Permanent single-chamber atrial pacing: an obsolete or viable alternative to dual-chamber pacing in selected patients with sinus node disease?

INTRODUCTION: Single atrial stimulation (AAI) has been commonly used for permanent pacing in sick sinus syndrome and significant bradycardia. OBJECTIVE: The study aimed to evaluate long­term AAI pacing and to identify timing and reasons for pacing mode change. PATIENTS AND METHODS: Retrospectively, we included 207 patients (60% women) with initial AAI pacing, who were followed­up for an average of 12 years. RESULTS: At the time of death or loss to follow­up, 71 patients (34.3%) had unchanged AAI pacing mode. The reason for an upgrade of the pacing system was development of atrial fibrillation (AF) in 43 patients (20.78%) and atrioventricular block (AVB) in 34 patients (16.4%). The cumulative ratio for a pacemaker upgrade reoperation reached 2.77 per 100 patient­years of the follow­up. Cumulative ventricular pacing below 10% after an upgrade to dual­chamber pacemaker was observed in 28.6% of the patients. Younger age at implant was the leading independent predictor of the change to dual­chamber simulation (hazard ratio, 1.98; 95% CI, 1.976-1.988; P = 0.001). There were 11 (5%) lead malfunctions that required reoperation. Subclavian vein occlusion was noted in 9 upgrade procedures (11%). One cardiac device-related infection was observed. CONCLUSIONS: The reliability of AAI pacing decreases with each year of observation due to development of AF and AVB. However, in the current era of effective AF treatment, the advantages of AAI pacemakers, such as lower incidence of lead malfunction, venous occlusion, and infection, as compared with dual-chamber pacemakers, may make AAI pacemakers a viable option.

Radiofrequency catheter ablation of ventricular tachycardia using combined endocardial techniques in patients with structural heart disease improves procedural effectiveness and reduces arrhythmia episodes.

BACKGROUND: Evidence indicates that radiofrequency catheter ablation (RFCA) of ventricular tachycardia (VT) in patients with structural heart disease (SHD) is safe and effective. However, arrhythmia recurrence is still relatively high, and the optimal procedural strategy is unclear. In clinical practice, several combinations of mapping and ablation techniques are used to improve VT ablation efficacy. AIM: The study aimed to evaluate and provide evidence on the efficiency and safety of a systematized combination of VT ablation (mapping) techniques in patients with SHD. METHODS: From 2016 to 2019, 47 patients (54 procedures) with SHD (89% heart failure, 94% ischemic heart disease, 37% VT storm) who underwent RFCA of VT were retrospectively analyzed from a group of 58 consecutive patients. During RFCA of VT, different combinations of three techniques, activation mapping (AM), pace mapping (PM), and substrate-based mapping (SbM), were used. The procedures were performed using the CARTO® 3 (Biosense Webster Inc., Diamond Bar, CA, US) electro-anatomical mapping system. RESULTS: During a median (interquartile range [IQR]) follow-up of 25.5 months (11.75-52.25), VT-free survival after ablation was 68.5% (n = 37/54 procedures). Acute procedural success was achieved in 85% (n = 46/54 procedures). The number of induced VT morphologies, induction of non-clinical or non-sustained VT after ablation, and fewer VT mapping techniques used during the procedure were related to decreasing VT-free survival. CONCLUSIONS: VT ablation strategy based on systemic use of combined techniques is effective and safe in long-term follow-up of patients with SHD.