Bone Marrow-Derived Progenitor Cells Are Functionally Impaired in Ischemic Heart Disease

To determine whether the presence of ischemic heart disease (IHD) per se, or rather the co-presence of heart failure (HF), is the primum movens for less effective stem cell products in autologous stem cell therapy, we assessed numbers and function of bone marrow (BM)-derived progenitor cells in patients with coronary artery disease (n?=?17), HF due to ischemic cardiomyopathy (n?=?8), non-ischemic HF (n?=?7), and control subjects (n?=?11). Myeloid and erythroid differentiation capacity of BM-derived mononuclear cells was impaired in patients with underlying IHD but not with non-ischemic HF. Migration capacity decreased with increasing IHD severity. Hence, IHD, with or without associated cardiomyopathy, is an important determinant of progenitor cell function. No depletion of hematopoietic and endothelial progenitor cells (EPC) within the BM was observed, while circulating EPC numbers were increased in the presence of IHD, suggesting active recruitment. The observed myelosuppression was not driven by inflammation and thus other mechanisms are at play.     

Catheter ablation for atrial fibrillation results in greater improvement in cardiac function in patients with low versus normal left ventricular ejection fraction

Purpose

It is still unknown whether left ventricular ejection fraction (LVEF) might affect the magnitude of improvement after atrial fibrillation (AF) ablation on cardiac function in persistent or longstanding persistent AF (CAF) patients.

Method

We performed echocardiography in 35 patients with CAF before and after catheter ablation (CA). Patients were stratified by LVEF into two groups prior to CA—normal LVEF (≥50 % LVEF, N group, n?=?24) and a low LVEF group (<50 % LVEF, L group, n?=?11). Patients were followed at 1 month, 3 months, 6 months, 1 year, and 2 years after ablation.

Results

After 15.8?±?7.4 months follow-up, the L group showed greater improvement in LVEF and left atrial ejection fraction (LAEF; N group vs L group: LVEF difference (%), 5?±8 vs 20±?13, p?<?0.01; LAEF difference (%), 11?±?12 vs 21?±?10, p?<?0.05). LA maximal volume and E/e′ showed the same tendency after ablation, although the extent of improvement was not statistically significant. Both groups showed almost the same time course of improvement up to 2 years, although the L group showed earlier recovery in LVEF.

Conclusion

The greater improvement in several cardiac functions was seen in patients with greater LV dysfunction, after the CA for CAF.     

Extent of myocardial viability predicts response to biventricular pacing in ischemic cardiomyopathy

BACKGROUND: The clinical response to biventricular pacing is unpredictable, especially in patients with ischemic cardiomyopathy. OBJECTIVES: The purpose of this study was to prospectively examine the relationship between the extent of myocardial viability and the response to cardiac resynchronization therapy. METHODS: Twenty-one patients with ischemic left ventricular (LV) dysfunction (left ventricular ejection fraction [LVEF] 21 +/- 5%), New York Heart Association (NYHA) functional class III-IV, and QRS >120 ms received biventricular devices. Myocardial viability was assessed by myocardial contrast echocardiography, and a perfusion score index (PSI) was calculated from summed segmental perfusion scores. LV performance was assessed by echocardiography on the day after implantation and at 6 months. RESULTS: PSI was closely correlated with acute improvement in LVEF (P = .003, r = 0.65), stroke volume (P = .02, r = 0.54), and end-systolic volume (P = .05, r = -0.49). PSI also correlated with early diastolic LV relaxation (E', P < .05, r = 0.50) and global myocardial performance or Tei index (P = .003, r = 0.63). By multiple linear regression analysis, PSI provided incremental predictive value to the degree of dyssynchrony, measured by tissue Doppler imaging, for predicting improvement in LVEF. At 6 months, PSI remained positively correlated with improvement in ventricular performance and with reduction in LV end-diastolic dimension (P = .003, r = -0.68). PSI also influenced the clinical variables of NYHA class, 6-minute walk distance, quality-of-life score, and number of hospitalizations for heart failure. CONCLUSION: In patients with ischemic cardiomyopathy, the extent of myocardial viability predicts acute and long-term improvement in LV performance, exercise tolerance, and reduction in LV end-diastolic dimension with biventricular pacing.     

