QT dispersion and left ventricular geometry in hypertensive patients

It has been shown that increased QT dispersion (QTd) reflects electrical inhomogeneity of the myocardium and is associated with high incidence of ventricular arrhythmias. In some cases increased QTd has also been found in some hypertensive patients with left ventricular hypertrophy. The aim of the study was to investigate the relation between QTd and left ventricular (LV) geometry in hypertensive patients (pts). Studied group consisted of 80 pts aged 52.5 +/- 12.6 yrs with mild, moderate and severe hypertension. Nineteen healthy subjects aged 50.5 +/- 9.6 yrs served as control group. QTd was calculated as a difference between the longest QT and shortest QT from the 12-leads of the standard electrocardiogram. Each subject underwent echocardiographic study to determine the pattern of LV geometry divided into: normal (NG), concentric remodeling (CR), excentric hypertrophy (EH) and concentric hypertrophy (CH). Significantly higher QTd was found out in pts with CH and EH as compared to CG (respectively 61 +/- 10 ms, 69 +/- 15 ms vs 46 +/- 14 ms, p < 0.01). Moreover, pts with CH had higher QTd than NG (69 +/- 15 ms vs 55 +/- 15 ms, p < 0.01). CONCLUSION: QTd is related to the pattern of LV geometry. As compared to healthy subjects it is increased in hypertensive pts with concentric and eccentric hypertrophy. In pts with CH QTd is significantly greater than in hypertensive pts with normal geometry.     

Echocardiographic left ventricular geometry in hypertensive patients with electrocardiographic left ventricular hypertrophy: The LIFE Study

Aim: To assess the prevalence of echocardiographic left ventricular hypertrophy (LVH) and concentric remodeling in hypertensive patients with electrocardiographic (ECG)-LVH and to estimate the costeffectiveness of echocardiography and ECG for detection of LVH.Design: Echocardiographic LV measurements and the prevalence of abnormal LV geometric patterns were compared between 964 hypertensive patients with ECG-LVH (Cornell voltage-duration product > 2440 and/or SV₁     

Relationship between Tei index of myocardial performance and left ventricular geometry in Nigerians with systemic hypertension

Introduction

Left ventricular geometry is associated with cardiovascular events and prognosis. The Tei index of myocardial performance is a combined index of systolic and diastolic dysfunction and has been shown to be a predictor of cardiovascular outcome in heart diseases. The relationship between the Tei index and left ventricular geometry has not been well studied. This study examined the association between the Tei index and left ventricular geometry among hypertensive Nigerian subjects.

Methods

We performed echocardiography on 164 hypertensives and 64 control subjects. They were grouped into four geometric patterns based on left ventricular mass and relative wall thickness. The Tei index was obtained from the summation of the isovolumic relaxation time and the isovolumic contraction time, divided by the ejection time. Statistical analysis was done using SPSS 16.0.

Results

Among the hypertensive subjects, 68 (41.4%) had concentric hypertrophy, 43 (26.2%) had concentric remodelling, 24 (14.6%) had eccentric hypertrophy, and 29 (17.7%) had normal geometry. The Tei index was significantly higher among the hypertensives with concentric hypertrophy (CH), concentric remodelling (CR) and eccentric hypertrophy (EH) compared to the hypertensives with normal geometry (0.83 ± 1.0, 0.71 ± 0.2, 0.80 ± 0.2 vs 0.61 ± 0.2, respectively). The Tei index was higher among hypertensives with CH and EH than those with CR. Stepwise regression analysis showed that the Tei index was related to ejection fraction, fractional shortening and mitral E/A ratio.

Conclusion

Among Nigerian hypertensives, LV systolic and diastolic functions (using the Tei index) were impaired in all subgroups of hypertensive patients according to their left ventricle geometry compared to the control group. This impairment was more advanced in patients with concentric and eccentric hypertrophy.     

