Device interaction between cardiac contractility modulation (CCM) and subcutaneous defibrillator (S-ICD)

Combined implantation of cardiac contractility modulation (CCM) with subcutaneous implantable cardioverter-defibrillator (S-ICD) appears a suitable option to reduce the amount of intracardiac leads and complications for patients. Here we report on a patient with ischemic cardiomyopathy carrying an S-ICD in which a CCM device was implanted. During crosstalk testing post-CCM implantation, the S-ICD misannotated QRS complexes and T waves. The problem was solved through reprogramming the CCM, while preserving S-ICD functionality and improving heart failure symptoms. In conclusion, S-ICD combined with CCM seems to be a good and safe option for patients when device interference is being ruled out.     

Avoiding sports-related sudden cardiac death in children with congenital channelopathy

For the past few years, children affected by an inherited channelopathy have been counseled to avoid (recreational) sports activities and all competitive sports so as to prevent exercise-induced arrhythmia and sudden cardiac death. An increased understanding of the pathophysiological mechanisms, better anti-arrhythmic strategies, and, in particular, more epidemiological data on exercise-induced arrhythmia in active athletes with channelopathies have changed the universal recommendation of “no sports,” leading to revised, less strict, and more differentiated guidelines (published by the American Heart Association/American College of Cardiology in 2015). In this review, we outline the disease- and genotype-specific mechanisms of exercise-induced arrhythmia; give an overview of trigger-, symptom-, and genotype-dependent guidance in sports activities for children with long QT syndrome (LQTS), Brugada syndrome (BrS), catecholaminergic polymorphic ventricular tachycardia (CPVT), or short QT syndrome (SQTS); and highlight the novelties in the current guidelines compared with previous versions. While it is still recommended for patients with LQT1 and CPVT (even when asymptomatic) and all symptomatic LQTS patients (independent of genotype) to avoid any competitive and high-intensity sports, other LQTS patients successfully treated with anti-arrhythmic therapies and phenotype-negative genotype-positive patients may be allowed to perform sports at different activity levels – provided they undergo regular, sophisticated evaluations to detect any changes in arrhythmogenic risk.

     

Propofol dose and efficacy of defibrillation testing during implantation of subcutaneous implantable cardioverter-defibrillators: A retrospective,single center cohort study

Introduction

Defibrillation testing (DFT) is recommended during subcutaneous implantable cardioverter-defibrillator (S-ICD) implantation. Previous studies analyzing the potential interference of propofol with defibrillation threshold are inconsistent. The purpose of this study was to analyze whether propofol affects DFT post S-ICD placement.

Methods

All patients with S-ICD implantation between 01/2017 and 11/2020 at the University Heart Center Freiburg were retrospectively analyzed. Two groups were generated depending on the success of the first shock during DFT. Implantation characteristics and dose of anesthetics were analyzed.

Results

In 12 of the included 80 (15%) patients, first shock during DFT failed. The absolute dose of propofol was significantly higher in patients with first shock failure (median 653 mg [IQR 503–855]) compared to patients with first shock termination (376 mg [200–600]; p = 0.027). Doses of opioids and midazolam as well as type of anesthesia did not differ between the groups. A multivariable binary logistic regression analysis confirmed an independent association of first shock termination and propofol dose (per 100 mg: OR 0.73 (95% CI: 0.56–0.95); p = 0.021).

Conclusion

There is an independent association of propofol dose and first shock failure in routine S-ICD defibrillation testing.