Efficiency of Intramyocardial Injections of Autologous Bone Marrow Mononuclear Cells in Patients with Ischemic Heart Failure: A Randomized Study

Intramyocardial transplantation of autologous bone marrow mononuclear cells (BMMC) is believed to be a promising method for the treatment of patients with chronic ischemic heart disease. The aim of this study was to evaluate long-term results of intramyocardial bone marrow cell transplantation in patients with severe ischemic heart failure. One hundred nine patients with chronic myocardial infarction and end-stage chronic heart failure were randomized into two groups: 55 patients received intramyocardial BMMC injection and 54 received optimal medical therapy. The NOGA system (Biosense-Webster) was used to administer 41?±?16?×?106 BMMC into the border zone of myocardial infarction. None of the patients developed periprocedural complications following BMMC injections. The injections led to improvement of CCS class (3.1?±?0.4 to 1.6?±?0.6 after 6 months and 1.6?±?0.4 after 12 months; p?=?0.001) and NYHA functional class (3.3?±?0.2 to 2.3?±?0.2 after 6 months and 2.5?±?0.1 after 12 months; p?=?0.006). Left ventricular ejection fraction increased significantly in the BMMC group (27.8?±?3.4% vs 32.3?±?4.1%; p?=?0.04) while it tended to decrease in the control group (26.8?±?3.8% to 25.2?±?4.1%; p?=?0.61). Summed rest score improved in the BMMC group after 12 months (30.2?±?5.6 to 27.8?±?5.1; p?=?0.032). The improvement of stress score was more noticeable (34.5?±?5.4 to 28.1?±?5.2; p?=?0.016). Neither stress nor rest score changed in patients numbers on medical therapy. In BMMC group 6 (10.9%) patients died at 12-month follow-up compared with 21 (38.9%) in control group (log-rank test, p?=?0.0007). Intramyocardial bone marrow cell transplantation to patients with ischemic heart failure is safe and improved survival, clinical symptoms, and has beneficial effect on LV function     

Prospective randomized trial of direct endomyocardial implantation of bone marrow cells for treatment of severe coronary artery diseases (PROTECT-CAD trial).

AIMS: Experimental studies have demonstrated that bone marrow (BM) cells can induce angiogenesis in ischaemic myocardium. Recently, several non-randomized pilot studies have also suggested that direct BM cells implantation appears to be feasible and safe in patients with severe coronary artery diseases (CAD). METHODS AND RESULTS: We performed a randomized, blinded, and placebo-controlled trial in 28 CAD patients. After BM harvesting, we assigned patients to receive low dose (1 x 10(6) cells/0.1 mL, n = 9), high dose (2 x 10(6) cells/0.1 mL, n = 10) autologous BM cells or control (0.1 mL autologous plasma/injection, n = 9) catheter-based direct endomyocardial injection as guided by electromechanical mapping. Our primary endpoint was the increase in exercise treadmill time and our secondary endpoints were changes in Canadian Cardiovascular Society (CCS) and New York Heart Association (NYHA) class, and myocardial perfusion and left ventricular ejection fraction (LVEF) assessed by single-photon emission computed tomography and magnetic resonance imaging, respectively. A total 422 injections (mean 14.6 +/- 0.7 per patient) were successfully performed at 41 targeted ischaemic regions without any acute complication. Baseline exercise treadmill time was 439 +/- 182 s in controls and 393 +/- 136 s in BM-treated patients, and changed after 6 months to 383 +/- 223s and 464 +/- 196 s [BM treatment effect +0.43 log seconds (+53%), 95% CI 0.11-0.74, P = 0.014]. Compared with placebo injection, BM implantation was associated with a significant increase in LVEF (BM treatment effect +5.4%, 95% CI 0.4-10.3, P = 0.044) and a lower NYHA class (odds ratio for treatment effect 0.12, 95% CI 0.02-0.73, P = 0.021) after 6 months, but CCS reduced similarly in both groups. We observed no acute or long-term complications, including ventricular arrhythmia, myocardial damage, or development of intramyocardial tumour or calcification associated with BM implantation. CONCLUSION: Direct endomyocardial implantation of autologous BM cells significantly improved exercise time, LVEF, and NYHA functional class in patients with severe CAD who failed conventional therapy.     