Action of labetalol on norepinephrine myocardial content in left ventricular hypertrophy in hypertensive patients]

The high incidence of cardiovascular morbidity and mortality in hypertensive patients with left ventricular hypertrophy shows the great interest in understanding the pathophysiology of this process. Many reports suggest the role of catecholamines in generating left ventricular hypertrophy. The aim of this study is to evaluate the effect of labetalol on myocardial norepinephrine content in hypertensive subjects with left ventricular hypertrophy by using an isotopic norepinephrine marker, the 123I-meta-iodobenzylguanidine (123I-MIBG). Eight male and female hypertensive patients with left ventricular hypertrophy were investigated after a 30 day placebo period. Resting, ambulatory and effort blood pressure was measured. Echocardiographic parameters allowed measure of left ventricular mass index according to Devereux. And we considered left ventricular hypertrophy as left ventricular mass index greater than 120 g/m2. Cardiac and mediastinal radioactivity is detected 4 h after a 4 mCi i.v. injection of 123I-MIBG and MIBG myocardial uptake is definite as the cardiac/mediastinal ratio (N : 1.78 +/- 0.19). All subjects received at the beginning of the study (D0) 2 tablets of labetalol 200 mg, increased to 4 tablets if diastolic blood pressure during follow-up remained above 95 mmHg. Patients again underwent these explorations after 3 months of treatment (D90). Labetalol decreases in considerable manner MIBG myocardial uptake as it has been shown that it decreases tissular norepinephrine content in experimental studies. Therefore, MIBG myocardial uptake seems to be a reliable tool in evaluating drugs effect on cardiac sympathetic nervous system.     

高血压病左心室构型对房室性心律失常的影响

目的探讨高血压病左室重构不同构型对房、室性心律失常发生及其严重程度的影响。方法入选高血压病患者153例,均经24小时动态心电图检查判定心律失常情况,超声心动图检查分析左心室构型。根据超声心动图检查结果分为4组:正常构型组（31例）,向心性重构型组（45例）,向心性肥厚型组（42例）和离心性肥厚型组（35例）;比较左心室不同构型间心律失常发生率和严重程度的差异。结果①共检出房性心律失常105例（占68.6%）,室性心律失常74例（占48.4%）,两组有统计学差异（P<0.05）。②不管是房性心律失常、复杂房性心律失常,还是室性心律失常、复杂室性心律失常,他们在高血压病左室重构不同构型组间的发生率均有显著差异（P<0.05）,且以向心性肥厚型组和离心性肥厚型组的发生率最高（P<0.05）。结论高血压病左室重构不同构型间心律失常的发生及严重程度存在差异,且向心性肥厚型和离心性肥厚型易发生复杂房、室性心律失常。     

Utility of myocardial performance index measured by left ventricular catheterization

BACKGROUND: Myocardial performance index (MPI) is a valuable index of global ventricular performance. It is almost always measured by Doppler echocardiography. The purposes of this study were (I) to compare MPI measured by catheterization (MPIc) and that measured by Doppler echocardiography (MPId), and (2) to compare it with the functional status. MATERIALS AND METHODS: The study included 80 patients who had undergone left heart catheterization.The MPIc was measured from the pressure recordings obtained at left ventricle and aorta. RESULTS: Mean MPId and MPIc were 0.40 +/- 0.12 and 0.42 +/- 0.12, respectively. Mean left ventricular end diastolic pressure (LVEDP) was 13 +/- 5 mm Hg. Mean heart rate was 77 +/- 11 beats/min. Mann-Whitney U test revealed that MPIc could discriminate between the functional statuses of the patients. The regression analysis revealed that there is a good correlation between MPIc and MPId, LVEDP or heart rate.There was no significant difference between MPIc and MPId (p > 0.05). CONCLUSION: The present data show that (I) the MPIc has a strong correlation with MPId; (2) it is a good discriminator of functional status. It may provide an additional information regarding the left ventricular performance in patients who underwent the cardiac catheterization.     

Association of myocardial strain with left ventricular geometry and progression of hypertensive heart disease

Different patterns of abnormal left ventricular (LV) geometry are associated with variations in prognosis, but the mechanisms of these effects remain undefined. We investigated the association of myocardial deformation with these findings and their evolution. Two-dimensional echocardiography was performed in 85 hypertensive patients referred for serial evaluation (age 58 +/- 13 years, 48% male). LV mass index and regional wall thickness were used to assign patients into groups with normal geometry, concentric remodeling, concentric hypertrophy, and eccentric hypertrophy. Septal strain and strain rate were measured using velocity vector imaging. The evolution of morphological changes was followed over 2.7 +/- 1.3 years. Analysis of LV geometry revealed normal geometry in 13 patients (15%), concentric remodeling in 20 (24%), concentric hypertrophy in 42 (49%), and eccentric hypertrophy in 10 (12%). Overall strain was -13.6 +/- 4.5%, and strain rate was -0.65 +/- 0.24/second. Strain was significantly lower in patients with concentric remodeling (-12.8 +/- 4.2%) or concentric hypertrophy (-12.5 +/- 4.1%) compared with patients with normal geometry (-17.5 +/- 5.5%, p < or =0.05), and these associations were independent of blood pressure. Strain rate was also significantly reduced in patients with concentric hypertrophy (p < or =0.01). There were no significant differences in baseline strain, wall stress, blood pressure, or age between patients who changed LV geometric class and those who did not. In conclusion, baseline myocardial tissue deformation, but not evolution, is associated with LV geometry in treated hypertensive patients.     

