The characteristics of left ventricular filling in a mild grade of physiological and pathological hypertrophy. A Doppler echocardiographic study

The aim of this study was to evaluate diastolic function in athletes and in young borderline hypertensives with mild left ventricular hypertrophy. To compare the effects on left ventricular filling of these two conditions we studied 15 borderline hypertensives (age 21 +/- 3 yrs, left ventricular mass index 137 +/- 9 g/m2), 18 soccer players (age 22 +/- 4 yrs, left ventricular mass index 136 +/- 12 g/m2) and 20 normotensive subjects (age 22 +/- 4 yrs, left ventricular mass index 94 +/- 10 g/m2) using the echo-Doppler technique. Left ventricular mass (LVM) was calculated with Devereux's formula. The criterion for left ventricular hypertrophy was left ventricular mass index greater than or equal to 120 g/m2. The following parameters of left ventricular filling were evaluated by Doppler transmitral flow analysis: the early (E) and late (A) peak velocity, the ratio E/A, the integral of early (Ei) and late (Ai) diastolic velocity. We concluded that the left ventricular filling profile was similar in borderline hypertensives, in athletes and in normotrophic subjects. These findings suggest that at least in its early stages, mild cardiac hypertrophy secondary to pathological stimulus is characterized by indices of diastolic function which are no different to those found in athletes with physiological hypertrophy.     

Influence of a rapid change of left ventricular dimensions on the echocardiographic measurement of left ventricular mass by the Penn convention.

OBJECTIVE: The purpose of this study was to test the robustness of the measurement of left ventricle mass (LVM), using Devereux's formula, in the presence of a rapid change in left ventricular volume induced by nitroglycerin. DESIGN: Forty-eight healthy volunteers with excellent echocardiographic recordings were included. The intrapatient variability of LVM measurement was assessed by two consecutive echocardiograms. The intraobserver reproducibility was assessed by the rereading of 19 echocardiograms by the same observer. The effects of nitroglycerin were compared with those of a placebo in a double-blind random manner on, the left ventricular internal dimension in diastole (LVIDd), the interventricular septum thickness, the posterior wall thickness and the LVM. RESULTS: It was shown that both the intrapatient and the intraobserver reproducibility were high. Nitroglycerin induced a significant decrease in LVIDd compared with placebo (-0.21 +/- 0.24 versus 0.01 +/- 0.21 cm, respectively, P < 0.01) and a non-significant increase in wall thickness. These variations were negatively correlated with each other (r= -0.58, P< 0.01). Despite the change of ventricular dimensions, the variation of LVM induced by nitroglycerin was not significantly different from that induced by placebo (2.0 +/- 16.0 versus 4.7 +/- 17.0 g, respectively, not significant) and close to the intrapatient variability. CONCLUSION: This experiment failed to demonstrate any influence of a rapid variation of ventricle size on the calculation of LVM with the Penn convention and strongly supports the robustness of the method in vivo.     

Comparison of M-mode echocardiography and angiography in the evaluation of left ventricular hypertrophy

The authors analysed in a group of 82 patients with a symmetric left ventricle and a homogeneous ventricular wall thickness the reliability of M-mode echocardiography in recognizing left ventricular hypertrophy. In concentric hypertrophies, a sufficient diagnostic criterion is ventricular wall thickness. Measurement of the interventricular septum offers a better correlation with angiographic values (r = 0.609, p less than 0.001) than measurement of the posterior wall (r = 0.358, p less than 0.01); a correct diagnosis can be determined in 84%. In excentric hypertrophies, the hypertrophy must be assessed on the basis of calculating the left ventricular mass. The most accurate of echocardiographic methods proved to be the calculation according to the authors' own formula (r = 0.760, p less than 0.001), which recognizes left ventricular hypertrophy correctly in 85%. The diagnostic correctness of Teichholz' formula is 80% and of the cubic formula 74%. Fortuin's equations proved to be of no value for documenting ventricular hypertrophy. In a group of 13 patients with hypertrophic cardiomyopathy, the correlation between angiographic and echocardiographic values of the left ventricular mass was very low (r = 0.534, p = 0.05).     

Interpretation of cardiac pathophysiology from pressure waveform analysis: mitral valve gradients: Part I.

The mitral valve gradient is dependent on the precise measurement of left atrial (or pulmonary capillary wedge) and left ventricular pressures. Artifacts involving either pressure measurement will produce inaccuracies which may have clinical significance. Several methods and formulas using both invasive and noninvasive techniques should verify clinical findings and confirm the severity of mitral valve disease prior to definite therapy. The changes in mitral valve gradients after balloon catheter valvuloplasty will be discussed in part II of this hemodynamic rounds.     