Changes of myocardial function after combined coronary revascularization and mitral valve downsizing in patients with ischemic mitral regurgitation and advanced cardiomyopathy

OBJECTIVE: At present not much data is available on changes in myocardial function after combined coronary artery bypass grafting (CABG) and downsizing of the mitral valve (MV) by restrictive prosthetic ring annuloplasty in patients with chronic ischemic mitral regurgitation (IMR) and advanced cardiomyopathy. METHODS: 63 patients with coronary artery disease, chronic IMR grade 3 - 4+, ischemic cardiomyopathy and reduced left ventricular (LV) function (LV ejection fraction [LVEF] of 30 +/- 9 %; range 12 - 45 %) underwent combined CABG and MV downsizing. Clinical follow-up and serial echocardiographic studies were performed to assess survival, New York Heart Association (NYHA) class, mitral regurgitation (MR), leaflet coaptation height (LCH), left atrial (LA) and LV end-systolic/end-diastolic dimensions/volumes and volume indices (LVESD, -EDD; LVESV, -EDV; LVESVI, -EDVI), fractional shortening (FS) and LVEF to evaluate the changes in myocardial function after surgery. RESULTS: Early mortality (< 30 days) was 1.6 %, survival at follow-up was 95 % (3 +/- 1 months) and 83 % (2 +/- 1 years), respectively. Functional class improved significantly after surgery; recurrence of relevant MR was absent in all patients. In general, LA/LV dimensions/volumes and volume indices, FS and LVEF improved significantly, even in patients with already severely reduced preoperative LV function (LVEF 相似文献   

Reversal of cardiomyopathy in patients with congestive heart failure secondary to tachycardia

Objectives

Tachycardia-induced cardiomyopathy (TCM) is a reversible cause of heart failure. Little is known of the characteristics of tachycardia associated with the development of left ventricular (LV) dysfunction and the reversal of cardiomyopathy after cure of tachycardia. This study aimed to examine the reversal of cardiomyopathy in patients undergoing ablation with congestive heart failure secondary to tachycardia.

Methods

A total of 625 patients underwent radiofrequency ablation for tachycardiarrhymias between January 2009 and July 2011. Echocardiography analysis was performed to identify patients with depressed LV function, defined as a left ventricular ejection fraction <50 %. Patients with preexisting structural heart disease (n?=?10) were excluded. NT-pro-B-type natriuretic peptide (NT-proBNP) assessment was performed before ablation in patients considered to have TCM (n?=?17). Repeated echocardiography study and NT-proBNP assessment were measured after a mean follow-up of 3 months. Levels of NT-proBNP before and after ablation were compared. Reversal of cardiomyopathy was also assessed.

Results

The incidence of TCM was 2.7 % (12 males; age, 35.8?±?17.1 years). Successful ablation was performed in 16 of 17 patients (94.1 %). There was a significant improvement in left ventricular ejection fraction (36.7?±?7.5 vs. 59.4?±?9.7 %; P?<?0.001). The mean left ventricular end-diastolic diameter before treatment was 59.5?±?8.3 mm (range, 43 to 70), compared with 51.9?±?7.4 mm (range, 40 to 67) (P?=?0.009) after 3 months follow-up. The levels of NT-proBNP decreased after ablation procedure, from 4,092.6?±?3,916.6 to 478.9?±?881.9 pg/ml (P?<?0.001). After successful ablation, ventricular function normalized in 15 of 17 (88.2 %) patients at a mean of 3 months.

Conclusions

Restoration of LV function and reversal of LV remodeling can be achieved with successful elimination of tachycardia in the majority of patients. NT-proBNP level elevates in subjects with TCM and decreases sharply after ablation.     

Long-term effects of carvedilol or metoprolol on left ventricular function in ischemic and nonischemic cardiomyopathy

Data regarding the effects of beta blockers on left ventricular (LV) function after 12 months are scarce in ischemic and nonischemic cardiomyopathy. Echocardiograms of 72 patients with ischemic and nonischemic cardiomyopathy, who were free of clinical events susceptible to alter LV function while receiving carvedilol or metoprolol for at least 24 months, were prospectively reanalyzed. Twelve months after beta-blocker initiation, LV ejection fraction (EF) increased by > or = 5% in 75% of patients, whereas EF failed to increase by 5% or decreased in the remaining 25%. Over the subsequent 32 months, LVEF increased further in patients who had experienced an initial EF increase by > or = 5%, whereas EF tended to further decrease in patients who had experienced an initial EF increase of <5% or a decrease. Thus, the benefits of carvedilol or metoprolol on LV function are long lasting in patients with ischemic or nonischemic cardiomyopathy who are free of events susceptible to alter LV function while receiving beta blockade.     

Does resting two-dimensional echocardiography identify patients with ischemic cardiomyopathy and low likelihood of functional recovery after coronary revascularization?

