants on drug efficacy and the development of genotype-guided or precision treatment for these diseases.

Characteristics and Outcomes of Hospitalized Patients with Heart Failure and Sarcoidosis: A Propensity-Matched Analysis of the Nationwide Readmissions Database 2010-2019

BACKGROUND

Sarcoidosis is associated with a poor prognosis. There is a lack of data examining the outcomes and readmission rates of sarcoidosis patients with heart failure (SwHF) and without heart failure (SwoHF). We aimed to compare the impact of non-ischemic heart failure on outcomes and readmissions in these two groups.

METHODS

The US Nationwide Readmission Database was queried from 2010 to 2019 for SwHF and SwoHF patients identified using the International Classification of Diseases, 9th and 10th Editions. Those with ischemic heart disease were excluded, and both cohorts were propensity matched for age, gender, and Charlson Comorbidity Index (CCI). Clinical characteristics, length of stay, adjusted healthcare-associated costs, 90-day readmission and mortality were analyzed.

RESULTS

We identified 97,961 hospitalized patients (median age 63 years, 37.9% male) with a diagnosis of sarcoidosis (35.9% SwHF vs 64.1% SwoHF). On index admission, heart failure patients had higher prevalences of atrioventricular block (3.3% vs 1.4%, P < .0001), ventricular tachycardia (6.5% vs 1.3%, P < .0001), ventricular fibrillation (0.4% vs 0.1%, P < .0001) and atrial fibrillation (22.1% vs 7.5%, P < .0001). SwHF patients were more likely to be readmitted (hazard ratio 1.28, P < .0001), had higher length of hospital stay (5 vs 4 days, P < .0001), adjusted healthcare-associated costs ($9,667.0 vs $9,087.1, P < .0001) and mortality rates on readmission (5.1% vs 3.8%, P < .0001). Predictors of mortality included heart failure, increasing age, male sex, higher CCI, and liver disease.

CONCLUSION

SwHF is associated with higher rates of arrhythmia at index admission, as well as greater hospital cost, readmission and mortality rates compared to those without heart failure.

Arrhythmic manifestations and outcomes of definite and probable cardiac sarcoidosis

BACKGROUND

The 2014 Heart Rhythm Society consensus statement defines histological (definite) and clinical (probable) diagnostic categories of cardiac sarcoidosis (CS), but few studies have compared their arrhythmic phenotypes and outcomes.

OBJECTIVE

The purpose of this study was to evaluate the electrophysiological/arrhythmic phenotype and outcomes of patients with definite and probable CS.

METHODS

We analyzed the arrhythmic/electrophysiological phenotype in a single-center North American cohort of 388 patients (median age 56 years; 39% female, n = 151) diagnosed with definite (n = 58) or probable (n = 330) CS (2000-2022). The primary composite outcome was survival to first ventricular tachycardia/fibrillation (VT/VF) event or sudden cardiac death. Key secondary outcomes were also assessed.

RESULTS

At index evaluation, in situ cardiac implantable electronic devices and antiarrhythmic drug use were more common in definite CS. At a median follow-up of 3.1 years, the primary outcome occurred in 22 patients with definite CS (38%) and 127 patients with probable CS (38%) (log-rank, P = .55). In multivariable analysis, only a higher ratio of the 18F-fluorodeoxyglucose maximum standardized uptake value of the myocardium to the maximum standardized uptake value of the blood pool (hazard ratio 1.09; 95% confidence interval 1.03-1.15; P = .003, per 1 unit increase) was associated with the primary outcome. During follow-up, patients with definite CS had a higher burden of device-treated VT/VF events (mean 2.86 events per patient-year vs 1.56 events per patient-year) and a higher rate of progression to heart transplant/left ventricular assist device implantation but no difference in all-cause mortality compared with patients with probable CS.

CONCLUSION

Patients with definite and probable CS had similarly high risks of first sustained VT/VF/sudden cardiac death and all-cause mortality, though patients with definite CS had a higher overall arrhythmia burden. Both CS diagnostic groups as defined by the 2014 Heart Rhythm Society criteria require an aggressive approach to prevent arrhythmic complications.

