2017 AHA/ACC/HRS guideline for management of patients with ventricular arrhythmias and the prevention of sudden cardiac death: Executive summary: A Report of the American College of Cardiology/American Heart Association Task Force on Clinical Practice Guidelines and the Heart Rhythm Society

Disparity in implantable cardioverter defibrillator therapy among minority South Asians in the United Kingdom

OBJECTIVE

There are large geographical differences in implantable cardioverter defibrillator (ICD) implantation rates for reasons not completely understood. In an increasingly multiethnic population, we sought out to investigate whether ethnicity influenced ICD implantation rates.

METHODS

This was a retrospective, cohort study of new ICD implantation or upgrade to ICD from January 2006 to February 2019 in recipients of Caucasian or South Asian ethnicity at a single tertiary centre in the UK. Data were obtained from a routinely collected local registry. Crude rates of ICD implantation were calculated for the population of Leicestershire county and were age-standardised to the UK population using the UK National Census of 2011.

RESULTS

The Leicestershire population was 980 328 at the time of the Census, of which 761 403 (77.7%) were Caucasian and 155 500 (15.9%) were South Asian. Overall, 2650 ICD implantations were performed in Caucasian (91.9%) and South Asian (8.1%) patients. South Asians were less likely than Caucasians to receive an ICD (risk ratio (RR) 0.43, 95% CI 0.37 to 0.49, p<0.001) even when standardised for age (RR 0.75, 95% CI 0.74 to 0.75, p<0.001). This remained the case for primary prevention indication (age-standardised RR 0.91, 95% CI 0.90 to 0.91, p<0.001), while differences in secondary prevention ICD implants were even greater (age-standardised RR 0.49, 95% CI 0.48 to 0.50, p<0.001).

CONCLUSION

Despite a universal and free healthcare system, ICD implantation rates were significantly lower in the South Asian than the Caucasian population residing in the UK. Whether this is due to cultural acceptance or an unbalanced consideration is unclear.

Ultrasound-guided serratus anterior plane block for subcutaneous implantable cardioverter defibrillator implantation using the intermuscular two-incision technique

PURPOSE

Operative anaesthetic requirements and perioperative discomfort are barriers to wide adoption of the subcutaneous implantable cardioverter defibrillator (S-ICD) system, especially when the intermuscular technique is used because of the greater amount of tissue dissection. The procedure is most commonly performed under general anaesthesia (GA). There is growing interest in transitioning away from the routine use of GA and towards several alternative anaesthesia modalities for the S-ICD implant procedure without the involvement of an anaesthesiologist. We assessed the feasibility of ultrasound-guided serratus anterior plane block (US-SAPB) in patients undergoing S-ICD implantation with the intermuscular two-incision technique.

METHODS

The study population included 38 consecutive patients (84% male; median, 53 [46-62] years) who received S-ICD implantation using the intermuscular two-incision technique. All procedures were performed under US-SAPB and conscious sedation without the involvement of an anaesthesiologist.

RESULTS

The average procedure time was 67 ± 14 min. No patient experienced significant haemodynamic changes or oxygen desaturation during the period of the US-SAPB procedure and sedation; there was no need for pharmacological interventions. The entire procedure was well tolerated without discomfort or complications and with no need for GA, except in one (2.6%) patient who received GA with a laryngeal mask airway. Patients always remained able to respond appropriately to neurological monitoring during the S-ICD implantation procedure. There were no procedure-related complications.

CONCLUSIONS

US-SAPB and the intermuscular two-incision technique may be a promising safe and feasible combination for S-ICD implantation, overcoming the potential barrier to wider S-ICD adoption in clinical practice.

Comparing and Contrasting Guidelines for the Management of Cardiac Sarcoidosis

Introduction: The Japanese Circulation Society (JCS) recently published new guidelines for the diagnosis and treatment of Cardiac Sarcoidosis (CS). There are two other guideline documents, the World Association of Sarcoidosis and Other Granulomatous Disorders Sarcoidosis Organ (WASOG) Assessment Instrument created in 1999 and updated in 2014. Also, in 2014, the Heart Rhythm Society (HRS) published their international guideline document. As co-chair of the HRS document I have been invited to compare and contrast the management aspects of the HRS guidelines with the new JCS document. Comments: (i) The HRS document recommended a stepwise approach to VT management and the JCS document is somewhat similar; but with some key differences. (ii) The HRS statement suggested that an ICD for CS patients with an indication for a pacemaker "can be useful". The JCS document take a similar position although with some additional criteria related to National Health Institute Coverage guidelines. (iii) Both HRS and the JCS documents agree that ICDs are recommended in patients with general guideline indications for primary prevention (i.e. LVEF less than 35%). However which additional patients should be considered for ICDs is controversial. The 2016 JCS document is broadly similar, with the major exception that it is recommended that all patients with LVEF 35-50% should have an EP study. Conclusion: The Japanese have been leaders in many aspects of CS including in guideline development. It is clear that the future of CS management is bright, with increasing international collaborations and also multiple efforts underway to obtain higher quality data to inform future guidelines.

Suspected Brugada Phenocopy Secondary to Coronary Slow Flow

Brugada syndrome (BrS) is a genetic condition that accentuates the risk of potentially lethal ventricular arrhythmias and sudden cardiac death (SCD) in a structurally normal heart. The Brugada electrocardiographic pattern may manifest separately from the syndrome—this clinical scenario has been described as Brugada phenocopy (BrP). Many etiologies of BrP have been reported, but it has not yet been reported as a result of coronary slow flow (CSF) phenomenon. This case report highlights a suspected coronary slow flow-associated Brugada type 1 electrocardiographic pattern, which subsequently normalized following the institution of guideline-directed medical therapy for acute coronary syndrome.

Decision-making regarding primary prevention implantable cardioverter-defibrillators among older adults

Most implantable cardioverter defibrillators (ICDs) are implanted for the purpose of primary prevention of sudden cardiac death among older patients with heart failure with reduced ejection fraction. Shared decision‐making prior to device implantation is guideline‐recommended and payer‐mandated. This article summarizes patient and provider attitudes toward device placement, device efficacy and effectiveness, potential periprocedural complications, long‐term events such as shocks, quality of life, costs, and shared decision‐making principles and recommendations. Most patients eligible for an ICD anticipate more than 10 years of survival. Physicians are less likely to offer an ICD to patients ≥80 years of age given a perceived lack of benefit. There is a dearth of data from randomized clinical trials addressing device efficacy among older patients; there is a need for more research in this area. However, currently available data support the use of ICDs irrespective of age provided life expectancy exceeds 1 year. Advanced age is independently associated with complications at the time of device placement but not the risk of device infection. The risk of inappropriate shock may be comparable or lower than that of younger patients. While quality of life is generally not adversely impacted by an ICD, a subset of patients experience post‐traumatic stress disorder. ICDs are cost‐effective from societal and health care sector perspectives; however, out‐of‐pocket costs vary according to insurance type and level. Shared decision‐making encounters may be incremental and iterative in nature. Providers are encouraged to partner with their patients, providing them counsel tailored to their values, preferences, and clinical presentation inclusive of age.

Absence of left bundle branch block and blood urea nitrogen predict improvement in left ventricular ejection fraction in patients with cardiomyopathy and wearable cardioverter defibrillators

Objective

To identify predictors of left ventricular ejection fraction (LVEF) improvement in patients with newly detected cardiomyopathy using wearable cardioverter defibrillators (WCDs).

Background

WCDs are useful in preventing sudden cardiac death in patients with reduced LVEF <35% while awaiting implantable cardioverter defibrillator (ICD) placement. In many patients, LVEF improves and an ICD is not indicated.

