Background: The value of an implantable cardioverter defibrillator(ICD) for primary prevention in dilated cardiomyopathy(DCM) is unclear, as randomized trials could not show a survival benefit compared to drug therapy...Background: The value of an implantable cardioverter defibrillator(ICD) for primary prevention in dilated cardiomyopathy(DCM) is unclear, as randomized trials could not show a survival benefit compared to drug therapy. It has not been investigated if patients with a very poor left ventricular function(LVEF) could profit from an ICD. Methods: Consecutive patients with DCM who received an ICD between December 1996 and November 2003 were included in this analysis. Patients were divided in group A(secondary prevention) and group B(primary prevention). Both groups were stratified in subgroups with left ventricular ejection fraction(LVEF) below and above 20% . Results: Fifty eight patients were included(male 50, age 56.4± 12.7 years). Follow-up was 34± 19 months. There was no difference regarding death(18% vs. 11% ), but significant differences(p value< 0.05) regarding any adverse events(55% vs. 22% ), any ICD intervention(48% vs. 17% ) and ICD interventions for life-threatening arrhythmias(27% vs. 0% )between group A and B. LVEF was not predictive for events in group A, whereas in group B only patients with a LVEF< 20% had events(p value 0.02). Over time there was an increase of the LVEF of more than 15% determined by echocardiography in 36% of patients, significantly more often in group B. Conclusions: Indication for primary prevention with an ICD in DCM should be made with caution. Larger studies are needed to determine if patients with LVEF of< 20% might benefit from an ICD.展开更多
Background: Loss of left ventricular capture in patients with cardiac resynchronization devices may account for worsening heart failure and can be difficult to diagnose without a programmer. Objective: To determine wh...Background: Loss of left ventricular capture in patients with cardiac resynchronization devices may account for worsening heart failure and can be difficult to diagnose without a programmer. Objective: To determine whether distinct morphologic changes on the surface electrocardiogram indicate loss of left ventricular capture. Design: After analysis of the R-S spike ratio in the 12-lead electrocardiogram during right ventricular and biventricular pacing in 10 patients, an algorithm to detect loss of left ventricular capture was developed. Setting: University hospital. Patients: 54 patients with a cardiac resynchronization device and underlying left bundle-branch block. Measurements: Leads V1 and I of a 12-lead electrocardiogram were assessed after biventricular pacing was confirmed and after the device was programmed to right ventricular pacing only(simulating loss of left ventricular capture). Results: The sensitivity of the algorithm to correctly identify loss of left ventricular capture was 94%(95%CI, 88.2%to 97.7%), and the specificity was 93%(CI, 86.3%to 95.8%). The likelihood ratio of a positive test result was 12.8(CI, 6.443 to 23.310), and the likelihood ratio of a negative test result was 0.06(CI, 0.024 to 0.137). Limitations: The algorithm was tested in patients in whom the right ventricular electrode was placed in the apex of the right ventricle only. Conclusion: Presence of biventricular capture-the prerequisite for successful cardiac resynchronization therapy-and loss of left ventricular capture can be accurately detected by an algorithm based on analysis of the R-S ratio on leads V1 and I of the surface electrocardiogram.展开更多
文摘Background: The value of an implantable cardioverter defibrillator(ICD) for primary prevention in dilated cardiomyopathy(DCM) is unclear, as randomized trials could not show a survival benefit compared to drug therapy. It has not been investigated if patients with a very poor left ventricular function(LVEF) could profit from an ICD. Methods: Consecutive patients with DCM who received an ICD between December 1996 and November 2003 were included in this analysis. Patients were divided in group A(secondary prevention) and group B(primary prevention). Both groups were stratified in subgroups with left ventricular ejection fraction(LVEF) below and above 20% . Results: Fifty eight patients were included(male 50, age 56.4± 12.7 years). Follow-up was 34± 19 months. There was no difference regarding death(18% vs. 11% ), but significant differences(p value< 0.05) regarding any adverse events(55% vs. 22% ), any ICD intervention(48% vs. 17% ) and ICD interventions for life-threatening arrhythmias(27% vs. 0% )between group A and B. LVEF was not predictive for events in group A, whereas in group B only patients with a LVEF< 20% had events(p value 0.02). Over time there was an increase of the LVEF of more than 15% determined by echocardiography in 36% of patients, significantly more often in group B. Conclusions: Indication for primary prevention with an ICD in DCM should be made with caution. Larger studies are needed to determine if patients with LVEF of< 20% might benefit from an ICD.
文摘Background: Loss of left ventricular capture in patients with cardiac resynchronization devices may account for worsening heart failure and can be difficult to diagnose without a programmer. Objective: To determine whether distinct morphologic changes on the surface electrocardiogram indicate loss of left ventricular capture. Design: After analysis of the R-S spike ratio in the 12-lead electrocardiogram during right ventricular and biventricular pacing in 10 patients, an algorithm to detect loss of left ventricular capture was developed. Setting: University hospital. Patients: 54 patients with a cardiac resynchronization device and underlying left bundle-branch block. Measurements: Leads V1 and I of a 12-lead electrocardiogram were assessed after biventricular pacing was confirmed and after the device was programmed to right ventricular pacing only(simulating loss of left ventricular capture). Results: The sensitivity of the algorithm to correctly identify loss of left ventricular capture was 94%(95%CI, 88.2%to 97.7%), and the specificity was 93%(CI, 86.3%to 95.8%). The likelihood ratio of a positive test result was 12.8(CI, 6.443 to 23.310), and the likelihood ratio of a negative test result was 0.06(CI, 0.024 to 0.137). Limitations: The algorithm was tested in patients in whom the right ventricular electrode was placed in the apex of the right ventricle only. Conclusion: Presence of biventricular capture-the prerequisite for successful cardiac resynchronization therapy-and loss of left ventricular capture can be accurately detected by an algorithm based on analysis of the R-S ratio on leads V1 and I of the surface electrocardiogram.