Gab1 Overexpression Attenuates Susceptibility to Ventricular Arrhythmias in Pressure Overloaded Heart Failure Mouse Hearts

PURPOSE

Grb2 associated binding protein 1 (Gab1) is an adaptor protein that is important for intracellular signal transduction which involved in several pathological process. However, the role of Gab1 in pressure overload-induced ventricular arrhythmias (VAs) remain poorly understood. In the current study, we aimed to test the role of Gab1 in VA susceptibility induced by pressure overload.

METHODS

We overexpressed Gab1 in the hearts using an adeno-associated virus 9 (AAV9) system through tail vein injection. Aortic banding (AB) surgery was performed in C57BL6/J mice to induce heart failure (HF). Four weeks following AB, histology, echocardiography, and biochemical analysis were conducted to investigate cardiac structural remodeling and electrophysiological studies were performed to check the electrical remodeling. Western blot analysis was used to explore the underlying mechanisms.

RESULTS

The mRNA and protein expression were downregulated in AB hearts compared to sham hearts. Gab1 overexpression significantly reversed AB-induced cardiac structural remodeling including ameliorated AB-induced cardiac dysfunction, cardiac fibrosis, and inflammatory response. Moreover, Gab1 overexpression also markedly alleviated AB-induced electrical remodeling including ion channel alterations and VA susceptibility. Mechanistically, we found that TLR4/MyD88/NF-κB contributes to the cardio protective effect of Gab1 overexpression on AB-induced VAs.

CONCLUSIONS

Our study manifested that Gab1 may serve as a promising anti-arrhythmic target via inhibiting TLR4/MyD88/NF-κB signaling pathway induced by AB.

Bipolar catheter ablation with dedicated radiofrequency system for highly refractory ventricular arrhythmia-Does the rate of success depend on arrhythmia origin?

INTRODUCTION

Despite rapid technological progress, some arrhythmias are still resistant to standard unipolar ablation. These include arrhythmias arising from the base of the heart, cardiac crux, or epicardium. Bipolar radiofrequency ablation (B-RFA) may be useful in some cases, however, data on the efficacy of this approach in various arrhythmia localizations are scarce. The aim of this study was to assess the efficacy of B-RFA in patients with ventricular arrhythmias originating from various locations, occurring refractory to standard unipolar ablation approaches.

METHODS

An observational, single center study was conducted over a 30-month period. B-RFA were performed using dedicated radio frequency (RF) generator and electroanatomic mapping system.

RESULTS

Twenty-four procedures, in 23 patients with a median (range) of 1 (1-2) previously failed unipolar ablation procedures, were included in the final analysis. There were 12 ablations of ventricular arrhythmias originating from interventricular septum with an acute success rate of 75%, and 12 from left ventricular (LV) summit with an acute success rate of 58%. The midterm success rate (median interquartile range follow-up of 205 days [188-338]) was 66% and 50%, respectively.

CONCLUSIONS

B-RFA is a promising method of catheter ablation for refractory cardiac arrhythmias. A higher success rate was observed in ablation for difficult ventricular arrhythmias originating from interventricular septal region than LV summit.

Early enteral nutrition in patients with out-of-hospital cardiac arrest under target temperature management was associated with a lower 7-day bacteremia rate: A post-hoc analysis of a retrospective cohort study

INTRODUCTION

Early enteral nutrition (EN) is a nutritional strategy for reducing the incidence of in-hospital infections. However, the benefits of early EN, under targeted temperature management (TTM) in patients with out-of-hospital cardiac arrest (OHCA), remain unclear. We aimed to evaluate the effect of early EN on the infective complications of OHCA patients who underwent TTM.

METHODS

We retrospectively searched the clinical databases of two adult emergency tertiary referral hospitals in southern Taiwan and identified patients admitted for OHCA who underwent TTM between 2017 and 2022. The 85 enrolled patients were divided into two groups based on timing: early EN (EN within 48 h of admission) and delayed EN (EN > 48 h after admission). Clinical outcomes of 7-day infective complications between the two groups were analyzed.

RESULTS

Early EN was provided to 57 (67 %) of 85 patients and delayed EN was provided to the remaining 28 (33 %) patients. No significant differences in baseline patient characteristics were observed between the two groups. In addition, no differences in clinical outcomes were observed, except that the early EN group had a lower 7-day bacteremia rate (5.3 % vs. 26.9 %, p = 0.013). Gram-negative bacteria were the major pathogen among the 7-day infective complications.

