Prevention Of Sudden Cardiac Death Research Articles

Catheter Ablation of Ventricular Fibrillation.

Ventricular fibrillation (VF) is a common cause of sudden cardiac death (SCD) and is unfortunately without a cure. Current therapies focus on prevention of SCD, such as implantable cardioverter-defibrillator (ICD) implantation and anti-arrhythmic agents. Significant progress has been made in improving our understanding and ability to target the triggers of VF, via advanced mapping and ablation techniques, as well as with autonomic modulation. However, the critical substrate for VF maintenance remains incompletely defined. In this review, we discuss the evidence behind the basic mechanisms of VF and review the current role of catheter ablation in patients with VF.

Echocardiographic Predictors of Ventricular Tachyarrhythmias in Patients With Cardioverter-Defibrillator Implanted for Primary Prevention of Sudden Cardiac Death. Results From a two-Year Prospective Follow-up Study

Aim To compare variables of transthoracic EchoCG for determining echocardiographic predictors and their prognostic role in the development of persistent paroxysmal ventricular tachyarrhythmias (VT) in patients with ischemic CHF who had been implanted with a cardioverter defibrillator (CD) for primary prevention of sudden cardiac death.Material and methods This single-site prospective study included 176 patients with CHF of ischemic origin aged 58.7±7.4 years with a left ventricular ejection fraction (LV EF) of 30 % [25; 34] % who had been implanted with CD. The follow-up duration was 24 months. The primary endpoint was a newly developed persistent paroxysm of VT (duration ≥30 sec) detected in the "monitored" VT area or a VT paroxysm that required electric treatment. The echocardiographic picture was evaluated by 28 variables. Statistical analysis was performed with the c2, Fisher's, and Mann-Whitney tests, and the one-factor logistic regression (LR). Prognostic models were developed with a multifactorial LR. The model accuracy was evaluated by 4 metrics: area under the ROC (AUC), sensitivity, specificity, and diagnostic efficacy.Results The primary endpoint was observed in 60 (34 %) patients. Mean time to a persistent VT episode was 19.2±0.8 months (95 % confident interval (CI): 17.5-20.8). Superior-inferior dimensions of the right and left atria (RA and LA, respectively) and the left atrial volume (LAv) were independent predictors for VT. The odds of VT development in patients of the study cohort increased with RAl ≥4.5 cm (odds ratio (OR), 1.6; 95 % CI: 1.4-1.9; р=0.03), LAl ≥5.5 cm (OR, 2.5; 95 % CI: 1.01-6.1; р=0.04), LAv ≥95 ml (OR, 3.2; 95 % CI: 1.3-17.5; р=0.01). A comprehensive analysis of echocardiographic variables proved the prognostic potential of LAv that was linearly associated with the development of VT. The metrics of the best prognostic model were AUC 0.7±0.07 with 95 % CI: 0.54-0.83; specificity, 20.9 %; sensitivity, 95.7 %; and diagnostic efficacy, 47 %.Conclusion This study allowed evaluation of capabilities of transthoracic EchoCG for predicting the probability of VT in patients with CHF of ischemic origin and reduced LV EF. It was shown that linear and volumetric atrial dimensions could be used for stratification of risk of VT and for determining the tactics for primary prevention of sudden cardiac death in this patient category.

The new ESC guidelines on the management of ventricular tachyarrhythmias : Implications for daily practice

The recently published guidelines of the European Society of Cardiology (ESC) on the management of patients with ventricular arrhythmias and the prevention of sudden cardiac death is an update of the 2015 guideline. For the first time anew section is dedicated to public basic life support. In the acute treatment of ventricular arrhythmias electrical cardioversion is upgraded, and there is anew focus on the management of electrical storm. Recommendations for the comprehensive diagnostic evaluation of patients with first manifestations of ventricular arrhythmias structured according to common clinical scenarios are also new. Both genetic testing and cardiac magnetic resonance imaging are upgraded, not only for diagnostic evaluation but also for risk stratification. In the long-term management, recommendations for pharmacotherapy are aligned with current heart failure guidelines. Catheter ablation has gained relevance not only for recurrent ventricular tachycardia under amiodarone treatment and as an alternative to implantable cardioverter defibrillation (ICD) implantation in selected patients with coronary artery disease but also particularly in the treatment of idiopathic ventricular extrasystoles and tachycardia. The ICD treatment remains an essential component of primary and secondary prevention of sudden cardiac death. Of note, the recommendation on primary preventive ICD treatment for patients with dilated cardiomyopathy and left ventricular ejection fraction (LVEF) ≤ 35% has been downgraded. In addition to LVEF acombination of risk factors and risk calculators is included in the recommendations on primary prophylactic ICD implantation. Overall, due to numerous tables and practical algorithms, the guidelines have become auser-oriented reference book.

