T波电交替对急性心肌梗死患者恶性心律失常的预测价值

目的探讨时域法微伏级T波电交替（MTWA）对急性心肌梗死（AMI）患者住院期间恶性心律失常的预测价值。方法 105例AMI患者（AMI组）,其中男性77例,女性28例;年龄32~84岁,平均年龄62岁。38例冠状动脉正常者（对照组）,其中男性25例,女性13例;年龄41~79岁,平均年龄59岁。分析2组24h动态心电图检查资料。依据住院期间有无室性心动过速或心室纤颤,将105例AMI患者分为恶性心律失常组（34例）和非恶性心律失常组（71例）。结果 AMI组MTWA高于对照组（P〈0.05）。AMI患者中恶性心律失常组与非恶性心律失常组MTWA差异具有显著统计学意义（P〈0.01）。以MTWA≥25μV为截点,预测AMI患者发生恶性心律失常的灵敏度、特异度、阳性预测值、阴性预测值分别为50.00%、80.28%、54.84%、77.03%。结论时域法测量MTWA对AMI患者住院期间恶性心律失常的发生有预测价值,可用于AMI患者的危险分层。     

T波交替的研究进展

T波交替是指在心电图T波的幅度、形态的逐搏交替变化。作为一项新的无创心电检测方法,T波交替已成为预测室性心律失常及心脏性猝死等疾病的有效手段。较全面地阐述了T波交替的产生机理、检测方法及临床研究等方面的内容,并指出了T波交替的研究方向和发展前景。     

A high triglyceride-glucose index is associated with left ventricular dysfunction and atherosclerosis

Background: The triglyceride-glucose (TyG) index has been reported to be a simple and reliable surrogate marker of insulin resistance. The aim of this study was to investigate associations between the TyG index and echocardiographic parameters including left ventricular mass (LVM), left atrial diameter (LAD) and left ventricular ejection fraction (LVEF), and markers of peripheral artery disease, ankle-brachial index (ABI) and brachial-ankle pulse wave velocity (baPWV).Methods: A total of 823 (483 males and 340 females) patients were enrolled from 2007 to 2011 at a regional hospital in southern Taiwan. Multivariable stepwise linear regression analysis was performed to identify the factors related to echocardiographic parameters and peripheral artery disease.Results: The patients were stratified into four groups according to TyG index quartile. Multivariable stepwise linear regression analysis showed that a higher TyG index was associated with elevated observed/predicted LVM (p = 0.081), increased LAD (p = 0.004), decreased LVEF (p = 0.003) and lower ABI (p = 0.030), but not observed/predicted LVM and baPWV.Conclusions: A high TyG index was significantly associated with high LAD, low LVEF and low ABI. However, the TyG index was not significantly associated with inappropriate LVM or baPWV. The results suggest that the TyG index, as a simple indicator of insulin resistance, may reflect cardiac remodeling and dysfunction and atherosclerosis.     

Evaluation of T-wave alternans in high-resolution ECG maps recorded during the stress test in patients after myocardial infarction

Introduction

Recent studies point to analysis of T-wave alternans as a promising indicator of an increased risk of life-threatening ventricular arrhythmias. In this study the occurrence of T-wave alternans in the high-resolution ECGs recorded during the exercise stress test and scintigraphic tests (SPECT) in patients with ischemic heart disease was examined.

Material and methods

The study group consisted of 33 patients after myocardial infarction. In the group of patients after myocardial infarction and with low left ventricular ejection fraction correlations of 70% between the test results of T-wave alternans and SPECT and 60% between the test results of T-wave alternans and stress test were found.

Results

In the group of patients after myocardial infarction but with high left ventricular ejection fraction correlations were respectively 39% and 48%. The analysis of the electrocardiographic maps showed a strong dependence of this correlation on the T-wave alternans amplitude and location of the ECG measuring electrode on the chest. The results might suggest that in patients after myocardial infarction and at increased risk for sudden cardiac death T-wave alternans may also provide information about cardiac electrical instability associated with ischemia.