CONCLUSION

In OHCA patients treated with TTM, early EN was associated with a lower 7-day bacteremia rate. Furthermore, the application of early EN in this population was well tolerated without significant adverse events.

2024 Australia-New Zealand Expert Consensus Statement on Cardiac Amyloidosis

Over the past 5 years, early diagnosis of and new treatments for cardiac amyloidosis (CA) have emerged that hold promise for early intervention. These include non-invasive diagnostic tests and disease modifying therapies. Recently, CA has been one of the first types of cardiomyopathy to be treated with gene editing techniques. Although these therapies are not yet widely available to patients in Australia and New Zealand, this may change in the near future. Given the rapid pace with which this field is evolving, it is important to view these advances within the Australian and New Zealand context. This Consensus Statement aims to update the Australian and New Zealand general physician and cardiologist with regards to the diagnosis, investigations, and management of CA.

A Multicenter Study of Stellate Ganglion Block as a Temporizing Treatment for Refractory Ventricular Arrhythmias

BACKGROUND

Ventricular tachycardia (VT) and ventricular fibrillation (VF) are life-threatening conditions and can be refractory to conventional drug and device interventions. Stellate ganglion blockade (SGB) has been described as an adjunct, temporizing intervention in patients with refractory ventricular arrhythmia. We examined the association of SGB with VT/VF in a multicenter registry.

OBJECTIVES

This study examined the efficacy of SGB for treatment/temporization of refractory VT/VF.

METHODS

The authors present the first analysis from a multicenter registry of patients treated for refractory ventricular arrhythmia at a clinical site in the Czech Republic and the United States. Data were collected between 2016 and 2022. SGB was performed at the bedside by anesthesiologists and/or cardiologists. Outcomes of interest were VT/VF burden and defibrillations at 24 hours before and after SGB.

RESULTS

In total, there were 117 patients with refractory ventricular arrhythmias treated with SGB at Duke (n = 49) and the Institute for Clinical and Experimental Medicine (n = 68). The majority of patients were male (94.0%), were White (87.2%), and had an implantable cardioverter-defibrillator (70.1%). The most common etiology of heart disease was ischemic cardiomyopathy (52.1%), and monomorphic VT was the most common morphology (70.1%). Within 24 hours before SGB (0-24 hours), the median episodes of VT/VF were 7.5 (Q1-Q3: 3.0-27.0), and 24 hours after SGB, the median decreased to 1.0 (Q1-Q3: 0.0-4.5; P < 0.001). At 24 hours before SGB, the median defibrillation events were 2.0 (Q1-Q3: 0.0-8.0), and 24 hours after SGB, the median decreased to 0.0 (Q1-Q3: 0.0-1.0; P < 0.001).

CONCLUSIONS

In the largest cohort of patients with treatment-refractory ventricular arrhythmia, we demonstrate that SGB use was associated with a reduction in the ventricular arrhythmia burden and need for defibrillation therapy.

Amiodarone and Dronedarone Causes Liver Injury with Distinctly Different Clinical Presentations

OBJECTIVE

To describe hepatotoxicity due to amiodarone and dronedarone from the DILIN and the US FDA's surveillance database.

METHODS

Hepatotoxicity due to amiodarone and dronedarone enrolled in the U.S. Drug Induced Liver Injury Network (DILIN) from 2004 to 2020 are described. Dronedarone hepatotoxicity cases associated with liver biopsy results were obtained from the FDA Adverse Event Reporting System (FAERS) from 2009 to 2020.

RESULTS

Among DILIN's 10 amiodarone and 3 dronedarone DILIN cases, the latency for amiodarone was longer than with dronedarone (388 vs 119 days, p = 0.50) and the median ALT at DILI onset was significantly lower with amiodarone (118 vs 1191 U/L, p = 0.05). Liver biopsies in five amiodarone cases showed fibrosis, steatosis, and numerous Mallory-Denk bodies. Five patients died although only one from liver failure. One patient with dronedarone induced liver injury died of a non-liver related cause. Nine additional cases of DILI due to dronedarone requiring hospitalization were identified in the FAERS database. Three patients developed liver injury within a month of starting the medication. Two developed acute liver failure and underwent urgent liver transplant, one was evaluated for liver transplant but then recovered spontaneously, while one patient with cirrhosis died of liver related causes.