Hospital utilisation and the costs associated with complications of ICD implantation in acontemporary primary prevention cohort.

Implantation of an implantable cardioverter defibrillator (ICD) is standard care for primary prevention of sudden cardiac death. However, ICD-related complications are increasing as the population of ICD recipients grows. ICD-related complications in anational DO-IT Registry cohort of 1442 primary prevention ICD patients were assessed in terms of additional use of hospital care resources and costs. During amedian follow-up of 28.7months (IQR 25.2-33.7) one or more complications occurred in 13.5% of patients. Acomplication resulted in asurgical intervention in 53% of cases and required on average 3.65 additional hospital days. The additional hospital costs were €6,876 per complication or €8,110 per patient, to which clinical re-interventions and additional hospital days contributed most. Per category of complications, infections required most hospital utilisation and were most expensive at an average of €22,892. The mean costs were €5,800 for lead-related complications, €2,291 for pocket-related complications and €5,619 for complications due to other causes. We estimate that the total yearly incidence-based costs in the Netherlands for hospital management of ICD-related complications following ICD implantation for primary prevention are €2.7million. Complications following ICD implantation are related to asubstantial additional need for hospital resources. When performing cost-effectiveness analyses of ICD implantation, including the costs associated with complications, one should be aware that real-world complication rates may deviate from trial data. Considering the economic implications, strategies to reduce the incidence of complications are encouraged.

Laser Doppler flow for the hemodynamic differentiation of tachycardia.

Implantable cardioverter defibrillators (ICDs) offer effective therapy for the prevention of sudden cardiac death (SCD) due to ventricular arrhythmias. However, inappropriate shocks have detrimental effects on survival and quality of life. The addition of hemodynamic monitoring may be useful in discriminating clinically important ventricular arrhythmias. In this study, we assess the ability of laser Doppler flowmetry to assess the hemodynamic effect of paced atrial and ventricular arrhythmias using mean arterial blood pressure as the reference. In this acute human study in patients undergoing an elective electrophysiological study, laser Doppler flowmetry, arterial blood pressure, and surface ECG were acquired during high-rate atrial and ventricular pacing to simulate supraventricular and ventricular tachycardias. Arterial blood pressure and laser Doppler flow signals correlated well during atrial and ventricular pacing (rho = 0.694, p<.001). The hemodynamic impairment detected by both methods was greater during ventricular pacing than atrial pacing (-1.0% vs. 19.0%, p<.001). Laser Doppler flowmetry performed better than rate alone to identify hemodynamic impairments. In this acute study, laser Doppler flowmetry tissue perfusion served as a good surrogate measure for arterial pressure, which could be incorporated into future ICDs.

From premature ventricular complexes to sustained ventricular tachycardia : An overview of innovations in the 2022 ESC Guideline on the therapy of ventricular arrhythmias

The recent 2022 European Society of Cardiology Guidelines for the management of patients with ventricular arrhythmias and the prevention of sudden cardiac death are an update of the former 2015 European guidelines. With multiple tables, algorithms, and comprehensive integration of underlying study data, the new guideline is auser-oriented reference book for clinical practice that also covers special clinical situations such as cardiac arrhythmias in pregnancy or in the context of sports. Regarding the acute treatment of ventricular arrhythmias, cardioversion is now recommended in case of hemodynamically tolerated arrhythmias. Beyond that, the guideline places special emphasis on the management of the electrical storm. In long-term therapy, recommendations for drug therapy have been aligned with current heart failure guidelines. Catheter ablation of ventricular arrhythmias has gained importance not only for recurrent ventricular tachycardia under chronic amiodarone therapy and as an alternative to implantable cardioverter-defibrillators (ICDs) in selected patients with coronary artery disease, but especially for the treatment of idiopathic premature ventricular contractions and tachycardias. Risk stratification and criteria for primary preventive ICDs are still controversial topics, which are discussed in detail based on the specific disease entities.