多普勒超声心肌作功指数评价氯沙坦钾对老年高血压患者左室功能的作用

目的 :应用多普勒超声指标心肌作功指数 (MPI)评价氯沙坦钾对老年原发性高血压 (EH)患者左室功能的作用。方法 :38例老年EH患者 ,按照超声心动图左室肥厚 (LVH)的诊断标准分成无LVH(2 8例 )和LVH(10例 )两组 ,给予氯沙坦钾 5 0mg每日 1次口服 ,疗程 2 4周。治疗前后多普勒超声心动图测定左室室壁厚度和收缩、舒张功能 ,根据等容舒张期时间 (IRT)和等容收缩期时间 (ICT)之和与射血时间 (ET)的比值计算MPI。结果 :LVH组患者经氯沙坦钾治疗后左室重量指数 (LVMI)降低 ,但差异无统计学意义。两组患者射血分数 (EF)治疗前后均在正常范围 ,经氯沙坦钾治疗后IRT均显著缩短 [(12 0 .4 6± 2 3.84 )ms∶(96 .4 6± 2 3.19)ms;(12 5 .4 0± 2 5 .81)ms∶(92 .5 6± 2 9.98)ms,P <0 .0 1],MPI降低 [(0 .6 1± 0 .14 )∶(0 .4 4± 0 .12 ) ,P <0 .0 1;(0 .6 0± 0 .14 )∶(0 .4 7± 0 .13) ,P <0 .0 5 ]。MPI与IRT呈正相关 (r =0 .80 ,P <0 .0 1) ,与LVMI不相关 (r =- 0 .0 95 ,P >0 .0 5 )。结论 :氯沙坦钾能提高老年EH患者的左室功能。MPI综合反映心脏的收缩和舒张功能 ,其不受左室构型的影响 ,在高血压患者收缩功能正常的情况下是反映早期左心功能不全的指标。     

高血压病患者左心室几何构型与舒张功能变化的关系

目的　研究高血压病患者左心室重构与舒张功能变化的关系及影响因素。方法　依照左心室质量指数 (L V-MI)和相对室壁厚度 (RWT)将 89例无合并症的高血压病患者分为左心室正常构型组 (17例 )、向心性重构组 (2 3例 )、向心性肥厚组 (33例 )、离心性肥厚组 (16例 )。对超声心动图心脏结构和功能测值进行多元逐步回归分析 ,筛选出对左心室舒张功能有独立影响因素。在校正这些因素影响后 ,比较不同左心室几何构型组间心脏舒张功能的差异 ,82例正常人作为对照。结果　左心室舒张功能的主要独立影响因素包括性别、年龄、心率、L VMI,部分指标还有体重指数 (BMl)和吸烟水平。不同构型组间舒张功能指标未经校正或仅经性别、年龄、心率和 BMI校正后差异虽都具有高度显著性 (P<0 .0 5 ) ,但再校正或排外血压水平的影响后 ,组间差异显著性已不复存在。结论　不同构型组间左心室舒张功能指标的差异主要是血压水平不同所致。左心室结构指标虽是舒张功能指标的独立影响因素 ,但其影响强度尚不足以达到使不同构型组间差异有统计学显著性的程度。     

Impact of myocardial geometry on left ventricular performance in healthy black and white young adults

Racial differences in left ventricular (LV) structure are suggested by clinical and experimental studies. This study evaluates if racial differences in LV performance exist comparing black to white young males, by tissue Doppler echocardiography and myocardial performance index (MPI). We examined 40 healthy males, 20 blacks (mean age 27.6 +/- 4.4 years) and 20 whites (mean age 26.5 +/- 6.7 years). All subjects underwent conventional echocardiography, tissue Doppler echocardiography, and MPI assessment. No differences were found in LV diameters, volumes, mass, and hemodynamic measurements. Septal and posterior wall thicknesses were significantly increased in black subjects as well as the relative wall thickness. Systolic and diastolic functions estimated by conventional parameters were superimposable in the two groups. In black subjects, a significant increase of septal S-wave, peak velocity, and time-velocity integral were found. MPI was significantly higher in black compared to white subjects (0.46 +/- 0.05 vs 0.40 +/- 0.06, P < 0.002). A significant correlation between MPI and relative wall thickness (r = 0.54) was demonstrated. Besides, MPI correlated with S(pv) (r = 0.55) and S(tvi) (r = 0.38) at the septal site. In conclusion our data show a higher MPI in black subjects that seems to be geometry-dependent. Correlations between MPI and tissue Doppler echocardiography systolic indexes were found. Our findings suggest that racial differences in LV performance exist, especially, in the systolic function, even in the absence of other conventional echocardiographic changes.     