Prognostic value of left ventricular hypertrophy and geometry in patients with a first, uncomplicated myocardial infarction

BACKGROUND: The prognostic impact of left ventricular (LV) geometry on cardiovascular risk for patients with a first, uncomplicated acute myocardial infarction (AMI), and echocardiographic ejection fraction > or =50% has not been well described. METHODS AND RESULTS: Accordingly, 111 AMI consecutive patients (mean age 59.3+/-10 years) performed echocardiographic examination at predischarge. LV mass was calculated by means of Devereux's formula and subsequently indexed by body surface area. Fifty-three patients had LV hypertrophy and 58 patients had normal LV mass. The two groups were homogeneous for demographic, clinical and angiographic variables as well as for the incidence of residual ischemia on predischarge stress testing. During follow-up period there were 24 cardiac events (cardiac death, unstable angina and non-fatal reinfarction) in the 53 patients with LV hypertrophy and only four events in the remaining 58 patients without LV hypertrophy (RR=2.45; CI=1.76-3.41; P<0.0001). The patients with concentric LV hypertrophy showed a higher incidence of events (64%) than patients with eccentric LV hypertrophy (32%, P<0. 05) and patients with normal geometry and mass (6%, P<0.0001). Multivariate Cox regression model identified concentric geometry as the most powerful predictor of combined end-points (chi(2)=32.7, P<0. 0001). CONCLUSIONS: An increased LV mass and concentric geometry resulted important independent markers of an adverse outcome in patients with a first, uncomplicated myocardial infarction and good LV function.     

The usefulness of the electrocardiogram in the diagnosis of left ventricular hypertrophy in essential arterial hypertension]

The aim of the study is to analyse the usefulness of electrocardiographic criteria of left ventricular hypertrophy in essential hypertension. Seventy four patients (27 males, 47 females), 49 +/- 11 years--old with mild--moderate systemic hypertension (blood pressure greater than or equal to 140/90 mmHg) have been prospectively studied. A 12-lead electrocardiogram and an echocardiogram (M and 2D mode) have been performed after the basic clinical study. A left ventricular mass index (Devereux's method) greater than 131 g/square meters (males) or greater than 110 g/square meters (females) has been considered as left ventricular hypertrophy. Sensitivity, specificity and accuracy of 11 current electrocardiographic criteria of left ventricular hypertrophy have been determined. Sensitivity of these criteria was very low (0-0.35), while specificity was high (0.71-1). Total QRS voltage showed the best accuracy (0.51), while V5 or V6 R wave amplitude greater than 26 mm showed the best sensitivity (0.35). Current electrocardiographic criteria of left ventricular hypertrophy are not very useful in the diagnosis of left ventricular hypertrophy in essential hypertension.     

Electrocardiographic changes and echocardiography variations in ventricular morphology in left ventricular overload

In order to compare the ECG patterns to several echocardiographic morphological indexes in different left ventricular overloadings, 15 cases of systolic left ventricular overloading (SLVO) and 17 cases of diastolic left ventricular overloading (DLVO) were analyzed. The current ECG changes of left ventricular hypertrophy and some original parameters of ventricular repolarization have been correlated with volumes, ejection fraction and mass of the left ventricle (calculated by Reichek's formula) and with left ventricular diastolic and systolic eccentricity indexes, derived by the application of Fishl's formula to the 2D echocardiographic four or two chamber apical view. In both SLVO and DLVO we found a correlation between the left ventricular mass and Romhilt-Estes point score system (p = 0.02) as well as the degree of ventricular repolarization abnormalities (p = 0.01). In SLVO we found a direct correlation between negative P wave deflection on lead V1 and diastolic as well as systolic eccentricity index: that is, the more negative P wave the more elongated left ventricular geometry. Moreover, in SLVO we found an interesting apposite correlation, compared with DLVO, between the systolic eccentricity index and the degree of ventricular repolarization abnormalities: in SLVO ST depression or T wave inversion on left limb or left precordial leads was associated with the maintenance of an elongated shape of left ventricle, while in DLVO the same ventricular repolarization abnormalities were associated with the loss of the elongated geometry of left ventricle which became spheric. Thus ECG correlates with echocardiographic left ventricular mass if poliparametric voltage indexes are considered.(ABSTRACT TRUNCATED AT 250 WORDS)     