Abstract 14643: Benefits and Risks of Single- vs. Dual- Chamber Implantable Cardioverter Defibrillators for Primary Prevention of Sudden Cardiac Death

Introduction: Implantable cardioverter defibrillator (ICD) is the more effective and safer treatment for the primary prevention of sudden cardiac death. It remains unclear whether dual-chamber ICD offers the clinical benefits over single-chamber ICD without increasing complications. Hypothesis: The study aimed to evaluate the benefits and risks of dual-chamber ICD compared with single-chamber ICD for primary prevention of sudden cardiac death in clinical practice. Methods: Using the Korean National Health Insurance Service database from January 2008 to December 2019, we include patients with primary prevention ICD and no documented indication for pacing. The propensity score matching method was used to balance covariates across single- and dual-chamber ICDs. Primary outcomes were all-cause mortality, hospitalization of heart failure, and hospitalization of cardiovascular cause. Results: Among 1,929 patients, 1,098 (56.9%) received a single-chamber ICD and 831 (43.1%) received a dual-chamber ICD. In 752 pairs of patients after propensity matching baseline characteristics were balanced between the 2 groups (median age 62 years; male 72%). Over a mean follow-up of 2.7±2.4 years, 1- and 5-year all-cause mortality (5.5% vs. 5.6%, P=0.910; 19.4% vs. 19.3%, P=0.948), 1- and 5-year hospitalization for cardiovascular cause (14.9% vs. 14.9%, P=1.000; 23.9% vs. 22.6%, P=0.542), and 1- and 5-year hospitalization for heart failure (10.8% vs. 8.6%, P=0.163; 16.8% vs. 14.0%, P=0.133) were similar in both groups. However, cardiac tamponade in the rates of device-related complications was 0.1% in the single-chamber ICD vs. 1.1% in dual-chamber ICD groups (P=0.013). Conclusions: In the real-world population receiving a primary prevention ICD, dual-chamber ICD was associated with higher rates of cardiac tamponade than single-chamber ICD. One and five-year rates of all-cause mortality and hospitalization did not differ significantly between the two groups.

Abstract 15205: Cardiovascular Outcomes With Use of Primary Prevention Implantable Cardioverter Defibrillators in Patients With Non-Ischemic Cardiomyopathy: A Meta-Analysis and Meta-Regression Analysis

Introduction: Guidelines recommend use of implantable cardioverter defibrillator (ICD) in all patients with non-ischemic cardiomyopathy (NICM) and ejection fraction (EF) &lt; 35% for primary prevention of sudden cardiac death (SCD) and hence reduction of overall mortality. Contemporary randomized clinical trials (RCTs) with longer follow up duration have thrown into question this beneficial effect of ICDs. Hypothesis: Prophylactic use of ICDs in addition to optimal medical therapy (OMT) does not reduce adverse outcomes in patients with NICM and EF &lt; 35% compared to OMT alone. Methods: Six RCTs (n=4541) comparing ICD + OMT vs OMT alone were selected from MEDLINE and EMBASE databases from inception through March 2022. Meta-analysis was performed using random effects model. Meta-regression analysis was performed with inverse-variance weighting and Knapp and Hartung adjustments for all-cause mortality. Results: ICDs did not reduce risk of all-cause mortality (Relative Risk (RR) 0.87, [95% confidence interval, 0.75-1.00], cardiovascular mortality (RR, 0.80 [0.49-1.31]), non-cardiovascular mortality (RR, 0.66 [0.13-3.34]) or non-sudden cardiac death (RR, 1.03 [0.51-2.08]). ICDs reduced the risk of sudden cardiac death (HR, 0.49 [0.26-0.92]). Meta-regression analysis did not show any association between all-cause mortality and follow up duration (p=0.09). Conclusions: ICDs reduce risk of SCD however this does not translate into meaningful improvement in long term cardiovascular outcomes.

