Sex-Specific Ventricular Arrhythmias and Mortality in Cardiac Resynchronization Therapy Recipients.

OBJECTIVES: The study goal was to examine whether there are sex-related differences in the incidence of ventricular arrhythmias and mortality in CRT-defibrillator (CRT-D) recipients. BACKGROUND: Few studies have evaluated sex-related benefits of cardiac resynchronization therapy (CRT). Moreover, data on sex-related differences in the occurrence of ventricular tachyarrhythmias in this population are limited. METHODS: A multicenter retrospective study was conducted in 460 patients (355 male subjects and 105 female subjects) from the UMBRELLA (Incidence of Arrhythmia in Spanish Population With a Medtronic Implantable Cardiac Defibrillator Implant) national registry. Patients were followed up through remote monitoring after the first implantation of a CRT-D during a median follow-up of 2.2 ± 1.0 years. Sex differences were analyzed in terms of ventricular arrhythmia-treated incidence and death during the follow-up period, with a particular focus on primary prevention patients. RESULTS: Baseline New York Heart Association functional class was worse in women compared with that in men (67.0% of women in New York Heart Association functional class III vs. 49.7% of men; p = 0.003), whereas women had less ischemic cardiac disease (20.8% vs. 41.7%; p < 0.001). Female sex was an independent predictor of ventricular arrhythmias (hazard ratio: 0.40; 95% confidence interval: 0.19 to 0.86; p = 0.020), as well as left ventricular ejection fraction and nonischemic cardiomyopathy. Mortality in women was one-half that of men, although events were scarce and without significant differences (2.9% vs. 5.6%; p = 0.25). CONCLUSIONS: Women with left bundle branch block and implanted CRT have a lower rate of ventricular tachyarrhythmias than men. All-cause mortality in patients is, at least, similar between female and male subjects.

Intermittent atrial undersensing in single-lead VDD pacemakers in patients with bradycardia-sensitive repolarization: a possible mechanism for ventricular arrhythmia.

Intermittent atrial undersensing in patients with single-lead VDD pacemakers is regarded as being of limited clinical significance. Nevertheless, in patients with bradycardia-mediated repolarization abnormalities, undersensing could result in RR-interval oscillations due to changes in pacemaker mode and this could act as a trigger for the initiation of torsades de pointes. We report our findings in three patients, which demonstrate the functioning of this trigger mechanism for ventricular arrhythmias.

Wide QRS tachycardia with ventriculoatrial dissociation in early postoperative aortic valve replacement period: an atypical nodal reentry presentation.

We report an atypical presentation of atrioventricular (AV) nodal reentry tachycardia with periods of ventriculoatrial Wenckebach and complete ventriculoatrial dissociation which appeared in a male patient in the postoperative period following aortic valve replacement and plication of Valsalva's posterior sinus. The context for the onset of this AV nodal reentry tachycardia and the concurrent electrophysiological findings support the hypothesis of a strictly nodal location of the circuit and suggest that the electrical modifications sustained by the perinodal region are the triggering agent for the reentry mechanism. Therefore, the AV nodal reentry is a mechanism that must be considered when tachycardia appears in the early postoperative period following aortic valve replacement.

[Intermittent atrioventricular block in an accessory pathway associated with complete infrahissian block]. / Sínsope por bloqueo auriculoventricular completo en un paciente con preexcitación.

The appearance of syncope in a patient with an accessory pathway is often a sign of high conduction capacity along the pathway, and calls for urgent ablation. Serious complications may ensue if it is assumed that these patients have an underlying mechanism of tachyarrhythmia, and ablation of the accessory pathway performed hastily without careful electrophysiological evaluation may lead to serious complications. The case described here, despite the patient's unusual presenting features, illustrates that the causal mechanism of syncope is not always what it appears to be. Although our patient had an obvious accessory pathway that was clearly evident in the electrocardiogram, the actual cause of the problem was complete infrahissian atrioventricular block.

[Retrospective study of patients who undergo pacemaker implantation in short-stay ambulatory surgery. Long-term follow-up and cost analysis]. / Estudio retrospectivo de pacientes sometidos a implante de marcapasos en cirugía mayor ambulatoria y de corta estancia. Seguimiento a largo plazo y análisis de costes.

INTRODUCTION AND OBJECTIVES: The aim of this study was to analyze data concerning mortality, morbidity, the number of re-admissions, complications, and cost per patient after pacemaker implantation, in groups of patients with different postoperative follow-up regimens. PATIENTS AND METHOD: Data from 2108 patients with definitive pacemakers implanted between January, 1991 and December, 2001 were analyzed retrospectively. We took into account the length of hospital stay and pacemaker dependence: group I, non-pacemaker dependent ambulatory patients with no hospital admission (NPMD) (n=710); group II, pacemaker-dependent patients with a short hospital stay of up to 48 hours (PMD) (n=779); group III, non-pacemaker-dependent patients with routine hospitalization for more than 48 hours (NPMD) (n=289); and group IV, pacemaker-dependent patients with routine hospitalization for more than 48 hours (PMD) (n=330). RESULTS: Total mortality was 3.9% (n=83), and no deaths were directly related to surgery. The cause of death was cardiac in 1.4% (n=30), non-cardiac in 2.3% (n=49), and unknown in 0.2% (n=4) of the patients. Mortality was premature (<30 days) in 38 patients (1.8%) and non-premature (>30 days) in 45 patients (2.1%). Total mortality was the same in Groups I and II (0.2%), and morbidity was 0.75%, and 0.9%, respectively. There were no premature deaths in these first 2 groups. In groups III and IV, mortality rose to 1.5% and 2% and morbidity to 0.9% and 1%. The total number of re-admissions (premature and non-premature) was higher in Groups III (6 re-admissions) and IV (9 re-admissions). The average total cost per patient, considering the sum of the average unit costs of the activities in each one of the medical processes which were studied (i.e., hospitalization, home visits, surgical activity, re-admissions, and second operations) was 117 euros in group I (ambulatory surgery) and 280 euros in group II (short stay). In both groups III and IV (hospitalization) the average total cost rose to 917.80 euros. CONCLUSIONS: Major ambulatory surgery may be an economical and efficient procedure for the health care system if it is used in carefully screened patients with cardiac stimulation.