Methods

Patients who received WCDs from November 2013 to November 2015 were identified and followed over a period of 2 years. Clinical variables were examined. The primary outcome was improvement in LVEF ≥35%. Predictors of outcome were determined using a multivariate logistic regression model.

Results

A total of 179 patients were followed. Median age was 65 (interquartile range [IQR]: 56, 73) years, 69.3% were men. Median baseline LVEF was 20% (IQR: 15, 30). LVEF improved ≥35% in 47.5% patients, with patients being younger (62 vs 68.5 years, P = .006), having lower blood urea nitrogen (BUN) (19 vs 24 mg/dL, P = .002), fewer left bundle branch block (LBBB 9.5% vs 25.8%, P = .004), shorter QRS duration (98 vs 112 ms, P < .001), and higher use of angiotensin converting enzyme inhibitors (ACEI)/angiotensin receptor blockers (ARB) (92.9% vs 74.4%, P = .001) compared to those without LVEF improvement. Absence of LBBB (odds ratio [OR] 0.28, 95% confidence interval [CI] 0.11‐0.70), lower BUN (OR 0.13, 95% CI 0.02‐0.76), and ACEI/ARB use (OR 3.53, 95% CI 1.28‐9.69) were identified as independent predictors. Ventricular tachycardia/ventricular fibrillation was observed in three patients, all of whom received successful WCD shocks.

Conclusion

Absence of LBBB, lower BUN, and ACEI/ARB use predicts LVEF improvement. WCDs help treat arrhythmic events.

Current Controversies and Challenges in Brugada Syndrome

More than three decades since its initial description in 1993, Brugada syndrome remains engulfed in controversy. This review aims to shed light on the main challenges surrounding the diagnostic pathway and criteria, risk stratification of asymptomatic patients, pharmacological and interventional risk modification strategies as well as our current pathophysiological understanding of the disease.

Use of Implantable Electronic Devices in Patients With Cardiac Amyloidosis

Arrhythmias are a major cause of morbidity and mortality in the course of cardiac amyloidosis (CA). Less commonly, they may be the initial manifestation that lead to the diagnosis. With improved therapeutic interventions for amyloidosis, it is no longer considered to be a terminal untreatable condition, and there is increasing recognition of the role of implantable electronic devices in CA. The frequency and nature of arrhythmias are largely determined by the type of amyloidosis. Bradyarrhythmias are more common in the transthyretin form of amyloidosis, and risk for ventricular arrhythmias is higher in the light-chain form. Pacemaker implantation is often required and effective for alleviation of symptoms. The role of implantable cardioverter-defibrillators (ICDs) remains controversial, especially for primary prevention of sudden death. Traditional risk stratification tools for sudden death do not appear to be applicable to CA, because decline of left ventricular (LV) systolic dysfunction to the point of the usual indication for an ICD implant in other cardiomyopathies, ie, LV ejection fraction ≤ 35%, usually marks end-stage disease in CA when pump failure becomes the predominant cause of death. The challenge remains the identification of markers for sudden death in early stages of the disease. Included in this review is a general overview of available data on the nature of bradycardia and ventricular arrhythmias, including the role of implantable electronic devices for the treatment of these conditions. Published series of ICD use in CA are summarized and the role of newer pacing techniques, including biventricular pacing, is discussed.

The Spectrum of Idiopathic Ventricular Fibrillation and J-Wave Syndromes: Novel Mapping Insights

Idiopathic ventricular fibrillation and J-wave syndromes are causes of sudden cardiac death (SCD) without any identified structural cardiac disease after extensive investigations. Recent data show that high-density electrophysiological mapping may ultimately offer diagnoses of subclinical diseases in most patients including those termed "unexplained" SCD. Three major conditions can underlie the occurrence of SCD: (1) localized depolarization abnormalities (due to microstructural myocardial alteration), (2) Purkinje abnormalities manifesting as triggering ectopy and inducible reentry; or (3) repolarization heterogeneities. Each condition may result from a spectrum of pathophysiologic processes with implications for individual therapy.

Mapping and Ablation of Ventricular Outflow Tract Arrhythmias

Arrhythmias arising from the ventricular outflow tracts are commonly encountered. Although largely benign, they can also present with heart failure and sudden cardiac death. Mapping and ablation of these arrhythmias is commonly performed in the electrophysiology laboratory with a high success rate, but occasionally can prove challenging to abolish. This article discusses the mapping and ablation of outflow tract arrhythmias and the challenges that can be overcome by a systematic approach.

[A new method for establishing a ventricular fibrillation model by TCEI in Tibetan miniature pig]

OBJECTIVE

To explore an economical, convenient, safe and efficient method for establishing a Tibetan miniature pig model of cardiac arrest (CA).

METHODS

Cardiac puncture was performed in 12 Tibetan miniature pigs using two acupuncture needles. One needle was inserted into the fourth intercostal near the right side of the sternum about 3 cm in depth at an angle of 30° to 60° between the chest and the needle, and the depth was adjusted until the handle of the needle vibrated with the heartbeat without premature ventricular contraction on the electrocardiogram; the other was inserted into the subcutaneous tissue of the left armpit about 3 cm in depth without damaging important organs. The handles of the two needles were connected with 9V dry batteries to form a circuit and generate direct current stimulation. Ventricular fibrillation was produced in the pigs to induce CA by stimulation of transcutaneous electrical induction (TCEI) for 3 s, and the success rate of modeling was recorded. After an interval of 4 min without intervention, cardiopulmonary resuscitation (CPR) was performed using the standard Utstein style, and the survival of the pigs after recovery was observed.

RESULTS

The success rate of ventricular fibrillation modeling was 91.67% (11/12) using this method, and CPR achieved a success rate of 45.45% (5/11) in these models. The subsequent survival of the pigs was 100% (5/5) at 24 h and 80% (4/5) at 72 h. After observation for 72 h, the resuscitated Tibetan miniature pigs were dissected, and no significant damage was found in the vital organs in the thoracic or abdominal cavities.

CONCLUSIONS

We successfully established a model of CA using acupuncture needles and dry batteries in Tibetan miniature pigs, and this method is economical, convenient, safe and efficient.

Quality of life, depression, and anxiety in patients with a subcutaneous versus transvenous defibrillator system

BACKGROUND

Use of the subcutaneous implantable defibrillator (S-ICD) has increased because the device received US Food and Drug Administration approval in 2012, but we still know little about whether the quality of life (QoL) of patients with an S-ICD versus a transvenous ICD (TV-ICD) is comparable. We compared S-ICD patients with TV-ICD patients on QoL, depression, and anxiety up to 12 months' follow-up.

METHODS

A matched cohort of S-ICD (N = 167) and TV-ICD patients (N = 167) completed measures on QoL, depression, anxiety, and personality at baseline, 3, 6, and 12 months post implant. Data were analyzed using multivariable modeling with repeated measures.

RESULTS

In adjusted analyses, we found no statistically significant differences between cohorts on physical and mental QoL and depression (all Ps > .05), while S-ICD patients reported lower anxiety than TV-ICD patients (P = 0.0007). Both cohorts experienced improvements in physical and mental QoL and symptoms of depression and anxiety over time (all Ps < .001), primarily between implant and 3 months. These improvements were similar for both cohorts with respect to physical and mental QoL and anxiety (Ps > .05), while S-ICD patients experienced greater reductions in depressive symptoms (P = .0317).

CONCLUSION

The QoL and depression levels were similar in patients with an S-ICD and a TV-ICD up to 12 months' follow-up, while S-ICD patients reported lower anxiety levels and a greater reduction in depression over time as compared to TV-ICD patients. This knowledge may be important for patients and clinicians, if the indication for implantation allows both the S-ICD and the TV-ICD, making a choice possible.