Abstract 11307: Longer Outflow Tract Conduction Time by Magnetocardiography as a Novel Non-Invasive Maker for Predicting Lethal Events in Patients With Brugada Syndrome Without Ventricular Fibrillation

Introduction: Many of the Brugada syndrome (BrS) patients have no symptom or only syncope without ventricular fibrillation (VF)/sudden cardiac death (SCD), thus to whom we should recommend implantable cardioverter defibrillator (ICD) for primary prevention of SCD is still the biggest concern in the BrS. Here we investigated whether a high spatial resolution magnetocardiography (MCG) could predict lethal events of the BrS without history of VF/SCD. Methods: This study retrospectively enrolled 157 BrS patients without VF or cardiopulmonary arrest (CPA) (150 male, 42±13 years old, 118 spontaneous and 39 drug-induced type-1 ECG). Outflow tract conduction time (OT-CT) from 2-D current map of MCG was measured in all patients as well as the standard 12-lead ECG and signal-averaged ECG (SAECG). Programmed electrical stimulation (PES) for VF induction was performed in 47 patients. Results: Patients with spontaneous type-1 ECG had longer OT-CT compared with type-2 BrS patients. Na channel blocker, pilsicainide (25-50mg) unmasked type-1 ECG as well as increased OT-CT (54±18 to 127±62 ms; p&lt;0.05), whereas additional isoproterenol (1ug/kg/min) reversed the pilsicainide-induced delayed OT-CT, thus normalized the ST elevation of ECG. During follow-up (mean 72 [6-147] months), 10 (6%) patients suffered VF/CPA, and those had a higher incidence of previous syncope (50% vs. 14.4%, p=0.01) and longer baseline OT-CT (83±31ms vs. 55±24ms, p=0.01) compared with event-free patients. Receiver operating curve (ROC) revealed OT-CT=65ms was a cut-off value of VF/CPA (AUC=0.78), whereas, spontaneous type-1 ECG, late potential of SAECG, family history, and VF inducibility by PES were not associated with VF/CPA events during follow-up. Multivariate Cox proportional analysis revealed that previous syncope (HR=1.70, 95%CI:1.01-3.05, p=0.04) and OT-CT≥65ms (HR=1.72, 95%CI=1.16-2.62) were the independent predictor for lethal events in the BrS without VF/CPA. Among asymptomatic BrS patients (n=131), OT-CT≥65ms was also an independent predictor for VF/CPA (HR=1.69, 95%CI=1.04-2.79, p=0.03). Conclusion: Longer OT-CT in the MCG may noninvasively demonstrate substrate of VF in BrS and stratify the risk of lethal events in patients with BrS without history of VF or CPA.

Abstract 14985: Artificial Intelligence Based Heart Rate Variability Analysis for Sudden Cardiac Arrest Risk Prediction

Introduction: Sudden Cardiac Arrest (SCA) is an unexpected life-threatening loss of cardiac function potentially leading to sudden cardiac death (SCD). It accounts for a half of cardiac mortality, posing a major public health problem. While SCA can be treated with implantable cardioverter defibrillators (ICD), most (80%) SCDs occur in relatively low risk patients, for whom risk benefit ratio of an ICD is unfavorable. Therefore, novel methods to identify high risk individuals and the time on which their risk is high may facilitate prevention of SCD. Methods : Long (~24h) ECG recordings from individuals who had an SCA on record (n=20), patients with other arrhythmias (n=84) and from healthy individuals (n=17) from PhysioNet databases were analyzed to extract inter beat intervals (IBI). For each step in the IBI series, 120 last IBIs were used to calculate 19 indices that quantify short term heart rate variability (HRV). An artificial intelligence model named temporal convolutional network (TCN) was used to continuously assess the risk of a future VF event based on the current HRV estimate combined with few hours of history of previous HRV estimates. Training and testing of the TCN was done using Leave One Out testing done twice. Patients being classified at any point in the record as high risk were considered high risk. Results : Only patients from the SCA population, and none from the other arrythmia and healthy patients, were classified as high risk (PPV=100%). On average, sensitivity and specificity were 62.5% and 100% respectively Conclusions : In this preliminary retrospective analysis, artificial intelligence based HRV analysis identified risk for a SCA event in the following 24 hours with high specificity. Larger cohort and prospective testing are needed to assess the clinical utility of such systems.