Accuracy of computerized electrocardiographic identification of left ventricular hypertrophy as determined by echocardiographic measurements of left ventricular mass: evaluation of a widely used computer program

The Hewlett-Packard 1000 electrocardiographic management system employs a user-interactive computer with revisable software. The diagnostic accuracy of this system in predicting left ventricular hypertrophy has been evaluated by comparing computer-predicted with anatomic left ventricular hypertrophy. The latter was defined as a left ventricular mass greater than 247 g as determined by M-mode echocardiography within 1 week of the computerized electrocardiogram. In this study, the Hewlett-Packard system was evaluated in 134 consecutive patients having anatomic left ventricular hypertrophy and 157 similarly studied patients with a normal left ventricular mass. By means of various combinations of voltage criteria, ST-T wave changes, abnormal QRS duration or ventricular activation time, left atrial enlargement and left axis deviation, the computer correctly identified 43 of 134 patients with left ventricular hypertrophy (sensitivity 32%); left ventricular hypertrophy was suggested or identified in an additional 18 patients with a normal left ventricular mass (specificity 89%). Graded probability statements (that is, the "strength" of the left ventricular hypertrophy diagnosis) increased with ventricular mass not only in patients with anatomic left ventricular hypertrophy but also in the patients with a "false positive" computerized electrocardiogram. Overall diagnostic accuracy was improved only in men by adjusting the definition of left ventricular hypertrophy for sex (at least 300 g for men and 220 g for women). Diagnostic accuracy was significantly better in patients 65 years of age and younger than in older patients (p = 0.007). It is concluded that the overall performance of this computer program (version ECLSB6) requires modification to improve its accuracy in identifying left ventricular hypertrophy.     

Effects of verapamil and nifedipine on blood pressure during rest and exertion and on left ventricular hypertrophy]

The effects of 6 months treatment with nifedipine 20 mg SR (N) or verapamil 240 mg SR (V) on rest and exercise BP and left ventricular mass (LVM) and function were evaluated in 31 essential hypertensive patients (mean age: 54, 19 males, 12 females), never treated with calcium antagonist. After a 15 days placebo run in, BP was measured at rest and during a maximal bicycle exercise test (stages: 30 watts, 3 min). 2D guided M mode echocardiography and pulsed Doppler allowed assessment of left ventricular mass (Devereux's formula) and function (fractional shortening FS, peak early (E) and late (A) velocities of LV filling). Patients were randomised to N (n = 18) or V (n = 13) and reassessed 6 months later. All echo-Doppler recordings were read blindly by 2 observers. Results: rest BP was similarly reduced in both groups (V: 148 +/- 12/88 +/- 5 vs 162 +/- 10/101 +/- 7; N: 148 +/- 15/90 +/- 7 vs 170 +/- 14/101 +/- 8), as well as exercise maximal BP (V: 224 +/- 32/93 +/- 11 vs 243 +/- 21/104 +/- 11; N: 206 +/- 27/90 +/- 10 vs 231 +/- 17/97 +/- 8). The duration of exercise was significantly increased with V (15 +/- 5 min vs 12 +/- 4, p < 0.05) and insignificantly decreased with N (11 +/- 2 vs 12 +/- 3). Left ventricular mass was higher in V group at entry and was significantly more reduced with V (250 g +/- 74 vs 302 g +/- 92, p < 0.01) than with N (225 g +/- 54 vs 234 g +/- 69).(ABSTRACT TRUNCATED AT 250 WORDS)     

Experimental study of quantitative assessment of left ventricular mass with contrast enhanced real-time three-dimensional echocardiography

OBJECTIVES: To evaluate the feasibility and accuracy of measurement of left ventricular mass with intravenous contrast enhanced real-time three-dimensional (RT3D) echocardiography in the experimental setting. METHODS: RT3D echocardiography was performed in 13 open-chest mongrel dogs before and after intravenous infusion of a perfluorocarbon contrast agent. Left ventricular myocardium volume was measured according to the apical four-plane method provided by TomTec 4D cardio-View RT1.0 software, then the left ventricular mass was calculated as the myocardial volume multiplied by the relative density of myocardium. Correlative analysis and paired t-test were performed between left ventricular mass obtained from RT3D echocardiography and the anatomic measurements. RESULTS: Anatomic measurement of total left ventricular mass was 55.6 +/- 9.3 g, whereas RT3D echocardiographic calculation of left ventricular mass before and after intravenous perfluorocarbon contrast agent was 57.5 +/- 11.4 and 55.5 +/- 9.3 g, respectively. A significant correlation was observed between the RT3D echocardiographic estimates of total left ventricular mass and the corresponding anatomic measurements (r = 0.95). A strong correlation was found between RT3D echocardiographic estimates of left ventricular mass with perfluorocarbon contrast and the anatomic results (r = 0.99). Analysis of intraobserver and interobserver variability showed strong indexes of agreement in the measurement of left ventricular mass with pre and post-contrast RT3D echocardiography. CONCLUSIONS: Measurements of left ventricular mass derived from RT3D echocardiography with and without intravenous contrast showed a significant correlation with the anatomic results. Contrast enhanced RT3D echocardiography permitted better visualization of the endocardial border, which would provide a more accurate and reliable means of determining left ventricular myocardial mass in the experimental setting.     