OBJECTIVE: To evaluate the potential of a simple and widely available technique as two-dimensional (2D) echocardiography to identify patients with ischemic cardiomyopathy and low likelihood of functional recovery after coronary revascularization. METHODS: Two-dimensional echocardiography and radionuclide ventriculography (RNV) were performed before coronary revascularization in 94 patients with ischemic cardiomyopathy. Left ventricular ejection fraction (LVEF) was measured by RNV. Regional wall motion abnormalities, wall motion score index, end-diastolic wall thickness (EDWT), left ventricular (LV) volumes and LV sphericity index were assessed in the echocardiographic images. RNV was repeated 9-12 months after revascularization to assess LVEF change; an improvement >or=5% was considered clinically significant. RESULTS: Nine hundred and ninety-nine segments were severely dysfunctional; 149 out of 999 (15%) had an EDWT or=100 ml/ml) and of the end-systolic volume index (>or=80 ml) was present in 32 (34%) and 21 (22%) patients, respectively. A spherical shape of the LV was observed in 35 (37%) patients. LVEF after revascularization increased in 30 out of 94 patients (32%) from 30+/-8% to 39+/-9% (P<0.0001). On multivariate analysis, the EDVI was the only predictor of no recovery in LVEF [odds ratio, 1.06, confidence interval (CI), 1.04-1.1, P<0.0001]. The cut-off value of EDVI >or=90 ml/ml accurately identified patients that virtually never recover. Post-operatively, LVEF increased in three out of 42 (7%, 95% CI 0-15%) patients with EDVI >or=90 ml/ml as compared to 27 out of 52 (52%) patients with EDVI<90 ml/ml (P<0.0001). CONCLUSIONS: In patients with ischemic cardiomyopathy and severe LV enlargement, improvement of LVEF after revascularization is unlikely to occur. Conversely, in patients with relatively preserved LV size, a higher likelihood of functional recovery may be anticipated.     

缺血性心肌病的左心室几何变化与心功能关系

目的 探讨缺血性心肌病(ischemic cardiomyopathy,ICM)病人左心室几何形态学变化与其心功能的关系.方法 应用彩色多普勒超声测量ICM 65例及正常人30名左心室几何形态学及其有关左心室收缩功能和舒张功能指标;以左心室球形指数(sphericity index,SI)即左心室长径/短径比值(L/D)作为反映左心室几何构型的变化,比较ICM病人及正常人左心室射血分数(left ventricular ejection fraction,LVEF)、短轴缩短率(shortening fraction,FS)、心脏指数(cardiac index,CI)、收缩期左心室球形指数(left ventricular geometry sphericity index at the end of systole,SIs)、舒张期左心室球形指数(left ventricular geometry sphericity index at the end of diastole,SId)差异,并对各参数行相关分析.结果 ICM病人SI明显降低,SIs与LVEF呈正相关(r=0.7452),SId与EVI/AVI呈正相关(r=0.6597).结论 ICM左心室几何形态变化与其心功能密切相关,心功能愈差,左心室愈趋球形,心室球形化的程度可能预示心功能的减退程度.     

Impact of Mental Stress and Anger on Indices of Diastolic Function in Patients With Heart Failure

BackgroundUnder controlled conditions, mental stress can provoke decrements in ventricular function, yet little is known about the effect of mental stress on diastolic function in patients with heart failure (HF).Methods and ResultsTwenty-four patients with HF with ischemic cardiomyopathy and reduced ejection fraction (n = 23 men; mean left ventricular [LV] ejection fraction 27 ± 9%; n = 13 with baseline elevated E/e’) completed daily assessment of perceived stress, anger, and negative emotion for 7 days, followed by a laboratory mental stress protocol. Two-dimensional Doppler echocardiography was performed at rest and during sequential anger recall and mental arithmetic tasks to assess indices of diastolic function (E, e’, and E/e’). Fourteen patients (63.6%) experienced stress-induced increases in E/e', with an average baseline to stress change of 6.5 ± 9.3, driven primarily by decreases in early LV relaxation (e’). Age-adjusted linear regression revealed an association between 7-day anger and baseline E/e’; patients reporting greater anger in the week before mental stress exhibited higher resting LV diastolic pressure.ConclusionsIn patients with HF with reduced ejection fraction, mental stress can provoke acute worsening of LV diastolic pressure, and recent anger is associated with worse resting LV diastolic pressure. In patients vulnerable to these effects, repeated stress exposures or experiences of anger may have implications for long-term outcomes.     

