Comparison of ventricular tachyarrhythmia characteristics in patients with idiopathic dilated or ischemic cardiomyopathy and defibrillators implanted for primary prevention

Background:

Implantable cardioverter‐defibrillator (ICD) therapy for primary prevention is well established in ischemic cardiomyopathy (ICM). Data on the role of ICDs in patients with dilated cardiomyopathy (DCM) and no history of ventricular tachyarrhythmia (VT/VF) are more limited.

Hypothesis:

DCM patients with an impaired left ventricular ejection fraction (LVEF) still represent a low arrhythmic risk subgroup in clinical practice.

Methods:

ICD stored data of DCM patients with an LVEF ≤35% was compared to data of ICM patients meeting Multicenter Automatic Defibrillator Implantation Trial (MADIT) eligibility criteria. VT/VF occurrences and electrical storm (ES) events were analyzed.

Results:

There were 652 patients followed for 50.9 ± 33.9 months. There were 1978 VT and 241 VF episodes analyzed in 66 out of 203 patients (32.5%) with DCM and in 118 out of 449 patients (26.3%, P = 0.209) with ICM. Freedom of appropriate ICD treatment due to VT/VF or ES events did not differ in both patient populations (log‐rank, P>0.05). In patients presenting with VT/VF episodes, mean event rates were comparable in both patient populations (3.2 ± 14.1 for DCM and VT vs 3 ± 13.9 for ICM and VT [P = 0.855], 0.4 ± 1.3 for DCM and VF vs 0.4 ± 1.8 for ICM and VF [P = 0.763], and 0.2 ± 0.7 for DCM and ES vs 0.2 ± 1 for ICM and ES [P = 0.666]).

Conclusions:

DCM patients with prophylactic ICDs implanted due to heart failure and patients fulfilling MADIT criteria reveal comparable patterns of VT/VF/ES events during long‐term follow‐up. Incidence, mean number of events, and time to first event did not differ significantly. Findings support the current guidelines for prophylactic ICD therapy in DCM patients with heart failure. © 2011 Wiley Periodicals, Inc. The authors have no funding, financial relationships, or conflicts of interest to disclose.     

应用鸡胚心脏左心室射血分数评估扩张型心肌病患者自身抑制性抗体的研究

目的使用心脏超声对鸡胚心脏左心室射血分数(LVEF)测定来评估扩张型心肌病心力衰竭患者是否存在心肌自身抑制性抗体。方法按随机数表法选取36例扩张型心肌病心力衰竭患者和23例冠心病心力衰竭患者的IgG血清,滴入18 d胚龄的鸡胚中,用超声心动图仪检测鸡胚心肌抑制状况。结果冠心病心力衰竭组LVEF为81.03%±2.67%,扩张型心肌病心力衰竭组中,心肌自身抑制性抗体阴性13例,其LVEF为81.24%±2.33%,而抗体阳性23例(63.9%),其LVEF为62.04%±2.98%。结论扩张型心肌病心力衰竭患者中可能存在心肌抑制性抗体。     

The Presence of Electromechanical Mismatch In Nonischemic Dilated Cardiomyopathy Is Associated With Ventricular Repolarization Instability

