Silva Ja

Benefit of cardiac resynchronization therapy in atrial fibrillation patients vs. patients in sinus rhythm: the role of atrioventricular junction ablation

AIMS To assess the clinical benefit of cardiac resynchronization therapy (CRT) in patients with atrial fibrillation (AF) compared with patients in sinus rhythm (SR), and to evaluate the impact of atrioventricular junction (AVJ) ablation on the outcome of AF patients undergoing CRT. METHODS AND RESULTS We conducted a retrospective analysis of 131 consecutive heart failure (HF) patients who underwent CRT implantation. Three groups were considered: SR (n = 78), AF with AVJ ablation (n = 26), and AF without AVJ ablation (n = 27). Patients were evaluated for the occurrence of cardiac death, hospitalization for HF, and responsiveness to CRT (survival with improvement of >or=1 New York Heart Association class at 6 months). The three groups showed a significant improvement in functional class. However, the proportion of responders was significantly lower in AF patients without AVJ ablation (52 vs. 79% in SR and 85% in AF with AVJ ablation, P < 0.008). Atrial fibrillation without AVJ ablation was also independently associated with mortality (HR 5.22, 95% CI: 1.60-17.01, P = 0.006) and hospitalization for HF during the first 12 months (HR 6.23, 95% CI: 2.09-18.54, P = 0.001). The outcomes of AF with AVJ ablation patients were similar to the outcomes of patients in SR. CONCLUSION Sinus rhythm and AF patients display similar survival and clinical improvement after CRT implantation, provided that AVJ ablation is performed in the latter.

Subacute left ventricle free wall rupture after acute myocardial infarction: awareness of the clinical signs and early use of echocardiography may be life-saving

Left ventricular free wall rupture (LVFWR) is a fearful complication of acute myocardial infarction in which a swift diagnosis and emergency surgery can be crucial for successful treatment. Because a significant number of cases occur subacutely, clinicians should be aware of the risk factors, clinical features and diagnostic criteria of this complication. We report the case of a 69 year-old man in whom a subacute left ventricular free wall rupture (LVFWR) was diagnosed 7 days after an inferior myocardial infarction with late reperfusion therapy. An asymptomatic 3 to 5 mm saddle-shaped ST-segment elevation in anterior and lateral leads, detected on a routine ECG, led to an urgent bedside echocardiogram which showed basal inferior-wall akinesis, a small echodense pericardial effusion and a canalicular tract from endo to pericardium, along the interface between the necrotic and normal contracting myocardium, trough which power-Doppler examination suggested blood crossing the myocardial wall. A cardiac MRI further reinforced the possibility of contained LVFWR and a surgical procedure was undertaken, confirming the diagnosis and allowing the successful repair of the myocardial tear. This case illustrates that subacute LVFWR provides an opportunity for intervention. Recognition of the diversity of presentation and prompt use of echocardiography may be life-saving.

Diaphragmatic myopotential oversensing in pacemaker-dependent patients with CRT-D devices

AIMS To evaluate the incidence and clinical significance of diaphragmatic myopotential (dMP) oversensing in pacemaker (PM)-dependent patients with CRT-Ds. METHODS AND RESULTS We retrospectively evaluated patients with CRT-Ds implanted at our institution between January 2000 and August 2006. PM-dependent patients were identified, and the incidence of inappropriate detections due to dMP oversensing and their possible clinical implications (inappropriate therapies, syncope, and death of any cause) were evaluated. CRT-Ds were implanted in 122 patients, 37 were or became PM dependent. During a mean follow-up of 22 +/- 17 months, 7(18.9%) PM-dependent patients revealed inappropriate detections due to dMP oversensing. All oversensing episodes occurred in CRT-Ds with automatic gain control (AGC) sensing and integrated bipolar (IBP) leads in the RV apex. These detections led to inappropriate shocks in 2(5.4%) patients and syncope in 1(2.7%). Five (13.5%) patients died. CONCLUSION dMP oversensing in PM-dependent patients with CRT-Ds is an important problem, particularly in CRT-Ds with AGC sensing and IBP leads, with over 20% of patients with these devices revealing inappropriate detections. The clinical impact of dMP oversensing is less marked but relevant, with both inappropriate therapies and syncope occurring in this small group of 37 patients and the possibility of related deaths.