Left atrial reverse remodeling and prevention of progression of atrial fibrillation with atrial resynchronization device therapy utilizing dual-site right atrial pacing in patients with atrial fibrillation refractory to antiarrhythmic drugs or catheter ablation

Introduction

Dual-site right atrial pacing (DAP) produces electrical atrial resynchronization but its long-term effect on the atrial mechanical function in patients with refractory atrial fibrillation (AF) has not been studied.

Methods

Drug-refractory paroxysmal (PAF) and persistent AF (PRAF) patients previously implanted with a dual-site right atrial pacemaker (DAP) with minimal ventricular pacing modes (AAIR or DDDR mode with long AV delay) were studied. Echocardiographic structural (left atrial diameter [LAD] and left ventricular [LV] end diastolic diameter [EDD], end systolic diameter [ESD]) and functional (ejection fraction [EF]) parameters were serially assessed prior to, after medium-term (n?=?39) and long-term (n?=?34) exposure to DAP.

Results

During medium-term follow-up (n?=?4.5 months), there was improvement in left atrial function. Mean peak A wave flow velocity increased with DAP as compared to baseline (75?±?19 vs. 63?±?23 cm/s, p?=?0.003). The long-term impact of DAP was studied with baseline findings being compared with last follow-up data with a mean interval of 37?±?25 (range 7–145) months. Mean LAD declined from 45?±?5 mm at baseline to 42?±?7 mm (p?=?0.003). Mean LVEF was unchanged from 52?±?9 % at baseline and 54?±?6 % at last follow-up (p?=?0.3). There was no significant change in LV dimensions with mean LVEDD being 51?±?6 mm at baseline and 53?±?5 mm at last follow-up (p?=?0.3). Mean LVESD also remained unchanged from 35?±?6 mm at baseline to 33?±?6 mm at last follow-up (p?=?0.47). During long-term follow-up, 30 patients (89 %) remained in sinus or atrial paced rhythm as assessed by device diagnostics at 3 years.

Conclusions

DAP can achieve long-term atrial reverse remodeling and preserve LV systolic function. DAP when added to antiarrhythmic drug (AAD) and/or catheter ablation (ABL) maintains long-term rhythm control and prevents AF progression in elderly refractory AF patients. Reverse remodeling with DAP may contribute to long-term rhythm control.     

Early and late results of restrictive mitral valve annuloplasty in 121 patients with cardiomyopathy and chronic mitral regurgitation

OBJECTIVE: This study investigated the early and late results of restrictive mitral valve (MV) annuloplasty in patients with chronic mitral regurgitation (MR) and advanced ischemic (ICM) or dilated cardiomyopathy (DCM). METHODS: From October 2001 to September 2006, 121 patients (age: 69 +/- 9 years) with a left ventricular ejection fraction (LVEF) of 30 +/- 9 % and chronic MR grade 3 - 4 (ICM: n = 102, DCM: n = 19) underwent restrictive prosthetic ring annuloplasty (downsizing of 2.7 +/- 0.8 ring sizes). Eighty-five ICM-patients had indications for concomitant coronary artery bypass grafting (CABG). All patients were restudied at 7 +/- 1 days, 3 +/- 1 and 30 +/- 12 months after surgery to assess survival, residual MR, New York Heart Association (NYHA) class and left ventricular (LV) function (end-systolic/end-diastolic dimensions/volume indexes and LVEF). Data were analyzed exploratively. RESULTS: 30-day mortality was 3.3 %; survival at follow-up was 95 % and 91 %, respectively. Postoperative recurrence of significant MR (> grade 2) was absent in all patients. NYHA class, LV dimensions/volume indexes and LVEF improved significantly after surgery in both groups ( P < 0.0005). A prediction of continuous postoperative improvement of myocardial function in the sense of reverse remodeling could be demonstrated by univariate logistic regression for ischemic etiology and concomitant CABG ( P = 0.0001). In DCM-patients or ICM-patients without CABG, the postoperative benefit on myocardial function was limited. CONCLUSION: Restrictive mitral valve (MV) annuloplasty corrected chronic MR in cardiomyopathy patients with low mortality and improved contractility. Surgery also prevented recurrence of significant MR, although the phenomenon of postoperative continuous reverse myocardial remodeling could not be verified in cases with a non-ischemic etiology or ICM without concomitant CABG.     