BackgroundWe analyzed electromechanical mismatch (EMM) and its relationship to ventricular repolarization in patients with nonischemic dilated cardiomyopathy (DCM).Methods and ResultsIn 39 DCM patients with left ventricular ejection fraction (LVEF) <40% and New York Heart Association functional class ≥III, electroanatomic mapping was used to quantify areas of EMM. High-resolution electrocardiograph was used to measure heart rate variability (HRV) and QT variability index (QTVI). EMM was present in 22 patients (56%, group 1), whereas 17 patients presented no mismatched segments (44%, group 2). The groups did not differ in age (56 ± 10 years in group 1 vs 57 ± 7 years in group 2; P = .82), sex (male: 82% vs 94%; P = .40), LVEF (27 ± 8% vs 25 ± 6%; P = .18), or N-terminal pro–B-type natriuretic peptide (2,350 pg/mL vs 2,831 pg/mL; P = .32). Although heart rate and HRV were similar in both groups (rate: 80 ± 20 beats/min in group 1 vs 74 ± 19 beats/min in group 2 [P = .47]; standard deviation of normal-to normal RR intervals: 106 ± 79 vs 88 ± 115 [P = .61]), we found significantly higher QTVI values in patients from group 1 (−1.15 ± 0.46 vs −1.62 ± 0.51 in group 2; P = .005). In patients with implantable cardioverter-defibrillators, ventricular arrhythmias recorded ≤1 year before enrollment were more frequent in group 1 than in group 2 (58% vs 13%; P = .02).ConclusionsEMM is present in a majority of patients with DCM and is associated with ventricular repolarization instability.     

Progression of Myocardial Fibrosis in Nonischemic DCM and Association With Mortality and Heart Failure Outcomes

ObjectivesThe purpose of this study was to assess whether the presence and extent of fibrosis changes over time in patients with nonischemic, dilated cardiomyopathy (DCM) receiving optimal medical therapy and the implications of any such changes on left ventricular ejection fraction (LVEF) and clinical outcomes.BackgroundMyocardial fibrosis on cardiovascular magnetic resonance (CMR) imaging has emerged as important risk marker in patients with DCM.MethodsIn total, 85 patients (age 56 ± 15 years, 45% women) with DCM underwent serial CMR (median interval 1.5 years) for assessment of LVEF and fibrosis. The primary outcome was all-cause mortality; the secondary outcome was a composite of heart failure hospitalization, aborted sudden cardiac death, left ventricular (LV) assist device implantation, or heart transplant.ResultsOn CMR-1, fibrosis (median 0.0 [interquartile range: 0% to 2.6%]) of LV mass was noted in 34 (40%) patients. On CMR-2, regression of fibrosis was not seen in any patient. Fibrosis findings were stable in 70 (82%) patients. Fibrosis progression (increase >1.8% of LV mass or new fibrosis) was seen in 15 patients (18%); 46% of these patients had no fibrosis on CMR-1. Although fibrosis progression was on aggregate associated with adverse LV remodeling and decreasing LVEF (40 ± 7% to 34 ± 10%; p < 0.01), in 60% of these cases the change in LVEF was minimal (<5%). Fibrosis progression was associated with increased hazards for all-cause mortality (hazard ratio: 3.4 [95% confidence interval: 1.5 to 7.9]; p < 0.01) and heart failure–related complications (hazard ratio: 3.5 [95% confidence interval: 1.5 to 8.1]; p < 0.01) after adjustment for clinical covariates including LVEF.ConclusionsOnce myocardial replacement fibrosis in DCM is present on CMR, it does not regress in size or resolve over time. Progressive fibrosis is often associated with minimal change in LVEF and identifies a high-risk cohort.     

Concordant Versus Discordant Left Bundle Branch Block in Heart Failure Patients: Novel Clinical Value of an Old Electrocardiographic Diagnosis

BackgroundOver the last 50 years left bundle branch block (LBBB) has been defined as homophasic (concordant: cLBBB) or heterophasic (discordant: dLBBB) when associated with a positive or negative T wave in leads I and V5-V6, respectively. LBBB is recognized as an adverse prognostic factor in heart failure (HF). The prevalence and clinical significance of cLBBB and dLBBB in HF patients are unknown.Methods and ResultsA total of 897 consecutive systolic HF patients (age 65 ± 13 years, left ventricular ejection fraction [LVEF], 34 ± 10%) underwent clinical characterization, electrocardiographic evaluation for LBBB diagnosis and classification, and follow-up for cardiac events (median 37 months, range 1-84). LBBB was diagnosed in 232 patients (26%), cLBBB in 71 (31%), and dLBBB in 161 (69%). The dLBBB patients were older than those with cLBBB, and presented with lower LVEF, greater left ventricular telediastolic diameter and left ventricular mass index, higher level of brain natriuretic peptide, N-terminal pro-brain natriuretic peptide, renin activity, and norepinephrine (all P < .05). At Kaplan-Meier analysis, LBBB (P = .003) and dLBBB (P = .036) were associated with a worse prognosis when the composite end point of sudden death and implantable cardioverter defibrillator shock was considered.ConclusionsIn systolic HF, dLBBB is associated with a worse clinical, neurohormonal, and prognostic profile. LBBB classification could represent a useful tool in routine clinical evaluation.     

