QRS Axis and the Benefit of Cardiac Resynchronization Therapy in Patients with Mildly Symptomatic Heart Failure Enrolled in MADIT‐CRT

Cardiac Resynchronization Therapy and QRS Axis . Background: Mildly symptomatic heart failure (HF) patients derive substantial clinical benefit from cardiac resynchronization therapy with defibrillator (CRT‐D) as shown in MADIT‐CRT. The presence of QRS axis deviation may influence response to CRT‐D. The objective of this study was to determine whether QRS axis deviation will be associated with differential benefit from CRT‐D. Methods : Baseline electrocardiograms of 1,820 patients from MADIT‐CRT were evaluated for left axis deviation (LAD: quantitative QRS axis ‐30 to ‐90) or right axis deviation (RAD: QRS axis 90–180) in left bundle branch block (LBBB), right bundle branch block (RBBB), and nonspecific interventricular conduction delay QRS morphologies. The primary endpoints were the first occurrence of a HF event or death and the separate occurrence of all‐cause mortality as in MADIT‐CRT. Results: Among LBBB patients, those with LAD had a higher risk of primary events at 2 years than non‐LAD patients (20% vs 16%; P = 0.024). The same was observed among RBBB patients (20% vs 10%; P = 0.05) but not in IVCD patients (22% vs 23%; P = NS). RAD did not convey any increased risk of the primary combined endpoint in any QRS morphology subgroup. When analyzing the benefit of CRT‐D in the non‐LBBB subgroups, there was no significant difference in hazard ratios for CRT‐D versus ICD for either LAD or RAD. However, LBBB patients without LAD showed a trend toward greater benefit from CRT therapy than LBBB patients with LAD (HR for no LAD: 0.37, 95% CI: 0.26–0.53 and with LAD: 0.54, 95% CI: 0.36–0.79; P value for interaction = 0.18). Conclusions: LAD in non‐LBBB patients (RBBB or IVCD) is not associated with an increased benefit from CRT. In LBBB patients, those without LAD seem to benefit more from CRT‐D than those with LAD. (J Cardiovasc Electrophysiol, Vol. 24, pp. 442‐448, April 2013)     

Are MADIT II Criteria for Implantable Cardioverter Defibrillator Implantation Appropriate for Chinese Patients?

MADIT II Criteria for Implantable Cardioverter. Background: MADIT‐II demonstrated that prophylactic implantation of an implantable cardioverter‐defibrillator (ICD) device prevents sudden cardiac death (SCD) in patients with myocardial infarction (MI) and impaired left ventricular ejection fraction (LVEF). It remains unclear whether the MADIT‐II criteria for ICD implantation are appropriate for Chinese patients. Methods and Results: We compared the clinical characteristics and outcome for a cohort of consecutive Chinese patients who satisfied MADIT‐II criteria for ICD implantation with the original published MADIT‐II population. Seventy consecutive patients who satisfied MADIT‐II criteria but did not undergo ICD implantation (age: 67 years, male: 77%) were studied. Their baseline demographics were comparable with the original MADIT‐II cohort with the exception of a higher incidence of diabetes mellitus. After follow‐up of 35 months, most deaths (78%) were due to cardiac causes (72% due to SCD). The 2‐year SCD rate (10.0%) was comparable with that of the MADIT‐II conventional group (12.1%), but higher than the MADIT‐II defibrillator group (4.9%). Similarly, the 2‐year non‐SCD rate was 3.0%, also comparable with the MADIT‐II conventional group (4.6%), but lower than the MADIT‐II defibrillator group (7.0%). Cox regression analysis revealed that advance NYHA function class (Hazard Ratio [HR]: 3.5, 95% Confidence Interval [CI]: 1.48–8.24, P = 0.004) and the lack of statin therapy (HR: 3.7, 95%CI: 1.35–10.17, P = 0.011) were independent predictors for mortality in the MADIT‐II eligible patients. Conclusion: Chinese patients who satisfy MADIT‐II criteria for ICD implantation are at similar risk of SCD and non‐SCD as the original MADIT‐II subjects. Implantation of an ICD in Chinese patients is appropriate. (J Cardiovasc Electrophysiol, Vol. 21, pp. 231–235, March 2010)     

Electrocardiographic characteristics in patients with pulmonary sarcoidosis indicating cardiac involvement