CONCLUSION

Amiodarone hepatotoxicity resembles that seen in alcohol related liver injury, with fatty infiltration and inflammation. Dronedarone is less predictable, typically without fat and with a shorter latency of use before presentation. These differences may be explained, in part, by the differing pharmacokinetics of the two drugs leading to different mechanisms of hepatotoxicity.

Canadian Cardiovascular Society 2023 Guidelines on the Fitness to Drive

Cardiovascular conditions are among the most frequent causes of impairment to drive, because they might induce unpredictable mental state alterations via diverse mechanisms like myocardial ischemia, cardiac arrhythmias, and vascular dysfunction. Accordingly, health professionals are often asked to assess patients' fitness to drive (FTD). The Canadian Cardiovascular Society previously published FTD guidelines in 2003-2004; herein, we present updated FTD guidelines. Because there are no randomized trials on FTD, observational studies were used to estimate the risk of driving impairment in each situation, and recommendations made on the basis of Canadian Cardiovascular Society Risk of Harm formula. More restrictive recommendations were made for commercial drivers, who spend longer average times behind the wheel, use larger vehicles, and might transport a larger number of passengers. We provide guidance for individuals with: (1) active coronary artery disease; (2) various forms of valvular heart disease; (3) heart failure, heart transplant, and left ventricular assist device situations; (4) arrhythmia syndromes; (5) implantable devices; (6) syncope history; and (7) congenital heart disease. We suggest appropriate waiting times after cardiac interventions or acute illnesses before driving resumption. When short-term driving cessation is recommended, recommendations are on the basis of expert consensus rather than the Risk of Harm formula because risk elevation is expected to be transient. These recommendations, although not a substitute for clinical judgement or governmental regulations, provide specialists, primary care providers, and allied health professionals with a comprehensive list of a wide range of cardiac conditions, with guidance provided on the basis of the level of risk of impairment, along with recommendations about ability to drive and the suggested duration of restrictions.

Pharmacological Approach for Symptomatic Nonsustained Ventricular Tachycardia

Nonsustained ventricular tachycardia (NSVT) is a common arrhythmia associated with heart failure, cardiomyopathy, coronary artery disease, electrolyte imbalances, and congenital heart disorders (Foth et al., 2023). NSVT is often asymptomatic depending on its burden percentage. However, typical NSVT presentation in the emergency department (ED) includes palpitations, near-syncope, dizziness, skipped beats, chest pain, and/or dyspnea (Katritsis et al., 2012). In some instances, NSVT can present with elevated or slightly elevated troponin from demand ischemia. A definite diagnosis of NSVT is not of high complexity; nevertheless, it is not always identified on electrocardiogram (ECG) by the time the patient arrives to the ED. Identification of NSVT usually requires prolonged cardiac monitoring, mobile cardiac telemetry (MCT), and in some instances internal loop recorder placement. The purpose of this case is to discuss the typical presentation and pharmacological approach of patients with stable NSVT.

The structure and function of lamin A/C: Special focus on cardiomyopathy and therapeutic interventions

Lamins are inner nuclear membrane proteins that belong to the intermediate filament family. Lamin A/C lie adjacent to the heterochromatin structure in polymer form, providing skeletal to the nucleus. Based on the localization, lamin A/C provides nuclear stability and cytoskeleton to the nucleus and modulates chromatin organization and gene expression. Besides being the structural protein making the inner nuclear membrane in polymer form, lamin A/C functions as a signalling molecule involved in gene expression as an enhancer inside the nucleus. Lamin A/C regulates various cellular pathways like autophagy and energy balance in the cytoplasm. Its expression is highly variable in differentiated tissues, higher in hard tissues like bone and muscle cells, and lower in soft tissues like the liver and brain. In muscle cells, including the heart, lamin A/C must be expressed in a balanced state. Lamin A/C mutation is linked with various diseases, such as muscular dystrophy, lipodystrophy, and cardiomyopathies. It has been observed that a good number of mutations in the LMNA gene impact cardiac activity and its function. Although several works have been published, there are still several unexplored areas left regarding the lamin A/C function and structure in the cardiovascular system and its pathological state. In this review, we focus on the structural organization, expression pattern, and function of lamin A/C, its interacting partners, and the pathophysiology associated with mutations in the lamin A/C gene, with special emphasis on cardiovascular diseases. With the recent finding on lamin A/C, we have summarized the possible therapeutic interventions to treat cardiovascular symptoms and reverse the molecular changes.