卡维地洛治疗扩张型心肌病心力衰竭患者的疗效

目的：观察卡维地洛治疗扩张型心肌病心力衰竭患者的临床疗效。方法：选择扩张型心肌病心力衰竭患者82例,采用随机分组的方法分为卡维地洛组（42例）和常规治疗组（40例）,卡维地洛组在常规治疗基础上加用卡维地洛3．125～25mg2次／d。比较两组左室舒张期末内径（LVEDd）、左室收缩期末内径（LVEsd）、左房内径（LAD）、左室射血分数（LVEF）、6min步行距离（6MWD）等指标变化情况。结果：治疗6个月后,两组患者心功能均有改善,卡维地洛组总有效率显著高于常规治疗组（90．5％比72．5％,P〈0．05）;两组治疗后患者的LVEDd、LVESd、LVEF及6MWD均有显著改善（P〈0．05）,且与常规治疗组比较,卡维地洛组治疗后患者的LVEDd[（59．1±9．6）mm比（54．2±10．2）mm]、LVESd[（46．1±8．7）mm比（41．4±12．2）mm]显著缩小,LVEF[（42．1±10．5）％比（48．4±9．6）％]及6MWD[（264．52±51．23）m比（309．26±45．24）m]显著增加（P均〈0．05）。结论：在常规治疗基础上加用卡维地洛可明显改善扩张型心肌病心力衰竭患者的疗效。     

Proton magnetic resonance spectroscopy can detect creatine depletion associated with the progression of heart failure in cardiomyopathy

OBJECTIVES: This study noninvasively examined total creatine (CR) of the myocardium in dilated cardiomyopathy (DCM) or hypertrophic cardiomyopathy (HCM) using proton magnetic resonance spectroscopy ((1)H-MRS). BACKGROUND: Abnormalities in CR metabolism in failing hearts have been reported. A biochemical study suggested that myocardial metabolic changes are very similar in DCM and HCM despite the different heart failure (HF) mechanisms. METHODS: Using cardiac-gated (1)H-MRS with magnetic resonance image (MRI)-guided point-resolved spectroscopy (PRESS) localization, we quantitatively measured septal CR. Patients with either DCM (n = 11) or HCM (n = 7) and age-matched normal subjects (n = 14) were examined. RESULTS: Myocardial CR was significantly lower in DCM patients (16.1 +/- 4.5 micromol/g wet weight [range 10.2 to 22.9], p < 0.05) than that in subjects with normal hearts (27.6 +/- 4.1 micromol/g [range 21.4 to 36.2]). Myocardial CR in HCM patients (22.6 +/- 8.1 micromol/g [range 12.2 to 34.5]) was significantly lower than that in subjects with normal hearts (p < 0.05) but was significantly higher than that in DCM patients (p < 0.05). In 18 patients with either DCM or HCM, myocardial CR correlated positively with left ventricular ejection fraction (LVEF) (y = 0.22x + 9.8, r = 0.73, p = 0.0006) but correlated negatively with plasma B-type natriuretic peptide (BNP) levels (y = -0.012x + 22.4, r = -0.54, p = 0.022). CONCLUSIONS: This study showed that (1)H-MRS can noninvasively detect CR depletion associated with the severity of HF in cardiomyopathy.     

