[Safety and effectiveness of single-lead VDD pacing]. / Seguridad y eficacia de los sistemas de estimulación VDD monosonda.

INTRODUCTION AND OBJECTIVES: Single-lead VDD pacing provides the physiological benefits of atrioventricular synchrony with the convenience of a single-lead system. However, concern remains about the method's safety and effectiveness. METHOD: In total, 700 patients with single-lead VDD pacemakers were evaluated retrospectively. The following parameters were recorded: age, sex, etiology, the symptoms and electrocardiographic diagnosis that justified pacemaker implantation, the venous access route used for implantation, atrial sensing at implantation, atrial undersensing at follow-up, the occurrence of supraventricular tachyarrhythmias, and final pacing mode. RESULTS: Third-degree atrioventricular block was the main indication for pacemaker implantation (66.4%). The most commonly used venous access route was via the right cephalic vein (49.1%). At implantation, the mean atrial signal was 1.8 (4 1.15) mV. During follow-up, significant atrial undersensing occurred in 7.7% of patients; in 1.9%, it could not be corrected by device reprogramming. Uncontrollable supraventricular arrhythmias were observed in 6.4% of patients. Symptomatic sinus node disease was rare. By the end of follow-up, 91.4% of patients were still on VDD pacing, while, in 8.3%, the pacemaker had to be reprogrammed to the VVI mode. Only 0.3% required atrial lead implantation for DDD pacing. Left-side venous access during implantation was a independent predictora of atrial undersensing at follow-up. Low values of atrial detection at implant did not reach statistical signification although it showed a remarkable trend. CONCLUSIONS: Single-lead VDD pacing seems to be safe and effective when appropriately indicated. Our findings are consistent with those of previously published studies.

Seguridad y eficacia de los sistemas de estimulación VDD monosonda / Safety and effectiveness of single-lead VDD pacing

Introducción y objetivos. La estimulación VDD monosonda proporciona los beneficios fisiológicos de la sincronía auriculoventricular, sumando a ello la comodidad de ser un sistema de cable único. No obstante, la inquietud que generan su seguridad y eficacia parece mantenerse todavía. Métodos. Estudio retrospectivo en 700 pacientes portadores de marcapasos con estimulación VDD monosonda. Los parámetros analizados fueron: edad, sexo, etiología, síntomas y diagnóstico electrocardiográfico que motivaron el implante, vía venosa de acceso, detección auricular al implante, infradetección auricular durante el seguimiento, episodios de taquiarritmias supraventriculares y modo de estimulación final. Resultados. La indicación prioritaria de implante fue el bloqueo auriculoventricular de tercer grado (66,4%). La vena cefálica derecha fue la vía de acceso más comúnmente utilizada (49,1%). La detección auricular media al implante fue 1,84 ± 1,15 mV. Durante el seguimiento un 7,7% de los casos presentó infradetección auricular inaceptable, que no se pudo corregir mediante reprogramación en el 1,9%. Se observó aparición de taquiarritmias supraventriculares incontrolables en el 6,4% de los pacientes. La presencia de disfunción sinusal sintomática fue testimonial. Al final del seguimiento, el 91,4% de los pacientes persistían en modo de estimulación VDD, se tuvo que reprogramar en VVI a un 8,3% y sólo un 0,3% precisó el implante de una sonda auricular para estimular en DDD. Las vías venosas de acceso izquierdo fueron un predictor independiente de infradetección auricular. Valores bajos de detección auricular al implante mostraron una clara tendencia, aunque sin llegar a la significación estadística. Conclusiones. La estimulación VDD monosonda es segura y eficaz cuando la indicación es correcta. Comparando nuestros resultados con los estudios publicados, encontramos correlación en términos de seguridad y eficacia (AU)

Introduction and objectives. Single-lead VDD pacing provides the physiological benefits of atrioventricular synchrony with the convenience of a single-lead system. However, concern remains about the method's safety and effectiveness. Method. In total, 700 patients with single-lead VDD pacemakers were evaluated retrospectively. The following parameters were recorded: age, sex, etiology, the symptoms and electrocardiographic diagnosis that justified pacemaker implantation, the venous access route used for implantation, atrial sensing at implantation, atrial undersensing at follow-up, the occurrence of supraventricular tachyarrhythmias, and final pacing mode. Results. Third-degree atrioventricular block was the main indication for pacemaker implantation (66.4%). The most commonly used venous access route was via the right cephalic vein (49.1%). At implantation, the mean atrial signal was 1.8 (4 1.15) mV. During follow-up, significant atrial undersensing occurred in 7.7% of patients; in 1.9%, it could not be corrected by device reprogramming. Uncontrollable supraventricular arrhythmias were observed in 6.4% of patients. Symptomatic sinus node disease was rare. By the end of follow-up, 91.4% of patients were still on VDD pacing, while, in 8.3%, the pacemaker had to be reprogrammed to the VVI mode. Only 0.3% required atrial lead implantation for DDD pacing. Left-side venous access during implantation was a independent predictora of atrial undersensing at follow-up. Low values of atrial detection at implant did not reach statistical signification although it showed a remarkable trend. Conclusions. Single-lead VDD pacing seems to be safe and effective when appropriately indicated. Our findings are consistent with those of previously published studies (AU)