Clinical outcomes of subcutaneous implantable cardiac defibrillator implantation - Iran SICD registry.

BACKGROUND: The subcutaneous implantable-defibrillator (S-ICD) is a relatively new alternative to the transvenous ICD system to minimize intravascular lead-related complications. This paper presents outcome of SICD implantation in patients enrolled in Iran S-ICD registry. METHODS: Between October 2015 and June 2022, this prospective multicenter national registry included 223 patients with a standard indication for an ICD, who neither required bradycardia pacing nor needed cardiac resynchronization to evaluate the early post-implant complications and long-term follow-up results of the S-ICD system. RESULTS: The mean age of the patients was 45 ± 17 years. The majority (79.4%) were male. Ischemic cardiomyopathy (39.5%) was the most common underlying disorder among patients selected for S-ICD implant. Most study patients (68.6%) had ICD for primary prevention of sudden cardiac death. Seven patients (3.1%) were found to have suboptimal lead positions. Six patients (2.7%) developed a pocket hematoma; all were managed medically. During a mean follow-up of 2 years, the appropriate therapy was recorded in 13% of the patients and inappropriate ICD intervention mainly due to supraventricular tachycardia in 8.9%. Pocket infection was observed in four patients (1.8%) and five patients (2.2%) died mainly due to heart failure. CONCLUSION: S-ICDs were effective at detecting and treating both induced and spontaneous ventricular arrhythmias. Major clinical complications were rare.

Automatic Mode Switch (AMS) Causes Less Synchronization.

INTRODUCTION: Cardiac resynchronization devices are part of modern heart failure management. After implantation, we analyze and program devices in an attempt to ensure their success. Biventricular pacing should be 98% or more for the lowest mortality and best symptom improvement. CASE PRESENTATION: In this case series, we present a combination of far field sensing and automatic mode switching (AMS) in six patients. It is found that this combination causes ventricular sensing (VS) episodes with wide QRS and no synchronization. We turn off the AMS and alleviate the problem. CONCLUSIONS: Switching AMS off may increase biventricular pacing in some patients.

The Impact of Hospital-Based Cardiac Rehabilitation on Signal Average ECG Parameters of the Heart After Myocardial Infarction.

BACKGROUND: Cardiac rehabilitation is a combination of integrated programs aimed at improving outcomes in patients recovering from heart events. OBJECTIVES: The present study aimed to evaluate the early benefits of supervised exercise training on electrophysiological function of post-ischemic myocardium. In this regard, signal-averaged electrocardiogram (SAECG) was used. PATIENTS AND METHODS: Between May and September 2012, all patients (n = 100) admitted to our center, with the diagnosis of acute Myocardial Infarction (MI), were enrolled in this study. Every other patient was assigned to two groups receiving either inpatient cardiac rehabilitation plus standard post-MI care (cases) or only standard post-MI care (controls). Electrophysiological function was assessed by SAECG in all the patients at baseline and on the day 5. The patients were considered as having late potential if they had abnormalities in at least two SAECG indices. RESULTS: Cardiac rehabilitation led to significant improvements in QRS duration (P < 0.001), square root of amplitude in the last 40 ms (P < 0.001) and duration of terminal signal with low amplitude (P < 0.001). Cardiac rehabilitation also resulted in amelioration of SAECG parameters; frequency of patients with late potential significantly decreased from 64% to 20% after five days (P < 0.001). CONCLUSIONS: Supervised in-hospital exercise training was associated with improvements in SAECG-measured electrical activity post-MI.