Abstract 11350: Arrhythmogenic Mitral Valve Prolaspe and Mitral Annular Disjunction

Background: Mitral valve prolapse (MVP) affects about 2-3% of the general population. A small proportion of persons may have arrhythmic symptoms, leading to ventricular arrhythmias and sudden cardiac death (SCD). Mitral annular disjunction is a recently described entity that may be present with MVP or independently. Case: A 55-year-old male patient presented to the hospital with cardiac arrest. He has a history of percutaneous coronary intervention with stenting to left anterior descending (LAD) and right coronary artery (RCA) in 2015. He had ventricular fibrillation (VF) and subsequently arrested and underwent resuscitation. Electrocardiogram (EKG) showed sinus rhythm with prolonged QTc 487msec with no ischemia; echocardiography showed mitral annular disjunction, severe left ventricular global hypokinesis with ejection fraction of 10%. Left heart catheterization revealed nonobstructive moderate coronary artery disease. Right heart catheterization showed a severely reduced cardiac index of 2.1, and he was placed on mechanical support (Impella) for cardiogenic shock. On day 5, repeat echocardiography revealed left ventricular ejection fraction of 60%. Subsequent cardiac magnetic resonance (CMR) showed no evidence of infiltrative diseases but revealed an inferolateral wall scar from previous myocardial infarction and MVP with MAD. An implantable cardiac defibrillator was placed for secondary prevention of SCD. Discussion: The potential etiology of our patient's ventricular fibrillation cardiac arrest may include a scar from previous myocardial infarction or arrhythmogenic MVP with MAD. Myocardial fibrosis arising from MAD may be an origin of ectopic activity and arrhythmia. EKG, echocardiographic, and cardiac magnetic resonance imaging (CMR) are essential in diagnosing arrhythmic MVP and MAD. Young patients with premature ventricular contractions without clear etiology should be evaluated for MAD, and incidental findings of MAD should warrant further investigations, given its arrhythmogenic potential. Conclusion: MVP with MAD is associated with life-threatening arrhythmias. Further studies are required to explore treatment options to reduce the incidence of malignant VAs and SCDs in patients with MVP.

Abstract 10951: Temporal and Global Trends of the Incidence of Sudden Cardiac Death in Hypertrophic Cardiomyopathy: A Meta-Analysis

Introduction: Since hypertrophic cardiomyopathy(HCM) initial description, sudden cardiac death (SCD) has been the most feared complication of HCM. Hypothesis: Temporal, geographical, and age-related trends of SCD rates in HCM have drastically decreased over time. Methods: Databases were systematically searched to Nov 2021 for studies reporting on SCD event rates in HCM. Patients with SCD equivalents (appropriate ICD shocks and non-fatal SCD) were excluded. Random-effects model was utilized to pool study estimates calculating the overall incidence rates(IR) for each time-era, geographical region, and age-group. We analyzed 2 eras (before vs. after 2000, following implementation of ICD in HCM). Following 2000, 5-year intervals were used to reflect the temporal change in SCD. Results: 98 studies (N=70,510patients and 431,407patient-years) met inclusion criteria. Overall rate of HCM SCD was 0.43%/year (95% CI: 0.37-0.50%; I 2 =75%; SCD events:1,938; person-years of follow-up: 408,715), with young patients(&lt;18 years) demonstrating a&gt;2-fold-risk for SCD vs. adults(18-60years) (IR:1.09%; 95% CI: 0.69-1.73% vs. IR: 0.43%; 95% CI: 0.37-0.50%)(P-value for subgroup differences:&lt;0.01). Contemporary SCD rates from 2015-present were 0.32%/year; significantly lower compared to 2000 or earlier (IR: 0.32%; 95% CI:0.20-0.52%, vs. IR: 0.73%; 95% CI:0.53-1.02%,respectively). Reported HCM-SCD rates were lowest in North America (IR: 0.28%;95% CI:0.18-0.43%) and highest in Asia(IR: 0.67%; 95% CI:0.54-0.84%). Conclusions: Contemporary HCM-related SCD are low (0.32%/year) representing a 2-fold decrease compared to prior treatment eras, with young HCM patients at the highest risk. SCD risk stratification maturation and primary prevention ICD application are likely responsible for the notable decline in SCD trends. Moreover, worldwide geographical disparities in SCD was evident, underscoring the need to increase access to SCD prevention for all HCM patients.

