Arrhythmia-Induced Cardiomyopathy: JACC State-of-the-Art Review

Management of Heart Failure With Improved Ejection Fraction: Current Evidence and Controversies

Heart failure with improved ejection fraction (HFimpEF) is defined by improved left ventricular ejection fraction (LVEF) among patients who previously had reduced LVEF. HFimpEF is associated with improved prognosis, albeit with persistent risk of relapse and adverse events in some patients. Current guidelines thus recommend sustained and indefinite guideline-directed medical therapy (GDMT) for all patients with HFimpEF. Emerging clinical experience suggests that heart failure arising from acute etiologies that fully resolve along with complete LVEF recovery may have a favorable prognosis with lower risk of relapse. Indeed, cohort and case series studies have demonstrated the feasibility of safe de-escalation of GDMT in select patients with specific etiologies, with multiple small trials ongoing. Future studies should investigate whether advanced imaging or blood biomarkers could aid in risk stratifying patients with recovered LVEF, whether partial de-escalation of GDMT could be safe and feasible, and whether implantable cardioverter-defibrillator therapy can be safely discontinued.

Usefulness of tissue tracking to differentiate tachycardia-induced cardiomyopathy from dilated cardiomyopathy in patients admitted for heart failure

INTRODUCTION

Differentiation of tachycardia-induced cardiomyopathy (TIC) from dilated cardiomyopathy (DCM) in patients admitted for heart failure (HF) with left ventricular dysfunction and supraventricular tachyarrhythmia (SVT) remains challenging. The role of tissue tracking (TT) in this setting remains unknown.

METHODS

Forty-three consecutive patients admitted for HF due to SVT with left ventricular ejection fraction (LVEF) < 50% undergoing CMR were retrospectively included. Those eventually evolving to LVEF > 50% at follow-up were classified as TIC and those maintaining a LVEF < 50% were classified as DCM. Clinical, echocardiography, and CMR findings, including TT, were analyzed to predict LVEF recovery.

RESULTS

Twenty-five (58%) patients were classified as TIC. Late gadolinium enhancement (LGE) was more frequent in DCM group (61% vs 16%, p = 0.004). Left ventricle (LV) peak systolic radial velocity and peak diastolic radial strain rate were lower in DCM group (7.24 ± 4.44 mm/s vs 10.8 ± 4.5 mm/s; p = 0.015 and -0.12 ± 0.33 1/s vs -0.48 ± 0.51 1/s; p = 0.016, respectively). Right ventricle (RV) peak circumferential displacement was lower in patients with TIC (0.2 ± 1.3 vs 1.3 ± 0.9°; p = 0.009). In the multivariate analysis, diabetes (p = 0.046), presence of LGE (p = 0.028), LV peak systolic radial velocity < 7.5 mm/s (p = 0.034), and RV peak circumferential displacement > 0.5° (p = 0.028) were independent predictors of lack of LVEF recovery.

CONCLUSION

In the setting of acute HF with LV dysfunction related to SVT, diabetes, LGE, LV peak systolic velocity, and RV peak circumferential displacement are independent predictors of lack of LVEF recovery and, therefore, represent clinically useful parameters to differentiate TIC from DCM.

Enhanced piezoelectric sensor to distinguish real-time arrhythmia for predicting heart failure

Monitoring cardiac rhythm is crucial for diagnosis of heart failure. However, the deficient sensitivity of polyvinylidene fluoride (PVDF) sensors impede their application in monitoring of cardiac rhythm due to the limited piezoelectricity. Here, doping of CoFe2O4 and aligning fibers were jointly adopted to enhance the piezoelectricity of PVDF, attributed to the transformation of α-PVDF to β-PVDF from 51.54 to 82.36 % confirmed by FTIR and First Principles simulation. Then the higher sensitivity piezoelectric sensors were developed based on aligned PVDF/CoFe2O4 accompanying with the superior frequency characteristics, rapid response, endurance stability, permeability and self-cleaning capabilities, compared to that of random PVDF/CoFe2O4 and PVDF sensors, which were 17.28, 13.40 and 2.16 mV kPa -1, respectively. Thus, the sensitivity of PVDF/CoFe2O4 sensors was sufficient to distinguish the variations of cardiac rhythm or arrhythmia of the established and verified heart failure rat model, including amplitude, cycle and frequency. The notable characteristic of an evolving heart failure was the significantly decreased amplitude initially, followed by a dramatic drop in the cycles of cardiac impulse. Hence, this non-invasive method is promise in providing valuable warning signs for predicting heart failure based on aligned PVDF/CoFe2O4 sensors, as well as in the prevention its occurrence.

Clinical impact of very high-power-short-duration catheters on biomarkers after atrial fibrillation ablation

Background

Very high-power short-duration (vHPSD) catheters are associated with less irrigation fluid load than standard (STD RF) ablation catheters. However, the impact of this fluid reduction on biomarkers in pulmonary vein isolation (PVI) for atrial fibrillation (AF) remains unknown.

Methods and Aim

Biomarkers of heart failure, myocardial injury, and systemic inflammation status as Brain Natriuretic Peptide (BNP), high-sensitivity Troponin I (hsTnI), and C-reactive protein (CRP) were collected pre- and post-procedure of PVI for symptomatic AF. The study aimed to assess the impact of vHPSD catheter compared to an STD catheter (respectively irrigation of 8 vs. 15 mL/min during ablation) on biomarker alterations.

Results

The study included 83 consecutive patients (59 males [71.1%], mean age 62.6 ± 11 years), with vHPSD catheters used in 53 cases (63.9%). No significant baseline differences were observed between groups.Fluid irrigation resulted in significantly lower with vHPSD catheter than STD RF (434.8 ± 105.6 vs. 806.6 ± 256.5 mL, p < .001). Correspondingly, BNP variation was significantly lower in the vHPSD group than in the STD RF group, both in absolute change (12 [IQR -9-47] pg/mL vs. 44.5 [IQR 21-88.7] pg/mL, p = .002) and percentage change (16.3 [IQR -13.2-108.6] % vs. 84.1 [IQR 32.5-172.1] %, p = .012). When considering absolute values, a statistically significant increase in BNP was found only in the STD catheter group (from 52 [IQR 35.2-113.5] to 113 [IQR 66.7-189.5] pg/mL, p < .001), whereas no significant increase was observed in the vHPSD group (p = .06). CRP levels increased post-PVI in both groups, but the delta was significantly lower in the vHPSD group (p = .025). No significant differences in post-procedural hsTnI were detected between groups.

Conclusion

The use of a vHPSD catheter is associated with reduced fluid irrigation and a correspondingly smaller increase in BNP, a biomarker indicative of fluid overload and heart failure.

Examining factors associated with experiencing cardiac arrhythmias in Black and White breast cancer survivors who received anthracyclines or trastuzumab

PURPOSE

Racial disparities exist regarding cardiovascular (CV) toxicities following breast cancer treatment; however, studies on racial differences in cardiac arrhythmias are lacking. This study examined associations between demographic and clinical factors and arrhythmia diagnosis in Black and White breast cancer survivors.

METHODS

This study included a retrospective cohort of Black and White women who were diagnosed with breast cancer and who received potentially cardiotoxic treatment. Cardiac arrhythmia data were captured via International Classification of Diseases, Tenth and Ninth Versions (ICD-10 and ICD-9). Experiences with cardiac arrhythmias were compared across racial groups. The associations of demographic and clinical factors with cardiac arrhythmias were evaluated using logistic regression for all women and in race-stratified models.

RESULTS

Thirty-three percent of the total 860 women in our study sample (mean (standard deviation) age 50.3 (10.7) years) old) experienced cardiac arrhythmias. In bivariate analyses, we observed a statistically discernible association between race and arrhythmia status following a breast cancer diagnosis (p = 0.004); however, this association was no longer significant in the multivariable model. In race-stratified multivariable analysis, the odds of experiencing arrhythmias in Black women over 50 years old are 51% lower than in Black women aged 50 years old or younger (adjusted odds ratio (OR): 0.49; 95% confidence interval (CI): 0.28, 0.86). All else being equal, Black women with hypertension had 2.68 times (95% CI: 1.51, 4.81) higher odds of experiencing arrhythmias than those without hypertension. White women with obesity had higher odds of experiencing arrhythmias than those with normal weight or underweight status. (adjusted OR 1.93: [1.17, 3.20]).

CONCLUSION

Survivors with chronic conditions like hypertension and obesity may require enhanced cardiac surveillance. Further investigation into hypertension management in Black survivors may shed light on its impact on CV toxicities in this group.

