RESUMEN
AIMS: We investigated the applicability of the Ventricular Capture Control (VCC) and Atrial Capture Control (ACC) algorithms for automatic management of cardiac stimulation featured by Biotronik pacemakers in a broad, unselected population of pacemaker recipients. METHODS AND RESULTS: Ventricular Capture Control and Atrial Capture Control were programmed to work at a maximum adapted output voltage as 4.8 V in consecutive recipients of Biotronik pacemakers. Ambulatory threshold measurements were made 1 and 12 months after pacemaker implant/replacement in all possible pacing/sensing configurations, and were compared with manual measurements. Among 542 patients aged 80 (73-85) years, 382 had a pacemaker implant and 160 a pacemaker replacement. Ventricular Capture Control could work at long term in 97% of patients irrespectively of pacing indication, lead type, and lead service life, performance being superior with discordant pacing/sensing configurations. Atrial Capture Control could work in 93% of patients at 4.8 V maximum adapted voltage and at any pulse width, regardless of pacing indication, lead type, and service life. At 12-month follow-up, a ventricular threshold increase ≥1.5 V had occurred in 4.4% of patients uneventfully owing to VCC functioning. Projected pacemaker longevity at 1 month was strongly correlated with the 12-month estimate, and exceeded 13 years in >60% of patients. CONCLUSION: These algorithms for automatic management of pacing output ensure patient safety in the event of a huge increase of pacing threshold, while enabling maximization of battery longevity. Their applicability is quite broad in an unselected pacemaker population irrespectively of lead choice and service of life.
Asunto(s)
Algoritmos , Estimulación Cardíaca Artificial/métodos , Marcapaso Artificial , Anciano , Anciano de 80 o más Años , Remoción de Dispositivos , Suministros de Energía Eléctrica , Seguridad de Equipos , Femenino , Atrios Cardíacos/fisiopatología , Ventrículos Cardíacos/fisiopatología , Humanos , Italia , Modelos Logísticos , Masculino , Análisis Multivariante , Sistema de Registros , Factores de Tiempo , Función VentricularRESUMEN
BACKGROUND: We hypothesized that a negative microvolt T-wave alternans (MTWA) test would identify patients unlikely to benefit from primary prevention implantable cardioverter defibrillator (ICD) therapy in a prospective cohort. METHODSâANDâRESULTS: Data were pooled from 8 centers where MTWA testing was performed specifically for the purpose of guiding primary prevention ICD implantation. Cohorts were included if the ratio of ICDs implanted in patients who were MTWA "non-negative" to patients who were MTWA negative was >2:1, indicating that MTWA testing had a significant impact on the decision to implant an ICD. The pooled cohort included 651 patients: 371 MTWA non-negative and 280 MTWA negative. Among non-negative patients, 62% underwent ICD implantation whereas only 13% of MTWA-negative patients received an ICD (P<0.01). Despite a substantially lower prevalence of ICDs, long-term survival (6.9 years) was significantly better among MTWA-negative patients (68.2% non-negative vs. 87.1% negative, P=0.026). CONCLUSIONS: MTWA-negative patients had significantly better survival than MTWA non-negative patients, the majority of whom had ICDs. Despite a very low prevalence of ICDs, long-term survival among patients with left ventricular ejection fraction ≤40% and a negative MTWA test was better than in the ICD arm of any study to date that has demonstrated a benefit of ICDs. This provides further evidence that MTWA-negative patients are unlikely to benefit from primary prevention ICD therapy.