A wearable telehealth system for the monitoring of parameters related to heart failure

Heart failure is a cardiovascular disease in which heart fails to pump sufficient blood required by the body. Significant signs of worsening heart failure include decreased thoracic impedance, increased heart rate, irregular electrocardiogram (ECG), and lack of motion activity of the patient. Heart failure can be better managed if monitored continuously and in real-time. The existing solutions for continuous monitoring of these parameters are invasive and hence are not only expensive but can also cause serious health risks. This paper discusses the development of a telehealth system that consists of an Internet of Things including a wearable device connected to a cloud-based database and a mobile application using Wi-Fi. The wearable device is a noninvasive monitor that consists of different sensors embedded with a microcontroller and can be a potential solution for better management of heart failure. It continuously monitors the above-mentioned parameters and sends data to the mobile application using a cloud-based system. The mobile application has separate portals for patients and doctors where doctor can monitor a specific patient enrolled under his profile. The performance of the developed device is validated in 10 healthy individuals.

Selection of social comparison standards in cardiac patients with and without experienced defibrillator shock

Patients with an implantable cardioverter-defibrillator (ICD) often report psychological distress. Literature suggests that patients with physical disease often compare their well-being and coping to fellow patients. However, we lack knowledge on social comparison among patients with ICD. In this study, we examined psychological distress and social comparison selection in patients with (ICD+) and without experienced ICD shocks (ICD-). We theorized that relative to ICD- patients, those with ICD+ display higher levels of psychological distress and thereby compare more frequently with fellow patients with more severe disease, but better disease coping and try to identify more strongly with these standards to improve their own coping. We recruited 92 patients with (ICD+, n = 38) and without an experienced ICD shock (ICD-, n = 54), who selected one of four comparison standards varying in disease severity and coping capacity. Relative to ICD-, ICD+ patients reported higher levels of device-related distress, but there were no significant differences in anxiety, depression, or quality of life. ICD+ patients selected more often comparison standards with poor coping and, irrespective of standard choice, displayed more negative mood following comparison. Our results show that ICD+ patients tend to perform unfavorable comparisons to fellow patients, which might explain higher psychological distress and worse coping. These findings warrant further research into social comparison as a relevant coping mechanism in ICD patients.

Exercise After Acute Myocarditis: When and How to Return to Sports

Myocarditis is an inflammatory disease of the myocardium secondary to infectious and noninfectious insults. The most feared consequence of myocarditis is sudden cardiac death owing to electrical instability and arrhythmia. Typical presenting symptoms include chest pain, dyspnea, palpitations and/or heart failure. Diagnosis is usually made with history, electrocardiogram, biomarkers, echocardiogram, and cardiac MRI (CMR). Application of the Lake Louise criteria to CMR results can help identify cases of myocarditis. Treatment is usually supportive with medical therapy, and patients are recommended to abstain from exercise for 3 to 6 months. Exercise restrictions may be lifted after normalization on follow-up testing.

Peri-Operative Outcomes Associated With the Placement of Implantable Cardioverter-Defibrillators in Patients With Sarcoidosis: A Nationwide Database Analysis