Thymoma-Induced Severe Biventricular Failure without Myasthenia Gravis: Investigating Tachycardia-Induced Cardiomyopathy

BACKGROUND Cardiomyopathy associated with thymoma is thought to be a cardiac manifestations of myasthenia gravis (MG). However, there are case reports of newly diagnosed thymoma presenting with cardiomyopathy without MG, and the mechanism remains unclear. The purpose of this report is to explore tachycardia-induced cardiomyopathy (TIC) as a potential mechanism for cardiomyopathy in thymoma without features of MG. CASE REPORT A 31-year-old man presented with atrial flutter with right bundle branch block and severe biventricular heart failure. Echocardiogram revealed severe left ventricle ejection fraction (LVEF) of 15% with biventricular dilation with impaired systolic function. Computer tomography coronary angiography demonstrated normal coronary artery disease. Cardiac magnetic resonance imaging showed normal T1 and T2 mapping, without inflammation or edema. A large anterior mediastinal mass was found on computer tomography chest. Mediastinal mass biopsy identified type B3 thymoma (WHO classification) with dual population of large, uniform epithelial thymic cells and immature T cell phenotype. Acetylcholine receptor antibody was positive without clinical features of MG and hypogammaglobulinemia indicating Good syndrome. He was treated with antiarrhythmic and heart failure pharmacotherapy, carboplatin and paclitaxel, and intravenous immunoglobulin. He demonstrated reversible heart failure following abolishment of tachyarrhythmia, consistent with tachycardia-induced cardiomyopathy. CONCLUSIONS We report a rare case of a newly diagnosed thymoma and Good syndrome without clinical features of MG presenting with tachyarrhythmia and severe biventricular failure. The reversibility of the cardiomyopathy following abortion of tachyarrhythmia with treatment highlights TIC as a potential cause.

Characterization of Myocardial Recovery in Patients With Tachycardiomyopathy

BACKGROUND

The degree and time course of improvement in left ventricular (LV) function with treatment in patients with tachycardiomyopathy (TCMP) is highly variable. This study aims to clinically characterize the recovery of TCMP based on the extent and course of improvement in LV function and identify predictors of complete myocardial recovery.

METHODS

In this prospective, single-center, observational study, patients with suspected TCMP who underwent successful tachyarrhythmia termination/control were included. Clinical and echocardiographic assessment of LV function was done at baseline, within 1 h after tachyarrhythmia termination, 24 h later, and at 12 weeks follow-up.

RESULTS

Ninety-nine patients were enrolled in the study. Six patients had immediate normalization of LV ejection fraction (LVEF) with reversion to sinus rhythm and were labeled as "pseudo-TCMP"; the remaining 93 patients were included in the analysis. Based on complete versus partial normalization of LVEF at 12-week follow-up, 50 patients (53.8%) were labeled as completely recovered TCMP and 43 (46.2%) as partially recovered TCMP respectively. Causative arrhythmias included atrial fibrillation (38%), focal atrial tachycardia (28%), atrial flutter (22%), ventricular arrhythmias (11%), and orthodromic re-entrant tachycardia (2%). The LVEF at presentation was 0.25 ± 0.05 which improved to 0.36 ± 0.11 within 1 h after tachycardia termination (p < 0.0001), 0.41 ± 0.14 24 h later (p = 0.009) and to 0.52 ± 0.12 at 12 weeks follow-up (p < 0.0001). Male gender was the only differentiating statistically significant variable between completely recovered and partially recovered TCMP, 24 (48%) versus 30 (69.7%) respectively (p = 0.0339).

CONCLUSION

Nearly half of the TCMP patients have complete recovery of LV function at 12 weeks follow-up, while the other half have a partial recovery only. There was no robust predictor of complete myocardial recovery.

Clinical neurocardiology: defining the value of neuroscience-based cardiovascular therapeutics - 2024 update

The intricate role of the autonomic nervous system (ANS) in regulating cardiac physiology has long been recognized. Aberrant function of the ANS is central to the pathophysiology of cardiovascular diseases. It stands to reason, therefore, that neuroscience-based cardiovascular therapeutics hold great promise in the treatment of cardiovascular diseases in humans. A decade after the inaugural edition, this White Paper reviews the current state of understanding of human cardiac neuroanatomy, neurophysiology and pathophysiology in specific disease conditions, autonomic testing, risk stratification, and neuromodulatory strategies to mitigate the progression of cardiovascular diseases.

Epidemiology of Atrial Fibrillation in Heart Failure

Atrial fibrillation and heart failure are common cardiovascular conditions that are intricately linked to each other, with a significant impact on morbidity, mortality, and quality of life. These two conditions can create a vicious pathophysiologic milieu associated with neurohormonal changes, elevated cardiac filling pressure, myocardial remodeling, systemic and regional inflammation, fibrosis, and diminished myocardial contractility. It is well known that cardiomyopathy can cause atrial fibrillation and vice-versa, but often it is difficult to sort which came first. Unfortunately, the disease burden will only continue to rise with an aging population, and understanding the epidemiology of the disease and the interplay of these two conditions is vital to improved patient care.

Pathophysiology of dilated cardiomyopathy: from mechanisms to precision medicine

Dilated cardiomyopathy (DCM) is a complex disease with multiple causes and various pathogenic mechanisms. Despite improvements in the prognosis of patients with DCM in the past decade, this condition remains a leading cause of heart failure and premature death. Conventional treatment for DCM is based on the foundational therapies for heart failure with reduced ejection fraction. However, increasingly, attention is being directed towards individualized treatments and precision medicine. The ability to confirm genetic causality is gradually being complemented by an increased understanding of genotype-phenotype correlations. Non-genetic factors also influence the onset of DCM, and growing evidence links genetic background with concomitant non-genetic triggers or precipitating factors, increasing the extreme complexity of the pathophysiology of DCM. This Review covers the spectrum of pathophysiological mechanisms in DCM, from monogenic causes to the coexistence of genetic abnormalities and triggering environmental factors (the 'two-hit' hypothesis). The roles of common genetic variants in the general population and of gene modifiers in disease onset and progression are also discussed. Finally, areas for future research are highlighted, particularly novel therapies, such as small molecules, RNA and gene therapy, and measures for the prevention of arrhythmic death.

Atrial Fibrillation Management with Guideline-Directed Medical Therapy and Comorbidity Treatment in Heart Failure Patients

Atrial myopathy is the underlying pathophysiological substrate of atrial fibrillation and contributes to the risk of heart failure as well. Atrial myopathy is caused by classic risk factors such as obesity, inflammation, diabetes, hypertension, and frequent alcohol use, in addition to structural heart and lung diseases that cause atrial pressure or volume overload. An optimal management of atrial fibrillation includes careful assessment of contributors to atrial myopathy, which can be treated by guideline-recommended medical therapies for heart failure, adequate control of congestion, and treatment of comorbid conditions such as sleep apnea syndrome. This approach works synergistically with rhythm control.

Guideline-directed medical therapy for heart failure in arrhythmia-induced cardiomyopathy with improved left ventricular ejection fraction

AIMS

No study has analyzed the impact of guideline-directed medical therapy in preventing heart failure (HF) relapse in patients with arrhythmia-induced cardiomyopathy (AiCM) following left ventricular ejection fraction (LVEF) improvement.

METHODS AND RESULTS

We analyzed data from a single-center cohort of 200 patients admitted for HF, LVEF <50% and cardiac arrhythmia considered by cardiologists to be the precipitating cause of the episode. The primary endpoint was time-to-HF relapse, defined as the composite of readmission for HF, Emergency Department (ED) visit for HF, or significant decline in LVEF. Changes in medication were recorded and a time-varying multivariate Cox regression was performed. After a median follow-up period of 6.14 years, diagnostic confirmation was achieved in 188 out of the initial 200 patients with suspected AiCM. A total of 89 patients (47.3%) met the primary endpoint. RAS inhibitors (adjusted hazard ratio (HR) 0.50 [0.31-0.81]; p = 0.005) and beta-blockers (adjusted HR 0.48 [0.28-0.81]; p = 0.006) were associated with a lower incidence of relapse. Mineralocorticoid receptor antagonists were associated with a significantly lower incidence of ED visits for HF (adjusted HR 0.38 [0.15-0.95]; p = 0.038), but did not achieve statistical significance for the combined primary endpoint. Antiarrhythmic drugs did not show a significant impact on the primary endpoint.

CONCLUSION

Maintaining RAS inhibitors and beta-blockers was associated with a significantly lower incidence of relapse in the setting of AiCM with improved LVEF.