Can Anatomical Left Ventricular Mass Be Estimated Reliably by M-Mode Echocardiography? A Clinicopathological Study of Ninety-Three Patients

To evaluate the accuracy ofM-mode echocardiography in the assessment of left ventricular mass, we compared various echocardiography-derived regression equations for left ventricular mass to postmortem left ventricular weights in 93 patients (mean age 68 ± 11 years) who had autopsy within 30 days of technically adequate two-dimensional guided M-mode echocardiography and who had normal left ventricular shape. The left ventricle was enlarged in 36 patients (39%) and was involved by chronic ischemic disease in 48 patients (52%). Only a modest correlation was found between M-mode echocardiography and anatomical left ventricular mass (range of correlation coefficients, 0.58 to 0.67). Each echocardiography formula demonstrated increasing deviations as left ventricular mass increased. A previously suggested correction formula lessened overestimation, but considerable data dispersion remained. Regional wall-motion abnormalities, present in 22%, did not affect the correlation. We conclude that M-mode echocardiography, performed with standard methods, does not reliably estimate anatomical left ventricular mass, especially in patients with large hearts. (ECHOCARDIOGRAPHY, Volume 8, January 1991)     

Correlates of left ventricular mass in hypertensive Nigerians: an echocardiographic study

Background

Studies have shown that left ventricular mass, diagnosed by echocardiography, correlated poorly with blood pressure, even when the 24-hour ambulatory blood pressure monitoring was taken into account in the analysis. This may be partly because there are other determinants of left ventricular mass such as age, gender, neurohormonal factors and heredity.Knowledge of the correlates of left ventricular mass could help design individual and population strategies to prevent or reverse left ventricular hypertrophy. To the best of our knowledge, there is a paucity of such studies in native Africans. Hence the purpose of this study was to define the correlates of left ventricular mass in hypertensive Nigerians.

Methods

The study was a retrospective analysis of prospectively collected data in 285 hypertensive subjects. Echocardiographic left ventricular mass was determined using the standard formula. Stepwise multiple regression analysis was used to determine the independent predictors of left ventricular mass with a probability value to enter and remove of p < 0.05.

Results

There were 153 men (53.7%) and 132 women (46.3%) in the study. The mean age of all subjects was 58.2 ± 13.7 years. There was no significant gender difference in most of the echocardiographic parameters. In a stepwise multiple regression analysis, left ventricular wall tension, left ventricular wall stress, left atrial size, diastolic blood pressure, alcohol consumption and a family history of hypertension were the independent predictors of left ventricular mass in this population. The optimum multivariate linear regression main effects had an adjusted model, r² of 0.945, thus explaining about 95% of left ventricular mass variability.

Conclusion

Mechanical or haemodynamic factors possibly interacting with genetic and social factors are the likely determinants of left ventricular mass in hypertensive Nigerians. Therefore modulation of some of these factors pharmacologically or non-pharmacologically will be of benefit in the management of this patient population.     

Role of the left atrium in adaptation of the heart to chronic mitral regurgitation in conscious dogs