扩张性心肌病患者左室射血分数与胆固醇水平的相关性

目的 目的 分析扩张性心肌病（DCM）患者左室射血分数(LVEF)与血清总胆固醇（TC）的关系。方法 选取住院DCM患者123例，分为LVEF>40％组（34例）和 LVEF≤40％组（89例）。入院后收集患者一般情况及测定血液生化，以超声心动图检查患者的心脏功能及结构，并进行比较。结果 LVEF>40%组与LVEF≤40%患者比较:LVEF>40%组年龄小于LVEF≤40%组(P<0.05)；LVEF>40%组TC显著高于LVEF≤40%组(P<0.05)。TC与LVEF呈正相关（r=0.287,P<0.01）。结论 DCM患者LVEF与TC有相关性。     

扩张型心肌病患者窦性心率震荡现象

目的研究窦性心率震荡(HRT)在扩张型心肌病(DCM)患者中的变化,以及与心率变异性时阈指标(SDNN)、左室射血分数(LVEF)、左室舒张末期内径(LVEDD)的关系。方法选择DCM患者30例,正常健康对照者20例,根据24 h动态心电图(Holter)记录资料,计算HRT的两个参数震荡初始(TO)和震荡斜率(TS),比较两组之间的差别,并计算TO、TS与SDNN、LVEF、LVEDD之间的相关性。结果DCM组TO值显著高于对照组(3.18%±6.25%vs-6.22%±3.68%,P<0.001);DCM组TS值显著低于对照组(6.06±6.13 ms/RR间期vs 13.08±5.54ms/RR间期,P<0.01)。TO与SDNN、LVEF、LVEDD之间明显相关。结论DCM患者室性早搏后的HRT现象减弱,HRT可能成为评价DCM患者自主神经功能状态的新指标。     

Role of cardiac multidetector computed tomography in the exclusion of ischemic etiology in heart failure patients

Introduction and AimsDifferentiation of ischemic from non-ischemic etiology in heart failure (HF) patients has both therapeutic and prognostic implications. One possible approach to this differentiation is direct visualization of the coronary tree. Multidetector computed tomography (MDCT) has emerged as an alternative to invasive coronary angiography (ICA), but its performance and additional clinical value are still not well validated in patients with left ventricular (LV) dysfunction. We aimed to assess the value of coronary MDCT angiography (CTA) in the exclusion of ischemic etiology in HF patients and to determine whether the Agatston calcium score could be used as a gatekeeper for CTA in this context.MethodsWe retrospectively selected symptomatic HF patients with LV ejection fraction (LVEF) <50%, as assessed by echocardiography, referred for CTA between April 2006 and May 2013. Patients with previously known CAD or valvular disease were excluded. The performance of MDCT in the detection of coronary artery disease (CAD) and/or exclusion of an ischemic etiology for HF was studied. Obstructive CAD was defined as the presence of ≥50% luminal stenosis in at least one epicardial coronary artery as assessed by CTA and was assumed in patients with an Agatston coronary artery calcium (CAC) score >400. In patients referred for ICA, an ischemic etiology was assumed in the presence of ≥75% stenosis in two or more epicardial vessels or ≥75% stenosis in the left main or proximal left anterior descending artery.ResultsDuring this period 100 patients (mean age 57.3±10.5 years, 64% men) with HF and systolic dysfunction were referred for MDCT to exclude CAD. Median effective radiation dose was 4.8 mSv (interquartile range 5.8 mSv). Mean LVEF was 35±7.7% (range 20-48%) and median CAC score was 13 (interquartile range 212). Seven patients were in atrial fibrillation.Almost half of the patients (40%) had no CAC and none of these had significant stenosis on CTA. In an additional group of 33 patients CTA was able to confidently exclude obstructive CAD. Twenty-seven patients were classified as positive for CAD (16 due to CAC >400 and 11 with ≥50% stenosis) and were associated with lower LVEF (p=0.004). Of these, 21 patients subsequently underwent ICA: obstructive CAD was confirmed in nine and only six had criteria for ischemic cardiomyopathy.ConclusionIn our HF population, MDCT was able to exclude an ischemic etiology in 73% of cases in a single test. According to our results the Agatston calcium score may serve as a gatekeeper for CTA in patients with HF, with a calcium score of zero confidently excluding an ischemic etiology.     