Arrhythmia-Induced Cardiomyopathy: Predictors of Improvement in Left Ventricular Systolic Function After Catheter Ablation

Background: Arrhythmia-induced cardiomyopathy (AIC) is a relatively common yet poorly understood cardiac condition that occurs when arrhythmias cause left ventricular systolic dysfunction, which can be reversed with the resolution of the arrhythmia. Catheter ablation serves as a cornerstone treatment for eliminating the arrhythmic trigger. However, the variability in left ventricular recovery following ablation highlights the need to identify reliable predictors of reverse remodeling. Methods: This review explores key studies on AIC patients undergoing catheter ablation, primarily derived from observational cohorts, to identify significant predictors of left ventricular function recovery. Results: While echocardiography and cardiac magnetic resonance imaging remain the primary diagnostic modalities, additional insights have emerged from electrocardiograms and laboratory biomarkers. Despite these advancements, a comprehensive framework for identifying optimal candidates for ablation remains lacking. Conclusions: By synthesizing existing evidence, this review aims to pinpoint the most robust predictors of systolic recovery in AIC patients following ablation.

Cardiovascular Consequences Unveiled: A Comprehensive Review of Hypopituitarism's Impact on the Heart

Hypopituitarism is a rare condition that presents significant diagnostic challenges, particularly in elderly patients (over 65 years of age). It often manifests with a range of symptoms affecting multiple organ systems, with cardiovascular involvement being uncommon. As a result, the underlying diagnosis may be easily overlooked. Physicians must maintain a high level of awareness about hypopituitarism to establish an accurate diagnosis and initiate appropriate treatment. This study reviews recent advances in understanding the cardiovascular manifestations of hypopituitarism.

Right Ventricular Systolic Dysfunction Predicts Recovery of Left Ventricular Systolic Function and Reduced Quality of Life in Patients With Arrhythmia-Induced Cardiomyopathy

INTRODUCTION

Arrhythmia-induced cardiomyopathy (AIC) is an underrecognized condition resulting in left ventricular systolic dysfunction (LVSD) that is primarily caused by atrial fibrillation (AFib). The relationship between AIC, right ventricular (RV) function, and quality of life (QoL) has not been well studied.

METHODS

We performed a post-hoc analysis of our AIC trial in which we prospectively screened for patients with tachyarrhythmia and newly diagnosed, otherwise unexplained LVSD. Following rhythm restoration, patients were followed up at 2, 4, and 6 months. Only patients with persistent sinus rhythm were analyzed. RV function was assessed via echocardiography (tricuspid annular plane systolic excursion [TASPE] and fractional area change [FAC]) and QoL by the Minnesota Living with Heart Failure Questionnaire.

RESULTS

Of a total of 50 patients recovering from LVSD, 41 were diagnosed with AIC and 9 with non-AIC. Initially, RV function was reduced in the AIC group and recovered after rhythm restoration, whereas no relevant changes were noted in the non-AIC group. QoL was reduced in both groups and also improved after rhythm restoration. Regression analysis identified low TAPSE as a predictive parameter for AIC diagnosis and worse QoL in AIC patients.

CONCLUSION

We demonstrated that RV function and QoL are impaired in patients with AIC. Six months after rhythm restoration, TAPSE may serve as an early indicator of AIC while also correlating with QoL. This underscores the importance of detailed echocardiographic evaluation with a focus on RV function in patients with concomitant tachyarrhythmia and LVSD.

Early Improvement in Cardiac Function and Dyssynchrony After Physiological Upgrading in Pacing-Induced Cardiomyopathy

BACKGROUND

Interventricular dyssynchrony derived from the classic non-physiological stimulation (n-PS) of the right ventricle (RV) is a known cause of left ventricular dysfunction (LVDys).

METHODS

This was a prospective descriptive single-center study. We analyzed patients who develop LVDys with n-PS, and the results after upgrading to conduction system pacing (CSP). Ultra-high frequency electrocardiogram (UHF-ECG) was performed pre and post-implantation of the last patients included. ECG recordings in 16 frequency bands (150-1000 Hz) were used to create maps of ventricular depolarization. The maximum time difference between the centers of mass of the complex UHF QRS of leads V1-V6 (electrical dyssynchrony [DYS-e] 16) and V1-V8 (DYS-e 18) defined ventricular dyssynchrony. Data were expressed as mean ± standard deviation.

RESULTS

27 patients were upgraded to CSP from January 2022 to January 2024 after developing LVDys. Permanent His bundle pacing (p-HBP) was achieved in 63% (n = 17); in the other 10 patients left bundle branch area pacing (LBBAp) was performed. The average baseline LVEF improved from 34.5% (27-42) to 47.6% (38.2-57), p < 0.001. Telediastolic left ventricle diameter as well as QRS width also decreased. Thresholds remained stable at 6-month follow-up. The last eight patients included were studied in terms of ventricular synchrony parameters by UHF-ECG (VDI Technologies), both His bundle pacing (HBP) and the LBBAp achieved significant improvement with respect to baseline parameters.

CONCLUSIONS

LVEF improved in patients with previous n-PS-induced cardiomyopathy after upgrading to CSP. LVDys due to dyssynchronopathy is frequent and probably underdiagnosed. UHF-ECG provides useful new information about ventricular activation and will likely improve patient selection for cardiac resynchronization therapy (CRT).

Catheter ablation for persistent atrial fibrillation after acute decompensated heart failure Attack: Earlier is Better?

Background

Acute decompensated heart failure (ADHF) is often accompanied by persistent atrial fibrillation (AF). However, the optimal timing for RFCA in patients with persistent AF and ADHF is still uncertain.

Objectives

The aim of this observational cohort study is to investigate the safety and efficacy of early RFCA in patients with persistent AF after ADHF attack.

Methods

Patients with persistent AF and ADHF who underwent early RFCA as soon as the ADHF symptoms were initially controlled (Early group, n = 63) and those who received elective procedures after a transitional period (Elective group, n = 67) were investigated. After 1:1 propensity score matching, 50 matched pairs were analyzed.

Results

The overall procedural complication rates were similar (Early group: 6.0 %, n = 3; Elective group: 6.0 %, n = 3; P = 1.000). Patients in the early group had significantly less HF rehospitalization than the elective group during the 1-year post-procedure follow-up period (Mantel-Cox test: P = 0.036; HR: 0.369; 95 %CI: 0.145-0.938), though AF recurrence showed no difference (Mantel-Cox test: P = 0.645; HR: 1.204; 95 %CI: 0.547-2.648). A 90-day rehospitalization rate was significantly higher in the transitional period in the elective group, compared with patients who already received early RFCA (Elective group: 13, 26.0 %; Early group: 2, 4.0 %; P = 0.002).

Conclusions

Early RFCA therapy for persistent AF after ADHF attack was safe and effective. Patients who received early RFCA therapy had significantly less HF rehospitalization in the 1-year post-procedure follow-up period. On the other hand, the elective procedure was accompanied by a higher risk of HF rehospitalization during the waiting period.

Right ventricular subclinical dysfunction in high-burden idiopathic outflow tract premature ventricular contraction population

BACKGROUND

The relationship between premature ventricular contractions (PVC) and right ventricular (RV) function is not widely known. Left ventricular (LV) dysfunction due to PVC is known as PVC-induced cardiomyopathy (PIC) and suppressing the PVC substrate would improve LV function. The effect of PVC ablation on changes in RV function in patients with subtle RV subclinical dysfunction remains unknown.

OBJECTIVE

Understanding the alterations in RV function parameters after PVC ablation.

METHOD

Basic and speckle-tracking echocardiography has been performed on 42 individuals with symptomatic idiopathic outflow tract PVC before and 1 month after a successful ablation.

RESULT

At the baseline of the study, there were 26 patients with RV subclinical dysfunction and 16 patients without RV dysfunction. Patients with RV subclinical dysfunction exhibited significantly higher PVC burden and QRS complex duration than those with normal RV function (p < 0.05). A PVC burden ≥ 21% (OR 9.11, 1.54-53.87, p = 0.015) and a QRS complex duration ≥ 138 ms (OR 5.74, 1.07-30.90, p = 0.042) were independently associated with RV subclinical dysfunction. In both groups, measurements of RV subclinical function before and after ablation, specifically by free wall longitudinal strain (FWLS) and global longitudinal strain (GLS), demonstrated significant changes. These improvements were more pronounced in the group with RV dysfunction (FWLS 9.7 ± 4.0, p < 0.001; GLS 7.5 ± 4.2, p < 0.001). Lower initial FWLS and GLS before ablation emerged as significant parameters in the multivariate analysis for the improvement of RV function post-ablation.