Rationale Sarcoidosis with cardiac involvement can be associated with serious life-threatening arrhythmias and an increased risk of sudden cardiac death. Implantable cardiac defibrillators (ICDs) have been used for primary and secondary prevention of sudden death in patients with cardiac sarcoidosis (CS). Post-ICD placement complications have been shown to be higher in patients with CS. However, data comparing postoperative ICD complications among sarcoidosis patients with the general population is limited. Here, we evaluated the association of postoperative complications with implantable cardioverter-defibrillators in sarcoidosis.  Methods Using the NIS database, we identified cases of adults aged ≥ 18 years undergoing surgical placement of implantable cardioverter-defibrillators between 2010 and 2019. Using ICD-9 and ICD-10 codes, we identified patients with sarcoidosis. In all statistical analyses, we applied weights provided by HCUP to produce results representative of national estimates. We compared categorical and continuous covariates in the baseline characteristics using the chi-square test and analysis of variance, respectively. We employed multivariable logistic and linear regression to compare binomial and continuous outcomes to assess differences in mortality rates. Results We analyzed 114073 patients during the study period. Of these, 1012 (0.9%) had sarcoidosis and were found to be significantly younger and female compared to patients without sarcoidosis (56.4 ±11.5 years vs. 65.6 ± 13.9 years, p <0.001) and (39.4% vs. 28.3%, p<0.001) respectively. Further, patients with sarcoidosis were more likely to be African American (45% vs. 16.3%), have private insurance (45.4% vs. 23.8%), and less likely to have Medicare (34.9% vs. 60.9%). Overall, post-ICD placement complications such as lead complications (4.2% vs. 6.9%, p = 0.03), post-procedure hemorrhage (4.1% vs. 5.5%, p=0.048), and requirement for transfusion (2.3% vs. 4.4%) were less likely in patients with sarcoidosis. Regarding post-ICD placement inpatient mortality, sarcoidosis was not associated with any difference (OR: 0.71, 95% CI 0.18-2.88 p=0.634). Conclusions Placement of implantable cardioverter-defibrillators in patients with sarcoidosis is a safe procedure and is associated with significantly lower rates of lead complications, post-procedure hemorrhage, and requirement for transfusion. This is of great importance as it is known that patients with underlying sarcoidosis are predisposed to developing more cardiac complications.

Subcutaneous cardioverter-defibrillator implantation in an adult with congenital heart disease and left infra-mammary pacemaker

The approach/type of an implantable cardioverter defibrillator (ICD) is determined by the underlying cardiac anatomy, venous access, and pre-existing cardiac implantable electronic devices. We describe a case of subcutaneous ICD implantation in an adult with congenital heart disease (CHD) with a pre-existing inframammary transvenous pacemaker. This was preferred over adding a defibrillator coil to existing pacing leads, extraction/replacement of pacing system, or a sternotomy/epicardial ICD placement. The procedure was accomplished uneventfully with successful defibrillation threshold testing. Innovative approaches are required to manage arrhythmias in adults with CHD, with shared decision making playing a critical role.

Implantable cardioverter defibrillators for primary prevention in cardiomyopathies

BACKGROUND

Implantable cardioverter defibrillators (ICD) are often used as primary prevention strategy for sudden cardiac death (SCD) in young individuals. This study analyzed appropriate therapies, complications and inappropriate shocks in the real-world Indian population.

METHODS

All patients in the cardiomyopathy cohort under follow up who had ICD implanted as a primary prevention strategy were studied. The objective was to assess the incidence of appropriate ICD therapies, inappropriate therapies and complications. ICD was interrogated and stored electrograms analyzed. Underlying arrhythmia or conditions resulting in appropriate or inappropriate ICD therapy were studied. Correlation and regression studies was done to assess for the predictors of appropriate therapy.

RESULTS

Fifty patients were followed up for a mean follow-up duration of 4.4 ± 3.1 years with total follow up of 220.2 patient years. Appropriate ICD therapy was delivered in 16 out of 50 (32%) patients, with 65 appropriate therapies (median 2 per patient, range: 0-20). Inappropriate therapy delivered in 7 of the 50 (14%) patients, with 44 inappropriate therapies (median 5 per patient, range: 0-20). Complications occurred in 8 of the 50 (16%) patients. Overall, the rate of appropriate therapy was 29.5 per 100 patient years, that of inappropriate therapy was 19.9 per 100 patient years and the rate of complications was 3.6 per 100 patient years.

CONCLUSIONS

When implanted for primary prevention in patients with cardiomyopathies over a mean period of 4.4 ± 3.1 years, appropriate ICD therapy was delivered in 32% patients. However, inappropriate therapy (14% patients) and complications (16% patients) were also common.

Myocarditis and Pericarditis

Pericarditis typically presents with classic symptoms of acute sharp, retrosternal, and pleuritic chest pain. It can have several different underlying causes including viral, bacterial, and autoimmune etiologies. The mainstays of pericarditis treatment are nonsteroidal anti-inflammatory drugs and colchicine with glucocorticoids or other immunosuppressive drugs used for refractory cases and relapse. Myocarditis is an inflammatory disease of the cardiac muscle that is caused by a variety of infectious and noninfectious conditions. It mainly affects young adults (median age 30-45 years), and men more than women. The clinical manifestations of myocarditis are highly variable, so a high level of suspicion in the early stage of disease is important to facilitate diagnosis. The treatment of myocarditis includes nonspecific treatment aimed at complications such as heart failure and arrhythmia, as well as specific treatment aimed at underlying causes. Pericarditis and myocarditis associated with vaccine have been extremely rare before coronavirus disease 2019 (COVID-19). There is a small increase of incidence after COVID-19 messenger ribonucleic acid vaccine, but the relative risk for pericarditis and myocarditis due to severe acute respiratory syndrome coronavirus 2 infection is much higher. Therefore, vaccination against COVID-19 is currently recommended for everyone aged 6 years and older.