COPD Predicts Mortality in HF: The Norwegian Heart Failure Registry

BackgroundChronic obstructive pulmonary disease (COPD) and chronic heart failure (HF) are common clinical conditions that share tobacco as a risk factor. Our aim was to evaluate the prognostic impact of COPD on HF patients.Methods and ResultsThe Norwegian Heart Failure Registry was used. The study included 4132 HF patients (COPD, n = 699) from 22 hospitals (mean follow-up, 13.3 months). COPD patients were older, more often smokers and diabetics, less often on β-blockers and had a higher heart rate. They were more often in New York Heart Association (NYHA) Class III or IV (COPD, 63%; no COPD, 51%), although left ventricular ejection fraction (LVEF) distribution was similar. COPD independently predicted death (adjusted hazard ratio [HR], 1.188; 95% CI: 1.015 to 1.391; P = 0.03) along with age, creatinine, NYHA Class III/IV (HR, 1.464; 95% CI: 1.286 to 1.667) and diabetes. β-blockers at baseline were associated with improved survival in patients with LVEF ≤40% independently of COPD.ConclusionCOPD is associated with a poorer survival in HF patients. COPD patients are overrated in terms of NYHA class in comparison with patients with similar LVEF. Nonetheless, NYHA class remains the strongest predictor of death in these patients.     

扩张型心肌病血清心肌钙蛋白I水平测定的临床意义

目的　探讨扩张型心肌病 (DCM)心力衰竭急性加重时心肌钙蛋白I(cTnI)水平的临床意义。方法　用化学发光免疫分析法测定 42例DCM患者的血清cTnI水平及用超声心动图测量左心室射血分数 (LVEF) ,并与对照组比较。结果　DCM患者血清cTnI水平显著高于对照组 ( 0 .3 11± 0 .3 78vs 0 .0 13± 0 .0 0 9ng/ml,P <0 .0 0 1) ,DCM组中 17例血清cTnI水平升高 ,且cTnI水平与LVEF呈负相关 (P <0 .0 1) ;DCM组中血清cTnI水平高者 6个月死亡率 2 9.4% ,而血清cTnI水平正常者为 4.0 % (P <0 .0 5 )。结论　DCM患者心力衰竭急性加重cTnI水平升高 ,其水平与心力衰竭严重程度呈正相关 ,对判断预后有价值     

Six Minute Walk Test Predicts Long-Term All-Cause Mortality and Heart Failure Rehospitalization in African-American Patients Hospitalized With Acute Decompensated Heart Failure

BackgroundThe prognostic value of the 6-minute walk test (6MWT) has been described in patients with heart failure (HF); however, limited data are available in an African-American (AA) population. We prospectively evaluated the usefulness of the 6MWT in predicting mortality and HF rehospitalization in AA patients with acute decompensated HF.Methods and ResultsTwo hundred AA patients (63.1% men, mean age 55.7 ± 12.9 years) with acute decompensated HF were prospectively studied. Patients were followed to assess 40-month all-cause mortality and 18-month HF rehospitalization. The median distance walked on the 6MWT was 213 m. Of the 198 patients with available mortality data, 59 patients (29.8%) died. Of the 191 patients with available rehospitalization data, 114 (59.7%) were rehospitalized for worsening HF. For patients who walked ≤200 m during the 6MWT, mortality was 41% compared with 19% in patients who walked >200 m (P = .001). For patients who walked ≤200 m during the 6MWT, HF rehospitalization was 68% compared with 52% in those who walked >200 m (P = .027). Multivariate Cox regression analysis showed that 6MWT distance ≤200 m was the strongest predictor of mortality (adjusted hazard ratio [HR], 2.14; confidence interval [CI], 1.20 to 3.81; P = .01) and HF rehospitalization (adjusted HR, 1.62; CI, 1.10 to 2.39; P = .015).ConclusionsIn AA patients hospitalized with acute decompensated HF, 6MWT strongly and independently predicts long-term all-cause mortality and HF rehospitalization.     

