Transveneuze versus subcutane defibrillator bij patiënten met hypertrofe cardio myopathie : een retrospectieve analyse in twee Belgische ziekenhuizen

Hypertrofe cardiomyopathie (HCM) is een erfelijke aandoening met een verhoogd risico op plotse dood (SCD). Er zijn geen gerandomiseerde studies om de implantatie van een implantable cardioverter-defibrillator (ICD) in patiënten met HCM te leiden. Aanbevelingen zijn gebaseerd op observationele, retrospectieve cohort studies

Different dynamics of new-onset electrocardiographic changes after balloon- and self-expandable transcatheter aortic valve replacement : implications for prolonged heart rhythm monitoring

Background: Newonset electrocardiographic (ECG) changes after transcatheter aortic valve replacement (TAVR) are used to assess the risk for late atrioventricular block. However, the time of ECG evaluation remains controversial. We aimed to compare the time course and dynamics of newonset ECG changes according to valve design in balloon- (BEV) and self-expandable (SEV) TAVR. Methods and results: This single center study enrolled 133 consecutive TAVR patients (28.6% SEV, 71.4% BEV). Patients with pre-existent permanent pacemaker implant (PPMI), procedural death or incomplete ECG registration were excluded. Standard 12-lead ECG was performed before the procedure, at 1, 24, 48 and 120 h and 1 month. In BEV patients, no significant PR prolongation occurred, whereas in SEV patients the PR interval prolonged significantly with 33.7 +/- 22.0 ms (p 24 h after TAVR) was higher in SEV compared to BEV patients (15.3% versus 1.5%, p= 0.008). Conclusion: Self-expandable valves cause more impairment in atrioventricular conduction with a delayed time course compared to balloon expandable valves. This might explain the higher pacemaker need beyond 24 h after TAVR. Our findings suggest that patients with self-expandable valves require at least 48 h ECG monitoring post TAVR. (c) 2020 Published by Elsevier Inc

Undersensing by an ICD due to alternans of the ventricular electrogram

Alternans of the ventricular electrogram (VEGM) during ventricular tachycardia (VT) is a rare cause of ventricular undersensing by an implantable cardioverter-defibrillator (ICD). This report describes a patient with a St. Jude ICD who exhibited sustained monomorphic VT associated with surface QRS alternans, alternating cycle lengths, alternans of the VEGM causing intermittent undersensing of the smaller component, and intermittent 2:1 counting of ventricular intervals during 1:1 sensing in response to the ICD detection algorithm. VEGM undersensing was corrected noninvasively simply by programming the threshold start from 62.5% to 50% which increased the sensitivity based on the amplitude of the VEGM. This maneuver did not affect the satisfactory and stable defibrillation threshold

Functional atrial undersensing associated with switching to a tracking mode of pacing

We have previously demonstrated that contemporary St. Jude devices (pacemakers and implantable cardioverter-defibrillators [ICDs]; St. Jude Medical, Sylmar, CA, USA) are designed to generate an extended postventricular atrial refractory period (PVARP) of 475 ms at the termination of conventional automatic mode switching (AMS) in response to atrial tachyarrhythmias . This response may cause functional atrial undersensing . A similar PVARP response unrelated to conventional AMS was found in four St. Jude devices (three ICDs and one pacemaker) whenever a nontracking pacing mode switched to a tracking DDD(R) mode. PVARP extension and functional atrial undersensing were observed when the VOO, VVI, and the DDI(R) modes (unrelated to conventional AMS) switched to the DDD(R) mode . In one patient the switch from the OOO mode (in the programmed noise reversion mode) to the DDD mode occurred after cessation of electromagnetic interference disturbing the ventricular channel. In this case PVARP extension was seen only in the corresponding markers because no P waves occurred coincidentally with the extended PVARP. The PVARP extension caused by a mode switch to the tracking function was designed to prevent sensing of a retrograde P wave on the first cycle of the reestablished tracking mode. The observed functional atrial undersensing is a normal manifestation of device function and must not be misinterpreted as a true atrial undersensing problem

Evaluating current implantable cardioverter defibrillator implantation procedures : can common complications be minimised?

The implantable cardioverter-defibrillator (ICD) is the cornerstone of treatment and prevention of malignant ventricular arrhythmias. Despite 30 years of experience, implantation of ICDs carries a risk of complications both during the procedure and long-term follow-up. Operator and procedure related factors may contribute to this risk. Furthermore, access, pocket, device and lead related problems occur, on top of problems related to arrhythmias and the patient themselves. Infection is the most feared complication, and its incidence seems to rise. Factors leading to complications are assessed, as well as measures to reduce these complications, including antibiotics and subcutaneous devices. Four patient categories with an increased risk are identified: the elderly with atrial fibrillation, diabetes or renal failure; the pediatric patient with or without congenital heart disease, the young patient with specific inherited diseases, and all those who undergo replacement, upgrade or concomitant lead extraction