Conclusions

It can also be assumed that the position of the electrode where the highest level of the T-wave alternans was detected can indicate the location of the ischemic region of the heart.     

Prognostic value of low-dose dobutamine stress echocardiography in patients with aortic stenosis and impaired left ventricular function

Introduction

The aim of this multicenter, prospective study was to evaluate the long-term prognostic value of low-dose dobutamine stress echocardiography (LDDSE) in patients with aortic stenosis (AS) and depressed left ventricular (LV) function.

Material and methods

The study group comprised 39 patients (34 male, mean age 59 ±13 years) with AS (peak gradient > 25 mm Hg), LV ejection fraction (LVEF) ≤ 45% and low transaortic gradient (peak gradient ≤ 45 mm Hg, mean gradient ≤ 35 mm Hg). The qualification for subsequent therapeutic procedures was based on generally accepted indications. All patients underwent LDDSE and coronary angiography. Twelve months after LDDSE patients underwent control resting echocardiography and clinical evaluation.

Results

Twenty-seven (69.2%) patients had preserved contractile reserve. In this subgroup, true-severe AS was diagnosed in 12 patients, whereas pseudo-severe AS was found in 15 patients. Nine patients with true-severe AS, 2 patients with pseudo-severe AS and 7 patients without contractile reserve were referred for surgical treatment. The independent risk factors of death during follow-up were: aortic valve area (AVA) at peak stress < 0.8 cm² (OR 1.4; p = 0.003) and LVEF at rest < 35% (OR 6.8; p = 0.05). The independent risk factors of composite end-point (death or myocardial infarctions or pulmonary edema) were: AVA at stress < 0.8 cm² (OR 4.0; p = 0.03), absence of AVA increase during LDDSE (OR 5.7; p = 0.005), absence of contractile reserve (OR 4.5; p = 0.01) and presence of significant CAD (OR 6.9; p = 0.02).

Conclusions

In patients with AS and depressed LVEF, LDDSE is a useful tool for long-term risk stratification.     

Childhood onset of left ventricular dysfunction in a female manifesting carrier of muscular dystrophy

Duchenne muscular dystrophy and Becker muscular dystrophy are X-linked disorders that result from a mutation in the dystrophin gene that reduces the production or effectiveness of the protein dystrophin. These disorders are clinically characterized by progressive muscle degeneration. Manifesting female carriers are generally not identified as such until after puberty, when symptoms such as muscle weakness may arise. This clinical report describes a female manifesting carrier who started to show deterioration of left ventricular systolic function, but no marked skeletal muscle weakness, at the age of 10 years. The patient's cardiac function improved significantly after dual drug therapy with an ACE inhibitor (enalapril) and a beta-blocker (carvedilol). Our case adds to the existing evidence that left ventricular myocardial dysfunction may occur during childhood in female carriers of dystrophinopathies.     

Assessment of fragmented QRS formation and its relationship with left ventricular hypertrophy in nonhypertensive acromegaly patients