Coronary endothelial dysfunction in patients with acute-onset idiopathic dilated cardiomyopathy

Objectives. This study sought to determine whether coronary endothelial dysfunction exists in patients with acute-onset idiopathic dilated cardiomyopathy (DCM) and to explore its relation to recovery of left ventricular systolic function in this patient population.Background. Coronary endothelial dysfunction exists in chronic DCM, but its importance in the development and progression of ventricular dysfunction is not known. To address this issue we studied coronary endothelial function in patients with idiopathic DCM <6 months in duration and explored the relation between coronary endothelial function and subsequent changes in left ventricular ejection fraction (LVEF).Methods. Ten patients with acute-onset idiopathic DCM (duration of heart failure symptoms 2.0 ± 0.4 months [mean ± SEM]) and 11 control patients with normal left ventricular function underwent assessment of coronary endothelial function during intracoronary administration of the endothelium-dependent vasodilator acetylcholine and the endothelium-independent vasodilator adenosine. Coronary cross-sectional area (CSA) was determined by quantitative coronary angiography and coronary blood flow (CBF) by the product of coronary CSA and CBF velocity measured by an intracoronary Doppler catheter. Patients with DCM underwent assessment of left ventricular function before and several months after the study.Results. Acetylcholine infusion produced no change in coronary CSA in control patients but significant epicardial constriction in patients with DCM (−36 ± 11%, p < 0.01). These changes were associated with increases in CBF in control patients (+118 ± 49%, p < 0.01) but no change in patients with DCM. Infusion of adenosine produced increases in coronary caliber and blood flow in both groups. Follow-up assessment of left ventricular function was obtained in nine patients with DCM 7.0 ± 1.7 months after initial study, at which time LVEF had improved by ≥0.10 in four patients. Multiple linear regression revealed a positive correlation between both the coronary CSA (r² = 0.57, p < 0.05) and CBF (r² = 0.68, p < 0.01) response to acetylcholine and the subsequent improvement in LVEF.Conclusions. Coronary endothelial dysfunction exists at both the microvascular and the epicardial level in patients with acute-onset idiopathic DCM. The preservation of coronary endothelial function in this population is associated with subsequent improvement in left ventricular function.     

QT间期动态性在扩张型心肌病猝死风险预测中的价值

目的 研究QT间期频率依赖性在原发性扩张型心肌病(扩心病)患者猝死风险预测中的作用.方法 选取55例原发性扩心病患者和27例健康志愿者(对照组).询问病史并行心脏超声、心电图和动态心电图检查.检测左室舒张末期内径(LVEDD)、左室射血分数(LVEF)、QT间期离散度(QTd)、心率变异性(SDNN)、QT/RR相关直线的斜率、24 h室性早搏(VPB)和非持续性室性心动过速(NSVT)的次数.随访扩心病患者,随访终点为全因死亡.结果 扩心病组的LVEDD、QTd、VPB、NSVT、QTe/RR(QTe为Q波起始至T波终点的间期)和QTp/RR(QTp为Q波起始至T波顶点的间期)斜率显著高于对照组;LVEF和SDNN显著低于对照组.扩心病猝死组、非猝死组和对照组相比,LVEDD、LVEF、QTd、SDNN、QTe/RR和QTp/RR斜率的差异有统计学意义.扩心病猝死组和非猝死组比较,LVEF、SDNN、QTe/RR和QTp/RR斜率的差异有统计学意义.扩心病NSVT阳性组和NSVT阴性组比较,LVEF、QTd、VPB、QTe/RR和QTp/RR斜率的差异有统计学意义.扩心病患者的猝死率,QTe/RR斜率≥0.210者显著高于＜0.210者(54.5%与21.1%,P＜0.05);QTp/RR斜率≥0.190者显著高于＜0.190者(52.2%与21.9%,P＜0.05);在LVEF≤35%和NSVT阳性的基础上结合应用QTe/RR≥0.210或QTp/RR≥0.190,猝死率显著提高.结论 扩心病猝死组QT/RR斜率显著高于非猝死组和对照组,QT频率依赖性对扩心病患者猝死有较高的预测价值,并可进一步提高NSVT和LVEF的预测价值.     