The impact of unrepaired versus repaired mitral regurgitation on functional status of patients with ischemic cardiomyopathy at one year after coronary artery bypass grafting

BACKGROUND AND AIM OF THE STUDY: The issues regarding the appropriate management of patients with ischemic mitral regurgitation (MR) and advanced left ventricular (LV) dysfunction are controversial and limited. The present study was undertaken to evaluate the mid-term dynamics of MR, LV dimensions, function and NYHA functional class in patients with ischemic cardiomyopathy (ICM) and MR who underwent coronary artery bypass grafting (CABG) either alone or combined with mitral valve (MV) repair. METHODS: A total of 199 patients with LV ejection fraction (LVEF) <35% were included in the study. Of these patients, 73 had MR grade 2+ (group 1), 66 had 0 or 1+ MR (group 2) and underwent isolated CABG, and 60 had MR > 2+ and underwent CABG with MV repair (group 3). RESULTS: At one year after surgery, the severity of MR was unchanged from preoperative grade in group 1 (2.1 +/- 0.5 vs. 1.97 +/- 0.8), and increased in group (0.76 +/- 0.43 vs. 1.44 +/- 0.77; p < 0.05), but was significantly lower in group (2.8 +/- 0.5 vs. 1.6 +/- 0.7; p <0.05). In group 1, the LV end-systolic volume index (LVESVI) tended to increase, the LV end-diastolic volume index (LVEDVI) increased from 69.6 +/- 22.6 to 79.6 +/- 23.2 ml/m2 with an increase in LVEF (from 27.9 +/- 5.9 to 31.3 +/- 9.4%), and pulmonary artery pressure (PAP) increased from 31.9 +/- 7.0 to 39.5 +/- 17.4 mmHg. In group 2, the LV volumes tended to increase, LVEF increased from 30. 3 +/- 4.1 to 34.9 +/- 9.1%, and PAP remained unchanged. In group 3, the LVESVI decreased from 55.4 +/- 16.9 to 47.1 +/- 21.7 ml/m2, LVED-VI tended to decrease, LVEF increased from 31.4 +/- 8.6 to 36.5 +/- 11.3%, and PAP decreased from 35.5 +/- 6.0 to 32.8 +/- 8.3 mmHg. CONCLUSION: Isolated CABG in patients with ICM had no favorable effect on MR reduction, and did not prevent its development. MR grade 2+ in patients with ICM at one year after isolated CABG had a deleterious effect on LV functional status, with progression of LV dilatation and increased PAP. A significant reduction or elimination of MR after combined surgery had a marked positive impact on reverse LV remodeling, including regression of LV dilatation, an increased LVEF, and decreased PAP.     

Echocardiographic parameters to predict inadequate defibrillation safety margin in patients receiving implantable cardioverter defibrillators for primary prevention

Background

Implantable cardioverter defibrillators (ICDs) have become an important part of the management of patients with congestive heart failure. At the time of ICD implantation, ventricular fibrillation (VF) is induced to assess adequate energy required for defibrillation. There are multiple parameters which influence the defibrillation safety margin (DSM); however, these factors are not well-established when ICDs are implanted for the primary prevention of sudden cardiac death (SCD) in patients with severe systolic dysfunction. We evaluated multiple clinical and echocardiographic parameters as predictors of adequate DSM in patients referred for ICD implantation for the primary prevention of SCD.

Methods

We prospectively enrolled 41 patients for ICD implantation with clinical indications for the primary prevention of SCD. Two blinded independent readers evaluated the prespecified echocardiographic parameters. These included left ventricular (LV) mass, indices of right ventricular and LV systolic and diastolic functions, and LV geometric dimensions. Basic clinical demographics, including age, gender, comorbidities, and etiology of cardiomyopathy, were also evaluated. DSM was established using our standard protocol for defibrillation testing which includes VF with successful first shock terminating VF at a value at least 10 J below the maximum output of the implanted device. High defibrillation thresholds (DFT) were defined as >21 J.

Results

The mean age is 61.8?±?14.7 years, with men comprising the majority of the patients (73 %). The only clinical variables which predicted the high DFT were age (in years) (54.5?±?17.5 vs. 65.7?±?11.3, p?=?0.044), QRS duration (in milliseconds) (116.0?±?29.5 vs. 110.5?±?21.8, p?=?0.03), LV mass (in grams) (241.0?±?77.9 vs. 181.9?±?52.3, p?=?0.006), and LV mass index (in grams per square meter) (111.1?±?38.2 vs. 86.4?±?21.1, p?=?0.02). On multivariate logistic regression analysis, LV mass was the only independent predictor of low DFT (≤22 J) in patients with ICD implanted for the primary prevention of SCD.