The manner in which the left atrium adapts to chronic mitral regurgitation and the role of the adapted left atrium as a modulator of excessive central blood volume were analyzed in seven conscious dogs, instrumented with high-fidelity pressure transducers and ultrasonic dimension gauges for measurement of left atrial and left ventricular pressure and cavity size. After obtaining data in a control situation, mitral regurgitation was produced by transventricular chordal sectioning. Heart rate was matched by right atrial pacing. In the "early" stage (7-14 days), left ventricular end-diastolic and mean left atrial pressures increased from 6 to 16 mm Hg and from 4 to 12 mm Hg, respectively. Both left ventricular end-diastolic segment length and left atrial diameter prior to atrial contraction increased by 7%. In the "late" stage (20-35 days), despite significant decreases in left ventricular filling pressure (11 mm Hg) and left atrial pressure (8 mm Hg), there was a continuous increase in left ventricular end-diastolic dimension (10%) and atrial end-diastolic diameter (10%). After the onset of mitral regurgitation, the left atrium performed greater work with a more enlarged cavity. Left atrial chamber stiffness was progressively decreased. These changes were associated with progressive increase in the left atrial diameter at zero stress, and there was a significant increase in the diameter of the left atrial myocyte. These results indicate that during chronic mitral regurgitation, the left atrium enlarges in size and mass, with a more potent booster action. The left atrial chamber becomes more compliant. Thus, the enlarged left atrium appears to exert an important compensatory mechanism in the case of excessive central blood volume by buffering pressure rise in the atrium and by providing an adequate ventricular filling volume.     

Pulsed Doppler evaluation of left ventricular filling in stable and borderline juvenile arterial hypertension

Left ventricular hypertrophy in hypertensive patients may be associated with changes in diastolic function. To examine whether or not any alteration in left ventricular function is also present in the early phases of hypertension, left ventricular filling was studied using the echo-Doppler method in 30 young mild hypertensive patients, 40 borderline untreated hypertensives and 30 age-matched normotensive controls. Left ventricular wall thickness, left ventricular mass (Dévereux formula) and shortening fraction were measured using M-mode echocardiogram under 2D control. Trans-mitral flow was measured by pulsed-Doppler and the following parameters were derived: peak early (E) and atrial (A) diastolic flow rate, their ratio E/A, the integral of early (Ei) and atrial (Ai) diastolic flow rates and their ratio (Ei/Ai). Our data show that left ventricular mass is greater in mild hypertensive patients than in borderline and normal controls. No differences in left ventricular systolic function were found in the three groups whereas diastolic function changes were present in the hypertensive group: in particular the peak early/atrial flow rate ratio was significantly reduced compared with the other two groups. Therefore, it appears that changes in diastolic function may also be present even in the early phases of mild hypertension.     

Limits of reproducibility of cross-sectional echocardiographic measurements of left ventricular muscle mass.

The total intrinsic variability of echocardiographically determined left ventricular muscle mass was evaluated in this study. Cross-sectional left ventricular echocardiograms were made in 13 normal volunteers (8 men, 5 women), ages 31 to 41 years (mean 36) with an interval period of about eleven months. We used the parasternal long axis view, the short axis view at the papillary muscle level and the four-chamber view from the apex. M-mode recordings were made from the parasternal long-axis view. Left ventricular muscle mass from M-mode recordings was calculated using a simple cube formula and from cross-sectional echo cardiography with an area-length formula. The reproducibility of the left ventricular muscle mass for the methods was respectively 10 +/- 6% and 5 +/- 3% (mean +/- SD). From both methods cross-sectional echo is the method of choice for determining left ventricular muscle mass in man in sequential studies.     

Should echocardiography be performed to assess effects of antihypertensive therapy? Test-retest reliability of echocardiography for measurement of left ventricular mass and function

Objectives. The purpose of this study was to determine the test-retest stability of echocardiography for the measurement of left ventricular mass and function in patients with hypertension.Background. Determination of changes in left ventricular mass may be impaired by study variability. The amount by which variables of mass and left ventricular function must change in an individual patient to exceed temporal variability has not been determined in a multicenter trial.Methods. Ninety-six patients with hypertension had two-demensional targeted, M-mode Doppler echocardiography repeated at 6 ± 8 days by the same technician utilizing the same machine. Left ventricular mass and variables of systolic and diastolic function were measured. Test-retest reliability and the width of the 95% confidence intervals of variable change, as well as the contributions of age, study quality and body size to measurement reliability, were determined.Results. Despite excellent reliability (intraclass coefficient of correlation 0.86), the 95% confidence interval width of a single replicate measurement of left ventricular mass was 59 g, exceeding usual decreases in mass during treatment. Study quality, which was dependent on age and weight, influenced test reliability. Although the confidence interval width for ejection fraction was narrow (5 U), those for peak early (E) and late (A) diastolic velocities were wide, resulting in a confidence interval width for the E/A ratio of 1.5.Conclusions. The temporal variability, particularly in obese or elderly patients, or both, of echocardiography for measurement of left ventricular mass precludes its use to measure changes in mass of the magnitude likely to occur with therapy. Measurement stability is affected by study quality, and age and body weight both influence study quality. Although ejection fraction shows little temporal variability, the large width of the confidence interval of the Doppler E/A ratio impairs its use to serially measure diastolic function.     

