Background: Conduction disturbances after transcatheter aortic valve replacement (TAVR) are often transient. Limited data exist on anatomic factors predisposing to pacemaker dependency after TAVR. We sought to assess the rate and the possible predictors of pacemaker dependency after TAVR. Methods: Consecutive patients undergoing pacemaker implantation up to 30 days after TAVR between May 2014 and September 2019 were included. Baseline electrocardiographic, computed tomography, and procedural characteristics were collected, including valve implantation depth and membranous septum length, an anatomic surrogate of the distance between the aortic annulus and the His bundle. Pacemaker dependency at 30 days and 1 year and all-cause mortality during follow-up were evaluated. Results: Of 728 TAVR patients, 112 (53.5% men; median age, 81 years) underwent pacemaker implantation after TAVR. Of these, 44.6% (50 of 112) were pacemaker dependent at 30 days and 46.7% (36 of 77) at 1 year. By multivariate analysis, independent predictors of 30-day pacemaker dependency included left ventricular outflow tract calcifications under the left coronary cusp (odds ratio, 5.69 [95% CI, 1.45–22.31]; P =0.013) and a difference between membranous septum length and implantation depth (ΔMSID) ≥3 mm (odds ratio, 7.58 [95% CI, 2.07–27.78]; P =0.002). Conversely, membranous septum length and implantation depth alone were not associated with pacemaker dependency (odds ratio, 0.79 [95% CI, 0.60–1.05]; P =0.11 and odds ratio, 1.11 [95% CI, 0.99–1.24]; P =0.08). At a median follow-up of 28.1 (11.7–48.6) months, pacemaker-dependent patients did not show a worse survival ( P =0.26). Conclusions: Less than half of the patients undergoing pacemaker implantation after TAVR are pacemaker-dependent at midterm follow-up. ΔMSID ≥3 mm and the presence of left ventricular outflow tract calcifications under the left coronary cusp, but not membranous septum length nor implantation depth alone, are predictive of long-term pacemaker dependency after TAVR, thus influencing device selection and programming.

Guidelines are important tools to guide the diagnosis and treatment of patients to improve the decision-making process of health professionals. They are periodically updated according to new evidence. Four new Guidelines in 2021, 2022 and 2023 referred to pediatric pacing and defibrillation. There are some relevant changes in permanent pacing. In patients with atrioventricular block, the heart rate limit in which pacemaker implantation is recommended was decreased to reduce too-early device implantation. However, it was underlined that the heart rate criterion is not absolute, as signs or symptoms of hemodynamically not tolerated bradycardia may even occur at higher rates. In sinus node dysfunction, symptomatic bradycardia is the most relevant recommendation for pacing. Physiological pacing is increasingly used and recommended when the amount of ventricular pacing is presumed to be high. New recommendations suggest that loop recorders may guide the management of inherited arrhythmia syndromes and may be useful for severe but not frequent palpitations. Regarding defibrillator implantation, the main changes are in primary prevention recommendations. In hypertrophic cardiomyopathy, pediatric risk calculators have been included in the Guidelines. In dilated cardiomyopathy, due to the rarity of sudden cardiac death in pediatric age, low ejection fraction criteria were demoted to class II. In long QT syndrome, new criteria included severely prolonged QTc with different limits according to genotype, and some specific mutations. In arrhythmogenic cardiomyopathy, hemodynamically tolerated ventricular tachycardia and arrhythmic syncope were downgraded to class II recommendation. In conclusion, these new Guidelines aim to assess all aspects of cardiac implantable electronic devices and improve treatment strategies.

Atrial fibrillation (AF) is a well-established post-cardiac surgery complication. Orthotopic heart transplantation (OHT) represents a peculiar condition where surgical thoracic veins isolation and autonomic denervation occur. This study aims at investigating AF incidence in OHT in order to define its risk factors and to evaluate its prognostic impact. 278 patients affected by OHT were recruited in our Cardiac Surgery Unit and retrospectively analyzed, using clinical, surgical and instrumental data. The patients cohort showed 45 post-operative (16.5%) and 20 late AF cases (7.2%). Only paroxysmal AF episodes were observed. Elderly donors and acute rejection resulted as risk factors in patients with post-operative AF episodes, who presented higher all-cause mortality at 11 years post-OHT (p < 0.001, Kaplan Meier analysis). The majority of late AF episodes occurred during hospitalization, due to renal failure or infections and more frequently in male patients; no significant correlation was observed with acute or chronic rejection or other characteristics. Pulmonary vein isolation and vagal denervation lead to low AF incidence in OHT recipients. Acute rejection and graft status are the main risk factors for post-operative AF episodes, while other systemic conditions act as late AF triggers. The occurrence of AF episodes is associated with poor outcome and AF should be considered as a marker of clinical frailty.

Overt or concealed accessory pathways are the anatomic substrates of ventricular preexcitation (VP), Wolff–Parkinson–White syndrome (WPW) and paroxysmal supraventricular tachycardia (PSVT). These arrhythmias are commonly observed in pediatric age. PSVT may occur at any age, from fetus to adulthood, and its symptoms range from none to syncope or heart failure. VP too can range from no symptoms to sudden cardiac death. Therefore, these arrhythmias frequently need risk stratification, electrophysiologic study, drug or ablation treatment. In this review of the literature, recommendations are given for diagnosis and treatment of fetal and pediatric age (≤12 years) WPW, VP, PSVT, and criteria for sport participation.