CONCLUSION

Patients with RV subclinical dysfunction had higher PVC burden and wider QRS duration. Patients with idiopathic outflow tract PVC with RV subclinical dysfunction may experience improvements in RV function after successful PVC ablation.

Identification of Lauric Acid as a Potent Sodium Channel NaV1.5 Blocker from Compound Chinese Medicine Wenxin Keli

Purpose

The major cardiac voltage-gated sodium channel NaV1.5 (INa) is essential for cardiac action potential initiation and subsequent propagation. Compound Chinese medicine Wenxin Keli (WXKL) has been shown to suppress arrhythmias and heart failure. However, its active components have not been fully elucidated. This study focused on identifying the active inhibitor of INa in WXKL and exploring their mode of action in electrophysiological conduction.

Methods

A chemical fraction library was constructed from an aqueous extract of WXKL and screened using an automated patch-clamping system in cells stably expressing the NaV1.5 gene SCN5A. Candidate fractions with INa-inhibition activity were analyzed by HPLC-ESI-IT-TOF-MS and GC-MS to identify the ingredients. NaV1.5 blocker molecules identified by single-cell electrocardiogram were tested in hiPSC-derived cardiomyocytes. We evaluated the SCN5A inhibitory potential of Wenxin Keli effective monomer employing molecular docking and molecular dynamics simulation approaches.

Results

A primary screen of the WXKL chemical library identified five fractions that significantly inhibited the NaV1.5 channel, with one of them rich in poly-saturated fatty acids. Molecular structural characterization revealed the presence of lauric acid, myristic acid, palmitic acid, and stearic acid in the active subfraction. Electrophysiological characterization demonstrated lauric acid (LA) as the most effective monomer for INa-inhibition with an IC50 at 27.40 ± 12.78 μM. LA shifted the steady-state inactivation of INa to more negative potentials and decreased the amplitude of extracellular field potential in hiPSC-derived cardiomyocytes. We demonstrate for the first time that naturally poly-saturated fatty acid, lauric acid, as a potential novel INa blocker. Molecular docking and molecular dynamics simulation suggested that LA binds to the NaV1.5 protein, with a significant binding affinity forming interactions with functionally essential residues and blocks the inward flow of Na+. Mechanistically, lauric acid acts on the fast inactivation of NaV1.5 alter electrophysiology conduction of hiPSC-derived cardiomyocytes and contribute to the antiarrhythmic effect of WXKL.

Conclusion

Lauric acid is a potent blocker for sodium channel NaV1.5 and alleviates arrhythmia via inhibiting INa.

Transcoronary study of biomarkers in patients with heart failure: Insights into intracardiac production

AIMS

Biomarkers are pivotal in the management of heart failure (HF); however, their lack of cardiac specificity could limit clinical utility. This study aimed to investigate the transcoronary changes and intracardiac production of these biomarkers.

METHODS

Transcoronary gradients for B-type natriuretic peptide (BNP) and five novel biomarkers-galectin-3 (Gal-3), soluble suppression of tumourigenicity 2 (sST2), tissue inhibitor of metalloproteinase 1 (TIMP-1), growth differentiation factor 15 (GDF-15) and myeloperoxidase (MPO)-were determined using femoral artery (FA) and coronary sinus (CS) samples from 30 HF patients and 10 non-HF controls. Intracardiac biomarker production was assessed in an HF canine model using real-time quantitative PCR (qPCR) and western blot (WB) analysis.

RESULTS

Compared with the control group, levels of all detected biomarkers were significantly elevated in the HF group, while transcoronary gradients were only observed for BNP, Gal-3 and TIMP-1 levels in the HF group (BNP: FA: 841.5 ± 727.2 ng/mL vs. CS: 1132.0 ± 959.1 ng/mL, P = 0.005; Gal-3: FA: 9.5 ± 3.0 ng/mL vs. CS: 19.7 ± 16.4 ng/mL, P = 0.002; and TIMP-1: FA: 286.7 ± 68.9 ng/mL vs. CS: 377.3 ± 108.9 ng/mL, P = 0.001). Real-time qPCR and WB analysis revealed significant elevation of BNP, Gal-3 and TIMP-1 in the cardiac tissues of the HF group relative to other groups.

CONCLUSIONS

This study provided evidence of transcoronary changes in BNP, Gal-3 and TIMP-1 levels in HF patients, offering insights into their intracardiac production. These findings enhance the understanding of the biology of these biomarkers and may inform their clinical application.

Advancing 3D Engineered In Vitro Models for Heart Failure Research: Key Features and Considerations

Heart failure is characterized by intricate myocardial remodeling that impairs the heart's pumping and/or relaxation capacity, ultimately reducing cardiac output. It represents a major public health burden, given its high prevalence and associated morbidity and mortality rates, which continue to challenge healthcare systems worldwide. Despite advancements in medical science, there are no treatments that address the disease at its core. The development of three-dimensional engineered in vitro models that closely mimic the (patho)physiology and drug responses of the myocardium has the potential to revolutionize our insights and uncover new therapeutic avenues. Key aspects of these models include the precise replication of the extracellular matrix structure, cell composition, micro-architecture, mechanical and electrical properties, and relevant physiological and pathological stimuli, such as fluid flow, mechanical load, electrical signal propagation, and biochemical cues. Additionally, to fully capture heart failure and its diversity in vivo, it is crucial to consider factors such as age, gender, interactions with other organ systems and external influences-thereby recapitulating unique patient and disease phenotypes. This review details these model features and their significance in heart failure research, with the aim of enhancing future platforms that will deepen our understanding of the disease and facilitate the development of novel, effective therapies.

Tachycardia-Induced Cardiomyopathy Following Prolonged Ritodrine Infusion During Pregnancy: A Case Report

Preterm birth remains a leading cause of neurodevelopmental disability in offspring, prompting various preventive measures. However, controversies persist surrounding these approaches, particularly regarding beta-mimetic drugs. In Japan, it remains a concerning reality that ritodrine infusion continues to be used for long-term tocolysis in preterm labor, despite the warning issued by the US Food and Drug Administration. Growing evidence suggests that the use of beta-adrenergic agonists during pregnancy is associated with an increased risk of maternal cardiac systolic dysfunction. Furthermore, tachycardia-induced cardiomyopathy (T-CM), a rare etiology of cardiomyopathy, can also be triggered by beta-adrenergic stimulation. Here, we present a case of a 35-year-old pregnant woman without prior arrhythmias who developed T-CM following prolonged ritodrine infusion for preterm labor. The patient experienced persistent, exacerbated tachycardia under continuous ritodrine infusion starting at 20 weeks of gestation and developed supraventricular tachycardia with an impaired left ventricular ejection fraction of 30% and an elevated N-terminal prohormone of brain natriuretic peptide (NT-proBNP) level of 2,122 pg/mL, at the time of transfer at 36 weeks of gestation. Administration of adenosine and verapamil revealed atrial tachycardia or flutter, and the patient was diagnosed with tachycardia-induced cardiomyopathy, which was confirmed by a dramatic improvement in systolic function following maternal heart rate control using a bisoprolol patch. The patient delivered a healthy female via cesarean section at 37 weeks of gestation and was discharged from the hospital with favorable maternal and neonatal outcomes. This report highlights another potential risk of maternal cardiac deterioration due to beta-adrenergic effects, emphasizing the importance of reconsidering the long-term use of ritodrine infusion, as well as the need for dose titration, discontinuation, or switching to the alternative agent in cases of persistent or exacerbated tachycardia. Careful monitoring, including more frequent daily checkups to assess pulse rate and respiratory changes, along with the use of early warning systems and occasional BNP or NT-proBNP measurements, should be considered to ensure the timely detection of deterioration and the implementation of earlier preventive interventions.

Cardiac Complications From Herbal Remedies

The safety of traditional Chinese medicine (TCM) herbal remedies, particularly when used with modern medications or in non-traditional dosages, requires careful consideration. We present a case of a 62-year-old male with pre-existing cardiovascular risk factors who developed tachycardia-induced cardiomyopathy (TIC) potentially linked to prolonged use of the TCM supplement "Tan Ke Jing." The supplement contains licorice root, caffeine, and apricot kernel, which have known cardiovascular effects. Discontinuation of the supplement and guideline-directed medical therapy significantly improved left ventricular ejection fraction over four months. This case highlights the potential for TCM herbal supplements to induce serious cardiac conditions, emphasizing the importance of thorough patient history taking, including alternative medicine use, and the need for further research into interactions and side effects. Clinicians should be aware of the cardiac risks associated with herbal supplement use and foster open communication with patients about alternative medicine use.