ECG Characteristics of Cardiac Sarcoidosis. Introduction: Sarcoidosis is a multisystem granulomatous disease that can affect the heart. Early identification of cardiac sarcoidosis (CS) is critical because sudden death can be the initial presentation. We sought to evaluate the potential role of the ECG for identification of cardiac involvement in a cohort of patients with biopsy‐proven pulmonary sarcoidosis. Methods: Our cohort consisted of referred patients with biopsy‐proven pulmonary sarcoidosis who demonstrated symptoms consistent with cardiac involvement. The ECG characteristics collected were PR, QRS duration, QT interval, rate, bundle branch block (BBB), fragmented QRS (fQRS). QRS fragmentation was defined as 2 anatomically contiguous leads demonstrating RSR’ patterns in the absence of BBB. Results: There were 112 subjects included in the cohort. Of the 52 subjects eventually diagnosed with CS, 39 had an ECG demonstrating fQRS while 21 of the 60 of non‐CS patients had fQRS (75% vs 33.9%, P < 0.01). A RBBB or LBBB pattern were both more prevalent in the CS population (RBBB: 23.1% vs 6.7%, P = 0.016; LBBB: 3.8% vs 1.7%, P = 0.6). QRS duration remained significantly associated with CS after exclusion of those with BBB (93.5 +/− 10.6 vs 88 +/− 11 ms; P = 0.04). When fQRS and bundle branch block were combined, 90.4% of CS patient's ECGs contained at least one of the features, compared to 36.7% of noncardiac CS (P < 0.01). Conclusions: The presence of fQRS or BBB pattern in patients with pulmonary sarcoidosis is associated with cardiac involvement and therefore should prompt further evaluation. (J Cardiovasc Electrophysiol, Vol. pp. 1‐6)     

Cost‐Effectiveness of Cardiac Resynchronization Therapy in the MADIT‐CRT Trial

Cost Effectiveness of MADIT‐CRT. Background: The Multicenter Automatic Defibrillator Implantation Trial‐Cardiac Resynchronization Therapy (MADIT‐CRT) trial demonstrated that cardiac resynchronization therapy (CRT) when added to the implantable cardiac defibrillator (ICD) reduces risk of heart failure or death in minimally symptomatic patients with reduced cardiac ejection fraction and wide QRS complex. Objectives: To evaluate 4‐year cost‐effectiveness of CRT‐ICD compared to ICD alone using MADIT‐CRT data. Research Design: Patients enrolled in the trial were randomized to implantation of either ICD or CRT‐ICD in a 2:3 ratio, with up to 4‐year follow‐up period. Cost‐effectiveness analyses were conducted, and sensitivity analyses by age, gender, and left bundle branch block (LBBB) conduction pattern were performed. Subjects: A total of 1,271 patients with ICD or CRT‐ICD (US centers only) who reported healthcare utilization and health‐related quality of life data. Measures: We used the EQ‐5D (US weights) to assess patient HRQOL and translated utilization data to costs using national Medicare reimbursement rates. Results: Average 4‐year healthcare expenditures in CRT‐ICD patients were higher than costs of ICD patients ($62,600 vs 57,050, P = 0.015), mainly due to the device and implant‐related costs. The incremental cost‐effectiveness ratio of CRT‐ICD compared to ICD was $58,330/quality‐adjusted life years (QALY) saved. The cost effectiveness improved with longer time horizon and for the LBBB subgroup ($7,320/QALY), with no cost‐effectiveness benefit being evident in the non‐LBBB group. Conclusions: In minimally symptomatic patients with low ejection fraction and LBBB, CRT‐ICD is cost effective within 4‐year horizon when compared to ICD‐only. (J Cardiovasc Electrophysiol, Vol. 24, pp. 66‐74, January 2013)     

Risk Factors for Recurrent Heart Failure Events in the Multicenter Automatic Defibrillator Implantation Trial II (MADIT‐II)