Septal Late Gadolinium Enhancement and Arrhythmic Risk in Genetic and Acquired Non-Ischaemic Cardiomyopathies

BACKGROUND

In many genetic and acquired non-ischaemic cardiomyopathies (NICM) there have been frequent reports of involvement of the interventricular septum (IVS) by late gadolinium enhancement (LGE) at cardiac magnetic resonance (CMR). However, no studies have investigated the relationship between septal LGE and arrhythmias in different NICM subtypes.

METHODS

This study enrolled 103 patients with septal LGE at baseline CMR and different NICM: hypertrophic (n=29) or lamin A/C gene (LMNA)-associated (n=23) cardiomyopathy, and acute (n=30) or previous (n=21) myocarditis. During follow-up, the occurrences of malignant ventricular arrhythmias (MVA) and major bradyarrhythmias (BA) were evaluated.

RESULTS

At 4.9±0.7 years of follow-up, the occurrence of MVA and major BA in genetic vs acquired NICM were 10 of 52 vs 12 of 51, and 10 of 52 vs 4 of 51, respectively (both p=n.s.). However, MVA occurred more frequently in LMNA-NICM (eight of 23 vs two of 29 hypertrophic, p=0.015) and in previous myocarditis (nine of 21 vs three of 30 acute, p=0.016), while major BAs were particularly common in LMNA-NICM patients only (nine of 23 vs one of 29 hypertrophic, p=0.003). Different patterns of septal LGE were consistently retrospectively identified at baseline CMR: junctional and limited to the base in 79.3% of uneventful hypertrophic NICM; extended and focally transmural in LMNA-NICM with follow-up arrhythmias (both p<0.05); transitory in patients with acute myocarditis, who, differently from the post-myocarditis ones, showed follow-up arrhythmias only in the presence of unmodified LGE at follow-up CMR (five of 13, p=0.009).

CONCLUSION

Septal LGE was significantly associated with MVA at the 5-year follow-up in LMNA-NICM or previous myocarditis, and with major BA in LMNA-NICM only. These differences correlated with heterogeneous patterns of IVS LGE in different NICM.

Mapping and Ablation of Ventricular Arrhythmias in Cardiomyopathies

Mapping and ablation of ventricular arrhythmias in patients with nonischemic cardiomyopathies remain a major challenge. The electroanatomic abnormalities are frequently inaccessible to conventional endocardial ablations. Diagnostic diligence with a thorough understanding of the potential mechanisms/substrate, coupled with detailed electroanatomic mapping, is essential. Careful procedural planning, advanced imaging, and unipolar recordings help to formulate ablation strategy, facilitate work flow, and improve outcomes. Inaccessibility of arrhythmogenic substrate and disease progression are important causes of ablation failure. Early intervention may help to improve outcome and minimize complications. Several novel adjunctive ablation techniques are capable of serving as alternative options in refractory cases.

Long-term follow-up of normal and structural heart ventricular tachycardia catheter ablation: real-world experience from a UK tertiary centre

Background

Ventricular tachycardia (VT) is associated with increased morbidity and mortality. There is growing evidence for the effectiveness of catheter ablation in improving outcomes in patients with recurrent VT. Consequently the threshold for referral for VT ablation has fallen over recent years, resulting in increased number of procedures.

Objective

To evaluate the effectiveness and safety of VT ablation in a real-world tertiary centre setting.

Methods

This is a prospective analysis of all VT ablation cases performed at University Hospital Coventry. Follow-up data were obtained from review of electronic medical records and patient interview. The primary endpoint for normal heart VT was death, cardiovascular hospitalisation and VT recurrence, and for structural heart VT was arrhythmic death, VT storm (>3 episodes within 24 hours) or appropriate shock.

Results

Forty-seven patients underwent 53 procedures from January 2012 to January 2018. The mean age ±SD was 57±15 years, 68% were male, 81% were Caucasian and 66% were elective cases. The aetiology of VT included normal heart (49%), ischaemic cardiomyopathy (ICM, 36%), dilated cardiomyopathy (9%), hypertrophic cardiomyopathy (4%) and valvular heart disease (2%). Procedural success occurred in 83%, with six major complications. After a median follow-up of 231 days (lower quartile 133, upper quartile 631), the primary outcome occurred in 28% of patients. There were two non-arrhythmic deaths (4%). At a median follow-up of 193 days (129–468), the primary outcome occurred in 19% of patients with ICM, while VT storm/appropriate shocks occurred in three patients (17%).

Conclusions

Our real-world registry confirms that VT ablation is safe, and is associated with high acute procedural success and long-term outcomes comparable with randomised controlled studies.

Severe chronic kidney disease is associated with poor survival after initial CRT-defibrillator tachyarrhythmia therapy

BACKGROUND

Implantable cardioverter-defibrillator (ICD) recipients who receive appropriate device therapies have limited survival, and survival benefit in chronic kidney disease (CKD) has been questioned. We examined the association between CKD and survival after cardiac resynchronization therapy (CRT)-defibrillator tachyarrhythmia therapies.

METHODS

We compared overall survival after appropriate shocks or anti-tachycardia pacing in 439 CRT-defibrillator recipients with left ventricular ejection fraction (LVEF) ≤35%, non-right bundle-branch block QRS pattern, and QRS duration >130 ms according to glomerular filtration rate (GFR) at implant, including 31 patients with GFR ≤30, 164 patients with GFR 31-60, and 244 patients with GFR >60. At least one shock occurred in 302 patients (24 with GFR ≤30, 102 with GFR 31-60, and 176 with GFR >60). Serial echocardiograms were also compared.

RESULTS

Patients were followed 64 months (interquartile range [IQR]: 29-94) after implant, including 32 months (IQR: 12-61) after first therapy. Time to first therapy or shock was similar across GFR groups. However, survival after first therapy declined directly with declining GFR (P < .001), with median postshock survival of 90 days for GFR ≤30 (95% confidence of interval [CI]: 0-233), 612 days (95% CI: 365-859) for GFR 31-60, and 1672 days (95% CI: 1396-1948) for GFR >60. Declining GFR category, ischemic heart disease, diabetes, and increasing age were independently associated with increased postshock mortality. Echocardiographic response was similar across GFR groups and was not associated with post-therapy survival.

CONCLUSIONS

Survival after appropriate tachyarrhythmia therapies, particularly shocks, is attenuated in patients with GFR ≤30. This raises concern over potential lack of survival benefit conferred by CRT-defibrillators versus CRT-pacemakers in this population.

A Statewide Assessment of Prehospital Electrocardiography Approaches of Acquisition and Interpretation for ST-Elevation Myocardial Infarction Based on Emergency Medical Services Characteristics

Background: The American Heart Association recommends acquiring and interpreting prehospital electrocardiograms (ECG) for patients transported by Emergency Medical Services (EMS) to the emergency department with symptoms highly suspicious of acute coronary syndrome. If interpreted correctly, prehospital ECGs have the potential to improve early detection of ST-elevation myocardial infarction (STEMI) and inform prehospital activation of the cardiac catheterization laboratory, thus reducing total ischemic time and improving patient outcomes. Standardized protocols for prehospital ECG interpretation methods are lacking due to variations in EMS system design, training, and procedures. Objectives: We aimed to describe approaches for prehospital ECG interpretation in EMS systems across North Carolina (NC), and examine potential differences among systems. Methods: A 35-item internet survey was sent to all NC EMS systems (n = 99). Questions pertaining to prehospital ECG interpretation methods included: paramedic, computerized algorithm (i.e., software interpretation), combined approaches, and/or transmission for physician interpretation, transmission capability, cardiac catheterization laboratory activation, and EMS system characteristics (e.g. rural versus urban). Data were summarized and compared. Results: A total of 96 EMS systems across NC responded to the survey (97% response rate); of these, 69% were rural. EMS medical directors (53%) or EMS administrative directors (42%) completed the majority of surveys. While 91% of EMS systems had a prehospital ECG interpretation protocol in place, only 61% had a written cardiac catheterization laboratory activation policy. More than half (55%) of systems reported paramedic interpretation of prehospital ECGs, followed by a combined paramedic and software interpretation approach (39%), physician interpretation (4%), or software interpretation only approach (2%). Nearly 80% of EMS systems transmitted prehospital ECGs to receiving hospitals (always or sometimes), regardless of interpretation method. All EMS systems had some paid versus non-paid EMS personnel and the majority (86%) had both basic and advanced life support capabilities. Conclusions: Most NC EMS systems had a paramedic only ECG interpretation or paramedic in combination with a computerized algorithm approach. Very few used a physician read approach following transmission, even in rural service areas.