Living with brain cancer: From researcher to patient

As an academic researcher, my work-life revolves around testing the efficaciousness of pharmaceutical drugs on the prevention of cardiac dysfunction, arrhythmias, and sudden cardiac death in animal models of heart disease. I never thought I would go from someone studying a life-threatening disease to a patient living with one in twenty-four hours. Yet, that transformation occurred October 8, 2019. I was just appointed to Assistant Professor at Johns Hopkins University School of Medicine (JHUSOM), yet after sitting for my professional headshot I had a grand mal seizure. I cannot recall this event, but I bit the tip of my tongue off, dislocated my right shoulder, and underwent violent contractions. I was rushed to the Emergency Department, thankfully within the same building (JHUSOM). A few scans later, I was told I had ‘a mass’ in my brain that needed to be removed immediately. Fearing the worst, I followed the advice of my newly appointed neurosurgeon and scheduled surgery for October 19, 2019. I had no time to process what had and what was about to happen. What followed was two years of post-surgical recovery during a global pandemic, my own personal awe in the power of medicine, resurgence of my seizures and tumors, and now – my road to recovery through chemotherapy and radiation. These two years have taught me so much about the day-to-day difficulties patients with chronic diseases live with, strategies I use to cope with my new normal, and most importantly, the necessity of caregivers.

Blue paper of China sudden cardiac death prevention and rescue system construction (2022)

In order to improve the comprehensive ability of China sudden cardiac death prevention and rescue, the Expert Committee of China Sudden Cardiac Death Prevention and Rescue System Construction organized 100 experts and scholars in the field of cardiopulmonary resuscitation to form Blue paper of China sudden cardiac death prevention and rescue system construction (2022). It mainly includes three parts: the organizational structure of the sudden cardiac death prevention and rescue system, the main functions of the sudden cardiac death prevention and rescue system, and the key projects of the sudden cardiac death prevention and rescue system. It is hoped that the China sudden cardiac death prevention and rescue system will be established to serve the life and health of the people wholeheartedly.

QT interval variability and athlete's heart remodeling

At present, the prevention of sudden cardiac death in athletes is of great interest. A large amount of literature data concerning the correlation between the length of the QT interval and the proarrhythmic potential of the myocardium has been accumulated. However, new potential predictors of the fatal arrhythmias occurrence in athletes have emerged in recent years — an increase in the dispersion of the QT interval, as well as short-term variability in repolarization. This review provides detailed data on the diagnosis, prevalence, classifi cation, etiology of long QT as one of the manifestations of QT variance. The variety of causes leading to long QT syndrome (LQTS) causes diffi culties in the diff erential diagnosis of this condition and, and as a result, LQTS often remains outside the attention of practitioners. The data of recent studies of the athlete’s heart remodelling are presented as well.

Dynamic Change of Cardiovascular Health Metrics and Long-Term Risk of Sudden Cardiac Death: The ARIC Study.