Ischemia testing and revascularization in patients with monomorphic ventricular tachycardia: A relic of the past?

Testing for myocardial ischemia in patients presenting with sustained monomorphic Ventricular Tachycardia(VT) even without evidence of acute myocardial infarction is a tempting strategy that is frequently utilized in clinical practice. Monomorphic VT is mainly caused by re-entry around chronic myocardial scar and active ischemia has no role in its pathogenesis, thus making testing for ischemia futile, at least in theory. This systematic literature review sought to address the usefulness of ischemia testing (mainly coronary angiography) in patients presenting with monomorphic VT through 8 selected studies after evaluating a total of 130 published manuscripts. Particularly, we sought to unveil whether coronary angiography and possibly concomitant revascularization leads to lesser tachycardia recurrence. Our conclusion can be summarized as follows: this approach whether combined with revascularization or not, does not seem to reduce VT recurrence nor does it affect mortality in such patients. Even though most of the published literature points at this direction, validation from randomized controlled trials is imperative.

Ultra-Low-Temperature Cryoablation for Ventricular Tachycardia: An Early Single-Centre Report of Acute Results

Background

Endocardial catheter ablation for ventricular tachycardia (VT) may fail because of the inability to deliver transmural lesions. Ultra-low-temperature cryoablation (ULTC) uses near-critical nitrogen and can generate temperatures as low as -196 °C. We report a series of 18 patients who underwent ULTC at the McGill University Health Centre (MUHC), representing the largest single-centre experience to date.

Methods

Eighteen patients with monomorphic drug-refractory VT underwent VT ablation with ULTC at our institution as part of the first-in-human CryoCure-VT trial (NCT04893317). After voltage map, the mapping catheter was replaced with the ULTC catheter, and lesions were applied over a fixed duration of time (60-180 seconds), followed by a 60-second thaw and another application at the original duration (freeze-thaw-freeze). Duration of ablation time was selected depending on the wall thickness of the left ventricle monitored with intracardiac echo to achieve tissue depths of 4.5 to 7.5 mm.

Results

Baseline left ventricular ejection fraction was 32%, mean age 71 years, 94% were male. A total of 32 sustained VTs were induced in 16 of 18 patients. A total of 177 cryoablation lesions were delivered (9.8 lesions per patient). Of the 16 patients with inducible VT, 15 (94%) were rendered noninducible postablation, and 1 was inducible only for a nonclinical VT. Complications included 1 pericardial effusion that required drainage. From 18 patients, 16 (89%) were discharged within the first 24 hours postablation.

Conclusions

ULTC is feasible and permits acute control of monomorphic VT during VT ablation procedures in drug-refractory patients.

Pregnancy Arrhythmias: Management in the Emergency Department and Critical Care

Pregnancy is closely associated with an elevated risk of arrhythmias, constituting the predominant cardiovascular complication during this period. Pregnancy may induce the exacerbation of previously controlled arrhythmias and, in some instances, arrhythmias may present for the first time in pregnancy. The most important proarrhythmic mechanisms during pregnancy are the atrial and ventricular stretching, coupled with increased sympathetic activity. Notably, arrhythmias, particularly those originating in the ventricles, heighten the likelihood of syncope, increasing the potential for sudden cardiac death. The effective management of arrhythmias during the peripartum period requires a comprehensive, multidisciplinary approach from the prepartum to the postpartum period. The administration of antiarrhythmic drugs during pregnancy necessitates meticulous attention to potential alterations in pharmacokinetics attributable to maternal physiological changes, as well as the potential for fetal adverse effects. Electric cardioversion is a safe and effective intervention during pregnancy and should be performed immediately in patients with hemodynamic instability. This review discusses the pathophysiology of arrythmias in pregnancy and their management.