Predictors of Late Mortality in D-Transposition of the Great Arteries After Atrial Switch Repair: Systematic Review and Meta-Analysis

Background

Existing data on predictors of late mortality and prevention of sudden cardiac death after atrial switch repair surgery for D‐transposition of the great arteries (D‐TGA) are heterogeneous and limited by statistical power.

Methods and Results

We conducted a systematic review and meta‐analysis of 29 observational studies, comprising 5035 patients, that reported mortality after atrial switch repair with a minimum follow‐up of 10 years. We also examined 4 additional studies comprising 105 patients who reported rates of implantable cardioverter‐defibrillator therapy in this population. Average survival dropped to 65% at 40 years after atrial switch repair, with sudden cardiac death accounting for 45% of all reported deaths. Mortality was significantly lower in cohorts that were more recent and operated on younger patients. Patient‐level risk factors for late mortality were history of supraventricular tachycardia (odds ratio [OR] 3.8, 95% CI 1.4–10.7), Mustard procedure compared with Senning (OR 2.9, 95% CI 1.9–4.5) and complex D‐TGA compared with simple D‐TGA (OR 4.4, 95% CI 2.2–8.8). Significant risk factors for sudden cardiac death were history of supraventricular tachycardia (OR 4.7, 95% CI 2.2–9.8), Mustard procedure (OR 2.2, 95% CI 1.1–4.1), and complex D‐TGA (OR 5.7, 95% CI 1.8–18.0). Out of a total 124 implantable cardioverter‐defibrillator discharges over 330 patient‐years in patients with implantable cardioverter‐defibrillators for primary prevention, only 8% were appropriate.

Conclusions

Patient‐level risk of both mortality and sudden cardiac death after atrial switch repair are significantly increased by history of supraventricular tachycardia, Mustard procedure, and complex D‐TGA. This knowledge may help refine current selection practices for primary prevention implantable cardioverter‐defibrillator implantation, given disproportionately high rates of inappropriate discharges.

Expression of Lmna-R225X nonsense mutation results in dilated cardiomyopathy and conduction disorders (DCM-CD) in mice: Impact of exercise training

AIMS

To recapitulate progressive human dilated cardiomyopathy (DCM) and heart block in the Lmna R225X mutant mice model and investigate the molecular basis of LMNA mutation induced cardiac conduction disorders (CD); To investigate the potential interventional impact of exercise endurance.

METHODS AND RESULTS

A Lmna R225X knock-in mice model in either heterozygous or homozygous genotype was generated. Electrical remodeling was observed with higher occurrence of AV block from neonatal and aged mutant mice as measured by surface electrocardiogram and atrio-ventricular Wenckebach point detection. Histological and molecular profiles revealed an increase in apoptotic cells and activation of caspase-3 activities in heart tissue. Upon aging, extracellular cellular matrix (ECM) remodeling appeared with accumulation of collagen in Lmna R225X mutant hearts as visualized by Masson's trichrome stain. This could be explained by the upregulated ECM gene expression, such as Fibronectin: Fn1, collagen: Col12a1, intergrin: Itgb2 and 3, as detected by microarray gene chip. Also, endurance exercise for 3 month improved the ventricular ejection fraction, attenuated fibrosis and cardiomyocytes apoptosis in the aged mutant mice.

CONCLUSIONS

The mechanism of LMNA nonsense mutation induced cardiac conduction defects through AV node fibrosis is due to upregulated ECM gene expression upon activation of cardiac apoptosis. Lmna R225X mutant mice hold the potential for serving as in vivo models to explore the mechanism and therapeutic methods for AV block or myopathy associated with the aging process.

Temporal changes of noninvasive electrocardiographic risk factors for sudden cardiac death in post-myocardial infarction patients with preserved ejection fraction: Insights from the PRESERVE-EF study

BACKGROUND

Several noninvasive risk factors (NIRFs) have been proposed for sudden cardiac death risk stratification in post-myocardial infarction (post-MI) patients with preserved ejection fraction (EF). However, it remains unclear if these factors change over time.

METHODS

We evaluated seven electrocardiographic NIRFs as they were described in the PRESERVE-EF trial in 80 post-MI patients with EF ≥ 40%, at least 40 days after revascularization and 1 year later.

RESULTS

Mean patient age was 56 ± 10 years, and 88% were men. Mean EF was 50 ± 5%. The prevalence of (a) positive late potentials (27.5% vs. 28.8%, p = .860), (b) >30 premature ventricular complexes/hour (8.8% vs. 11.3%, p = .598), (c) nonsustained ventricular tachycardia (8.8% vs. 5%, p = .349), (d) standard deviation of normal RR intervals <75 ms (3.8% vs. 3.8%, p = 1.000), (e) QTc derived from 24-hr electrocardiography >440 ms (men) or >450 ms (women) (17.5% vs. 17.5%, p = 1.000), (f) deceleration capacity ≤4.5 ms and heart rate turbulence onset ≥0% and slope ≤2.5 ms (2.5% vs. 3.8%. p = 1.000), and (g) ambulatory T-wave alternans ≥65 μV in two Holter channels (6.3% vs. 6.3%, p = 1.000) were similar between the two measurements. However, five patients (6.3%) without any NIRFs during the first assessment had at least one positive NIRF at the second assessment and six patients (7.5%) with at least one NIRF at baseline had no positive NIRFs at 1 year.

CONCLUSIONS

While the prevalence of the examined electrocardiographic NIRFs between the two examinations was similar on a population basis, some patients without NIRFs at baseline developed NIRFs at 1 year and vice versa, highlighting the need for risk factor reassessment during follow-up.

Deactivation of Implantable Cardioverter Defibrillator in Patients With Terminal Diagnoses

Implantable cardioverter defibrillators (ICDs) prevent sudden cardiac death. However, in patients with terminal illnesses, these devices may disrupt the dying process. This study was undertaken to review our current strategies surrounding device deactivation. A retrospective chart review was performed at Kingston Health Sciences Centre of patients with an ICD who died from 2015 to 2018. Data collected included patient demographics, clinical details surrounding device implantation, patient co-morbidities leading to deactivation, time to deactivation, physical place of deactivation, and device programming information. Ethics approval was obtained from the Queen's University Health Sciences Research Ethics Board. A total of 49 patients were included for analysis. Mean age at the time of death was 77.5 years (range: 57 to 94 years) and 12.2% (6/49) were women. The indications for ICD implantation were primary prevention of sudden cardiac death in 69.4% (34/49) and secondary prevention in 30.6% (15/49). Deactivation as part of end-of-life care was performed in 32.7% of patients (16/49). Deactivations occurred in clinic in 6.1% (3/49) of patients, on hospital inpatient wards in 12.2% (6/49) of patients, and in critical care settings in 14.2% (7/49) of patients. The remaining 67.3% (33/49) of patients died with fully functioning devices in place. The most prevalent terminal diagnoses were metastatic cancer (22.4%) and end-stage congestive heart failure (20.4%). On average, patients had their devices deactivated 13 months (range: 0 to 62 months) after their terminal diagnosis was established. Once a patient was documented as Do Not Resuscitate (DNR), deactivation was discussed and carried out within a mean time of 38 days (range: 0 to 400 days). Seven patients had their device active for more than 1 month after being documented as DNR. Ten patients (20.4%) received ICD shocks after their terminal diagnosis, 9 received shocks in the month before death, and 2 received shocks after formal DNR orders were in place. Approximately one-third of patients with ICDs received deactivation of their cardioversion/defibrillation therapies as part of their end-of-life care plan. A relatively high proportion of patients (20%) received an ICD shock in the last month of life. In conclusion, addressing device programming needs, including deactivation of cardioversion/defibrillation therapies, should be considered in the context of a patient's goals of care in every patient with an ICD who has a co-existing life-limiting diagnosis.

