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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.

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 ≥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.

Patients with dilated cardiomyopathy and implantable cardioverter-defibrillator (ICD) are a high-risk group for arrhythmias. They regularly undergo cardiopulmonary exercise testing (CPET) to assess cardiac reserve and to guide clinical decisions or therapeutic adjustments. Data from previous studies demonstrate that prognosis in patients with heart failure (HF) worsens with the presence of appropriate shocks.The purpose of this study was to evaluate the value of CPET parameters to predict shocks and other arrhythmic events in HF patients with ICD, in order to identify a high-risk group for arrhythmias.This was a prospective single-center registry of 61 consecutive patients (mean age 55 +/- 15 years, 18% female), with dilated cardiomyopathy (ischemic etiology in 57%) and ICD, who underwent symptom-limited maximal CPET six months or less before device implantation. Minimum follow-up was 180 days. The primary endpoint was appropriate shock and the composite endpoint was appropriate shock and/or ventricular fibrillation (VF) and/or sustained ventricular tachycardia (VT), which were then correlated with hemodynamic variables (heart rate and blood pressure) and CPET parameters.During a mean follow-up of 27 months, eight patients died (13%), two of them from arrhythmic cause (3.3%), and 16 (26%) patients received at least one appropriate ICD shock, eight (13%) due to VF. Sustained VT was recorded in 23 patients (38%) and nonsustained VT in 42 patients (69%). CPET showed that the group with the primary end point had lower peak VO2, anaerobic threshold and chronotropic reserve. On multivariate analysis, resting heart rate was the only independent predictor of appropriate shock (HR 1.06; 95% CI 1.01-1.10; p = 0.025). Univariate analysis identified peak VO2, anaerobic threshold, VE/VCO2 slope, resting heart rate and heart rate decrease during the first minute of recovery, and systolic blood pressure during exercise as predictive of the composite endpoint (shock/VF/sustained VT). Multivariate analysis identified resting heart rate and peak VO2 as independent predictors, with HR 1.04; 95% CI 1.00-1.09 (p = 0.050) and HR 0.88; 95% CI 0.78-0.98 (p = 0.026), respectively. The best cut-off for resting heart rate to predict the composite and primary endpoints was76 bpm (area under the ROC curve: 0.67; 95% CI 0.53-0.78 and 0.65; 95% CI 0.51-0.76, respectively).Resting heart rate and peak VO2 were identified in multivariate analysis as good predictors of arrhythmic events and resting heart rate was the only independent predictor of appropriate shock in HF patients with ICD. Both advanced stage heart failure and sympathetic overdrive may be associated with the development of malignant arrhythmias.

Cardiac allograft vasculopathy is the main cause of morbidity and mortality after cardiac transplantation. Intravascular ultrasound (IVUS) is a sensitive imaging technique that provides detailed quantification of coronary atherosclerosis burden and could be a complement to routine angiography.To determine the value of IVUS for detecting silent atherosclerotic disease in cardiac allograft recipients.The study cohort consisted of 40 consecutive patients (mean age 55 +/- 11 years, 25% female) who underwent left anterior descending coronary artery IVUS (Volcano Therapeutics, Inc.) examination after transplantation. None of the patients had suspected or documented ischemia. Cardiac transplantation was due to ischemic cardiomyopathy in 30% (12 patients). Coronary artery disease (CAD) was defined as the presence ofor = 30% stenosis of vessel diameter (QCA analysis - Siemens CASS) on angiography and atherosclerotic lesions causingor = 30% stenosis of vessel area by IVUS. The angiographic definition of significant CAD lesions wasor = 50% stenosis of vessel diameter, and by IVUS a minimum cross-sectional area ofor = 4 mm2.CAD was identified in 20% (8 patients) by angiography and in 55% (22 patients) by IVUS (p = 0.003). Significant CAD was detected in 15% (6 patients) by angiography and in 7.5% (3 patients) by IVUS (p = 0.3).The use of IVUS on routine screening coronary angiography detects a higher prevalence of early atherosclerotic disease than normal angiography, which should lead to implementation of preventive strategies to control disease progression. IVUS was no more sensitive than angiography in detecting severe coronary stenosis. IVUS should be used as a standard imaging technique together with routine coronary angiography to assess atherosclerosis burden in cardiac allograft recipients.