Risk Factors for Recurrent Heart Failure . Background: This study was designed to identify risk factors for recurrent heart failure (HF) events in patients with ischemic left ventricular dysfunction enrolled in the Multicenter Automatic Defibrillator Implantation Trial II (MADIT‐II). Methods and Results: The Prentice, Williams, and Peterson (PWP) statistical model was utilized to identify and compare risk factors for 1 or ≥2 HF hospitalizations among 1,218 patients with ischemic left ventricular dysfunction enrolled in the MADIT‐II trial. Risk factors for a first HF hospitalization included treatment with an ICD (HR = 1.31; P = 0.05), New York Heart Association class >II (HR = 1.95; P < 0.001), female gender (HR = 1.38; P = 0.05), atrial fibrillation (HR = 1.90; P = 0.001), QRS >120 ms (HR = 1.41; P = 0.01), diabetes mellitus (HR = 1.51; P = 0.003), heart rate ≥80 (HR = 1.35; P = 0.04), diuretic therapy (HR = 1.82; P < 0.001), and the presence of prerenal azotemia (defined as blood urea nitrogen:creatinine >20; HR = 1.45; P = 0.01). In contrast, prerenal azotemia was the only risk factor that was independently associated with a significant increase in the risk of ≥2 HF hospitalizations (HR = 1.52; P = 0.027). The occurrence of 1 HF event after enrolment was associated with a 2.8‐fold (P < 0.001) increase in the risk of death, whereas after the occurrence of a second event there was a 6.7‐fold (P < 0.001) increase in the risk of subsequent mortality. Conclusions: In MADIT‐II, prerenal azotemia was the only significant and independent risk factor for HF progression after a first event, and recurrent HF was the most powerful predictor of mortality. These findings stress the importance of identifying risk factors for HF progression among patients who receive an ICD for primary prevention. (J Cardiovasc Electrophysiol, Vol. 21, pp. 1217‐1223, November 2010)     

Wie viele Elektroden braucht der ICD?

In addition to secondary prevention of sudden cardiac death (SCD), the number of cardioverter defibrillator implantations (ICD) for primary prevention is increasing. An indication for primary prevention of SCD is supported by results of the MADIT II, Companion and SCD-HeFT trials. The main risk factor for SCD is the reduced left ventricular function (LVEF < or = 35%). For selecting the appropriate ICD device and the number of leads, several clinical parameters are important. For the primary prevention of SCD a single-lead VVI ICD is usually sufficient. In case of AV conduction delay and symptomatic heart failure with a prolonged QRS duration a biventricular ICD device is preferred in favor of a ventricular resynchronization. The use of a dual-chamber device should be limited to sinus nodal disease and better discrimination capabilities for slow ventricular tachycardias.     

Implantable cardioverter‐defibrillators in heart failure patients with reduced ejection fraction and diabetes

Aim

There is limited information on the outcomes after primary prevention implantable cardioverter‐defibrillator (ICD) implantation in patients with heart failure (HF) and diabetes. This analysis evaluates the effectiveness of a strategy of ICD plus medical therapy vs. medical therapy alone among patients with HF and diabetes.

Methods and results

A patient‐level combined‐analysis was conducted from a combined dataset that included four primary prevention ICD trials of patients with HF or severely reduced ejection fractions: Multicenter Automatic Defibrillator Implantation Trial I (MADIT I), MADIT II, Defibrillators in Non‐Ischemic Cardiomyopathy Treatment Evaluation (DEFINITE), and Sudden Cardiac Death in Heart Failure Trial (SCD‐HeFT). In total, 3359 patients were included in the analysis. The primary outcome of interest was all‐cause death. Compared with patients without diabetes (n = 2363), patients with diabetes (n = 996) were older and had a higher burden of cardiovascular risk factors. During a median follow‐up of 2.6 years, 437 patients without diabetes died (178 with ICD vs. 259 without) and 280 patients with diabetes died (128 with ICD vs. 152 without). ICDs were associated with a reduced risk of all‐cause mortality among patients without diabetes [hazard ratio (HR) 0.56, 95% confidence interval (CI) 0.46–0.67] but not among patients with diabetes (HR 0.88, 95% CI 0.7–1.12; interaction P = 0.015).

Conclusion

Among patients with HF and diabetes, primary prevention ICD in combination with medical therapy vs. medical therapy alone was not significantly associated with a reduced risk of all‐cause death. Further studies are needed to evaluate the effectiveness of ICDs among patients with diabetes.

     

Number of Leads With Fragmented QRS Predicts Response to Cardiac Resynchronization Therapy

Background:

Cardiac resynchronization therapy (CRT) is an effective option in the treatment of patients with heart failure (HF) and wide QRS. Fragmented QRS (fQRS) on 12‐lead electrocardiography has been shown to predict cardiac events in several patient populations. However, the relationship between the number of leads with fQRS and response to CRT has not been investigated.