Cardiac and Neuromuscular Features of Patients With LMNA-Related Cardiomyopathy

BACKGROUND

Mutations in the LMNA (lamin A/C) gene have been associated with neuromuscular and cardiac manifestations, but the clinical implications of these signs are not well understood.

OBJECTIVE

To learn more about the natural history of LMNA-related disease.

DESIGN

Observational study.

SETTING

13 clinical centers in Italy from 2000 through 2018.

PATIENTS

164 carriers of an LMNA mutation.

MEASUREMENTS

Detailed cardiologic and neurologic evaluation at study enrollment and for a median of 10 years of follow-up.

RESULTS

The median age at enrollment was 38 years, and 51% of participants were female. Neuromuscular manifestations preceded cardiac signs by a median of 11 years, but by the end of follow-up, 90% of the patients had electrical heart disease followed by structural heart disease. Overall, 10 patients (6%) died, 14 (9%) received a heart transplant, and 32 (20%) had malignant ventricular arrhythmias. Fifteen patients had gait loss, and 6 had respiratory failure. Atrial fibrillation and second- and third-degree atrioventricular block were observed, respectively, in 56% and 51% of patients with combined cardiac and neuromuscular manifestations and 37% and 33% of those with heart disease only.

LIMITATIONS

Some of the data were collected retrospectively. Neuromuscular manifestations were more frequent in this analysis than in previous studies.

CONCLUSION

Many patients with an LMNA mutation have neurologic symptoms by their 30s and develop progressive cardiac manifestations during the next decade. A substantial proportion of these patients will have life-threatening neurologic or cardiologic conditions.

PRIMARY FUNDING SOURCE

None.

Update on prevention and treatment of sudden cardiac arrest

Sudden cardiac arrest is the leading cause of cardiovascular mortality, posing a substantial public health burden. The incidence and epidemiology of sudden death are a function of age, with primary arrhythmia syndromes and inherited cardiomyopathies representing the predominant causes in younger patients, while coronary artery disease being the leading etiology in those who are 35 years of age and older. Internal cardioverter defibrillators remain the mainstay of primary and secondary prevention of sudden cardiac arrest. In the acute phase, cardiac chain of survival, early reperfusion, and therapeutic hypothermia are the key steps in improving outcomes. In the chronic settings, ventricular tachycardia ablation has been shown to improve patients' quality of life by reducing frequency of defibrillator shocks. Moreover, recent studies have suggested that it may increase survival. Neuromodulation represents a novel therapeutic modality that has a great potential for improving treatment of ventricular arrhythmias.

Frailty, Implantable Cardioverter Defibrillators, and Mortality: a Systematic Review

BACKGROUND

Evidence for the benefit of implantable cardioverter defibrillators (ICD) in preventing sudden cardiac death (SCD) in older adults is mixed; age alone may not predict benefit. Frailty may help identify patients in whom an ICD does not improve overall mortality risk.

METHODS

Structured search of PubMed, Embase, Web of Science, and Cochrane Central Register of Controlled Trials on 1/31/2019, without language restriction, with terms for ICD, frailty, and mortality. Frailty was defined broadly using any validated single component (e.g., walking speed, weight loss) or multi-component tool (e.g., cumulative deficit index). Each study was assessed for quality and risk of bias.

RESULTS

We identified and screened 2649 titles, reviewed 280 abstracts, and extracted 71 articles. Nine articles, including two RCTs, one prospective cohort, and six retrospective cohort studies met all criteria. The most common reason for exclusion was a lack of frailty definition. Frailty definitions were heterogeneous, including cumulative deficit models, low weight, and walking speed. Follow-up time for mortality differed: from days to > 6 years. All studies indicated that mortality was higher amongst individuals identified as frail, regardless of definition. In one RCT, slow walkers did not benefit from ICD therapy after 3 years. A cohort of 83,792 Medicare beneficiaries in an ICD registry reported higher 1-year mortality following ICD in those with frailty or dementia. Four studies reported an association between being underweight and increased mortality following ICD placement.

CONCLUSION

Existing literature suggests that individuals with frailty may not benefit from ICD placement for primary prevention of SCD.

Renal denervation as adjunctive therapy to cardiac sympathetic denervation for ablation refractory ventricular tachycardia

BACKGROUND

Autonomic modulation is finding an increasing role in the treatment of ventricular arrhythmias. Renal denervation (RDN) has been described as a treatment modality for refractory ventricular tachycardia (VT) in case series.

OBJECTIVE

The purpose of this study was to evaluate RDN as an adjunctive therapy to cardiac sympathetic denervation (CSD) for ablation refractory VT.

METHODS

Patients who underwent RDN after radiofrequency ablation and CSD procedures at our center from 2012 to 2019 were evaluated.

RESULTS

Ten patients underwent RDN after CSD (9 bilateral and 1 left-sided only) with a median follow-up of 23 months. The mean age was 59.9 ± 10.4 years, and 9/10 (90%) were men. All had cardiomyopathy with a mean ejection fraction of 33% ± 11% (20% ischemic). Four (40%) underwent CSD during the same hospitalization as that for RDN. Patients who underwent RDN as adjunctive therapy to CSD had a decrease in all implantable cardioverter-defibrillator therapies (shocks + antitachycardia pacing [ATP]) from 29.5 ± 25.2 to 7.1 ± 10.1 comparing 6 months pre-RDN to 6 months post-RDN (P = .028). Implantable cardioverter-defibrillator shocks were significantly decreased from 7.0 ± 6.1 to 1.7 ± 2.5 comparing 6 months pre-RDN to 6 months post-RDN (P = .026). This benefit was driven by a decrease in therapies for 6 patients who had a staged procedure, not performed during the same hospitalization (28.5 ± 24.3 to 1.0 ± 1.2; P = .043).

CONCLUSION

RDN demonstrates the potential benefit when VT recurs after radiofrequency ablation and CSD. The benefit is seen in patients who undergo a staged procedure. The need for acute RDN after CSD portends a poor prognosis.

Ten-year trends in catheter ablation for ventricular tachycardia vs other interventional procedures in Australia

AIMS

Major technological and procedural advancements have reinvigorated catheter ablation as adjunctive therapy for drug-refractory ventricular tachycardia (VT). We examined temporal trends in VT ablations as compared to other interventional cardiovascular procedures namely, percutaneous coronary intervention (PCI) and atrial fibrillation (AF) ablation in Australia.