Assessments of left ventricular function during exercise in patients with dilated cardiomyopathy: comparison with ischemic cardiomyopathy

Responses to supine bicycle ergometer exercise were assessed in a study population consisting of 26 patients with dilated cardiomyopathy (DCM) and 23 patients with ischemic cardiomyopathy (ICM). Left ventricular ejection fraction (LVEF) and regional wall motion were analyzed at rest and during supine bicycle ergometer exercise with radionuclide ventriculography. Although the same degree of LVEF between DCM (23 +/- 8%) and ICM (26 +/- 4%) occurred at rest, the left ventricular regional wall motion abnormality was more prominent in DCM. LVEF during the peak exercise stage in DCM was almost unchanged (24 +/- 8%), but in ICM it decreased significantly (22 +/- 5%). Exercise-induced regional wall motion abnormalities were detected in nine patients (35%) in DCM and 13 patients (57%) in ICM. Although patients with DCM are believed to have diffuse hypokinesis of the left ventricle, severe regional wall motion abnormalities (akinesis or dyskinesis) were frequently observed. During the follow-up period of up to six years, eight patients with DCM died of congestive heart failure. In eight patients with DCM who showed decreased LVEF during exercise, five patients died. However, only three of 18 patients without decreased LVEF during exercise died. Exercise-induced left ventricular dysfunction in DCM seems to be a poor prognostic sign.     

扩张型心肌病患者心率减速力的临床研究

目的:研究心率减速力(DC)在扩张型心肌病(DCM)患者中的变化以及与左室射血分数(LVEF)、心率变异性(HRV)之间的关系。方法:32例DCM患者和34例正常人接受24h动态心电图检查和超声心动图检查,计算机分别测定2组患者的DC、LVEF及HRV时域指标(SDNN,RMSSD)与标化的频域指标(LFn、HFn);比较2组患者的DC、LVEF、SDNN,RMSSD、LFn及HFn,并研究DCM患者的DC与LVEF及HRV各指标之间的关系。结果:DCM患者的DC值明显小于正常对照组(3.3±2.3msvs6.9±1.4ms,P<0.01),其异常DC的发生率高达89.7%,明显高于正常对照组(P<0.01);DCM组患者的DC与LVEF、SDNN、RMSSD、LFn及HFn之间呈明显的正相关关系。结论:DCM患者的DC值明显降低,DC是一项可用以定量评估DCM患者自主神经张力并筛选高危患者的新的可靠指标。     

Characteristics of congestive heart failure accompanied by atrial fibrillation with special reference to tachycardia-induced cardiomyopathy.