A new perspective on atrial tachycardia-induced cardiomyopathy: The misdiagnosis of epigastric pain in an 11-year-old girl

Epigastric pain can be a common clinical manifestation of many diseases, but severe subxiphoid pain caused by tachycardia-induced cardiomyopathy is extremely rare in children. Therefore, the clinical manifestations of the disease are diverse, and improving early detection and treatment of the disease can avoid possible risks. In the case, we report an 11-year-old girl who was initially diagnosed with acute gastritis in a local hospital, but was later diagnosed with atrial tachycardia-induced cardiomyopathy in our hospital after active diagnosis and effective treatment, suggesting early detection and intervention is possible to prevent subsequent serious events.

Catheter ablation for atrial tachycardia in pediatric patients: a single-center experience

Purpose

Atrial tachycardia is an uncommon supraventricular tachycardia in children. It is often drug-resistant and likely to occur concomitantly with tachycardia-induced cardiomyopathy, making radiofrequency catheter ablation the preferred treatment. The aim of this study was to assess the feasibility, safety, and effectiveness of radiofrequency catheter ablation for the treatment of different types of atrial tachycardia in children, particularly in those with drug-resistant and tachycardia-induced cardiomyopathy.

Methods

A total of 28 children with atrial tachycardia (including focal atrial tachycardia and atrial flutter) who underwent atrial radiofrequency ablation at the Children's Hospital Affiliated to Chongqing Medical University from May 2018 to December 2023 were included. The baseline characteristics, preoperative medication, surgical information, and postoperative follow-up data of these children were analyzed statistically.

Results

The mean age patients at ablation was 10.24 ± 3.40 years. A total of 78.6% of the patients (22/28) who received preoperative pharmacological treatment had intermittent or persistent atrial tachycardia. Of the 28 children who underwent radiofrequency ablation, 24 (85.7%) were diagnosed with focal atrial tachycardia, three (10.7%) with atrial flutter, and one (3.6%) with both. No postoperative complications occurred in any patient. The immediate ablation success rate in the 25 patients with focal atrial tachycardia was 96.0% (24/25). After 26.89 ± 18.17 months of follow-up, only three patients had recurrence. The ablation difficulty of focal atrial tachycardia originating in the appendage was higher than that originating in the non-atrial appendage (44.4% vs. 6.3%, p = 0.01). The success rate of ablation for atrial flutter was 100%, except in one child with underlying cardiomyopathy who experienced recurrence. Final success was achieved in 25 of the 28 patients (89.2%) at the end of the follow-up period. In addition, eight children (28.6%) in this study were diagnosed with tachycardia-induced cardiomyopathy, with significantly increased ejection fraction and shortening rate after radiofrequency ablation (p < 0.01), whereas the left ventricular end-systolic diameter were not significantly reduced during the follow-up period (p > 0.05).

Conclusion

Radiofrequency catheter ablation is safe and effective for the treatment of atrial tachycardia in children in the short- and long-term.It can be used as the first treatment option for children with medically refractory atrial tachycardia and tachycardia-induced cardiomyopathy.

Characteristics, Predictors, and Clinical Outcomes in Heart Failure With Reduced Ejection Fraction According to a 1-Year Left Ventricular Ejection Fraction Following Sacubitril/Valsartan Treatment

BACKGROUND

Optimal medical treatment can lead to improvement in left ventricular ejection fraction (LVEF) in patients with heart failure with reduced EF (HFrEF). We investigated the characteristics, predictors, and outcomes of HFrEF according to the 1-year LVEF following angiotensin receptor-neprilysin inhibitors therapy (ARNI).

METHODS AND RESULTS

Using the STRATS-HF-ARNI (Strain for Risk Assessment and Therapeutic Strategies in Patients With Heart Failure Treated With Angiotensin Receptor-Neprilysin Inhibitor) registry, we identified 1074 patients with HFrEF who took ARNI and underwent baseline and 1-year echocardiography. Patients were classified as HF with improved ejection fraction (HFimpEF) and persistent HFrEF (perHFrEF) (1-year LVEF >40% and ≤40%). The primary and secondary outcomes were all-cause and cardiac mortality from the 1-year follow-up. Among 1074 included patients, 498 (46.4%) had HFimpEF, and 576 (53.6%) had perHFrEF. Older age, male sex, and large LV end-diastolic volumes were positive predictors of perHFrEF, whereas atrial fibrillation and high systolic blood pressure were identified as inverse predictors. Patients with HFimpEF showed lower all-cause and cardiac mortality rates (both log-rank P<0.001). In the multivariable analysis, perHFrEF (hazard ratio, 2.402 [95% CI, 1.251-4.610]; P=0.008) was an independent predictor of poor outcomes. The risk of all-cause mortality decreased as the 1-year LVEF increased up to 40%; however, no additional risk reduction was observed beyond 40%. Compared with patients taking renin-angiotensin-aldosterone system inhibitors in the STRATS-AHF (Strain for Risk Assessment and Therapeutic Strategies in Patients With Acute Heart Failure) registry, those in the STRATS-HF-ARNI registry demonstrated better outcomes in both HFimpEF and perHFrEF.

CONCLUSIONS

Patients with HFimpEF had better prognosis than those with perHFrEF, and ARNI treatment in HFrEF could be more beneficial than renin-angiotensin-aldosterone system inhibitors for both HFimpEF and perHFrEF.

REGISTRATION

URL: https://www.who.int/clinical-trials-registry-platform; Unique identifier: KCT0008098.

Predictors of systolic function recovery after atrial fibrillation ablation in heart failure patients

INTRODUCTION AND OBJECTIVES

Atrial fibrillation (AF) and heart failure (HF) often coexist. AF catheter ablation improves left ventricular ejection fraction (LVEF), but its impact varies between patients. We aimed to identify predictors of LVEF improvement in HF patients with impaired LVEF undergoing AF ablation.

METHODS

We conducted a retrospective single-center study in HF patients with LVEF <50% undergoing AF catheter ablation between May 2016 and May 2022. The primary endpoint was the LVEF recovery rate ('responders'). Secondary endpoints were one-year safety and effectiveness. We also aimed to validate a prediction model for LVEF recovery.

RESULTS

The study included 100 patients (79% male, median age 60 years, 70% with probable tachycardia-induced cardiomyopathy [TIC], mean LVEF 37%, 29% with paroxysmal AF). After a median follow-up of 12 months after catheter ablation, LVEF improved significantly (36±10% vs. 53±10%, p<0.001), with an 82% responder rate. A suspected diagnosis of TIC (OR 4.916 [95% CI 1.166-20.732], p=0.030), shorter QRS duration (OR 0.969 [95% CI 0.945-0.994], p=0.015), and smaller left ventricle (OR 0.893 [95% CI 0.799-0.999], p=0.049) were independently associated with LVEF improvement. Freedom from any documented atrial arrhythmia was 86% (64% under antiarrhythmic drugs), and the rate of adverse events was 2%. The prediction model had a good discriminative performance (AUC 0.814 [95% CI 0.681-0.947]).

CONCLUSION

In AF patients with HF and impaired LVEF, suspected TIC, shorter QRS duration, and smaller LV diameter were associated with LVEF recovery following AF catheter ablation.

Myocardial work in idiopathic premature ventricular contractions: Assessing left ventricular function and prognosis

BACKGROUND

Premature ventricular contractions (PVCs) can lead to impairment of left ventricular function. The noninvasive myocardial work technique, which incorporates left ventricular afterload, represents a new method for assessing left ventricular functional.

AIM

The aim of this study is to explore the value of noninvasive myocardial work technique in assessing left ventricular systolic function in patients with PVCs.

METHODS

Compare the clinical data, two-dimensional echocardiography parameters, and myocardial work parameters of 66 patients with PVCs and 35 healthy volunteers and explore the relevant risk factors for postoperative recurrence in patients with PVCs.

RESULTS

In patients with PVCs compared to the control group, they exhibit enlargement of left atrial diameter (LAD) and left ventricular internal dimension in diastole (LVIDd), as well as thickening of the left ventricular wall. The global work waste (GWW) increases, while the global work efficiency (GWE) decreases. There is a significant negative correlation between the PVC burden and GWE (r = -0.70, p <0.01), and a significant positive correlation between the PVC burden and GWW (r = 0.58, p <0.01). GWE is a sensitive indicator for predicting the recurrence of PVCs after radiofrequency ablation. Patients with GWE <91.5%, global longitudinal strain (GLS) <15.5%, and ejection fraction (EF) <62.5% have a higher postoperative recurrence rate.

CONCLUSION

PVCs can cause impairment of left ventricular systolic function. GWE is the most sensitive indicator for predicting postoperative recurrence in patients with PVCs. Patients with GWE <91.5%, GLS <15.5%, and EF <62.5% have a higher postoperative recurrence rate.