Hypothesis:

The number of leads with fQRS may predict response to CRT.

Methods:

One hundred five patients with HF undergoing CRT were prospectively studied. The presence of fQRS was assessed using standardized criteria. Echocardiographic response to CRT was defined by a ≥15% reduction in left ventricular end‐systolic volume at 6 months follow‐up.

Results:

Seventy‐four patients (71%) had CRT response after 6 months of follow‐up. In multivariate analysis, significant associates of response to CRT were evaluated adjusting for gender, etiology of cardiomyopathy, QRS width, baseline left ventricular ejection fraction, and the number of leads with fQRS. The number of leads with fQRS was the only predictor of response to CRT (odds ratio: 0.61, 95% confidence interval: 0.48‐0.77, P < 0.001).

Conclusions:

The more leads with fQRS predicts nonresponse to CRT and may help in the selection of CRT candidates. Clin. Cardiol. 2011 DOI: 10.1002/clc.22061 The authors have no funding, financial relationships, or conflicts of interest to disclose.     

Frequency of fragmented QRS on ECG is increased in patients with rheumatoid arthritis without cardiovascular disease: a pilot study

Abstract

Myocardial fibrosis causes the fragmentation of QRS complexes (fQRS) on ECGs. We hypothesized that the frequency of fQRS could be more common in patients with rheumatoid arthritis (RA) than in control subjects. A total of 56 patients with RA were compared with 35 age- and gender-matched fibromyalgia subjects for fQRS. The fQRS was defined as the presence of an additional R wave, or notching of the R or S wave, or the presence of fragmentation in 2 contiguous leads corresponding to the territory of a major coronary artery. Patients with bundle block on ECG and cardiovascular disease were excluded. Twenty-one patients (37.5%) in the RA group had fQRS, while two patients in the control group (5.7%) had fQRS (p = 0.001). No differences were found between the groups in terms of age, gender, or drug use. Duration of disease—years (interquartile range [IQR])—was 10 (8) in the fQRS (+) group, while it was 5 (2) in the fQRS (?) group (p < 0.001). Multivariate logistic regression analysis revealed that duration of disease was associated with the presence of fQRS (B = 1.5, odds ratio = 4.5, p = 0.004, 95% confidence interval = 1.6–12.7). We found that fQRS on ECG was more common in patients with RA without cardiovascular disease than in age- and gender-matched control subjects.     

QRS Fragmentation Is Not Associated with Poor Response to Cardiac Resynchronization Therapy

Background: QRS fragmentation (fQRS) has been shown to be a marker of scar in patients with left ventricular dysfunction. Whether fQRS is associated with progressive left ventricular remodeling and increased mortality in patients receiving cardiac resynchronization therapy (CRT) is unclear. Methods: We reviewed the preimplant and follow‐up echocardiograms in 233 patients undergoing the new implantation of a CRT device between December 2001 and November 2006. Patients were included if they had a pre‐CRT ECG with appropriate filter settings (filter 0.16–100 or 0.16–150 Hz, 25 mm/s, 10 mm/mV), a left ventricular ejection fraction (LVEF) ≤40%, and New York Heart Association class II–IV symptoms on standard medical therapy. The 12‐lead electrocardiogram (ECG) was interpreted by two blinded reviewers for the presence of fQRS. Remodeling end points, including changes in LVEF and left ventricular end‐diastolic (LVEDV) and systolic (LVESV) volumes, were compared between patients with and without contiguous fQRS, and an assessment of all‐cause mortality was made. Results: Two hundred thirty‐two patients met inclusion criteria, of which 50 demonstrated fQRS in contiguous leads. There was no difference in improvement in LVEF (%) (7.9 ± 12.9 vs 6.8 ± 11.0, P = 0.60) or reduction in LVEDV (mL) (?30.1 ± 57.2 vs ?15.7 ± 47.6) or LVESV (mL) (?33.7 ± 58.1 vs ?22.7 ± 50.6, P = 0.40) between patients with and without contiguous fQRS. At a mean follow‐up of 4.4 ± 1.9 years, there were a total of 89 deaths, 22 (44.0%) in patients with contiguous fQRS and 67 (36.8%) without (log rank P = 0.31). Conclusions: QRS fragmentation is not a predictor of progressive ventricular remodeling or mortality in heart failure patients undergoing CRT. Ann Noninvasive Electrocardiol 2011;16(2):165–171     