Effects of angiotensin-converting enzyme gene polymorphism and serum vitamin D levels on ambulatory blood pressure measurement and left ventricular mass in Turkish hypertensive population

INTRODUCTION: Regulation of angiotensin converting enzyme (ACE) and angiotensin II (ang-II) levels is under genetic control. 1,25(OH)2 vitamin D3 treatment has been shown to reduce the ang-II level, reduce myocardial hypertrophy and to decrease blood pressure. This study was designed to examine the effect of ACE gene polymorphisms on 24-h ambulatory blood pressure measurement (24 h) values, vitamin D levels and target organ damage in hypertensive patients. METHODS: This study was carried on 118 patients with essential hypertension (female/male: 70/48, mean age: 49.1+/-7.6 years, hypertension duration: 56+/-40.5 months). All patients were assessed for target organ damage; the eye by retinal examination, the heart with echocardiography and the kidney with blood and 24-h urine analysis. 24-h ambulatory blood pressure measurement was performed in all patients. PCR amplification was employed to detect ACE genotypes. RESULTS: ACE genotypes were as follows: DD (n=49) 41.5%; ID (n=37) 31.4% and II (n=32) 27.1%. No difference was present between groups of ACE polymorphism when 24-h ambulatory blood pressure measurement values, retinal vascular changes and microalbuminuria were taken into account. Statistically significant left ventricular mass index levels were obtained in the DD group when compared with the non-DD (ID+II) group (P : 0.009). Positive correlations have been noted between left ventricular mass index and day/night and early morning systolic pressures. A negative correlation exists between serum 25 (OH) vitamin D levels and 24-h ambulatory blood pressure measurement values (P<0.05). CONCLUSIONS: The presence of the D allele is linked with a higher risk for left ventricular mass index in the Turkish hypertensive population.     

Reproducibility of quantitative two-dimensional echocardiography

In order to assess reproducibility of quantitative planimetry, three physicians trained in two-dimensional echocardiography performed five successive studies on one another over 2 weeks (30 total studies). Then each physician traced each study (90 total tracings) for left ventricular and atrial volumes and ejection fraction by means of a modification of Simpson's rule, and left ventricular mass and average wall thickness by means of a truncated ellipsoid formula. Calculation of intertechnician variability, intertracer variability, and 95% confidence limits showed that measurements of volumes were less reproducible than measurements of ejection fraction, average wall thickness, and mass. Mean intertracer variability of 15% exceeded mean intertechnician variability of 11%; this disparity was magnified in the subject who was technically difficult to image. Ninety-five percent confidence limits were: ejection fraction +/- 7%, average wall thickness +/- 9%, left ventricular mass +/- 12%, left ventricular end-diastolic volume +/- 11%, stroke volume +/- 14%, left ventricular end-systolic volume +/- 15%, and left atrial volume +/- 19%. Reproducible planimetry data can be obtained in normal hearts with the use of a protocol for quantitative imaging and planimetry.     

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。     

Reproducibility of left ventricular mass measurements by two-dimensional and M-mode echocardiography

Both two-dimensional and M-mode echocardiography provide accurate estimates of left ventricular mass. However, their reproducibility in serial studies has not been compared, although this issue is critical to evaluation of regression of hypertrophy. To determine which technique provides more reproducible estimates of left ventricular mass, three serial studies were performed prospectively in each of eight normal adults over 5 months. Both two-dimensional and M-mode echocardiograms were obtained at each of these 24 studies. Measurements were performed by two independent observers who did not know patient identity. For the two-dimensional method, left ventricular mass was determined with use of a computer light-pen system and the truncated ellipsoid formula. For the M-mode method, mass was calculated from Penn convention measurements with use of the cube formula. At study 1 the group mean left ventricular mass by two-dimensional echocardiography (115 +/- 20 g) did not differ from that by M-mode study (127 +/- 37 g, p = NS). However, serial estimates of left ventricular mass were more reproducible by two-dimensional echocardiography. The mean difference among the three serial two-dimensional studies in each individual was 4.8 +/- 4 g (4.2 +/- 3%) by the two-dimensional method, but was 18.5 +/- 13 g (14.9 +/- 10%) by the M-mode method (p = 0.01). Interobserver results for left ventricular mass by two-dimensional echocardiography correlated closely (r = 0.95, n = 24, p less than 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)