METHODS AND RESULTS

A retrospective review of procedural numbers for VT ablations, AF ablations, and PCI was performed from 2008/09-2016/17 the Australian Institute of Health, Welfare and Aging (AIHW), and Medicare Australia (MA) databases. Linear regression models were fitted to compare the trends in population-adjusted procedural numbers over the 10-year period. Data from the AIHW and MA sources respectively showed that (a) PCI had a 1.3% (AIHW data P = .15) and 1.8% (MA data P < .001) population-adjusted increment per year, (b) AF ablations had a 12.7% (P < .001) and 11.7% (P < .001) per year population-adjusted increment, and (c) VT ablations showed an 18% (P < .001) and 12.7% (P < .001) per year population-adjusted increment. Growth of PCI was increasing at a lower rate than AF ablations (P < .001 for both AIHW and MA sources). Growth of VT ablation was significantly higher than AF ablations and PCI (AIHW: 18% vs 12.7% [P = .004] and 1.3% per year [P < .001]).

CONCLUSION

Catheter-based VT ablation has increased significantly in Australia over the last decade, consistent with worldwide trends, and now surpassing all ablation procedures, including AF ablation and PCI for CAD. This data highlight the provision of additional resources to match the increasing demand for VT ablation procedures in Australia.

Who Should Receive a Wearable Defibrillator Vest at Hospital Discharge?

PURPOSE OF REVIEW

To discuss the role of wearable cardioverter defibrillator (WCD) vests in preventing sudden cardiac death (SCD) in at-risk populations.

RECENT FINDINGS

The impact of randomized-controlled trials with implantable cardioverter-defibrillators (ICD) therapy is well established in randomized clinical trials in ischemic cardiomyopathy. Although the benefits are not as clear in non-ischemic cardiomyopathy, meta-analyses show significant mortality benefits from immediate electrical cardioversion strategies. The role of WCDs in at-risk populations in whom ICD therapy is temporarily not indicated is not as well-established. Smaller cohort trials have shown efficacy in patients with newly-diagnosed cardiomyopathy, requiring temporary ICD explantation, and others with less common indications for WCD therapy. The Vest Prevention of Early Sudden Death Trial was a landmark randomized control study seeking to examine the benefits of WCD therapy in at-risk population, and although the primary endpoint of reducing arrhythmic death was not reached, the structure of the trial and significant differences in total mortality make a compelling case for continued use of WCD therapies in our healthcare systems.

Association between potassium concentrations, variability and supplementation, and in-hospital mortality in ICU patients: a retrospective analysis

BACKGROUND

Serum potassium concentrations are commonly between 3.5 and 5.0 mmol/l. Standardised protocols for potassium range and supplementation in the ICU are lacking. The purpose of this retrospective analysis of ICU patients was to investigate potassium concentrations, variability and supplementation, and their association with in-hospital mortality.

METHODS

ICU patients ≥ 18 years, with ≥ 2 serum potassium values, treated at the Charité - Universitätsmedizin Berlin between 2006 and 2018 were eligible for inclusion. We categorised into groups of mean potassium concentrations: < 3.0, 3.0-3.5, > 3.5-4.0, > 4.0-4.5, > 4.5-5.0, > 5.0-5.5, > 5.5 mmol/l and potassium variability: 1st, 2nd and ≥ 3rd standard deviation (SD). We analysed the association between the particular groups and in-hospital mortality and performed binary logistic regression analysis. Survival curves were performed according to Kaplan-Meier and tested by Log-Rank. In a subanalysis, the association between potassium supplementation and in-hospital mortality was investigated.

RESULTS

In 53,248 ICU patients with 1,337,742 potassium values, the lowest mortality (3.7%) was observed in patients with mean potassium concentrations between > 3.5 and 4.0 mmol/l and a low potassium variability within the 1st SD. Binary logistic regression confirmed these results. In a subanalysis of 22,406 ICU patients (ICU admission: 2013-2018), 12,892 (57.5%) received oral and/or intravenous potassium supplementation. Potassium supplementation was associated with an increase in in-hospital mortality in potassium categories from > 3.5 to 4.5 mmol/l and in the 1st, 2nd and ≥ 3rd SD (p < 0.001 each).

CONCLUSIONS

ICU patients may benefit from a target range between 3.5 and 4.0 mmol/l and a minimal potassium variability. Clear potassium target ranges have to be determined. Criteria for widely applied potassium supplementation should be critically discussed. Trial registration German Clinical Trials Register, DRKS00016411. Retrospectively registered 11 January 2019, http://www.drks.de/DRKS00016411.

Ventricular Arrhythmias

Ventricular tachycardia is commonly seen in medical practice. It may be completely benign or portend high risk for sudden cardiac death. Therefore, it is important that clinicians be familiar with and able to promptly recognize and manage ventricular tachycardia when confronted with it clinically. In many cases, curative therapy for a given ventricular arrhythmia may be provided after a thorough understanding of the underlying substrate and mechanism. In this article, the authors broadly review the current classification of the different ventricular arrhythmias encountered in medical practice, provide brief background regarding the different mechanisms, and discuss practical diagnosis and management scenarios.

Risk stratification for cardiac mortality using electrocardiographic markers based on 24-hour Holter recordings: the JANIES-SHD study

BACKGROUND

Recent guidelines have stated that left ventricular ejection fraction (LVEF) is the gold standard marker for identifying patients at risk for cardiac mortality. However, little information is present regarding electrocardiographic (ECG) markers. This study aimed to assess ECG markers for predicting mortality or serious arrhythmia in patients with structural heart disease (SHD).

METHODS

In total, 1829 patients were enrolled into the Japanese Multicenter Observational Prospective Study (JANIES study). In this study, we analyzed data of 719 patients (569 men, age 64 ± 13 years) with SHD including mainly ischemic heart disease (65.8%). As ECG markers based on 24-hour Holter recordings, nonsustained ventricular tachycardia (NSVT), ventricular late potentials, and heart rate turbulence (HRT) were assessed. The primary endpoint was all-cause mortality, and the secondary endpoint was fatal arrhythmic events.

RESULTS

During a mean follow-up of 21 ± 11 months, all-cause mortality was eventually observed in 39 patients (5.4%). Among those patients, 32 patients (82%) suffered from cardiac causes such as heart failure and arrhythmia. Multivariate Cox regression analysis showed that after adjustment for age and LVEF, documented NSVT [hazard ratio = 2.46, 95% confidence interval (CI): 1.16-5.18, p = 0.02] and abnormal HRT (hazard ratio = 2.40, 95% CI: 1.16-4.93, p = 0.02) were significantly associated with the primary endpoint. These two ECG markers also had significant predictive values with the secondary endpoint. The combined assessment of two ECG markers improved predictive accuracy.

CONCLUSION

This study demonstrated that combined assessment of documented NSVT and abnormal HRT based on 24-hour Holter ECG recordings are recommended for predicting future serious events in this population.

[Arrhythmias in patients with pulmonary hypertension and chronic lung disease]

Pulmonary arterial hypertension (PAH) occurs in 1% of the global population and can be divided in different disease groups. Pathophysiological aspects leading to supraventricular arrhythmias in these patients are due to increased pulmonary and right atrial pressure, increased activity of the sympathetic nervous system leading to right atrial electrical remodeling and ischemia in the right atrium. In the clinical setting these patients present with atrial flutter, atrial fibrillation or with ectopic atrial tachycardia. Regarding ventricular tachycardia there is a lack of data. Occurrence of arrhythmia in these patients leads to a deterioration of PAH, so rhythm control should be the aim. This can be achieved by right atrial ablation, especially in patients presenting with atrial flutter; electric cardioversion or antiarrhythmic drug therapy are without definite guideline recommendations since there are too few clinical trials. Ablation with a transseptal approach in the left atrium is considered rather dangerous and should be avoided. Regarding arrhythmias in patients with chronic lung disease, few data are available. For patients with chronic obstructive pulmonary disease (COPD), there are good data available. These patients often suffer from coronary heart disease, atrial fibrillation, and ventricular tachycardia. Beta-blockers play an important role in COPD patients, even during exacerbation. Interventional therapies are safe but the arrhythmogenic foci often located outside of the pulmonary veins (in the right atrium).