Fragmented ECG as a Risk Marker in Cardiovascular Diseases

Various noninvasive tests for risk stratification of sudden cardiac death (SCD) were studied, mostly in the context of structural heart disease such as coronary artery disease (CAD), cardiomyopathy and heart failure but have low positive predictive value for SCD. Fragmented QRS complexes (fQRS) on a 12-lead ECG is a marker of depolarization abnormality. fQRS include presence of various morphologies of the QRS wave with or without a Q wave and includes the presence of an additional R wave (R’) or notching in the nadir of the R’ (fragmentation) in two contiguous leads, corresponding to a major coronary artery territory. fQRS represents conduction delay from inhomogeneous activation of the ventricles due to myocardial scar. It has a high predictive value for myocardial scar and mortality in patients CAD. fQRS also predicts arrhythmic events and mortality in patients with implantable cardioverter defibrillator. It also signifies poor prognosis in patients with nonischemic cardiomyopathy, arrhythmogenic right ventricular cardiomyopathy and Brugada syndrome. However, fQRS is a nonspecific finding and its diagnostic prognostic should only be interpreted in the presence of pertinent clinical evidence and type of myocardial involvement (structural vs. structurally normal heart).     

Reduced ejection fraction, sudden cardiac death, and heart failure death in the mode selection trial (MOST): implications for device selection in elderly patients with sinus node disease

Background: The purpose of this study was to describe the incidence and predictors of sudden cardiac death (SCD) and heart failure (HF) death, and coexisting indications for ICDs and CRT, in patients with sinus node disease (SND) treated with pacemakers. Methods and Results: Baseline variables were used to predict SCD and HF death among 1,135 patients in the Mode Selection Trial, a 6‐year trial of pacing mode in SND. There were 73 deaths among 177 patients with EF ≤ 35% (41.2%), 46/156 (29.5%) with EF 36–49%, and 147/802(18.3%) with EF ≥ 50%. SCD accounted for 21.9%, 23.9%, and 14.3% of deaths with EF ≤ 35%, 36–49%, and ≥ 50%. HF deaths accounted for 23.3%, 19.6%, and 3.4% of deaths with EF ≤ 35%, 36‐49%, and ≥ 50%. EF ≤ 35% predicted SCD (hazard ratio [HR] 3.68, 95% confidence interval [CI] 1.72‐7.89, P = 0.002) and HF death (HR 10.17, 95% CI 3.35, 30.82, P = 0.001). Four‐year SCD rate with EF ≤ 35% was 15.5% (3.9% annually). Nearly one‐fifth of patients qualified for ICDs (EF ≤ 35%) and half of these had QRS ≥ 120 ms. However, >40% died within 33 months (4‐year noncardiac death rate ～22%). Conclusions: Reduced EF predicts SCD and HF death in SND treated with pacemakers. SCD rates among patients with EF ≤ 35% are similar to control arms of primary prevention ICD trials, but mortality rates are significantly higher. Whether ICDs or CRT to provide bradycardia support would prolong life in elderly patients with EF ≤ 35% and SND merits prospective investigation.     

碎裂QRS波在致心律失常性右心室心肌病诊断中的价值

目的评价碎裂QRS波（fQRs波）在致心律失常性右心室心肌病（ARVC）诊断中的价值。方法43例符合ARVC诊断标准的患者,男性33例,平均年龄（40．4±13．9）岁。采集临床资料,记录静息状态下标准12导联心电图,描述fQRs波的心电图特征,判断是否存在fQRs波、epsilon波和右胸前导联T波倒置（TWI）并比较其阳性率之间的差异。结果本组患者fQRs波以下壁导联（44．3％）和右胸前导联（24．2％）最为多见。QRS波中,fQRs波见于R波者多于S波者（58．4％对32．9％,Z=4．30,P〈0．01）。共31例患者判断为fQRS波阳性,2～9（4．6±1．7）个／例。fQRs波阳性率较epsilon波（73．8％VS30．2％,Z=3．67,P〈0．01）和TWI（73．8％对41．9％,Z=2．61,P〈0．01）显著增高。结论fQRs波阳性是ARVC患者常见的心电图异常,常见于下壁和右胸前导联,可作为提示诊断的无创心电指标。     

Sex-Specific Mortality Risk by QRS Morphology and Duration in Patients Receiving CRT : Results From the NCDR

Background

Prior studies have suggested that women have better outcomes than men after cardiac resynchronization therapy-defibrillator (CRT-D) implantation.

