体重指数校正心电图QRS电压对左心室肥大诊断的影响

目的探讨体重指数校正心电图QRS电压诊断左心室肥大的临床意义.方法检测58例原发性高血压患者和健康体检者心脏超声左心室质量指数(LVMI)、QRS电压校正值[实测值(SV11+Rv5/v6)×(BMI/22)2],观察QRS电压实测值、校正值与LVMI的相关性.结果QRS电压校正值与LVMI呈明显相关,回归方程为y(Sv1+Rv5/v6)c=0.298X(LVMI)-2.481,当LVMI=134g/m2时,取(Sv1+Rv5/v6)c近似值≥40mm,诊断左心室肥大敏感性69.6%,特异性91.4%、准确性82.8%,阳性预测值84.2%,阴性预测值82.1%.结论体重指数校正心电图QRS电压能显著提高左心室肥大的诊断价值.     

Relation of regional echo amplitude to left ventricular function and the electrocardiogram in left ventricular hypertrophy.

In order to determine the relation between three manifestations of left ventricular hypertrophy--ST-T wave changes on the electrocardiogram, diastolic disturbances, and increased myocardial echo intensity--M mode and cross sectional echocardiograms were recorded in 12 normal subjects, 15 athletes, 16 patients with hypertrophic cardiomyopathy, and 42 patients with secondary left ventricular hypertrophy due to aortic stenosis (20), severe essential hypertension (8), coarctation (7), or subaortic stenosis (7). M mode echocardiograms were digitised and cross sectional echocardiograms were analysed for regional echo intensity. In patients with hypertrophy regional echo amplitude was significantly increased in mid and basal septum and posterior left ventricular wall. Patients with increased echo amplitude in any region showed a higher incidence of ST-T wave abnormalities than those without and of diastolic abnormalities--including prolongation of isovolumic relaxation time, delay in mitral valve opening with respect to minimum cavity dimension, and a reduction in peak rate of posterior wall thinning and dimension increase. There was a significant rank order correlation between median pixel count and these diastolic abnormalities. No significant differences were demonstrable in these relations between the diagnostic groups. By contrast, electrocardiographic findings, diastolic function, and pixel count were uniformly normal in athletes, although the increase in left ventricular mass was similar to that in the patients. Thus an increase in left ventricular mass alone is not responsible for repolarisation or wall motion abnormalities occurring in pathological left ventricular hypertrophy. These latter changes are, however, strongly associated with the change in myocardial properties detected as an increase in echo intensity and may be due to increased interstitial fibrosis.     

Relation of regional echo amplitude to left ventricular function and the electrocardiogram in left ventricular hypertrophy

In order to determine the relation between three manifestations of left ventricular hypertrophy--ST-T wave changes on the electrocardiogram, diastolic disturbances, and increased myocardial echo intensity--M mode and cross sectional echocardiograms were recorded in 12 normal subjects, 15 athletes, 16 patients with hypertrophic cardiomyopathy, and 42 patients with secondary left ventricular hypertrophy due to aortic stenosis (20), severe essential hypertension (8), coarctation (7), or subaortic stenosis (7). M mode echocardiograms were digitised and cross sectional echocardiograms were analysed for regional echo intensity. In patients with hypertrophy regional echo amplitude was significantly increased in mid and basal septum and posterior left ventricular wall. Patients with increased echo amplitude in any region showed a higher incidence of ST-T wave abnormalities than those without and of diastolic abnormalities--including prolongation of isovolumic relaxation time, delay in mitral valve opening with respect to minimum cavity dimension, and a reduction in peak rate of posterior wall thinning and dimension increase. There was a significant rank order correlation between median pixel count and these diastolic abnormalities. No significant differences were demonstrable in these relations between the diagnostic groups. By contrast, electrocardiographic findings, diastolic function, and pixel count were uniformly normal in athletes, although the increase in left ventricular mass was similar to that in the patients. Thus an increase in left ventricular mass alone is not responsible for repolarisation or wall motion abnormalities occurring in pathological left ventricular hypertrophy. These latter changes are, however, strongly associated with the change in myocardial properties detected as an increase in echo intensity and may be due to increased interstitial fibrosis.     

Overestimation of left ventricular mass

Overestimation of left ventricular mass: yes, but with whichimaging? We read with interest the article by     

Isolated left ventricular noncompaction mimicking ventricular mass

Isolated left ventricular noncompaction is an inherited cardiomyopathy characterized by multiple prominent trabeculations with deep intertrabecular recesses. The diagnosis is often missed because echocardiography poses inherent problems of poor echo window in assessment of the LV apex, which is most commonly involved in noncompaction. We report a case in which conventional 2D echocardiography failed to demonstrate multiple prominent trabeculations. Contrast echocardiography confirmed the presence of multiple trabeculations with deep intertrabecular recesses. This report emphasizes the importance of contrast echocardiography in the diagnosis of ventricular noncompaction.     

