Predicted Need for Atrial and Ventricular Pacing Per Indication Group in Patients With Dual-Chamber Pacemakers.

BACKGROUND: Bradyarrhythmias are adequately treated with pacemakers. There are different pacing modes (single-chamber, dual-chamber, cardiac resynchronisation therapy [CRT] and conduction system pacing [CSP]) and a choice between leadless or transvenous pacemakers. The expected pacing need is important for determining optimal pacing mode and device type. This study aimed to evaluate atrial pacing (AP) and ventricular pacing (VP) percentages over time for the most common pacing indications. METHODS: Included patients were aged ≥18 years with a dual-chamber rate-modulated [DDD(R)] pacemaker implantation and ≥1 year of follow-up at a tertiary centre between January 2008 and January 2020. Baseline characteristics, AP and VP at yearly follow-up visits up to 6 years after implantation were retrieved from the medical records. RESULTS: A total of 381 patients were included. Primary pacing indications were incomplete atrioventricular block (AVB) in 85 (22%), complete AVB in 156 (41%) and sinus node dysfunction (SND) in 140 (37%) patients. Mean age at implantation was 71±14, 69±17 and 68±14 years, respectively (p=0.23). Median follow-up was 42 months (25-68 months). Overall, AP was highest in SND with median 37% (7%-75%) versus 7% (1%-26%) in incomplete AVB and 3% (1%-16%) in complete AVB (p<0.001); VP was highest in complete AVB with median 98% (43%-100%) versus 44% (7%-94%) in incomplete AVB and 3% (1%-14%) in SND (p<0.001). Ventricular pacing significantly increased over time in patients with incomplete AVB and SND (both p=0.001). CONCLUSIONS: These results confirm the pathophysiology of different pacing indications, causing clear differences in pacing need and expected battery longevity. They may help guide optimal pacing mode and suitability for leadless or physiological pacing.

Pulmonary vein anatomy addressed by computed tomography and relation to success of second-generation cryoballoon ablation in paroxysmal atrial fibrillation.

BACKGROUND: Cryoballoon isolation is considered a safe and effective treatment for atrial fibrillation (AF). However, recurrence of AF after first cryoballoon ablation occurs in ~30% of patients. Pre-procedurally identifying patients at risk of AF recurrence could be beneficial. HYPOTHESIS: Our aim was to determine how pulmonary vein (PV) anatomy influences the recurrence of AF using the second-generation cryoballoon in patients with paroxysmal AF. METHODS: We included 88 consecutive patients with paroxysmal AF undergoing PVI procedure with a second-generation 28-mm cryoballoon. All patients were evaluated at 3, 6 and 12 months using a 12-lead ECG and 24-hour Holter monitoring. PV anatomy was assessed by creating three-dimensional models using computed tomography (CT) segmentations of the left atrium. RESULTS: Fifty-one patients (61%) had left PVs with a shared carina, 35 patients (42%) had a shared right carina. Nine patients (11%) were classified having a right middle PV. In total 17 (20.2%) of patients had a left common PV. At 12 months, 14 patients (17%) had experienced AF recurrence. Neither PV ovality, variant anatomy, the presence of shared carina nor a common left PV was a predictor for AF recurrence. CONCLUSIONS: No specific characteristics of PV dimensions nor morphology were associated with AF recurrence after cryoballoon ablation in patients with paroxysmal AF.