动态脉压指数对高血压患者左心室肥厚的影响

目的:探讨动态收缩压(SBP)、舒张压(DBP)、脉压(PP)和脉压指数(PPI)对高血压患者左心室肥厚的影响,评价PPI反映左心室肥厚的价值。方法:用动态血压监测仪测量128例高血压患者的PPI,按PPI≤0.40(28例)、0.41~0.50(47例)、0.51~0.60(35例)和>0.60(18例)分为4组;进行超声心动图检查,并测量各种参数,计算左室重量指数(LVMI);比较各组LVMI的差异。结果:随着PPI的增加,LVMI明显增大(P<0.05);经Spearman's相关分析,PPI与LVMI的相关系数r值(0.467)大于PP、SBP及DBP的r值(0.423,0.304,0.296)。结论:PPI可作为高血压患者左心室肥厚的预测指标。     

The effect of oral diltiazem on left ventricular performance in postinfarction patients

The purpose of the present study was to evaluate the effect of diltiazem on the left ventricular function in postinfarction patients. Twelve patients without cardiac decompensation at rest began diltiazem therapy beginning 3 months after an acute myocardial Q-wave infarction. Oral diltiazem was administered on the first day in a single dose (120 mg) and the following 2 weeks in a 60 mg three times a day (tid) regimen. The therapeutic effect was studied by isotope angiocardiography at rest using equilibrium measurements with technetium-99m. Acute as well as continuous treatment improved left ventricular function in terms of increased synergy of the contraction (decreased phase deviation from a median of 20.0 degrees to median of 12.4 degrees and 13.0 degrees, respectively, p less than 0.01) and increased ejection fraction from a median of 46% to a median of 50% and 51%, respectively, p less than 0.05. It is suggested that the improvement of left ventricular function may be due in part to decreased pressure rate product. This improved left ventricular function during diltiazem treatment may explain the improved prognosis induced by diltiazem in postinfarction patients.     

Impact of valvular regurgitation on left ventricular geometry and function in hypertensive patients with left ventricular hypertrophy: the LIFE study

Mild-to-moderate aortic and mitral regurgitation are frequently detected by echocardiogram in asymptomatic hypertensive patients. Our goal was to assess the prevalence and impact of mild-to-moderate mitral and/or aortic regurgitation on left ventricular (LV) structure and function in patients with hypertension and LV hypertrophy (LVH). Hypertensive patients with ECG LVH enrolled in the Losartan Intervention For Endpoint reduction in hypertension (LIFE) echocardiography substudy were evaluated. Among 939 patients with needed LV measurements and Doppler data, 242 had mild (1+) valvular regurgitation, and 51 patients had moderate (2+ or 3+) regurgitation of one or both valves. In analyses adjusting for gender, patients with mild mitral and/or aortic regurgitation had larger LV internal dimensions (5.25 vs 5.33 cm, P<0.05), higher LV mass indexed for body surface area (122 vs 125 g/m(2), P<0.05) or height(2.7) (55.4 vs 57.3, P<0.05), and larger left atrial diameter. Patients with moderate regurgitation of one or both valves had larger LV chambers (5.25 vs 5.9 cm, P<0.001), greater mean LV mass (232 vs 248 g, P<0.001) and LV mass indexed for body surface area or height(2.7), and higher Doppler stroke volume. Patients with moderate valvular regurgitation also had a higher prevalence of LVH due to an increased prevalence of eccentric LVH. There were no differences among groups defined by the presence and severity of valvular regurgitation in cardiac output, total peripheral resistance, or pulse pressure/stroke volume, indicating that the observed inter-group differences in LV geometry were not due to differences in the haemodynamic severity of hypertension. Hypertensive patients with mild-to-moderate mitral or aortic valvular insufficiency have additional LV structural and functional changes that may affect prognosis.     