Prediction of the extent and severity of left ventricular dysfunction in anterior acute myocardial infarction by the admission electrocardiogram

BACKGROUND: The grade of ischemia, as detected by the relation between the QRS complex and ST segment on the admission electrocardiogram, is associated with larger infarct size and increased mortality rates in acute myocardial infarction. METHODS: We assessed the correlation between left ventricular function and the admission electrocardiogram in 151 patients with first anterior acute myocardial infarction who received thrombolytic therapy and underwent cardiac catheterization at 90 minutes and before hospital discharge. The number of leads with ST elevation, sum of ST elevation, maximal Selvester score, and the presence of severe (grade 3) ischemia were determined in each electrocardiogram. Left ventricular ejection fraction, the number of chords with wall motion abnormalities, and the severity of dysfunction (SD/chord) were determined. RESULTS: At 90 minutes, the 39 ischemia grade 3 patients had lower ejection fraction than the 112 grade 2 patients. Both at 90 minutes and at hospital discharge, the grade 3 group had more chords with wall motion abnormalities and more severe regional dysfunction (SD/chord). However, the number of leads with ST elevation, sum of ST elevation, and maximal Selvester score had no correlation with ejection fraction at 90 minutes and only mild correlation with the extent of dysfunction (number of chords) at 90 minutes. There was no correlation between either the number of leads with ST elevation or the sum of ST elevation and the severity of regional dysfunction. CONCLUSIONS: The number of leads with ST elevation, sum of ST elevation, and maximal Selvester score had only mild correlation with the extent of myocardial dysfunction but not with the severity of dysfunction. Grade 3 ischemia is predictive of more extensive myocardial involvement and greater severity of regional dysfunction.     

Electrocardiographic measures of left ventricular hypertrophy show greater heritability than echocardiographic left ventricular mass.

AIMS: To assess the heritability (i.e. relative contribution of genetic factors to the variability) of continuous measures of left ventricular hypertrophy determined by electrocardiography and echocardiography. METHODS AND RESULTS: We studied 955 members of 229 Caucasian families, ascertained through a hypertensive proband. Electrocardiographic measurements were performed manually on resting 12-lead electrocardiograms, and echocardiographic measurements were made on M-mode images. Sex-specific residuals for the left ventricular phenotypes were calculated, adjusted for age, systolic blood pressure, weight, height, waist-hip ratio, and presence of diabetes. Heritability was estimated in two ways: firstly, from familial correlations with adjustment for spouse resemblance; and secondly by using variance components methods with ascertainment correction for proband status. The heritability estimates (given as a range derived from the two methods) were higher for Sokolow-Lyon voltage (39-41%) than for echocardiographic left ventricular mass (23-29%). Electrocardiographic left ventricular mass, Cornell voltage, and Cornell product had heritability estimates of 12-18%, 19-25%, and 28-32%, respectively. CONCLUSIONS: Genetic factors may explain a substantial proportion of variability in quantitative electrocardiographic and echocardiographic measures of left ventricular hypertrophy. The greater heritability of Sokolow-Lyon voltage suggests that electrocardiographic phenotypes may be particularly important for the molecular investigation of the genetic susceptibility to cardiac hypertrophy.     

Use of the electrocardiogram as an aid in screening for left ventricular aneurysm.

Attempting to cull from a population of patients with coronary artery disease or cardiomyopathy, a subgroup in whom left ventriculography might most reasonably be performed in search of a surgically resectable ventricular aneurysm, the electrocardiograms (ECGs) and ventriculograms of 96 patients were analyzed. This study was conceived to test the value of the ECG as an initial screening technique. Patients with normal ventricular contractile motion in the presence of coronary artery disease rarely showed ST segment elevation exceeding 2 mm in any lead, and even more rarely showed Q waves in corresponding leads. All patients with well defined left ventricular aneurysms had at least 1 mm ST segment elevation, and the majority (73%) had ST elevation of 2 mm or greater; in 80% of these, there were associated Q waves in the same lead. In patients with only local areas of hypocontractility, the frequency of ST segment elevation with concomitant Q waves was significantly less (approximately 50%) than that seen in patients with aneurysms. It is concluded that patients with suspected or proven coronary disease who fail to demonstrate ST segment elevation are unlikely to have ventricular aneurysms and, thus, would receive little diagnostic benefit from left ventriculography. The presence of ST segment elevation, with or without associated Q waves in the same leads, is a helpful screening sign, raising the possibility of a surgically remediable lesion such as a ventricular aneurysm, but similar electrocardiographic patterns are also seen in patients with non-operable localized or generalized disorders of contraction. Having discovered ST elevation, then, left ventriculography becomes a reasonable next step - when otherwise indicated - in delineating the type of contractile disorder as well as the amount of adequately functioning muscle.     

Mean QRS, ventricular gradient and left ventricular mass in patients with eccentric left ventricular hypertrophy.

The spatial ventricular gradient (G) and the mean QRS-T angle were examined in 12 patients with angiographically determined eccentric left ventricular hypertrophy (LVH), as compared with 12 normal control subjects. In these 24 patients, a high significant correlation (r = 0.88) was obtained between the magnitude of the spatial mean QRS and LV mass. Although correlations were obtained between the magnitude of the spatial G or the spatial mean QRS-T angle and LV mass, they were lower (r = 0.56, 0.71 respectively). The magnitude of the spatial G (0.190 +/- 0.049 MVSec) in the eccentric LVH group increased significantly (p less than 0.001) in comparison with the control value (0.105 +/- 0.032 mVSec), while in the eccentric LVH group, decreased G/QRS (p less than 0.02), decreased T/QRS (p less than 0.05), and increased QRS-T angle (p less than 0.02) were observed. Furthermore, decreased G/QRS and widening of the QRS-T angle were observed in cases of LVH only. In cases of mild or moderate LVH, normal G/QRS ratios with definitely increased G magnitude and normal QRS-T angle were observed. It is concluded that the magnitude of the spatial mean QRS closely relates to an increase in LV mass. Therefore, should the magnitude of G increase proportionally to an increase in total muscle volume in ideal hypertrophy, then the widening of the QRS-T angle observed in LVH would be due not only to the large ARS complex but also to an alteration in the ventricular gradient.