Background The change of cardiovascular health (CVH) status has been associated with risk of cardiovascular disease. However, no studies have explored the change patterns of CVH in relation to risk of sudden cardiac death (SCD). We aim to examine the link between baseline CVH and change of CVH over time with the risk of SCD. Methods and Results Analyses were conducted in the prospective cohort ARIC (Atherosclerosis Risk in Communities) study, started in 1987 to 1989. ARIC enrolled 15 792 individuals 45 to 64 years of age from 4 US communities (Forsyth County, North Carolina; Jackson, Mississippi; suburbs of Minneapolis, Minnesota; and Washington County, Maryland). Subjects with 0 to 2, 3 to 4, and 5 to 7 ideal metrics of CVH were categorized as having poor, intermediate, or ideal CVH, respectively. Change in CVH over 6 years between 1987 to 1989 and 1993 to 1995 was considered. The primary study outcome was physician adjudicated SCD. The study population consisted of 15 026 subjects, of whom 12 207 had data about CVH change. Over a median follow-up of 23.0 years, 583 cases of SCD were recorded. There was a strong inverse association between baseline CVH metrics and time varying CVH metrics with risk of SCD. Compared with subjects with consistently poor CVH, risk of SCD was lower in those changed from poor to intermediate/ideal (hazard ratio [HR], 0.67 [95% CI, 0.48-0.94]), intermediate to poor (HR, 0.73 [95% CI, 0.54-0.99]), intermediate to ideal (HR, 0.49 [95% CI, 0.24-0.99]), ideal to poor/intermediate CVH (HR, 0.23 [95% CI, 0.10-0.52]), or those with consistently intermediate (HR, 0.49 [95% CI, 0.36-0.66]) or consistently ideal CVH (HR, 0.31 [95% CI, 0.13-0.76]). Similar results were also observed for non-SCD. Conclusions Compared with consistently poor CVH, other patterns of change in CVH were associated with lower risk of SCD. These findings highlight the importance of promotion of ideal CVH in the primordial prevention of SCD.

Kamizelka defibrylująca w okresie poporodowym u pacjentki z kardiomiopatią

Cardiovascular diseases during pregnancy increase the risk of morbidity and mortality in pregnant women and their children. We present the case of a 37-year-old patient with cardiomyopathy who developed significant deterioration of left ventricular function accompanied by fetal death at 28 gestational week, and who was subsequently provided with a wearable cardioverter defibrillator as a part of sudden cardiac death prevention.

Two Implantable Devices for Cardiac Rhythm Management

A 53-year-old, 104- kg, 165- cm woman with nonischemic cardiomyopathy with a reduced ejection fraction of 30%-to-35% secondary to cardiac sarcoidosis was admitted for decompensated heart failure. She previously had a single-chamber implantable cardioverter-defibrillator (ICD) placed via a left pectoral approach for the primary prevention of sudden cardiac death. Considering that the patient was on maximally tolerable guideline-directed medical therapy for heart failure with reduced ejection fraction, and was not a candidate for cardiac resynchronization therapy, the decision was made to augment her systolic function with a cardiac rhythm management device. After an uneventful implantation of her new device, a chest radiograph (Fig 1) and electrocardiogram showing changes (Fig 2, Fig 3) were obtained. What is the diagnosis? Fig 2Electrocardiogram with cardiac contractility modulation therapy OFF. View Large Image Figure Viewer Download Hi-res image Fig 3Electrocardiogram with cardiac contractility modulation therapy ON. View Large Image Figure Viewer Download Hi-res image

Subcutaneous versus transvenous implantable cardioverter defibrillators in children and young adults: A meta-analysis.

The implantable cardioverter defibrillator (ICD) has been demonstrated to successfully prevent sudden cardiac death (SCD) in children and young adults. A wide range of device-related complications/malfunctions have been described, which depend on the intrinsic design of the defibrillation system (transvenous-implantable cardioverter defibrillator [TV-ICD] vs. subcutaneous-implantable cardioverter defibrillator [S-ICD]). To compare the device-related complications and inappropriate shocks with TV-ICD versus S-ICD. Electronic databases were queried for studies focusing on the prevention of SCD in children and young adults with TV-ICD or S-ICD. The effect size was estimated using a random-effect model as odds ratio (OR) and relative 95% confidence interval (CI). The primary endpoint was a composite of any device-related complications and inappropriate shocks. We identified a total of five studies including 236 patients (Group S-ICD: 76 patients; Group TV-ICD: 160 patients) with a mean follow-up time of 54.2±24.9months. S-ICD implantation contributed to a significant reduction in the risk of the primary endpoint of any device-related complications and inappropriate shocks (OR: 0.18; 95% CI: 0.05-0.73; p=.02). S-ICD was also associated with a significantly lower incidence of inappropriate shocks (OR: 0.28; 95% CI: 0.11-0.74; p=.01) and lead-related complications (OR: 0.18; 95% CI: 0.05-0.66; p=.01). A trend toward a higher risk of pocket complications (OR: 5.91; 95% CI: 0.98-35.63; p=.05) was recorded in patients with S-ICD. Children and young adults undergoing S-ICD implantation may have a lower risk of a composite of device-related complications and inappropriate shocks, compared to TV-ICD patients.

