应变率成像评估肺动脉高压右心室心肌机械运动不同步的研究

目的探讨应变率成像（SRI）评估肺动脉高压（PH）患者右心室心肌机械运动不同步的价值。方法应用SRI定量检测36例PH患者（PH组）及35例健康受检者（对照组）,观察右心室6节段及右心室整体心肌非同步相关参数,包括：QRS波至右心室6节段及右心室整体心肌收缩期达峰时间（Ts）、右心室机械不同步指数（RV—DI）,并对所获参数进行心率校正;测量右心室功能相关参数：右心室面积变化分数（RVFAC）、右心室MPI指数（RVMPI）、右心室游离壁三尖辩环收缩期位移（TAPSE）、右心室射血分数（RVEF）、右心宣整体应变率（RV Strain）及右心室整体收缩期峰值应变（RV Sas）。结果PH组RV—DI、右心室整体Ts大于对照组（P〈0．05）,右心室游离壁基底段殁中间段Ts长于室间隔相应节段TB及对照组相应节段Ts（P〈0．05）;PH组右心室功能相关参数均低于对照组（P〈0．01）;RV-DI与RVFAC及RVEF呈负相关（r=-0．81,P〈0．05;r=-0．85,P〈0．01）。结论PH患者存在右心室机械运动不同步,SRI可作为临床判断右心室机械不同步重要方法。     

Obstructive sleep apnea, hypertension, and their interaction on arterial stiffness and heart remodeling

STUDY OBJECTIVES: Obstructive sleep apnea (OSA) and hypertension are independently associated with increased stiffness of large arteries that may contribute to left ventricular (LV) remodeling. We sought to investigate the impact of OSA, hypertension, and their association with arterial stiffness and heart structure. DESIGN: We studied 60 middle-aged subjects classified into four groups according to the absence or presence of severe OSA with and without hypertension. All participants were free of other comorbidities. The groups were matched for age, sex, and body mass index. MEASUREMENTS AND RESULTS: Full polysomnography, pulse-wave velocity (PWV), and transthoracic echocardiography were performed in all participants. Compared with normotensive subjects without OSA, PWV, left atrial diameter, interventricular septal thickness, LV posterior wall thickness, LV mass index, and percentage of LV hypertrophy had similar increases in normotensive OSA and patients with hypertension and no OSA (p < 0.05 for all comparisons), with a significant further increase in PWV, LV mass index, and percentage of LV hypertrophy in subjects with OSA and hypertension. Multivariate regression analysis showed that PWV was associated with systolic BP (p < 0.001) and apnea-hypopnea index (p = 0.002). The only independent variable associated with LV mass index was PWV (p < 0.0001). CONCLUSIONS: Severe OSA and hypertension are associated with arterial stiffness and heart structure abnormalities of similar magnitude, with additive effects when both conditions coexist. Increased large arterial stiffness contributes to ventricular afterload and may help to explain heart remodeling in both OSA and hypertension.     

Transcatheter closure of postinfarction ventricular septal defects using Amplatzer devices

We carried out transcatheter procedures to close postinfarction ventricular septal defects (PIVSDs) in 19 patients: two had recanalization after surgical closure, and 17 had a primary PIVSD. In three of the latter patients, who had acute PIVSDs, the procedure was carried out in the first 3 weeks after infarction; in the 13 patients with subacute PIVSD, it was carried out 3.5-12 weeks after infarction. There was another procedure in one patient with chronic PIVSD. In total, 22 procedures were completed: 17 using an Amplatzer atrial septal occluder, two using an Amplatzer postinfarction ventricular septal defect occluder, and two using an Amplatzer muscular ventricular septal defect occluder. The procedure was successful in 14 patients: in 11 with subacute PIVSD, one with chronic PIVSD, and two with postsurgical PIVSD. Transcatheter closure of PIVSDs using an Amplatzer atrial septal occluder is probably the treatment of choice in patients undergoing surgery more than 3.5 weeks after myocardial infarction and in those with recanalization after previous surgical closure.     

Filtered QRS duration on signal-averaged electrocardiography correlates with ventricular dyssynchrony assessed by tissue Doppler imaging in patients with reduced ventricular ejection fraction

Objectives

The relationships between filtered QRS duration and ventricular dyssynchrony were studied.

Methods

We measured filtered QRS duration on signal-averaged electrocardiography and analyzed tissue Doppler imaging in chronic heart failure patients with ejection fraction less than 50%.

Results

In 64 patients, interventricular and intraventricular dyssynchronies were observed in 25 and 38 patients, respectively. All patients with interventricular dyssynchrony were associated with intraventricular dyssynchrony. Filtered QRS showed 0.82 and 0.78 of the area under the curve (AUC) in the receiver operating characteristic curve (ROC) for the detection of interventricular and intraventricular dyssynchrony, respectively, with 89.7% and 96.2% specificity and 52.0% and 52.6% sensitivity, with cutoff values of 174 and 153 milliseconds. Specificity and sensitivity as well as AUC were lower in the ROC of QRS duration than filtered QRS duration.

Conclusion

Filtered QRS duration provided more reliable information to estimate ventricular dyssynchrony in patients with reduced ventricular ejection fraction than QRS duration did.     

Optimized cardiac resynchronization therapy in patients with congestive heart failure

Heart failure was a major and increasing public health problem, with an almost ＂epidemic＂ increase in the number of patients. Despite recent advances in pharmacotherapy, the prognosis remains poor. Cardiac resynchronization therapy （CRT）, by pacing right and left ventricles, has been proved to improve symptoms and reduce mortality for heart failure patients with cardiac dyssynchrony, However, 20% to 30% of patients did not respond to CRT. The good cardiac synchronicity before CRT and the remaining atrioventficular, inter- and intra-ventricular dyssynchrony after CRT may explain the non-response. New echocardiographic techniques, and in particular tissue Doppler imaging （TDI） analysis, has been proved to be a helpful tool in evaluating cardiac dyssynchrony, as well as in assessing the degree of cardiac resynchronization after biventricular device implantation. So, in this study, we optimized the pacing parameters to determine whether echo-guided optimizing of AV/VV delays would enhance the effect of CRT on cardiac function and synchronicity.     

Aneurysm of the great cardiac vein

Anatomical variations in the cardiac veins have the potential to cause iatrogenic injuries during cardiac surgical procedures or cardiac resynchronization therapy. We present a case of an 86-year-old man, which presented with a great cardiac vein aneurysm. The great cardiac vein arose near the apex of the interventricular sulcus to the right of the anterior interventricular branch (AIB) of the left coronary artery and crossed the AIB anteriorly to the left. The great cardiac vein aneurysm appeared to be due to a possible distal constriction of the great cardiac vein by a small muscular branch of the circumflex branch and a possible proximal constriction by the left marginal artery. Cardiologists who interpret imaging of the cardiac veins and cardiac surgeons who operate close to the great cardiac vein should be aware of such a variation.