Assessing the Malignant Ventricular Arrhythmic Substrate in Patients With Brugada Syndrome

Background

Guidelines recommend the use of implanted cardioverter-defibrillators in patients with Brugada syndrome and induced ventricular tachyarrhythmias, but there is no evidence supporting it.

Arrhythmias in Patients ≥80 Years of Age: Pathophysiology,Management, and Outcomes

Advances in medical care have led to an increase in the number of octogenarians and even older patients, forming an important and unique patient subgroup. It is clear that advancing age is an independent risk factor for the development of most arrhythmias, causing substantial morbidity and mortality. Patients ≥80 years of age have significant structural and electrical remodeling of cardiac tissue; accrue competing comorbidities; react differently to drug therapy; and may experience falls, frailty, and cognitive impairment, presenting significant therapeutic challenges. Unfortunately, very old patients are under-represented in clinical trials, leading to critical gaps in evidence to guide effective and safe treatment of arrhythmias. In this state-of-the-art review, we examine the pathophysiology of aging and arrhythmias and then present the available evidence on age-specific management of the most common arrhythmias, including drugs, catheter ablation, and cardiac implantable electronic devices.     

Clinical Impact of Circulating Galectin-3 on Ventricular Arrhythmias and Heart Failure Hospitalization Independent of Prior Ventricular Arrhythmic Events in Patients with Implantable Cardioverter-defibrillators

Objective For risk stratification of sudden cardiac death in patients with structural heart disease, more precise predictors in addition to left ventricular ejection fraction (LVEF) are clinically needed. The present study assessed the utility of galectin-3 as an independent indicator for the prognosis of heart failure patients with implantable cardioverter-defibrillators (ICD). Methods The study population consisted of 91 consecutive patients who underwent a routine ICD checkup in our ICD outpatient clinic. Circulating galectin-3 was assessed using a commercially available enzyme-linked immunosorbent assay kit. The enrolled patients were prospectively followed. The primary endpoint was defined as the occurrence of appropriate ICD therapy (AIT), and the secondary endpoint was defined as the occurrence of unplanned overnight hospitalization due to decompensated heart failure (dHF). Results During a mean follow-up of 472±107 days, AIT occurred in 18 patients (20%). Unplanned hospitalizations due to dHF were noted in 12 patients (13%). A receiver-operative characteristics analysis demonstrated a sensitivity of 83% and specificity of 68% for AIT occurrences with a galectin-3 cut-off value of 13.1 ng/mL (area under the curve =0.82). A Kaplan-Meier analysis demonstrated that patients with galectin-3 >13.1 ng/mL had significantly higher incidences of AIT as compared to those with lower galectin-3 (log-rank, p<0.001). This significance was also observed in both subgroup analyses with ischemic and non-ischemic etiology. Cox regression demonstrated that higher galectin-3 was an independent predictor of AIT and dHF, even after adjusting for previous arrhythmic events. Conclusion The circulating galectin-3 level can be used as a clinical indicator of subsequent occurrence of ventricular arrhythmic events and decompensated heart failure, regardless of a history of ventricular arrhythmias.     

Disorders of the Autonomic Nervous System in Patients With Brugada Syndrome: A Pilot Study

Autonomic Disorders in Brugada Syndrome . Introduction: The aim of this study was to examine autonomic disorders in patients with Brugada syndrome by performing a cardiac sympathetic innervation evaluation, a head‐up tilt‐test (HUT) and heart rate variability (HRV) analysis. Methods and Results: We enrolled 20 patients with Brugada syndrome (mean age 42.5 ± 8.8 years), 9 with spontaneous and 11 with an induced type 1 electrocardiogram (ECG) in the setting of symptoms and 20 age‐matched controls. All subjects underwent a HUT with parallel measurements of plasma catecholamines and cortisol, a ¹²³I‐metaiodobenzylguanidine single photon emission tomography, and HRV evaluation. Ten control subjects participated in the innervation portion of the study. The tilt‐test with clomipramine challenge was positive in 15 of 20 (75%) patients (7 spontaneous, 8 induced) and in 1 in controls (P < 0.01). A sympathoadrenal imbalance was shown in positive tests. The pattern of innervation in all groups was heterogenic and similar to controls with a trend towards lower measurements in patients with a spontaneous type 1 ECG and a positive HUT. HRV analysis did not reveal any significant differences during day and night. Four patients (20%) had sustained ventricular arrhythmias during a follow‐up of 31.1 ± 8.6 months, but no correlations with innervation or response to tilting were found. Conclusion: A high susceptibility to vasovagal syncope was observed in patients with Brugada syndrome, which could be disease‐related symptoms. Conversely, sympathetic innervation was observed to follow a physiological, heterogenic pattern; however, these factors did not have prognostic value for life‐threatening arrhythmias. (J Cardiovasc Electrophysiol, Vol. pp. 773‐780, July 2010)     