BACKGROUND: Sustained tachycardia causes left ventricular (LV) systolic dysfunction leading to heart failure (HF), which is widely known as "tachycardia-induced cardiomyopathy (TIC)", but its prevalence and prognosis in Japanese remain unclear. METHODS AND RESULTS: Of 213 consecutive patients with HF associated with atrial fibrillation (AF) requiring hospitalization (n=213) between January 1999 and December 2004, and 104 (83 males, 67+/-12.6 years) were identified as not having any structural heart disease. Of them 41 (39%) had a normal LV ejection fraction (LVEF) at the initial admission, and the remaining patients fell into 2 groups: those with rapid (<6 months) normalization of the LVEF after AF management (presumed TIC, 30 patients, 29%) and those with persistent LV systolic dysfunction (dilated cardiomyopathy (DCM), 33 patients, 32%). Although the B-type natriuretic peptide value and LVEF did not differ between the 2 groups, the LV size on admission was significantly smaller in the TIC group (LV end-diastolic dimension (LVDd) 57.6+/-7.2, LV end-systolic dimension (LVDs) 49.4+/-8.0) than in the DCM group (LVDd 63.4 +/-8.8, LVDs 55.3+/-9.6, p<0.05). During a follow-up period of 42.1+/-21.2 months, cardiac death and recurrent HF hospitalization were significantly less frequent in the TIC group than in the DCM group. CONCLUSIONS: In AF-associated HF requiring hospitalization, TIC is the presumed cause in approximately one-third of patients without any previously known structural heart disease. That particular group is characterized by a relatively smaller LV and better prognosis under medical treatment.     

The impact of age on ablation outcomes in AF-mediated cardiomyopathy

Introduction

The absence of ventricular scar in patients with atrial fibrillation (AF) and systolic heart failure (HF) predicts left ventricular (LV) recovery following AF ablation. It is unknown whether age impacts the degree of LV recovery, reverse remodeling, or AF recurrence following catheter ablation (CA) among this population.

Objectives

To evaluate the impact of age on LV recovery and AF recurrence in a population with AF and systolic HF without fibrosis (termed AF-mediated cardiomyopathy) following CA.

Methods

Consecutive patients undergoing CA between 2013 and 2021 with LV ejection fraction (LVEF) < 45% and absence of cardiac magnetic resonance imaging (CMR) detected LV myocardial fibrosis were stratified by age (<65 vs. ≥65 years). Following CA, participants underwent remote rhythm monitoring for 12 months with repeat CMR for HF surveillance.

Results

The study population consisted of 70 patients (10% female, mean LVEF 33 ± 9%), stratified into younger (age < 65 years, 63%) and older (age ≥ 65 years, 37%) cohorts. Baseline comorbidities, LVEF (34 ± 9 vs. 33 ± 8 ≥65 years, p = .686), atrial and ventricular dimensions (left atrial volume index: 55 ± 21 vs. 56 ± 14 mL/m² age ≥ 65, p = .834; indexed left ventricular end-diastolic volume: 108 ± 40 vs. 104 ± 28 mL/m² age ≥ 65, p = .681), pharmacotherapy and ablation strategy (pulmonary vein isolation in all; posterior wall isolation in 27% vs. 19% age ≥ 65, p = .448; cavotricuspid isthmus in 9% vs. 11.5% age ≥ 65) were comparable (all p > .05) albeit a higher CHADS₂VASc score in the older cohort (2.7 ± 0.9 vs. 1.6 ± 0.6 age < 65, p < .001).   Freedom from AF was comparable (hazard ratio: 0.65, 95% confidence interval: 0.38–1.48, LogRank p = .283) as was AF burden [0% (interquartile range, IQR: 0.0–2.1) vs. age ≥ 65: [0% (IQR 0.0–1.7), p = .516], irrespective of age. There was a significant improvement in LV systolic function in both groups (ΔLVEF + 21 ± 14% vs. +21 ± 12% age ≥ 65, p = .913), with LV recovery in the vast majority (73% vs. 69%, respectively, p = .759) at 13 (IQR: 12–16) months. This was accompanied by comparable improvements in functional status (New York Heart Association class p = .851; 6-min walk distance 50 ± 61 vs. 93 ± 134 m in age ≥ 65, p = .066), biomarkers (ΔN-terminal-pro brain natriuretic peptide −139 ± 246 vs. −168 ± 181 age ≥ 65,p = .629) and HF symptoms (Short Form-36 survey Δphysical component summary p = .483/Δmental component summary, p = .841).

Conclusion

In patients undergoing CA for AF with systolic HF in the absence of ventricular scar, comparable improvements in ventricular function, symptoms, and freedom from AF are achieved irrespective of age.