The effect of isolated left bundle branch block on the myocardial velocities and myocardial performance index

OBJECTIVES: This study was planned in order to investigate the effect of left bundle branch block (LBBB) on myocardial velocities obtained by tissue Doppler echocardiography (TDE) and myocardial performance index (MPI). METHODS: Subjects with LBBB (n = 61) and age-matched healthy subjects (n = 60) were enrolled in the study. Left ventricular (LV) ejection fraction (EF), mitral inflow velocities (E-wave and A-wave), isovolumetric contraction and relaxation time (ICT and IRT), ejection time (ET), and flow propagation velocity (Vp) were measured by conventional echocardiography. Systolic velocity (Sm), early and late diastolic velocities (Em and Am) and time intervals were measured by TDE. MPI was calculated by the formula (ICT + IRT)/ET. RESULTS: LVEF and mitral E/A ratio were similar in both groups. Vp was lower in the LBBB group than in the control group, whereas the E/Em and the E/Vp ratio was higher. LV Sm and Em/Am ratio were lower in LBBB group. Right ventricular Sm and Em/Am ratio were similar in both groups. LV mean and RV MPI were significantly increased in LBBB group. CONCLUSION: These findings obtained by TDE show that isolated LBBB impairs the ventricular functions. Both of the LV and RV dysfunctions shown by the new parameters may contribute to increased morbidity and mortality in cases with isolated LBBB.     

Importance of the index of myocardial performance in evaluation of left ventricular function

The index of myocardial performance (MPI) has been used as an easily obtainable parameter that reflects both systolic and diastolic functions of the myocardium and correlates closely with invasive measurements. This study investigated the importance of MPI on assessment of left ventricular function in patients with critical coronary artery disease. Methods: We studied 82 patients who had coronary angiography and echocardiography. Patients in Group A were without critical coronary stenosis (n = 37, 17 females, 20 males, mean age 54 +/- 11 years) and patients in Group B had critical coronary stenosis (> 70%) without previous myocardial infarction (n = 45, 18 female, 27 male, mean age 57 +/- 10 years). Using echocardiographic parameters, left ventricular isovolumetric relaxation time (IRT), isovolumetric contraction time (ICT), ejection time (ET), ratio of velocity time integrals (vti) of early and late diastolic mitral flow (E/Avti), E deceleration time (EDT), MPI [(IRT + ICT) / ET], ejection fraction (EF), and fractional shortening (FS) were calculated. During cardiac catheterization, Dp/Dt [(diastolic blood pressure - left ventricular end diastolic pressure) / ICT] was calculated. Results: There were significant differences in IRT, EDT, E/Avti, and the MPI between Groups A and B (95.9 +/- 14.7 and 113.4 +/- 14.3 msec, P < 0.001; 164.5 +/- 44.8 and 186.2 +/- 33.6 msec, P < 0.05; 1.51 +/- 0.45 and 1.24 +/- 0.80 msec, P < 0.05; and 0.45 +/- 0.08 and 0.53 +/- 0.07 msec, P < 0.001, respectively), but there were no significant differences in ICT, ET, EF, FS, and Dp/Dt between the two groups. Both groups showed a close correlation between MPI and Dp/Dt (r = - 0.78 for Group A and r = - 0.82 for Group B). There were no significant differences in heart rate and systolic and diastolic blood pressure between the two groups. Conclusion: These data suggest that MPI may be a useful parameter and an early indicator of left ventricular dysfunction in patients with critical coronary artery disease and normal systolic function.     

社区运动疗法对老年高血压病人左心室重量指数的影响

目的:观察社区运动疗法对老年原发性高血压病人左心室重量指数的影响。方法:80名社区老年高血压病人随机分为运动组和对照组,每组40人。对照组只给予药物治疗,运动组在药物治疗的基础上给予运动疗法。超声心动仪测量舒张末期左室内径(LVd)、室间隔厚度(IVST)、左室后壁厚度。按Deverux公式计算左室肌重(LVM)及左室重量指数(LVMI)。动态血压监测仪记录血压并计算24小时平均收缩压(SBP)和舒张压(DBP)。结果:经1年规律性运动训练后,运动组平均SBP和平均DBP、IVST、LVPWT、LVMI较对照组和运动前明显下降(P<0.01);而对照组血压、左室结构各参数虽较1年前有下降趋势,但无统计学意义。结论:社区内运动疗法对老年原发性高血压病人降低血压、减轻左室肥厚,具有显著疗效。