Background/aim It is known that the presence of fragmented QRS (fQRS) on electrocardiography (ECG) is associated with cardiovascular events. The aim of this study was the evaluation of fQRS formation and its relationship with the left ventricular hypertrophy (LVH) parameters in acromegaly patients. Materials and methods In total, 47 previously diagnosed with non-hypertensive acromegaly patients and 48 control subjects were included in the study. ECG and transthoracic echocardiography (TTE) were performed for each participant. Acromegaly patients were divided into two groups according to the fQRS formation on the ECG. Left ventricular wall thicknesses, and left atrial diameter (LAD), left ventricular mass (LVM), left ventricular mass index (LVMi), and relative wall thickness (RWT) were obtained. Results In control group 5 (10.4%) and in acromegaly group 17 (36.2%) patients had fQRS on ECG (p = 0.003). LAD [36.0 (34.0–38.0) vs. 38.0 (35.0–41.0) mm, p < 0.001], LVM [155.27 ± 27.00 vs. 173.0 (153.0–235.0) g, p < 0.001], LVMi [83.12 ± 13.19 vs. 92.0 (83.0–118.0) g/m², p < 0.001] and RWT [0.39 ± 0.03 vs. 0.43 (0.41–0.45), p = 0.001] were significantly higher in patients with acromegaly. Disease duration was significantly higher (11.59 ± 1.3 vs. 8.2 ± 1.8 years, p < 0.001) in the fQRS (+) group. LAD [41.0 (39.0–42.5) vs. 37.0 (34.7–38.0) mm, p < 0.001], LVM [219.0 (160.5–254.5) vs. 164.0 (153.0–188.0) g, p = 0.017], LVMi [117.0 (92.5–128.5) vs. 86.0 (82.0–100.2) g/m², p = 0.013] and RWT [0.44 (0.42–0.49) vs. 0.43 (0.40–0.44), p = 0.037] were significantly higher in fQSR (+) acromegaly patients. In multivariate logistic regression analysis, disease duration (odds ratio: 10.05, 95% CI: 1.099–92.012, p = 0.041) and LAD (odds ratio: 2.19, 95% CI: 1.030–4.660, p = 0.042) were found to be the independent predictors of fQRS formation.Conclusion The results of our study revealed that fQRS (+) acromegaly patients had increased LVH parameters compared to fQRS (-) patients.     

二维超声心动图和M型超声心动图评价左心室扩大患者左心室收缩功能的对比研究

目的评价二维超声心动图（2DE）法和M型超声心动图（ME）法测量心瓣膜病中重度二尖瓣和（或）主动脉瓣反流（VR）、扩张型心肌病（DCM）和缺血性心肌病（ICM）患者左心室收缩功能相关指标的一致性及其影响因素。方法用2DE和ME同时测量100例左心室扩大患者（VR35例、DCM32例和ICM33例）的左心室舒张末期内径（LVEDD）、左心室舒张末期容积（LVEDV）和左心室射血分数（LVEF）,分别记为LVEDD2DE、LVEDDME、LVEDV2DE、LVEDVME、LVEF2DE和LVEFME。结果①患者的LVEDD2DE与LVEDDME、LVEDV2DE与LVEDVME差异有统计学意义,LVEF2DE与LVEFME差异无统计学意义,且具有良好的相关性,r=0．869;②组内比较：3组的LVEDD2DE与LVEDDME差异均有统计学意义,VR组LVEDV2DE与LVEDVME差异无统计学意义,其他两组差异有统计学意义,3组的LVEF2DE与LVEFME差异无统计学意义;③组间比较：LVEDD2DE在DCM组与ICM组之间差异有统计学意义,在VR组与ICM组之间差异也有统计学意义,LVEDDME、LVEDV2DE。和LVEDVME有相同的结果,LVEF2DE在3组间差异均有统计学意义,LVEFME在3组间差异也均有统计学意义,2DE和ME法均得到LVEDVVR≈LVEDVDCM〉LVEDVICM和LVEFDCM〈LVEFICM〈LVEFVR的一致结论;④按LVEDD2DE分为〈80mm大左心室组和≥80mm巨大左心室组,两组的LVEDV2DE与LVEDVME差异有统计学意义,LVER2DE与LVEFME各组差异无统计学意义。结论二维法和M型超声评价VR、DCM和ICM患者左心室收缩功能的指标中LVEF一致性较好．较少受左心室形状及节段性室壁运动异常的影响。2DE和ME均得出VR组与DCM组左心室增大的程度相近．但LVEF减低的程度却不同．而ICM组左心室增大的程度小于前两组。但LVEF却较VR组减低明显。     

Association of natriuretic peptide polymorphisms with left ventricular dysfunction in southern Han Chinese coronary artery disease patients