The Hidden Heart: Exploring Cardiac Damage Post-Stroke: A Narrative Review

Stroke-heart syndrome (SHS), a critical yet underrecognized condition, encompasses a range of cardiac complications that arise following an ischemic stroke. This narrative review explores the pathophysiology, clinical manifestations, and implications of SHS, focusing on the complex interplay between the brain and the heart. Acute ischemic stroke (AIS) triggers autonomic dysfunction, leading to a surge in catecholamines and subsequent myocardial injury. Our review highlights the five cardinal manifestations of SHS: elevated cardiac troponin (cTn) levels, acute myocardial infarction, left ventricular dysfunction, arrhythmias, and sudden cardiac death. Despite the significant impact of these complications on patient outcomes, there is a notable absence of specific guidelines for their management. Through a comprehensive literature search, we synthesized findings from recent studies to elucidate the mechanisms underlying SHS and identified gaps in the current understanding. Our findings underscore the importance of early detection and multidisciplinary management of cardiac complications post-stroke. Future research should focus on establishing evidence-based protocols to improve clinical outcomes for stroke patients with SHS. Addressing this unmet need will enhance the care of stroke survivors and reduce mortality rates associated with cardiac complications.

Catheter ablation for focal atrial tachycardias during pregnancy: A systematic review

OBJECTIVE

Pregnancy can trigger maternal tachycardias, and the onset of recurrent or incessant focal atrial tachycardia (AT) can lead to tachycardia-induced cardiomyopathy. Medical interventions are commonly employed, but they carry potential fetal and maternal risks. Catheter ablation (CA), particularly with non-fluoroscopic navigation systems, may be considered as an alternative. This systematic review aims to explore the feasibility and outcomes of CA for focal AT during pregnancy.

METHODS

A thorough literature search was conducted until September 30th, 2023, on PubMed, Embase, and Cochrane databases. Included articles described maternal focal ATs diagnosed through electrophysiological studies and treated with CA. Data derived from these studies were organized into tables and subsequently analyzed.

RESULTS

Out of 278 papers reviewed, 15 articles involving 24 patients were retrieved. CA, utilizing radiofrequency energy achieved acute success in 95.8% of cases. Sixteen patients (66.7%) underwent complete fluoroless procedures, with two adverse events directly related to the procedure reported. Long-term follow-up revealed minimal AT recurrences, with a 0.06% arrhythmia burden in one case.

CONCLUSION

Focal ATs during pregnancy can be incessant and refractory to medical intervention, precipitating an acute decline in left ventricular ejection fraction. In this setting, CA emerges as an efficacious treatment modality, particularly in cases of tachycardia-induced cardiomyopathies. Whenever feasible, it is advisable to perform these procedures with minimal or no fluoroscopy guidance. Larger studies are needed to establish the safety and the efficacy of CA for focal ATs during pregnancy, as current research consists of case reports or small case series.

ST-segment depression and left ventricular systolic function recovery post-atrial fibrillation ablation in heart failure

AIMS

Catheter ablation (CA) of atrial fibrillation (AF) improves left ventricular ejection fraction (LVEF) in patients with heart failure with reduced ejection fraction (HFrEF). The impact of ST-segment depression before CA on LVEF recovery and clinical outcomes remains unknown. In the present study, we aimed to investigate the relationship between ST-segment depression during AF rhythm before CA and improvement in the LVEF and clinical outcomes in persistent atrial fibrillation (PerAF) patients with HFrEF.

METHODS AND RESULTS

The present study included 122 PerAF patients (male; 98 patients, 80%, mean age: 69 [56, 76] years) from the Osaka Rosai Atrial Fibrillation ablation (ORAF) registry who had LVEF < 50% and underwent an initial ablation. The patients who underwent percutaneous coronary intervention or coronary artery bypass grafting within the past 1 month were not included in the enrolled patients. We assigned the patients based on the presence of ST-segment depression before CA during AF rhythm and evaluated improvement in the LVEF (LVEF ≥ 15%) 1 year after CA and the relationship between ST-segment depression and heart failure (HF) hospitalization/major adverse cardiovascular events (MACE), which are defined as a composite of HF hospitalization, cardiovascular death, hospitalization due to coronary artery disease, ventricular arrhythmia requiring hospitalization and stroke. The percentage of patients with improvement in the LVEF 1 year after CA was significantly lower in the patients with ST-segment depression than those without (58.6% vs. 79.7%, P = 0.012). Multiple regression analysis showed ST-segment depression was independently and significantly associated with improvement in the LVEF 1 year after CA (HR: 0.35; 95% CI: 0.129-0.928, P = 0.035). Kaplan-Meier analysis showed that the patients with ST-segment depression significantly had higher risk of HF hospitalization and MACE than those without (log rank P = 0.022 and log rank P = 0.002, respectively). Multivariable Cox proportional hazards analysis showed that ST-segment depression was independently and significantly associated with a higher risk of MACE (HR: 2.82; 95% CI: 1.210-6.584, P = 0.016).

CONCLUSIONS

ST-segment depression before CA during AF rhythm was useful prognostic predictor of improvement in the LVEF and clinical outcomes including HF hospitalization and MACE in PerAF patients with HFrEF.

Effects of Ventricular Extrasystoles on Right Ventricle Functions (a Speckle Tracking Study). VES and RV Strain Imaging

AIM

The adverse effects of ventricular extrasystoles (VES) on the heart, such as induced dyssynchrony, irregular heart rate, and atrioventricular dissociation, have been demonstrated. The aim of this study was to investigate the effects of VES on the right ventricle (RV) using strain imaging.

MATERIAL AND METHODS

Fifty patients with 5000 or more VES detected during 24hr Holterrhythm monitoring between April 2022 and September 2022 in the cardiology outpatient clinic were included in this study.A volunteer control group of 50 individuals matching the patients' age and demographic characteristics was selected. Right heart function parameters were compared echocardiographically between the two groups.

RESULTS

In the VES group, both RV free wall strain (22.03±3.67, 29.52±3.01; p<0.001) and RV four-chamber strain (19.37±2.95, 22.34±2.11; p<0.001) were lower compared to the control groupIn the univariate regression analysis for decreased RV four-chamber strain, the presence of VES (p<0.001) was identified as a predictor, whereaas in the multivariate regression analysis, it was not considered to be an independent predictor. When evaluating the characteristics of the VES patients, the number of VES detected during Holter monitoring and delta QRS were observed as negative predictors of RV strain.

CONCLUSION

This study demonstrated the adverse effects of VES on the right ventricle, as it is on the left ventricle.Therefore, regular monitoring of RV function with echocardiography is important in the follow-up of patients with VES.

Clinical Features of Tachycardia-induced Cardiomyopathy in Patients with Atrial Fibrillation

Objective Atrial fibrillation (AF) is the most common cause of tachycardia-induced cardiomyopathy (TIC). However, which patients with AF are prone to developing TIC remains unclear. In this study, we investigated the clinical features of AF patients with TIC. Methods This single-center study included 722 patients with AF (average age, 63.1±10.2 years old; 191 women) who underwent radiofrequency catheter ablation. We defined TIC as an initial left ventricular ejection fraction (LVEF) of <40% and a >20% recovery of the LVEF after successful AF ablation and compared the clinical characteristics between the TIC and control groups. Results The proportions of type 2 diabetes (30.5% vs. 14.7%), renal dysfunction (34.2% vs. 23.8%), hypertension (67.1% vs. 54.8%), and persistent AF (62.2% vs. 32.2%) were significantly higher in the TIC group (n=82) than in the control group (n=640). The atrioventricular nodal effective refractory period (AVNERP) (303±72 ms vs. 332±86 ms; p=0.017) was significantly shorter in the TIC group than in the control group. A multivariable analysis found that persistent AF [odds ratio (OR), 3.19; 95% confidence interval (CI), 1.94-5.24], renal dysfunction (OR, 1.87; 95% CI, 1.06-3.32), and type 2 diabetes (OR, 2.30; 95% CI, 1.31-4.05) were significantly associated with TIC. Conclusion Comorbid renal dysfunction and type 2 diabetes were clinical features of AF patients with TIC. Persistent AF, and short AVNERP may be involved in the development of TIC.

Biomarkers to predict improvement of left ventricular ejection fraction after atrial fibrillation ablation

BACKGROUND

Atrial fibrillation (AF) and heart failure frequently coexist. Prediction of left ventricular ejection fraction (LVEF) recovery after catheter ablation (CA) for AF remains difficult.