Cardiac Implantable Electronic Devices in Patients With Left Ventricular Assist Systems

Recent progress and evolution in device engineering, surgical implantation practices, and periprocedural management have advanced the promise of durable support with left ventricular assist systems (LVAS) in patients with stage D heart failure. With greater uptake of LVAS globally, a growing population of LVAS recipients have pre-existing cardiac implantable electronic devices (CIEDs). Strategies for optimal clinical management of CIEDs in patients with durable LVAS are evolving, and clinicians will increasingly face complex decisions regarding implantation, programming, deactivation, and removal of CIEDs. Traditional decision-making pathways for CIEDs may not apply to LVAS-supported patients, as few patients die of arrhythmic causes and many arrhythmias may be well tolerated. Given limited data, treatment decisions must be individualized and made collaboratively among electrophysiologists, advanced heart failure specialists, and patients and their caregivers. Large, prospective, well-conducted studies are needed to better understand the contemporary utility of CIEDs in patients with newer-generation LVAS.     

J‐Wave Disappearance Immediately After an Episode of Ventricular Fibrillation in a Patient With Resuscitated Sudden Cardiac Death and Brugada Syndrome

J‐Wave Disaapearance After an Episode of Ventricular Fibrillation . Early repolarization (ER) abnormalities in the inferior‐lateral leads are a matter of intense scientific debate because of their demonstrated association with Brugada syndrome (BS) and idiopathic ventricular fibrillation (VF). To add fuel to the fire, we present a case in which ER abnormalities are associated with BS but in which, more importantly, they were shown to be transient and strictly correlated with an episode of VF. (J Cardiovasc Electrophysiol, Vol. 21, pp. 1413‐1415, December 2010)     

Prediction of Life-Threatening Ventricular Arrhythmia in Patients With Arrhythmogenic Cardiomyopathy: A Primary Prevention Cohort Study

Objectives

This study aimed to identify clinical, electrocardiographic (ECG) and cardiac imaging predictors of first-time life-threatening ventricular arrhythmia in patients with arrhythmogenic cardiomyopathy (AC).

High-Altitude Exposure in Patients with Cardiovascular Disease: Risk Assessment and Practical Recommendations

Because of the development of modern transportation facilities, an ever rising number of individuals including many patients with preexisting diseases visit high-altitude locations (>2500 m). High-altitude exposure triggers a series of physiologic responses intended to maintain an adequate tissue oxygenation. Even in normal subjects, there is enormous interindividual variability in these responses that may be further amplified by environmental factors such as cold temperature, low humidity, exercise, and stress. These adaptive mechanisms, although generally tolerated by most healthy subjects, may induce major problems in patients with preexisting cardiovascular diseases in which the functional reserves are already limited. Preexposure assessment of patients helps to minimize risk and detect contraindications to high-altitude exposure. Moreover, the great variability and nonpredictability of the adaptive response should encourage physicians counseling such patients to adapt a cautionary approach. Here, we will briefly review how high-altitude adjustments may interfere with and aggravate/decompensate preexisting cardiovascular diseases. Moreover, we will provide practical recommendations on how to investigate and counsel patients with cardiovascular disease desiring to travel to high-altitude locations.     

Mapping of ventricular arrhythmias using a novel noninvasive epicardial and endocardial electrophysiology system

Introduction

The aim of this study was to assess the use of a novel noninvasive epicardial and endocardial electrophysiology system (NEEES) for mapping of ventricular arrhythmias.