Background: Left ventricular dysfunction (LVD) occurs with myocardial ischemia and coronary artery disease (CAD). The natriuretic peptide system has compensatory vasodilatory, natriuretic and paracrine effects on LVD and subsequent heart failure. The aim of this study was to investigate the relationship between natriuretic peptide polymorphisms and risk of LVD in CAD patients. Methods: We recruited 747 consecutive Southern Han Chinese patients with angiographically confirmed CAD, 201 had a reduced left ventricle ejection fraction (LVEF ≤45%, LVD group) and 546 had a preserved left ventricle ejection fraction (LVEF >45%). The reduced and preserved LVEF groups were matched by gender and age. Taqman assays were performed to identify five polymorphisms in the NPPA-NPPB locus (rs5065, rs5063, rs632793, rs198388 and rs198389). Results: Single-locus analyses found no significant difference in the allele and genotype frequencies of the reduced and preserved LVEF group, even after adjusting for confounding factors. Subgroup analyses performed by hyperlipidemia (HLP) demonstrated 3 polymorphisms, rs632793 (OR = 0.31, 95% CI 0.1-0.93, P = 0.04), rs198388 (OR = 0.26, 95% CI 0.09-0.79, P = 0.02) and rs198389 (OR = 0.26, 95% CI 0.09-0.80, P = 0.02) were associated with the reduced risk of LVD. No CAD-susceptible haplotypes were identified. Multifactor dimensionality reduction analysis did not detect any gene-to-gene interactions among the five loci. Three loci (rs5063, rs632793 and rs198388) formed the best model with the maximum testing accuracy (39.89%) and cross-validation consistency (10/10). Conclusion: Three NPPA-NPPB polymorphisms (rs632793, rs198388 and rs198389) were associated with reduced risk of LVD in CAD patients with HLP.     

Circulating endothelial cells in patients with heart failure and left ventricular dysfunction

Introduction and Aims: Acute and chronic heart failure may manifest different degrees of endothelial damage and angiogenesis. Circulating endothelial cells (CEC) have been identified as marker of vascular damage. The aim of our study was to evaluate the evolution of the CEC at different stages of patients with heart failure. We also investigated a potential correlation between CEC and markers of vascular damage and angiogenesis. Methods: We studied 32 heart failure patients at hospital admission (acute phase) and at revision after 3 months (stable phase) and 32 controls. Circulating markers of endothelial damage (CEC; von Willebrand factor, vWF and soluble E-selectin, sEsel) and angiogenesis (vascular endothelial growth factor, VEGF and thrombospondin-1) were quantified. Results: Levels of CEC, vWF, sEsel and VEGF are significantly higher in heart failure patients than in controls. Levels of CEC (36.9 ± 15.3 vs. 21.5 ± 10.0 cells/ml; p< 0.001), vWF (325 ± 101 vs. 231 ± 82%; p< 0.001) and VEGF (26.3 ± 15.2 vs. 21.9 ± 11.9 ng/ml; p< 0.001) are significantly higher in the acute phase than in the stable phase of heart failure. CEC levels correlate with vWF and VEGF. Results show than 100% of patients in acute phase and 37.5% in stable phase have levels of CEC higher than the 99th percentile of the distribution of controls (16 cells/ml). Therefore, increases in CEC represent a relative risk of 9.5 for heart failure patients suffering from acute phase. Conclusions: CEC, in addition to being elevated in heart failure, correlate with vWF levels, providing further support for CEC as markers of endothelial damage. Levels of CEC are associated with the acute phase of heart failure and could be used as a marker of the worsening in heart failure.     

Prognostic role of troponin and natriuretic peptides as biomarkers for deterioration of left ventricular ejection fraction after chemotherapy

Cardiotoxicity due to anthracyclines, trastuzumab and other potential cardiotoxic drugs is still a problem of modern chemotherapy. For years researchers have tried to find biological markers that can predict changes in the heart. The most thoroughly tested markers are troponin and natriuretic peptides. Some studies have proven that these markers can indeed be useful. In studies which have shown the predictive role of troponin I the assessment of this marker was performed very frequently. It is not possible to carry out such serial measurements in many centers because of typical 1-day hospital stay times. The predictive role of natriuretic peptides still needs further investigation. This review considers the newest research from recent years.     

