Evaluating the magnet response in deep subcutaneous implanted cardioverter defibrillator implants.

Introduction: The manufacturer of subcutaneous implantable cardioverter defibrillators (S-ICDs) acknowledges that 'deep implants' may fail to elicit a magnet response, however, does not define 'deep implant' or recommend a maximum implant depth. This study aims to systematically evaluate the effect of subcutaneous tissue depth and magnet types on evoked magnet response.

Methods: Sunshine Coast University Hospital's S-ICD cohort underwent magnet response evaluation; where bar and donut magnets were compared and the evoked magnet response was recorded in three separate zones, guided by a template.

Electrogram analysis to detect cathodal and anodal capture in left ventricular cardiac resynchronization pacing leads.

Aims: Our study analyzed cardiac electrograms (EGMs) to identify characteristics for detecting cathodal, anodal, or cathodal-anodal (simultaneous) capture in left ventricular (LV) quadripolar pacing leads of cardiac resynchronization therapy (CRT) patients. The relationship between these EGM characteristics and the electrocardiogram (ECG) was also examined.

Methods: We performed a retrospective analysis of 54 bipolar pacing configurations across nine patients with implanted CRT devices and quadripolar leads who had undergone a 12 lead ECG optimization.

Atrioventricular block masked by posteroseptal bypass tract located in coronary sinus aneurysm.

Atrial fibrillation with concurrent ventricular preexcitation identifies a high-risk arrhythmic substrate and usually results in catheter ablation of the atrioventricular bypass tract. Electrocardiography can only approximate the anatomical location of an accessory pathway. Here we report a case where a bypass tract was localised to a coronary sinus aneurysm and antegrade atrioventricular conduction masked underlying atrioventricular nodal block.