OBJECTIVE

The purpose of this study was to evaluate the value of biomarkers, alone and in combination with the Antwerp score, to predict LVEF recovery after CA for AF.

METHODS

Patients undergoing CA for AF with depressed LVEF (<50%) were included. Plasma levels of 13 biomarkers were measured immediately before CA. Patients were categorized into "responders" and "nonresponders" in a similar fashion to the Antwerp score performance derivation and validation cohorts. The predictive power of the biomarkers alone and combined in outcome prediction was evaluated.

RESULTS

A total of 208 patients with depressed LVEF were included (median age 63 years; 39-19% female; median indexed left atrial volume 42 (33-52) mL/m2; median LVEF 43 (38-46)%). At a median follow-up time of 30 (20-34) months, 161 (77%) were responders and 47 (23%) were nonresponders. Of 13 biomarkers, -4-angiopoietin 2 (ANG2), growth differentiation factor 15 (GDF15), fibroblast growth factor 23, and myosin binding protein C3-were significantly different between responders and nonresponders (P ≤ .001) and their combination could predict the end point with an area under the curve of 0.72 (95% confidence interval [CI] 0.64-0.81) overall, 0.69 (95% CI 0.59-0.78) in heart failure with mildly reduced ejection fraction, and 0.88 (95% CI 0.77-0.98) in heart failure with reduced ejection fraction. Only ANG2 and GDF15 remained significantly associated with LVEF recovery after adjustment for age, sex, and Antwerp score and significantly improved the accuracy of the Antwerp score predictions (P < .001). The area under the curve of the Antwerp score in the outcome prediction improved from 0.75 (95% CI 0.67-0.83) to 0.78 (95% CI 0.70-0.86).

CONCLUSION

A biomarker panel (ANG2 and GDF15) significantly improved the accuracy of the Antwerp score.

Risk Factors for PVC Induced Cardiomyopathy and Post-Ablation Left Ventricular Systolic Dysfunction Reversibility: A Systematic Review and Meta-Analysis of Observational Studies

Background

Premature ventricular complex (PVC) induced cardiomyopathy (PVC-CMP) and exacerbated left ventricular systolic dysfunction (LVSD) are common in clinical scenarios. However, their precise risk factors are currently unclear.

Methods

We performed a systematic review of PubMed, EMBASE, Web of Science, and Chinese-based literature database (CBM) to identify observational studies describing the factors associated with PVC-CMP and post-ablation LVSD reversibility. A total of 25 and 12 studies, involving 4863 and 884 subjects, respectively, were eligible. We calculated pooled multifactorial odds ratios (OR) and 95% confidence intervals (CI) for each parameter using random-effects and fixed-effects models.

Results

The results showed that 3 independent risk factors were associated with PVC-CMP: being asymptomatic (OR and 95% CI: 3.04 [2.13, 4.34]), interpolation (OR and 95% CI: 2.47 [1.25, 4.92]), and epicardial origin (epi-origin) (OR and 95% CI: 3.04 [2.13, 4.34]). Additionally, 2 factors were significantly correlated with post-ablation LVSD reversibility: sinus QRS wave duration (QRSd) (OR and 95% CI: 0.95 [0.93, 0.97]) and PVC burden (OR and 95% CI: 1.09 [0.97, 1.23]).

Conclusions

the relatively consistent independent risk factors for PVC-CMP and post-ablation LVSD reversibility are asymptomatic status, interpolation, epicardial origin, PVC burden, and sinus QRS duration, respectively.

Catheter Ablation of Atrial Fibrillation in Patients with Heart Failure: Focus on the Latest Clinical Evidence

Atrial fibrillation and heart failure are two common cardiovascular conditions that frequently coexist, and it has been widely demonstrated that in patients with chronic heart failure, atrial fibrillation is associated with a significant increase in the risk of all-cause death and all-cause hospitalization. Nevertheless, there is no unanimous consensus in the literature on how to approach this category of patients and which therapeutic strategy (rhythm control or frequency control) is the most favorable in terms of prognosis; moreover, there is still a lack of data comparing the different ablative techniques of atrial fibrillation in terms of efficacy, and many of the current trials do not consider current ablative techniques such as high-power short-duration ablation index protocol for radiofrequency pulmonary vein isolation. Eventually, while several RCTs have widely proved that in patients with heart failure with reduced ejection fraction, ablation of atrial fibrillation is superior to medical therapy alone, there is no consensus regarding those with preserved ejection fraction. For these reasons, in this review, we aim to summarize the main updated evidence guiding clinical decision in this complex scenario, with a special focus on the most recent trials and the latest meta-analyses that examined the role of catheter ablation (CA) in rhythm control in patients with AF and HF.

Premature ventricular complexes: Assessing burden density in a large national cohort to better define optimal ECG monitoring duration

BACKGROUND

Premature ventricular contraction (PVC) burden is a risk factor for heart failure and cardiovascular death in patients with structural heart disease. Long-term electrocardiographic monitoring can have a significant impact on PVC burden evaluation by further defining PVC distribution patterns.

OBJECTIVE

This study aimed to ascertain the optimal duration of electrocardiographic monitoring to characterize PVC burden and to understand clinical characteristics associated with frequent PVCs and nonsustained ventricular tachycardia in a large US cohort.

METHODS

Commercial data (iRhythm's Zio patch) from June 2011 to April 2022 were analyzed. Inclusion criteria were age >18 years, PVC burden ≥5%, and wear period ≥13 days. PVC burden cutoffs were determined on the basis of AHA/ACC/HRS guidelines for very frequent PVCs (10,000-20,000 during 24 hours). Patients were assigned to categories by PVC densities: low, <10%; moderate, 10% to <20%; and high, ≥20%. Mean measured error was assessed at baseline and daily until the wear period's end for overall PVC burden and different PVC densities.

RESULTS

Analysis of 106,705 patch monitors revealed a study population with mean age of 70.6 ± 14.6 years (33.6% female). PVC burden was higher in male patients and those >65 years of age. PVC burden mean error decreased from 2.9% at 24 hours to 1.3% at 7 days and 0.7% at 10 days. Number of ventricular tachycardia episodes per patient increased with increasing PVC burden (P < .0001).

CONCLUSION

Extending ambulatory monitoring beyond 24 hours to 7 days or more improves accuracy of assessing PVC burden. Ventricular tachycardia frequency and duration vary by initial PVC density, highlighting the need for prolonged cardiac monitoring.

Understanding Arrhythmia-Induced Cardiomyopathy: Symptoms and Treatments

Arrhythmia-induced cardiomyopathy is a complex condition that causes a decline in heart function as a result of irregular heart rhythms. This disorder highlights the link between irregular heart rhythm and heart failure, necessitating prompt identification and intervention. It often occurs due to ongoing fast heart rhythms like atrial fibrillation or tachycardia. Understanding the mechanisms, symptoms, and available treatments is essential for enhancing patient outcomes given the complicated nature of the condition. This article delves into various aspects of arrhythmia-induced cardiomyopathy, including pathogenesis, clinical presentation, diagnostic methods, epidemiology, typical arrhythmias associated with the condition, and management options. It assesses patients' future outlook and necessary follow-up, aiming to provide healthcare providers with a comprehensive understanding of how to handle this intricate condition. The article emphasizes the important effect an integrative approach can have on both patients' lives and the clinical consequences of diagnosing and treating this condition. This extensive understanding enhances the resources at the disposal of physicians, enabling targeted treatments that enhance cardiomyopathy by targeting arrhythmia regulation. More research and development are needed in the field of cardiomyopathy and arrhythmia relationship. The presentation urges the medical field to delve deeper into the complexities of illness by emphasizing the need for continuous research and a multifaceted treatment plan. By combining these understandings, our goal is to enhance patient outcomes and create opportunities for further studies on cardiovascular wellness.

Alcoholic cardiomyopathy: an update

Alcohol-induced cardiomyopathy (AC) is an acquired form of dilated cardiomyopathy (DCM) caused by prolonged and heavy alcohol intake in the absence of other causes. The amount of alcohol required to produce AC is generally considered as >80 g/day over 5 years, but there is still some controversy regarding this definition. This review on AC focuses on pathogenesis, which involves different mechanisms. Firstly, the direct toxic effect of ethanol promotes oxidative stress in the myocardium and activation of the renin-angiotensin system. Moreover, acetaldehyde, the best-studied metabolite of alcohol, can contribute to myocardial damage impairing actin-myosin interaction and producing mitochondrial dysfunction. Genetic factors are also involved in the pathogenesis of AC, with DCM-causing genetic variants in patients with AC, especially titin-truncating variants. These findings support a double-hit hypothesis in AC, combining genetics and environmental factors. The synergistic effect of alcohol with concomitant conditions such as hypertension or liver cirrhosis can be another contributing factor leading to AC. There are no specific cardiac signs and symptoms in AC as compared with other forms of DCM. However, natural history of AC differs from DCM and relies directly on alcohol withdrawal, as left ventricular ejection fraction recovery in abstainers is associated with an excellent prognosis. Thus, abstinence from alcohol is the most crucial step in treating AC, and specific therapies are available for this purpose. Otherwise, AC should be treated according to current guidelines of heart failure with reduced ejection fraction. Targeted therapies based on AC pathogenesis are currently being developed and could potentially improve AC treatment in the future.