Tei指数评价卡维地洛治疗充血性心力衰竭患者左心室功能的变化

目的与传统评价心功能指标比较，探讨多普勒超声左心室Tei指数在评价充血性心力衰竭患者治疗前后心功能的临床意义。方法60例充血性心力衰竭患者随机分为卡维地洛组和对照组（各30例），治疗前和治疗后3、6个月时分别用彩色多普勒超声测量左心室Tei指数、左心室射血分数（EF）、二尖瓣血流频谱舒张早期和晚期血流峰值之比（E，A）、E峰减速时间（Dn、等容舒张时间0VRT）、肺静脉血流频谱收缩波和舒张波峰值之比（S／D）及反向波（ARW）。结果两组EF在治疗后3个月及6个月逐渐增大（P＜0．01～0．05），卡维地洛组EF在治疗后6个月较对照组同期增大（P＜0．05）。两组治疗后舒张功能指标E／A先减小后增大，DT、IVRT及ARW逐渐减小，S，D逐渐增大（P＜0．01～0．05），组间差异未见有统计学意义（P＞0．05）。两组Tei指数在治疗后逐渐减低，组内比较差异均有显著统计学意义（P＜0．01），卡维地洛组减低更明显，与对照组同期比较差异有统计学意义（P＜0．01～0．05）。结论Tei指数可简便、敏感地评价心脏的整体收缩舒张功能。充血性心力衰竭患者卡维地洛治疗后左心室功能得到改善。     

Presence of lobeline-like sensations in exercising patients with left ventricular dysfunction

Since there is evidence that lobeline-induced sensations, associated with discomfort in the mouth, throat and chest arise by stimulating juxtapulmonary or J receptors, we were interested in investigating if similar sensations are felt by patients with left ventricular dysfunction (LVD) in whom a natural stimulation of these receptors would occur by transient interstitial oedema or during augmentation of the stimulus, by increased pulmonary blood flow during exercise. Threshold doses of lobeline produced three or more respiratory sensations simultaneously in 9 out of 10 patients, which was greater than the response of the controls (P < 0.01). With mild exercise, a greater number of patients (7) than controls (1) reported feeling two or more sensations (P < 0.01); in fact half the controls did not express a respiratory sensation with equivalent exercise (P < 0.05). The predominant lobeline-like sensations reported by patients with exercise were a feeling of heat or burning and pressure in the throat or chest (P < 0.05). The presence of cough in three patients and in none of the controls was noteworthy. The mean latency with which sensations appeared during exercise in patients (4.4 +/- 0.3 min) was almost half that in controls (7.4 +/- 0.2 min) (P < 0.005). Since, respiratory sensations in response to lobeline and exercise were intensified in patients compared to controls and since both lobeline and exercise-induced sensations were similar (P < 0.05), we speculate that a common origin exists. Despite important caveats, that we discuss, in our view these respiratory sensations and cough arise from stimulation of J receptors.     

射血分数-压差比值评价伴左心功能不全的主动脉瓣狭窄程度

目的初步探讨射血分数-压差比值评价伴左心功能不全的主动脉瓣狭窄程度可行性。方法80例左心室收缩功能不全的主动脉瓣狭窄患者，其中男32例，女性48例，年龄38～85岁，平均年龄42岁。用彩色多普勒超声测量主动脉瓣口面积（AVA）、左心室射血分数（EF），Bernoulli方程计算主动脉瓣口跨瓣压差（△P），Simpson容积描记法计算射血分数压差比值即EFPR（EFPR=EF／△P），分析AVA与△P、EFPR之间的相关性；用ROC曲线比较△P、EFPR两参数评价主动脉瓣狭窄程度的敏感度和特异度。结果对主动脉瓣狭窄伴左心室收缩功能不全患者，用Simpson容积描记法计算ERPR估测AVA较Bemoulli方程计算的△P法更准确（r=0.9172对r=-0.6796，P〈0.001）；将EFPR小于1.0、△P大于10.7kda（80mmHg）来估测重度主动脉瓣狭窄伴左心功能不全时，EFPR和△uP的敏感度和特异度分别为87.5％、68.6％（P〈0.05）和98.3％、37.2％（P〈0.01），表明EFPR估测重度主动脉瓣狭窄伴左心功能不全患者的特异度及敏感度较高。结论EFPR能准确估测主动脉瓣狭窄患者主动脉瓣狭窄程度，特别对伴左心功能不全的重度主动脉瓣狭窄患者瓣膜狭窄程度的评价。EFPR较传统参数有更高敏感性和特异性。     