Long QT syndrome: long story short.

The first report of long QT syndrome (LQTS) dates back to 1856 when Friedrich Ludwig Meissner, a German obstetrician and pediatrician, described a child with deafness, who died while being publicly reprimanded by the schoolteacher.1 It took nearly a century to document the very first electrocardiogram (ECG) of a prolonged QT interval coinciding with deafness and syncope.2 The association between sudden deaths in children with congenital deafness and QT prolongation was brought up by two concurrent publications authored by Anton Jervell with Fred Lange-Nielsen and Samuel A. Levine with Clyde R. Woodworth.3 Following closely, Cesarino Romano et al. and Owen C. Ward described analogous cases in the absence of the auditory component.3 Although Levine and Woodworth’s contribution was never acknowledged, two eponyms, Jervell-Lange-Nielsen and Romano-Ward syndromes, were coined with reference to the congenital form of LQTS with or without deafness, respectively.3 Because syncope and cardiac arrest mainly occurred in stressful situation, sympathetic imbalance was long believed to underlie LQTS.3 It would take 40 years to find the fault in the genes. With the biological Rosetta stone deciphered, research has become ever more crucial to translate gene expression into clinical care for LQTS. While the spectrum of mutations initially encompassed 17 genes reported to be linked to LQTS, 7 are now classified as having disputed evidence.4 Mutations in three genes (KCNQ1, KCNH2, and SCN5A) encoding for cardiac voltage-gated K+ (Kv7.1 or KCNQ1, Kv11.1 or hERG) and Na+ channels (Nav1.5) causing a delay in cardiac repolarization account for the majority of LQTS forms (types 1, 2, and 3, respectively).4 LQTS types 1 and 2 are based on a loss-of-function in Kv7.1 and Kv11.1 channels, respectively, reducing repolarizing outward K+ currents (IKs and IKr). In contrast, LQTS type 3 relates to an increased late Na+ inward current (INa, late) resulting from gain-of-function in Nav1.5 channels.4 While LQTS type 1 typically manifests during childhood, LQTS types 2 and 3 patients become symptomatic after the onset of puberty. Because of the decreased Kv11.1 channel density compared to male as well as the direct inhibitory effect of estrogen, female LQTS type 2 patients are at particular risk for arrhythmias.4 Such cardiac events predominantly occur at rest in LQTS type 3. In contrast, exercise and acoustic/emotional stimuli may trigger malignant arrhythmias in patients with LQTS type 1 and type 2, respectively. Mechanistically, the LQTS heart fails to adapt (impaired repolarization reserve) in response to the excess Ca2+ inflow resulting from sustained adrenergic tone (exercise) or an adrenergic surge (sudden arousal).4 Given the crucial role of sympathetic activity, it is no surprise that beta-blockers are advocated for LQTS patients. Late Na+ channel blockers present a viable adjunct in the pharmacological treatment of LQTS type 3. Left cardiac sympathetic denervation is a surgical antiadrenergic intervention mainly reserved to patients refractory to standard of care. An implantable cardioverter-defibrillator is considered in high-risk and resuscitated patients for the prevention of sudden cardiac death.4 Collectively, none of these treatment modalities addresses the cause of LQTS. In addition, some LQTS patients continue to experience breakthrough cardiac events despite maximal therapy, sparking research efforts in developing new treatment strategies.