Conclusion

LV mass may help predict an adequate DSM in patients who are referred for ICD implantation for the primary prevention of SCD. These results may help distinguish the patients who may require high-energy devices prior to the implantation procedure. These results may help distinguish patients requiring high-energy devices, coils, or advanced programming prior to implantation and appropriate referral to electrophysiologists.     

电生理标测冠状静脉窦分支最延迟电激动处植入左室导线行心脏再同步化治疗

目的探讨电生理标测冠状静脉窦(CS)分支最延迟电激动处植入左室导线行心脏再同步治疗(CRT)。方法 10例中重度心力衰竭患者,均满足NYHA心功能Ⅲ～Ⅳ级,左室射血分数(LVEF)<0.35且QRS波时限≥120 ms。CRT术中在可植入左室导线的CS分支内进行电生理标测,将标测的最延迟心室电激动处作为左室导线的植入部位,观察该方法的可行性及临床疗效。结果 10例中,扩张型心肌病7例,缺血性心脏病3例;7例为窦性心律,3例为心房颤动;9例ECG表现为左束支传导阻滞,1例为室内传导阻滞。对10例的28个可作为左室导线植入部位的CS分支进行了电生理标测,10例均成功将左室导线植入在标测的最延迟电激动处,该处局部电位较体表ECG的QRS波起始延迟116±28 ms。术后即刻QRS波时限为121±17 ms,比术前153±30 ms明显缩短,P<0.01。8例CRT术后随访时间超过3个月,均有CRT应答(8/8,100%),其中3例超应答(3/8,37.5%),另外1例缺血性心肌病患者CRT术后2个月死于急性前壁心肌梗死;8例CRT应答患者NYHA心功能分级、6 min步行距离、LVEF值、左室收缩末容积、二尖瓣返流速度均较术前明显改善(1.6±0.5级vs 3.3±0.5级;405±92 m vs 307±82m;0.42±0.06 vs 0.30±0.04;121±38 ml vs 153±44 ml;3.9±1.2 m/s vs 4.5±1.5 m/s,P均<0.01)。结论电生理标测指引CS分支最延迟电激动处植入左室导线的CRT方法可行且短期疗效明显。     

Left ventricular systolic dysfunction predicts long-term major microvascular complication outcomes in type 1 diabetes. The Pittsburgh Epidemiology of Diabetes Complications (EDC) study of childhood onset diabetes

Objectives

We aimed to assess association between abnormal LVEF, in the absence of coronary artery disease (CAD), and 25-year incidence of major outcomes of diabetes (MOD) in a cardiology substudy of the Pittsburgh Epidemiology of Diabetes Complications cohort of childhood-onset type 1 diabetes.

Comparison of gated single-photon emission computed tomography with magnetic resonance imaging for evaluation of left ventricular function in ischemic cardiomyopathy

To perform a head-to-head comparison between magnetic resonance imaging (MRI) and gated single-photon emission computed tomography (SPECT) for the evaluation of left ventricular (LV) function (LV ejection fraction [LVEF], LV volumes, and regional wall motion) in patients with ischemic cardiomyopathy, we studied 22 patients with chronic coronary artery disease and LV dysfunction. Multislice, multiphase echoplanar MRI was performed with Philips Gyroscan ACS-NT15. Image analysis was performed using the MASS software package to determine LV end-systolic volume, LV end-diastolic volume, and LVEF. The same parameters were calculated using quantitative gated SPECT software (QGS, Cedars-Sinai Medical Center). The different parameters were compared using linear regression, and correlation coefficients were calculated. Regional wall motion was also determined from both techniques, according to a 13-segment model and a 3-point scoring system (from 1 = normokinesia to 3 = akinesia or dyskinesia). A summed wall motion score was also calculated for MRI and gated SPECT. Good correlations were found between MRI and gated SPECT for all parameters: (1) summed wall motion score^MRI versus summed wall motion score^SPECT: Y = 0.74x + 8.0, R = 0.88, p <0.01; (2) LV end-systolic volume^MRI versus LV end-systolic volume^SPECT: Y = 0.94x − 12.3, R = 0.87, p <0.01; (3) LV end-diastolic volume^MRI versus LV end-diastolic volume^SPECT: Y = 0.93x − 18.4, R = 0.84, p <0.01; and (4) LVEF^MRI versus LVEF^SPECT: Y = 0.97x + 0.68, R = 0.90, p <0.01. For regional wall motion, an exact agreement of 83% was found, with a kappa statistic of 0.77 (95% confidence intervals 0.71 to 0.83, SE 0.03), indicating essentially excellent agreement. Thus, close and significant correlations were observed for assessment of LVEF, LV volumes, and regional wall motion by MRI and gated SPECT in patients with ischemic cardiomyopathy.     