Ventricular Tachycardia Storm Presenting as Vague Complaints to the Emergency Department

We present the case of a 75-year-old man with vague symptoms and hypotension found to be in electrical storm secondary to sustained ventricular tachycardia. The patient did not respond to intravenous amiodarone, magnesium, lidocaine, or four cardioversion attempts. This case illustrates the challenges in managing patients with electrical storm presenting to the emergency department.

Subcutaneous ICD: Current standards and future perspective

The subcutaneous implantable cardioverter-defibrillator (S-ICD) system is an established therapy for prevention of sudden cardiac death (SCD) and an alternative to a transvenous implantable cardioverter-defibrillator (ICD) system in selected patients. Since introduction of S-ICD in 2010, the device has undergone further development. Based on the unique feature of an entirely extracardiac implantation, S-ICD is able to reduce the known common perioperative and long-term complications of conventional transvenous implanted ICD systems. Especially for patients with a complex anatomy and no option of an endovascular lead implantation, the S-ICD offers a potential alternative. Initial uncertainty existed, questioning whether this ICD approach would be reliable in detecting and terminating ventricular arrhythmias. Multiple clinical studies, however, provided evidence for an effective treatment. Based on obvious advantages compared to conventional ICD systems, the question arises whether the S-ICD should actually be the first choice in the majority of all primary prevention patients in the future. Recent data from large registries show that S-ICD indications are also expanding in secondary prevention patients. As a consequence, the S-ICD was listed in the 2015 ESC guidelines as an alternative therapeutic option with a class-IIa recommendation in patients with an ICD indication not requiring pacing for bradycardia, cardiac resynchronization therapy or anti-tachycardia pacing (ATP). In addition, the American Heart Association guidelines refer to class-I recommendation for patients with a complex anatomy and venous access problems or at a high risk for infections who need ICD therapy. Limitations with respect to the not available pacing option of S-ICD might be also overcome by a potential combination with a leadless pacemaker in the near future. This article provides an overview of recent developments of S-ICD and reviews the most recent literature and ongoing studies.

Rationale and design of the PRAETORIAN-DFT trial: A prospective randomized CompArative trial of SubcutanEous ImplanTable CardiOverter-DefibrillatoR ImplANtation with and without DeFibrillation testing

In transvenous implantable cardioverter-defibrillator (TV-ICD) implants, routine defibrillation testing (DFT) does not improve shock efficacy or reduce arrhythmic death but patients are exposed to the risk of complications related to DFT. The conversion rate of DFT in subcutaneous ICD (S-ICD) is high and first shock efficacy is similar to TV-ICD efficacy rates. STUDY DESIGN: The PRAETORIAN-DFT trial is an investigator-initiated, randomized, controlled, multicenter, prospective two-arm trial designed to demonstrate non-inferiority of omitting DFT in patients undergoing S-ICD implantation in which the S-ICD system components are optimally positioned. Positioning of the S-ICD will be assessed with the PRAETORIAN score. The PRAETORIAN score is developed to systematically evaluate implant position of the S-ICD system components which determine the defibrillation threshold on post-operative chest X-ray. A total of 965 patients, scheduled to undergo a de novo S-ICD implantation without contra-indications for either DFT strategy, will be randomized to either standard of care S-ICD implantation with DFT, or S-ICD implantation without DFT but with evaluation of the implant position using the PRAETORIAN score. The study is powered to claim non-inferiority of S-ICD implantation without DFT in de novo S-ICD patients in respect to the primary endpoint of first shock efficacy in spontaneous arrhythmia episodes. Patients with a high PRAETORIAN score (≥90) in the interventional arm of this study will undergo DFT according to the same DFT protocol as in the control arm. CONCLUSION: The PRAETORIAN-DFT trial is a randomized trial that aims to gain scientific evidence to safely omit a routine DFT after S-ICD implantation in patients with correct device positioning.

QT Prolongation and Associated Ventricular Tachycardia due to Cardiac Iron Load in a Patient with Thalassemia Major

We report the case of a 23-year-old male with thalassemia major who developed long QT and continuous ventricular tachycardia (VT). Electrocardiography, echocardiography, and cardiac magnetic resonance imaging (MRI) were used for diagnosis and risk stratification. VT causes and treatments are presented and discussed. Ventricular arrhythmia can be treated by normalizing QT interval with high-dose beta-blocker therapy. However, MRI-compatible internal cardiac defibrillator implantation was performed due to the high risk in this patient.

Impact of Late Ventricular Arrhythmias on Cardiac Mortality in Patients with Acute Myocardial Infarction

Objectives

This study investigated the relationship between the timing of ventricular tachycardia or ventricular fibrillation (VT or VF) and prognosis in patients undergoing primary percutaneous coronary intervention (PCI) for acute myocardial infarction (AMI).

Background

It is unknown whether the timing of VT/VF occurrence affects the prognosis of patients with AMI.

Methods

From January 2004 to December 2014, 1004 patients with AMI underwent primary PCI. Of these patients, 888 did not have VT/VF (non-VT/VF group) and 116 had sustained VT/VF during prehospitalization or hospitalization. Patients with VT/VF were divided into two groups: early VT/VF (VT/VF occurrence before and within 2 days of admission, 92 patients) and late VT/VF (VT/VF occurrence >2 days after admission; 24 patients) groups.

Results

The frequency of VT/VF occurrence was high between the day of admission and the 2nd day and between days 6 and 10 of hospitalization. The late VT/VF group had a significantly longer onset-to-balloon time, lower ejection fraction, poorer renal function, and higher creatine phosphokinase (CK)-MB level on admission (p< 0.001). They also had a lower 30-day cardiac survival rate than the early VT/VF and non-VT/VF groups (42% vs. 76% vs. 96%, p < 0.001). Moreover, independent predictors of in-hospital cardiac mortality among patients with AMI who had sustained VT/VF were higher peak CK-MB [Odds ratio (OR: 1.001, 95%confidence interval (CI): 1.000-1.002, p= 0.03)], higher Killip class (OR: 1.484, 95%CI 1.017-2.165, p= 0.04), and late VT/VF (OR: 3.436, 95%CI 1.115-10.59, p= 0.03).

Conclusions

The timing of VT/VF occurrences had a bimodal peak. Although late VT/VF occurrence after primary PCI was less frequent than early VT/VF occurrence, patients with late VT/VF had a very poor prognosis.

Use of pulsed electron avalanche knife (PEAK) PlasmaBlade™ in patients undergoing implantation of subcutaneous implantable cardioverter-defibrillator

Introduction

Surgical implantation of subcutaneous implantable cardioverter-defibrillators (S-ICD) requires preparation of a deeper and larger pocket. Infection and bleeding complications are reported, particularly in patients requiring antiplatelet therapy (APT) or being on oral anticoagulation (OAC), with rates up to 25%. The pulsed electron avalanche knife (PEAK) PlasmaBlade™ has been reported to reduce bleeding complications. The purpose of this study was to evaluate the safety and feasibility of a PEAK guided S-ICD implantation with respect to perioperative complications.

Methods and results

We enrolled 36 consecutive patients (75% male; mean age 52.1 ± 14.4 years) undergoing S-ICD implantation. Periprocedural safety endpoints comprised major complications including pocket hematomas, wound infections, bleeding (BARC ≥2) or events requiring interventions. Patients were divided into three groups according to management of their anticoagulation: i.) APT, n = 15 (41.7%); ii.) OAC, n = 10 patients (27.8%); iii.) none (neither OAC nor APT), n = 11 (30.6%). Mean procedure duration was 33.1 ± 13.4 min. Mean length of hospital stay was 3.3 ± 2.1 days. Overall analysis showed no differences between the 3 groups with respect to major complications, major bleeding episodes or other procedural parameters, beside a trend towards more minor hematomas in the OAC group (OAC: 22.2% vs. APT: 11.4% vs. none: 9.1%; p = 0.15).