Longitudinal analysis of echocardiographic and cardiac biomarker variables in dogs with atrial fibrillation: The optimal rate control in dogs with atrial fibrillation II study

BACKGROUND

Rate control (RC; meanHRHolter ≤ 125 bpm) increases survival in dogs with atrial fibrillation (AF). The mechanisms remain unclear.

HYPOTHESIS/OBJECTIVES

Investigate echocardiographic and biomarker differences between RC and non-RC (NRC) dogs. Determine if changes post-anti-arrhythmic drugs (AAD) predict successful RC in subsequent Holter monitoring. Evaluate if early vs late RC affects survival.

ANIMALS

Fifty-two dogs with AF.

METHODS

Holter-derived mean heart rate, echocardiographic and biomarker variables from dogs receiving AAD were analyzed prospectively at each re-evaluation and grouped into RC or NRC. The primary endpoint was successful RC. Between group comparisons of absolute values, magnitude of change from admission to re-evaluations and end of study were performed using Mann-Whitney tests or unpaired t-tests. Logistic regression explored variables associated with inability to achieve RC at subsequent visits. Kaplan-Meier survival analysis was used to compare survival time of early vs late RC.

RESULTS

At visit 2, 11/52 dogs were RC; at visit 3, 14/52 were RC; and at visit 4, 4/52 were RC. At the end of study, 25/52 remained NRC. At visit 2, both groups had increased cardiac dimensions, but NRC dogs had larger dimensions; biomarkers did not differ. At the end of study, RC showed decreased cardiac dimensions and end-terminal pro-brain natriuretic peptide (NT-proBNP) compared with NRC. No variables were useful at predicting RC success in subsequent visits. Survival analysis found no differences between early vs late RC.

CONCLUSIONS AND CLINICAL IMPORTANCE

The RC dogs had decreased cardiac dimensions and NT-proBNP, suggesting HR-mediated reverse-remodeling might benefit survival, even with delayed RC achievement. Pursuit of RC is crucial despite initial failures.

Aberrancy masquerading as ventricular tachycardia: Importance of invasive electrophysiology study for diagnosis of wide complex tachycardias

BACKGROUND

Differentiation between ventricular tachycardia (VT) and supraventricular tachycardia (SVT) with aberrancy based on the 12‑lead ECG alone can be imprecise. Implantable cardiac defibrillators (ICD) may be inserted for presumed VT, particularly in patients with syncopal presentation or atypical aberrancy patterns. Accurate diagnosis of these patients facilitated by an electrophysiology study (EPS) may alter diagnosis and management.

METHODS

We present a prospective collection of cases across 3 cardiac centers of consecutive patients with WCT presumed to be VT who were referred for consideration of an ICD, and in whom further evaluation including an EPS ultimately demonstrated SVT with aberrancy as the culprit arrhythmia.

RESULTS

22 patients were identified (17 male, mean age 50±13 years. Available rhythm data at the time of referral was presumptively diagnosed as monomorphic VT in 16 patients and polymorphic VT in 6 patients. Underlying structural heart disease was present in 20 (91%). EPS resulted in a diagnosis of SVT with aberrancy in all cases: comprising AV nodal re-entry tachycardia (n=10), orthodromic reciprocating tachycardia (n=3), focal atrial tachycardia (n=3), AF/AFL (n=3) and 'double fire' tachycardia (n=2). 21 (95%) patients underwent successful ablation. All patients remained free of arrhythmia recurrence at a median of 3.4 years of follow-up. ICD insertion was obviated in 18 (82%) patients, with 1 patient proceeding to ICD extraction.

CONCLUSION

SVT with atypical aberrancy may mimic monomorphic or polymorphic VT. Careful examination of all available rhythm data and consideration of an EPS can confirm SVT and obviate the need for ICD therapy.

Atrial fibrillation: age at diagnosis, incident cardiovascular events, and mortality

BACKGROUND AND AIMS

Patients with atrial fibrillation (AF) are at increased risks of cardiovascular diseases and mortality, but risks according to age at diagnosis have not been reported. This study investigated age-specific risks of outcomes among patients with AF and the background population.

METHODS

This nationwide population-based cohort study included patients with AF and controls without outcomes by the application of exposure density matching on the basis of sex, year of birth, and index date. The absolute risks and hazard rates were stratified by age groups and assessed using competing risk survival analyses and Cox regression models, respectively. The expected differences in residual life years among participants were estimated.

RESULTS

The study included 216 579 AF patients from year 2000 to 2020 and 866 316 controls. The mean follow-up time was 7.9 years. Comparing AF patients with matched controls, the hazard ratios among individuals ≤50 years was 8.90 [95% confidence interval (CI), 7.17-11.0] for cardiomyopathy, 8.64 (95% CI, 7.74-9.64) for heart failure, 2.18 (95% CI, 1.89-2.52) for ischaemic stroke, and 2.74 (95% CI, 2.53-2.96) for mortality. The expected average loss of life years among individuals ≤50 years was 9.2 years (95% CI, 9.0-9.3) years. The estimates decreased with older age.

CONCLUSIONS

The findings show that earlier diagnosis of AF is associated with a higher hazard ratio of subsequent myocardial disease and shorter life expectancy. Further studies are needed to determine causality and whether AF could be used as a risk marker among particularly younger patients.

Atrioventricular re-entrant tachycardia and atrioventricular node re-entrant tachycardia in a patient with cancer under chemotherapy: a case report and literature review

Cardio-oncology is a new field of interest in cardiology focusing on the detection and treatment of cardiovascular diseases, such as arrhythmias, myocarditis, and heart failure, as side-effects of chemotherapy and radiotherapy. The association between chemotherapeutic agents and arrhythmias has previously been established. Atrial tachyarrhythmias, particularly atrial fibrillation, are most common, but ventricular arrhythmias, including those related to treatment-induced QT prolongation, and bradyarrhythmias can also occur. However, the association between chemotherapeutic agents and atrioventricular re-entrant tachycardia (AVRT)/atrioventricular node re-entrant tachycardia (AVNRT) remains poorly understood. Here, we report a patient with new-onset AVRT/AVNRT and lung cancer who underwent chemotherapy. We considered that chemotherapy or cancer itself may have been a trigger for the initiation of paroxysmal AVRT/AVNRT, and that radiofrequency catheter ablation was effective in treating this type of tachycardia. Here, possible mechanisms and potential genes (mostly ion channels) involved in AVRT/AVNRT are summarized and the mechanisms underlying the possible regulatory patterns of cancer cells and chemotherapy on ion channels are reviewed. Finally, we considered that ion channel abnormalities may link cancer or chemotherapy to the onset of AVRT/AVNRT. The aim of the present study was to highlight the association between chemotherapeutic agents and AVRT/AVNRT and to provide new insights for future research. Understanding the intermediate mechanisms between chemotherapeutic agents and AVRT/AVNRT may be beneficial in preventing chemotherapy-evoked AVRT/AVNRT (and/or other arrhythmias) in future.

Arrhythmia-Induced Cardiomyopathy: JACC State-of-the-Art Review

Arrhythmias frequently accompany heart failure and left ventricular dysfunction. Tachycardias, atrial fibrillation, and premature ventricular contractions can induce a reversible form of dilated cardiomyopathy (CM) known as arrhythmia-induced CM (AiCM). The intriguing question is why certain individuals are more susceptible to AiCM, despite similar arrhythmia burdens. The primary challenge is determining the extent of arrhythmias' contribution to left ventricular systolic dysfunction. AiCM should be considered in patients with a mean heart rate of >100 beats/min, atrial fibrillation, or a PVC burden of >10%. Confirmation of AiCM occurs when CM reverses upon eliminating the responsible arrhythmia. Therapy choice depends on the specific arrhythmia, patient comorbidities, and preferences. After left ventricular function is restored, ongoing follow-up is essential if an abnormal myocardial substrate persists. Accurate diagnosis and treatment of AiCM have the potential to enhance patients' quality of life, improve clinical outcomes, and reduce hospital admissions and overall health care costs.