Objectives

The purpose of this study was to compare mortality after CRT-D implantation by sex, QRS morphology, and duration.

Methods

Survival curves and covariate adjusted hazard ratios (HR) were used to assess mortality by sex in 31,892 CRT-D patients in the National Cardiovascular Data Registry (NCDR), implantable cardioverter defibrillator (ICD) registry between 2006 and 2009, with up to 5 years’ follow-up (median 2.9 years, interquartile range: 2.0 to 3.9 years). Patients were grouped by QRS morphology and 10-ms increments in QRS duration.

Results

Among patients with left bundle branch block (LBBB), women had a 21% lower mortality risk than men (HR: 0.79; 95% CI: 0.74 to 0.84; p < 0.001); however, there was no sex difference in non-LBBB (HR: 0.95; 95% CI: 0.85 to 1.06; p = 0.37). Longer QRS duration was associated with better survival in both sexes with LBBB, but not in patients without LBBB. Compared with women with LBBB and QRS of 120 to 129 ms, women with LBBB and QRS of 140 to 149 ms had a 27% lower mortality (HR: 0.73; 95% CI: 0.60 to 0.88; p = 0.001); this difference was 18% in men (HR: 0.82; 95% CI: 0.71 to 0.93; p = 0.003). Mortality in LBBB and QRS of 150 ms or longer compared with those with LBBB and QRS of 120 to 129 ms was similar between sexes (HR: 0.61 to 0.68; p < 0.001 for women and HR: 0.58 to 0.66; p < 0.001 for men). Sex interactions within 10-ms groups were not significant.

Conclusions

Among patients with LBBB who received CRT-D, mortality is lower in women than men. Additionally, longer QRS duration in LBBB is associated with better survival in both sexes. In contrast, there is no sex difference in patients without LBBB, regardless of QRS duration. Further studies should include a non-CRT comparator group to confirm these findings.     

Clinical course and implantable cardioverter defibrillator therapy in postinfarction women with severe left ventricular dysfunction

BACKGROUND: There are limited data regarding implantable cardioverter defibrillator (ICD) therapy in postinfarction women with severe left ventricular dysfunction. The aim of this study was to evaluate the risk of cardiac events and effects of ICD therapy in women as compared to men enrolled in the Multicenter Automatic Defibrillator Implantation Trial II (MADIT II). METHODS AND RESULTS: Among 1,232 patients enrolled in MADIT II, there were 192 (16%) women and 1,040 (84%) men. When compared to men, women had an increased frequency of NYHA class > or =II (70 vs 63%; P = 0.067), hypertension (60% vs 52%; P = 0.047), diabetes (42% vs 34%; P = 0.027), and LBBB (25% vs 17%; P = 0.011), and less frequent CABG surgery (42% vs 60%; P < 0.001). The 2-year cumulative mortality in patients randomized to conventional therapy was not significantly different in women and men (30% and 20%, respectively; P = 0.19). Adjusting for relevant clinical covariates, the hazard ratios for ICD effectiveness were similar in women (0.57; 95% CI = 0.28-1.18; P = 0.132) and men (0.66; 95% CI = 0.48-0.91; P = 0.011). The risk of appropriate ICD therapy for VT/VF was lower in women than in men (hazard ratio = 0.60 for female vs male gender; 95% CI = 0.37-0.98; P = 0.039). CONCLUSIONS: MADIT II women had similar mortality and similar ICD effectiveness when compared to men. MADIT II women with ICDs had a lower risk of arrhythmic events with fewer episodes of ventricular tachycardia than men.     