Targeted panel sequencing in adult patients with left ventricular non-compaction reveals a large genetic heterogeneity

Left ventricular non-compaction (LVNC) is a cardiomyopathy that may be of genetic origin; however, few data are available about the yield of mutation, the spectrum of genes and allelic variations. The aim of this study was to better characterize the genetic spectrum of isolated LVNC in a prospective cohort of 95 unrelated adult patients through the molecular investigation of 107 genes involved in cardiomyopathies and arrhythmias. Fifty-two pathogenic or probably pathogenic variants were identified in 40 patients (42%) including 31 patients (32.5%) with single variant and 9 patients with complex genotypes (9.5%). Mutated patients tended to have younger age at diagnosis than patients with no identified mutation. The most prevalent genes were TTN, then HCN4, MYH7, and RYR2. The distribution includes 13 genes previously reported in LVNC and 10 additional candidate genes. Our results show that LVNC is basically a genetic disease and support genetic counseling and cardiac screening in relatives. There is a large genetic heterogeneity, with predominant TTN null mutations and frequent complex genotypes. The gene spectrum is close to the one observed in dilated cardiomyopathy but with specific genes such as HCN4. We also identified new candidate genes that could be involved in this sub-phenotype of cardiomyopathy.     

高血压患者心肌缺血性改变与左室后壁厚度的相关性研究

目的探讨高血压患者Holter上心肌缺血性改变与左心室后壁（LVPW）厚度之间的相关性。方法收集2005年5月至2008年9月在本院经查冠脉CTA及超声心动图排除冠心病的高血压患者共138例,首先根据Holter上有无发作性ST段压低将资料分为有缺血性改变与无缺血性改变两组,分析缺血性改变与LVPW厚度之间的相关性,并比较两组间LVPW厚度的大小;然后以单因素及多因素分析筛选Holter上缺血性改变的影响因素;最后建立ROC曲线评估LVPW厚度预测发生缺血性改变的价值。结果高血压患者Holter上有或无缺血性改变与LVPW厚度及收缩压（SBP）均呈正相关（r=0.429,P=0.000;r=0.274,P=0.034）,高血压伴有缺血性改变的患者其LVPW厚度与无缺血性改变的患者相比差异有统计学意义（z=-5.025,P=0.000）;伴有LVPW增厚的高血压患者出现Holter上缺血性改变的机率高于无LVPW增厚的患者（χ2=23.670,P=0.000）;多因素分析中只有LVPW厚度被筛选出来（OR=26.024,P=0.001）;以LVPW厚度预测心肌缺血的AUC为（0.760±0.044）,P=0.000。最佳分界值为9.5mm,以LVPW≥9.5mm来预测高血压患者Holter上出现缺血性改变,敏感性为63.6%,特异性为80.9%。结论高血压患者Holter上出现缺血性改变与LVPW厚度呈正相关;以LVPW预测高血压患者Holter上出现缺血性改变的特异性较高,但敏感性较差。     

超声心动图评价高血压患者血清脂联素水平与左心室心肌质量和舒张功能的关系

目的探讨高血压患者血清脂联素水平对左心室心肌质量(LVM)及舒张功能的影响。方法入选单纯高血压患者65例(其中男性36例,女性29例;年龄34～78岁,平均年龄53.78岁)和正常对照组33例(其中男性17例,女性16例;年龄32～65岁,平均年龄52岁)。采用酶联免疫吸附分析法测定血清脂联素水平。采用超声心动图测定LVM、左心室射血分数和代表左心室舒张功能的指标E/e比值、舒张早期左心室内血流传播速度(Vp)和左心室Tei指数。结果高血压组左心室心肌质量指数显著高于正常对照组[(123.58±45.40)g/m2 vs(87.29±17.40)g/m2;P<0.05]。高血压组Vp显著低于正常对照组[(41.25±9.86)cm/s vs(56.31±8.79)cm/s,P<0.01],而E/e比值和Tei指数显著高于正常对照组(8.28±1.96 vs 7.26±1.56,0.46±0.15 vs 0.39±0.12;P<0.05)。在高血压组中血清脂联素水平与左心室心肌质量指数、E/e比值和Tei指数均呈显著负相关(r分别为-0.36、-0.56、-0.58,P<0.05),而与Vp呈显著正相关(r为0.67,P=0.023)。多元逐步回归分析表明血清脂联素水平能分别进入以Vp和Tei指数为因变量的回归方程中。结论血清脂联素水平与左心室心肌质量指数呈显著负相关,血清脂联素水平降低是导致左心室舒张功能降低的危险因素之一。     