Conclusion

The results of our pilot study suggest that intermuscular S-ICD implantation using PEAK is safe and potentially beneficial in patients receiving OAC or APT with respect to prevention of bleeding complications. These results support the rationale for large prospective controlled trials evaluating a beneficial effect of PEAK use in S-ICD implantation procedures.

Risk of sudden sensorineural hearing loss in patients with dysrhythmia: A nationwide population-based cohort study

Objective

Whether dysrhythmia is a risk factor of sudden sensorineural hearing loss (SSNHL) remains unclear. In this study, we aimed to investigate the risk of developing SSNHL among patients with dysrhythmia in different age and gender groups by using population-based data in Taiwan.

Methods

We conducted a matched cohort study by analyzing data between January 2000 and December 2013 obtained from the Taiwan National Health Insurance Research Database. 41,842 newly diagnosed dysrhythmia patients and 83,684 comparison subjects without dysrhythmia were selected from claims. The incidence of sudden sensorineural hearing loss at the end of 2013 was determined in both groups. Univariate and multivariate logistic regression analyses were used to investigate the risk of SSNHL among patients with dysrhythmia.

Results

The incidence of SSNHL was 1.30-fold higher in the dysrhythmia group compared with the control group (53.2 versus 40.9 per 100,000 person-years), and using Cox proportional hazard regressions, the adjusted hazard ratio (HR) was 1.40 (95% confidence interval [CI], 1.15–1.70). Gender-stratified analysis revealed a significantly higher risk of SSNHL in patients with dysrhythmia than in those without dysrhythmia for both men and women (HR = 1.34, 95% CI = 1.02–1.76, P = 0.039, HR = 1.35, 95% CI = 1.02–1.78, P = 0.035, respectively). Age-stratified analysis revealed remarkable associations between dysrhythmia and SSNHL among those aged less than 40 years and more than 65 years (HR = 2.18, 95% CI = 1.03–4.64, P = 0.043 and HR = 1.54, 95% CI = 1.14–2.09, P = 0.006, respectively).

Conclusions

Our findings support dysrhythmia as an independent risk factor for SSNHL. Based on the study results, clinicians managing patients with dysrhythmia should be aware of the increased risk of developing SSNHL, especially among patients aged <40 and >65 years, and counsel patients to seek medical advice immediately if they experience any acute change in their hearing ability.

Non-fluoroscopic catheter ablation: A randomized trial

Background

Catheter ablation provides curative treatment for tachyarrhythmias. Fluoroscopy, the method used for this, presents several risks. The electroanatomical mapping (MEA) presents a three-dimensional image without using X-rays, and may be adjunct to fluoroscopy.

Objectives

We evaluated the possibility of performing catheter ablation with the exclusive use of electroanatomical mapping (MEA), dispensing with fluoroscopy. We compared the total time of procedure and success rates against the technique using fluoroscopy (RX) with emission of X-rays.

Methods

Randomized, unicentric, uni-blind study of patients referred for tachyarrhythmia ablation.

Results

Twelve patients were randomized to the XR group and 11 to the EAM group. The mean age was 48.5 (±12.6) vs 46.3 (±16.6) (P = ns). Success occurred in 11 patients (91.7%) in the RX group and 9 (81.8%) in the MEA group (P = 0.46). The procedure time in minutes was higher in the MEA group than in the RX group (79-47-125min vs 49-30-100min; P = 0.006). The mean fluoroscopy time was 11 ± 9 min versus zero (RX vs MEA: P < 0.001). The mean radiofrequency applications were lower in the RX group against the MEA group (6 ± 3.5 × 13.2 ± 18.2 p < 0.019). There were no complications.

Conclusion

MEA opened new therapeutic possibilities for patients with arrhythmias, reducing the risk of radiation. In this study, it was possible to demonstrate that it is feasible to perform ablation only with the use of MEA, with similar success with fluoroscopy, at the expense of a longer procedure time.

Update in Electrical Storm Therapy

BACKGROUND

Electrical storm (ES) is a major life-threatening event, which announces a possible negative outcome and poor prognosis and poses challenging questions concerning etiology and management.

DATA SOURCES

A literature search was conducted through MEDLINE and EMBASE (past 30 years until the end of September 2018) using the following search terms: ES, ventricular fibrillation, ventricular tachycardia, ablation, and implantable defibrillator. Clinicaltrials.gov was also consulted for studies that are ongoing or completed. Additional articles were identified through bibliographical citations.

AREA OF UNCERTAINTY

There is no homogeneous attitude, and therapeutic strategies vary widely.

THERAPEUTIC ADVANCES

The aim of this review is to define the concept of ES, to review the incidence and prognostic implications, and to describe the most common strategies of therapeutic advances and trends. The management strategy should be decided after an accurate risk stratification is done in initial evaluation according to hemodynamic tolerability and presence of triggers and comorbidities. General care should be provided in an intensive cardiovascular care unit. The cornerstone of acute medical therapy used in ES is mainly represented by amiodarone and beta-blockers. Deep sedation and mechanical ventilation should provide comfort for treatment administration. First-choice drugs are benzodiazepines and short-acting analgesics. General care may also include thoracic epidural anesthesia to modulate neuroaxial efferents to the heart and to decrease sympathetic hyperactivity. We include a special focus on ablation as a reliable tool to target the mechanism of arrhythmia, finally building an up-to-date standardization.

CONCLUSIONS

ES management needs a complex assessment and interpretation of a critical situation in a life-threatening condition. Optimal implantable cardioverter-defibrillator-reprogramming, antiarrhythmic drug therapy and sedation are in first-line approach. Catheter ablation is the elective therapy and plays a central key role in the treatment of ES if possible in combination with hemodynamic support.

Digitalis Therapy and Risk of Recurrent Ventricular Tachyarrhythmias and ICD Therapies in Atrial Fibrillation and Heart Failure

OBJECTIVE

This study sought to assess the impact of treatment with digitalis on recurrences of ventricular tachyarrhythmias in implantable cardioverter defibrillator (ICD) recipients with atrial fibrillation (AF) and heart failure (HF).

BACKGROUND

The data regarding outcomes of digitalis therapy in ICD recipients are limited.

METHODS

A large retrospective registry was used, including consecutive ICD recipients with episodes of ventricular tachyarrhythmia between 2002 and 2016. Patients treated with digitalis were compared to patients without digitalis treatment. The primary prognostic outcome was first recurrence of ventricular tachyarrhythmia at 5 years. Kaplan-Meier and multivariable Cox regression analyses were applied.

RESULTS

A total of 394 ICD recipients with AF and/or HF was included (26% with digitalis treatment and 74% without). Digitalis treatment was associated with decreased freedom from recurrent ventricular tachy-arrhythmias (HR = 1.423; 95% CI 1.047-1.934; p = 0.023). Accordingly, digitalis treatment was associated with decreased freedom from appropriate ICD therapies (HR = 1.622; 95% CI 1.166-2.256; p = 0.004) and, moreover, higher rates of rehospitalization (38 vs. 21%; p = 0.001) and all-cause mortality (33 vs. 20%; p = 0.011).

CONCLUSION

Among ICD recipients suffering from AF and HF, treatment with digitalis was associated with increased rates of recurrent ventricular tachyarrhythmias and ICD therapies. However, the endpoints may also have been driven by interactions between digitalis, AF, and HF.