Differences in Outcomes Between Patients Treated with Single‐ versus Dual‐Chamber Implantable Cardioverter Defibrillators: A Substudy of the Multicenter Automatic Defibrillator Implantation Trial II

Objectives: We sought to evaluate the influence of single‐ versus dual‐chamber implantable cardioverter defibrillators (ICDs) on the occurrence of heart failure and mortality as well as appropriate and inappropriate ICD therapy in the Multicenter Automatic Defibrillator Implantation Trial II (MADIT‐II). Background: In MADIT‐II, ICD therapy in patients with a prior myocardial infarction and ejection fraction ≤0.30 was associated with a 31% reduction in risk of mortality when compared to conventionally treated patients. An unexpected finding was an increased occurrence of hospitalization for heart failure in the ICD group. Methods: Data from 717 patients randomized to ICD therapy with single‐ or dual‐chamber pacing devices in MADIT‐II were retrospectively analyzed. Endpoints selected for analysis included death from any cause, new or worsening heart failure requiring hospitalization, death or heart failure, appropriate therapy for ventricular tachycardia (VT) or ventricular fibrillation (VF), and inappropriate ICD therapy for atrial fibrillation or supraventricular tachycardia. Results: A total of 404 single‐chamber ICDs (S‐ICDs) and 313 dual‐chamber ICDs (D‐ICDs) were implanted. Patients receiving D‐ICDs were at a higher risk at baseline than those receiving S‐ICDs, with older age, higher NYHA class, more frequent prior CABG, wider QRS complex, more LBBB, higher BUN level, a history of more atrial arrhythmias requiring treatment, and a longer time interval from their index myocardial infarction to enrollment. While there was a trend toward an increase in adverse outcomes in the D‐ICD group, no statistically significant differences in heart failure or mortality were observed between S‐ICD versus D‐ICD groups. Conclusions: Patients with D‐ICDs had a nonsignificant trend toward higher mortality and heart failure rates than patients with S‐ICDs.     

心电图对陈旧性心肌梗死风险评估的价值探讨

目的通过对陈旧性心肌梗死（OMI）患者碎裂QRS波（fQRS）、病理性Q波及其与室性心律失常的发生情况进行分析,探讨fQRS及病理性Q波与室性心律失常的关系,以评估心电图对陈旧性心肌梗死风险的预测价值。方法对335例确诊陈旧性心肌梗死的患者进行动态心电图检查,将OMI伴单纯fQRs波患者分为前壁组（61例）、下壁组（40例）和侧壁组（15例）,并对各组间室性心律失常发生率进行比较分析;根据fQRS波时限,将OMI伴fQRs波患者分为fQRS≥110ms组（36例）、fQRS〈110ms（156例）,并对两组间室性心律失常发生率进行对比分析;根据病理性Q波QRS波群时限,将OMI伴病理性Q波患者分为QRS≥110ms组（21例）、QRS〈110ms（75例）,并对两组间室性心律失常发生率进行对比分析。结果OMI伴单纯fQRs波患者不同部位间室性心律失常发生率无明显差异（P均〉0．05）;OMI伴fQRs波患者fQRS≥110ms组室性心动过速发生率明显高于fQRS〈110ms组（P=0．026）;OMI伴病理性Q波患者QRS≥110ms组成对室性期前收缩（P=0．045）发生率明显高于QRS〈110ms组。结论OMI患者fQRs时限越长,发生室性心动过速的风险越高;OMI患者QRS波时限越长,发生成对室性期前收缩的风险越高,QRS时限是OMI患者室性心律失常预警的心电图指标。     

Risk Stratification Using Heart Rate Turbulence and Ventricular Arrhythmia in MADIT II: Usefulness and Limitations of a 10‐Minute Holter Recording

Background: We evaluated the usefulness of heart rate turbulence (HRT) parameters and frequency of ventricular premature beats (VPBs) for risk‐stratifying postinfarction patients with depressed left ventricular function enrolled in Multicenter Automatic Defibrillator Trial II (MADIT II). Methods: In 884 MADIT II patients, 10‐minute Holter monitoring at enrollment was used to evaluate HRT parameters and frequency of VPBs. The primary endpoints were defined as all‐cause mortality in patients randomized to conventional treatment and as appropriate therapy for ventricular tachycardia or fibrillation in patients randomized to implantable cardioverter defibrillator (ICD) therapy. Results: The median turbulence slope was lower in patients who died in comparison to survivors in the conventional arm (2.3 vs 4.5 ms/RR; P < 0.05); but it was not a significant predictor of mortality after adjustment for clinical covariates (age, ejection fraction, beta‐blocker use, and BUN levels). There was no association between HRT parameters and arrhythmic events in ICD patients. Conventionally treated patients who died and ICD patients who had appropriate ICD therapy had significantly more frequent VPBs than those without such adverse events. After adjustment for clinical covariates, frequent VPBs>3/10 min were associated with death in the conventional arm (HR = 1.63; P = 0.070) and were predictive for appropriate ICD therapy in the ICD arm (HR = 1.75; P = 0.003). Conclusion: In postinfarction patients with severe left ventricular dysfunction, frequent VPBs are associated with increased risk of mortality and with appropriate ICD therapy. HRT obtained from 10‐min Holter ECG showed a trend toward the association with mortality in univariate analysis but HRT parameters were not predictive of the outcome in multivariate analyses.     