兔在体左室肥厚心肌跨室壁电异质性的实验研究

目的：探讨兔在体左室肥厚心肌单相动作电位跨室壁的不均一性变化。方法：以腹主动脉缩窄术制备家兔高血压左室肥厚模型，并设假手术组（仅游离腹主动脉未缩窄）作为对照。采用自制复合式电极在兔左心室前壁同步记录心内膜、心肌中层、心外膜在体3层心肌单相动作电位（MAP），比较两组间跨室壁复极离散度(TDR)等各项参数的差异。结果：腹主动脉缩窄组平均动脉压、全心重量及其与体重比率、左心室游离壁厚度均大于假手术组。缩窄组3层心肌MAPD100［内膜：(191±19)ms；中层：(244±24)ms;外膜：(196±15)ms］均长于对照组［内膜：(170±18)ms ;中层：(172±15)ms;外膜：(168±16)ms，P<0.01］，以中层心肌MAPD100延长最为明显，缩窄组TDR（65±10)ms较对照组（4±3)ms明显增大（P<0.01）。结论：兔在体左室肥厚心肌跨室壁电不均一性明显增大，可能是肥厚心肌心律失常发生增多的原因之一。     

Doppler echocardiographic analysis of diastolic left ventricular function in dialysis patients and its relation to intradialytic hypotension

Summary Doppler echocardiography was used to evaluate left ventricular relaxation and filling in 20 patients on chronic maintenance hemodialysis. In comparison with 11 normal controls hemodialysed patients showed a marked prolongation of isovolumic relaxation period (83±23 ms vs 67±11 ms,P<0.01). Peak velocity of early diastolic filling was similar in both groups, but peak velocity of late ventricular filling due to atrial contraction was substantially increased in dialysis patients (66±23 cm/s vs 37±7 cm/s,P<0.01) and the ratio late to early peak velocity was significantly enlarged (0.97±0.35 vs 0.58±0.19,P<0.01). Although left ventricular mass index, as determined by Echo, was markedly increased in dialysis patients, no significant correlation was found between ventricular mass and indexes of diastolic function. When patients were divided into two groups on the basis of development of hypotension during dialysis clinical and echocardiographic characteristics were similar, although patients with dialysis hypotension (n=9) were significantly older (53±9 years) than normotensiv patients (n=11, 42±14 years,P<0.05). Indexes of diastolic function showed a great overlap between the two groups, but ratio late to early peak velocity was significantly greater in patients with intradialytic hypotension (1.13±0.35 vs 0.83±0.32,P<0.05). It is concluded that dialysis patients exhibit significant alterations of left ventricular relaxation and diastolic filling as assessed by Doppler echocardiography which might be independent of left ventricular hypertrophy. Impaired diastolic function might contribute to intradialytic hypotension.Abbreviations DEF deceleration of early diastolic flow - IVRP isovolumic relaxation period - peakA peak velocity of late left ventricular filling - peakE peak velocity of early left ventricular filling     

Uncommon cause of obstruction in the left ventricular outflow tract by a metastasis of adenocarcinoma

Cardiac metastases are rare diagnoses among cardiac disorders. This case demonstrates a unique presence of an obstruction in the left ventricular outflow tract caused by the metastasis of a renal carcinoma. Adequate diagnostic and therapeutic procedures were lifesaving in this potentially fatal diagnosis.