Recent studies have shown that obesity is an independent predictor of lower N-terminal pro-BNP (NT-proBNP) levels and raised concerns about the validity of this biomarker in obese subjects. We evaluated the influence of obesity (body mass index>or=30 kg/m(2)) on the correlation between exercise capacity and serum NT-proBNP levels in 100 chronic heart failure (CHF) patients referred for cardiopulmonary exercise testing. Circulating NT-proBNP levels correlated well with lean body mass-adjusted peak oxygen consumption (VO(2)) in the entire cohort (R=-0.72, p

The growing use of abciximab during coronary angioplasty, with 12 hours of intravenous perfusion, prolongs hospital stay and increases the risk of hemorrhage after sheath removal at the puncture site. Femoral percutaneous closure devices can reduce immobilization time, but their safety in the presence of abciximab in respect to hemorrhage has not been clearly determined.To evaluate the safety and efficacy of the Perclose system in patients undergoing angioplasty with abciximab.The Perclose system was used in 79 patients undergoing angioplasty, with abciximab in 31 patients (58.6 +/- 12.2 years, 90% male, p = NS)--Group 1, and 48 pts without abciximab (61.8 +/- 10.9 years, 79% male, p = NS)--Group 2. We compared heparin dose, sheath diameters, primary success rate, coronary care unit admissions and minor and major complications. One patient was previously anticoagulated with warfarin and all the others were on oral antiplatelet therapy before and after angioplasty.Primary success with the use of the Perclose system was 78%. We found no significant statistical differences between groups in respect to the presence of diabetes, sheath diameter or referral for intervention. Heparin dosage was slightly higher in group 2 (p = 0.09) and ACT was also higher in group 2 (p = 0.01). More patients in group 1 had delayed ambulation (p = 0.04) due to abciximab perfusion. In 7 patients in group 1 and 9 in group 2, additional manual/mechanical compression was needed for moderate bleeding in the first hours (p = NS). One rupture of the femoral artery with need for surgical repair (primary failure) and another delayed rupture (48 hours) occurred in group 1 (both with an associated infection), and 1 pseudoaneurysm in a patient from group 2, without abciximab but taking warfarin (p = NS). None of the variables analyzed determined the occurrence of complications. Only oral anticoagulation determined the occurrence of major complications.User of the Perclose system for percutaneous closure of the femoral artery in patients undergoing coronary angioplasty with simultaneous use of abciximab was not associated with greater morbidity than in patients without glycoprotein IIb/IIIa receptor antagonists.

Several studies relate cytomegalovirus (CMV) infection to the development of atherosclerosis. Its influence in triggering acute coronary syndromes (ACS) is not known.We set out to identify a relationship between CMV infection, occurrence of ACS and prognosis.Serologic markers (IgM and IgG) for CMV were tested prospectively at admission and at 30 days, in patients (pts) admitted to our CCU for ACS. Serologic markers for CMV were also tested in a group of pts with stable coronary artery disease admitted for elective coronary angiography. A greater than two-fold elevation of IgG titer at 30 days was defined as reactivation/reinfection. At 30 days and six months, the composite endpoint of death, myocardial (re)infarction and re-admission for unstable angina was evaluated.There were 60 pts with ACS in the study group (age 63 +/- 10 years, 75% male) and 31 pts in the control group (age 64 +/- 10 years, 71% male). On admission, 95% of the pts with ACS and 81% in the control group presented a positive IgG (p = 0.029). In the study group, at 30 days, the only pt with a 3-fold titer elevation had an endpoint. The percentage was 17% for the group with aor = 2- and3-fold elevation and 11% in the group without reactivation (p = 0.034). At six months, 50% of the patients with a greater than 2-fold titer elevation and 15% of the remaining patients had an endpoint (p = 0.017). In the control group, at 30 days, 3 pts (10%) had a significant elevation in IgG titer,or = 2- and3-fold, without endpoint.In pts with ACS, we found a higher prevalence of serologic markers for CMV than in pts with stable coronary disease. An elevation in IgG titer for CMV was associated with a worse outcome at 30 days and six months.