Longitudinal changes in left ventricular architecture and function in peripartum cardiomyopathy

Left ventricular (LV) function was quantitated in 14 patients with peripartum cardiomyopathy, in 10 using 2-dimensional (2-D) echocardiography and in 4 radionuclide ventriculography, and values were compared with those in 11 normal women in the immediate postpartum period. LV end-diastolic and end-systolic volume indexes, LV wall mass index and ejection fraction were calculated during the acute phase of the illness and serially through long-term follow-up (mean 24 months). During the acute phase of illness there was marked LV dilatation: mean end-diastolic volume index was 95 ± 22 MI/M², vs 67 ± 9 ml/m² in control subjects (p <0.005), and mean end-systolic volume index was 66 ± 18 ml/m², compared to 27 ± 5 ml/m² in control subjects (p <0.001). Mean heart rates and mean systolic pressures in the patients with peripartum cardiomyopathy and the control subjects were similar, 91 ± 24 vs 79 ± 14 beats/min and 120 ± 14 vs 117 ± 10 mm Hg, respectively. LV wall mass index was higher, 139 ± 38 vs 96 ± 8 g/m² (p <0.005), and ejection fraction much lower, 29 ± 5% vs 67 ± 5% (p <0.001), in control subjects. Five patients underwent endomyocardial biopsy during the acute illness, which showed interstitial fibrosis but no evidence of active inflammation. There was rapid and early improvement in LV function in 13 of 14 patients. Changes in LV volume, mass and ejection fraction all followed an exponential time course during LV remodeling. By late follow-up, LV size and function had returned to normal in more than half the patients. The severity of early compromise in LV function did not predict long-term functional outcome.     

Incidence of very high defibrillation thresholds (DFT) and efficacy of subcutaneous (SQ) array insertion during implantable cardioverter defibrillator (ICD) implantation

Background

The incidence, risk factors, and management of very high defibrillation thresholds (DFTs) during present-day implantable cardioverter defibrillator (ICD) testing are not well known.

Objectives

The purpose of this study was to assess (1) the incidence of very high DFTs and (2) the efficacy/safety of routinely adding a subcutaneous (SQ) array for these patients.

Methods

The study evaluated patients undergoing first-time ICD implantation at Southlake Regional Healthcare Centre from January 2006 to December 2007. All implanted ICDs had a maximal output of 35 J. Patients with DFTs greater than a 10-J safety margin from maximum output were considered to have very high readings and underwent SQ array insertion after other attempts at lowering DFT (group I). These patients were compared with the rest of the patients who had acceptable DFTs (group II) using both univariate and multivariate logistic regression analysis. Outcomes of array insertion were also assessed.

Results

A total of 313 patients underwent first-time ICD implantation during the analysis period. Of those, 16 (5.1%) had very high DFTs (group I). By univariate analysis, advanced New York Heart Association class (3 or 4), congestive heart failure hospitalization, non-ischemic cardiomyopathy, amiodarone use, implant of a biventricular device, and highest quartile of left ventricular (LV) chamber enlargement were all significant predictors of very high DFTs (p?<?0.05). By multivariate analysis, only amiodarone use [odds ratio (OR)?=?10.3, 95% confidence interval (95% CI)?=?3.7–32.6] and being in the highest quartile for LV diastolic diameter [OR?=?5.4, 95% CI?=?1.4–20.8] predicted very high DFT. In all 16 cases, other methods to lower DFT prior to array insertion were attempted but failed for all patients: reversing shock polarity (n?=?15), removing the superior vena cava coil (n?=?14), reprogramming shock waveform (n?=?9), and repositioning right ventricular lead (n?=?9). Addition of the array successfully decreased DFT to within safety margin for all patients (33?±?2 vs 21?±?5 J, p?=?0.02). Complication due to array insertion occurred in one patient (pneumothorax).

Conclusions

Very high DFTs occur in about 5% of patients undergoing ICD implantation and may be predicted by LV dilation and amiodarone use. SQ array insertion reliably corrects this problem over other interventions with a low rate of procedural complication.