Implantable cardioverter-defibrillator therapy and risk of congestive heart failure or death in MADIT II patients with atrial fibrillation

BACKGROUND: Atrial fibrillation (AF) contributes to increased risk of morbidity and mortality. Data regarding the effectiveness of implantable cardioverter-defibrillator (ICD) therapy in AF patients are limited. OBJECTIVES: The purpose of this study was to evaluate the effectiveness of ICD therapy in patients with AF enrolled in the Multicenter Automatic Defibrillator Implantation Trial II (MADIT II) and to identify their risk for the combined endpoint of hospitalization for congestive heart failure or death. METHODS: The MADIT II cohort served as the source for data on the clinical course, cardiac events, and effectiveness of ICD therapy in AF patients. RESULTS: AF was found as baseline rhythm at enrollment in 102 (8%) MADIT II patients. In comparison to 1,007 patients in sinus rhythm, AF patients were older, more frequently were males, had wider QRS complex, and had higher blood urea nitrogen and creatinine levels (P <.05 for all parameters). ICD therapy was effective in reducing 2-year mortality in AF patients from 39% in 41 conventionally treated patients to 22% in 61 ICD-treated patients (hazard ratio = 0.51, P = .079). However, the combined endpoint of hospitalization for heart failure or death at 2 years was 69% and 59%, respectively (NS). AF was predictive for the combined endpoint of heart failure hospitalization or death (hazard ratio = 1.68, P = .040). New-onset AF in patients with baseline sinus rhythm was associated with increased risk of mortality (hazard ratio = 2.70, P <.001). CONCLUSION: MADIT II patients with AF benefit from ICD therapy, which reduces their mortality. MADIT II patients with AF are at high risk for developing heart failure.     

Fragmented QRS Is Associated with All‐Cause Mortality and Ventricular Arrhythmias in Patient with Idiopathic Dilated Cardiomyopathy

Background: Several studies have showed that fragmented QRS complexes (f ‐ QRS, defined as different RSR′ patterns) on a routine 12 ‐ lead electrocardiogram were associated with increased mortality and arrhythmic events in patients with coronary artery disease, but relatively little data were available regarding idiopathic dilated cardiomyopathy (IDCM). Objective: The purpose of this study was to evaluate the relationship between fragmentation of QRS and the combined end point of all‐cause mortality and ventricular arrhythmias in patients with IDCM. Methods: One hundred twenty‐eight patients with IDCM and left ventricular dysfunction (ejection fraction, EF ≤ 40%) were analyzed, respectively. According to QRS duration and the existence of f ‐ QRS on 12‐lead electrocardiograph (ECG), the study populations were divided into three groups: (1) the f ‐ QRS group (QRS <120 ms and with fragmented QRS, n = 51), (2) the wide QRS (wQRS) group (QRS ≥ 120 ms, n = 48), and (3) the nonfragmented QRS (non‐fQRS) group (QRS < 120 ms and without f ‐ QRS, n = 29). Results: During a mean follow‐up of 14 ± 5 months, 25 (19.5%) patients had deaths and ventricular arrhythmic events. The combined end point of all‐cause mortality and ventricular tachyarrhythmias was significantly higher in the f ‐ QRS and wQRS groups than the non‐fQRS group (23.5%, 25%, and 3.4%, respectively; P < 0.05 for both). Event‐free was significantly decreased in the f ‐ QRS group versus the non‐fQRS group (P = 0.02). Univaritae regression analysis revealed that f ‐ QRS was a stronger predictor of mortality and arrhythmic events in IDCM patients. Conclusion: f ‐ QRS on 12‐lead ECG has a high predictive value for the combined end point of all‐cause mortality and ventricular tachyarrhythmias in IDCM patients with left ventricular dysfunction. Ann Noninvasive Electrocardiol 2011;16(3):270–275