New gender-specific partition values for ECG criteria of left ventricular hypertrophy: recalibration against cardiac MRI

ECG criteria for left ventricular hypertrophy (LVH) were mostly validated using left ventricular mass (LVM) as measured by M-mode echocardiography. LVM as measured by cardiac MRI has been demonstrated to be much more accurate and reproducible. We reevaluated the sensitivity and specificity of 4 ECG criteria of LVH against LVM as measured by cardiac MRI. Patients with systemic hypertension (n=288) and 60 normal volunteers had their LVM measured using a 1.5-Tesla MRI system. A 12-lead ECG was recorded, and 4 ECG criteria were evaluated: Sokolow-Lyon voltage, Cornell voltage, Cornell product, and Sokolow-Lyon product. Based on a cardiac MRI normal range, 39.9% of the hypertensive males and 36.7% of the hypertensive females had elevated LVM index. At a specificity of 95%, the Sokolow-Lyon product criterion had the highest sensitivity in females (26.2%), the Cornell criterion had the highest sensitivity in males (26.2%), and the Cornell product criteria had a relatively high sensitivity in both males and females (25.0% and 23.8%). Receiver operating characteristic curves showed the Cornell and Cornell product criteria to be superior for males whereas the Sokolow-Lyon product criterion was superior for females. Comparing the mean LVM index values of the subjects who were ECG LVH positive to the normal volunteers indicated that the ECG LVH criteria detect individuals with an LVM index substantially above the normal range. We have redefined the partition values for 4 different ECG LVH criteria, according to gender, and found that they detect subjects with markedly elevated LVM index.     

Association between electrocardiographic left ventricular hypertrophy with strain pattern and left ventricular structure and function

BACKGROUND AND PURPOSE: Electrocardiographic left ventricular hypertrophy (LVH) with strain pattern has been documented as a marker for LVH. Its presence on the ECG of hypertensive patients is associated with poor prognosis. The study was carried out to assess the association of the electrocardiographic strain with left ventricular mass (LVM) and function in hypertensive Nigerians. MATERIAL AND METHODS: ECG as well as echocardiograms were performed in 64 hypertensive patients with ECG-LVH and strain pattern, 65 patients with ECG-LVH by Sokolow-Lyon (SL) voltage criteria and 62 normal controls. RESULTS: The study showed that electrocardiographic left ventricular (LV) strain pattern is associated with dilated left atrium, larger LV internal dimensions and greater absolute and indexed LVM in hypertensive Nigerians compared with ECG-LVH by SL voltage criteria alone or normal controls. CONCLUSION: The findings of this study support the fact that the ECG strain pattern is associated with increased LVM and an increased risk of developing abnormal LV geometry.     

Classification Accuracy of Electrocardiographic Criteria for Left Ventricular Hypertrophy in Normal Weight and Overweight Older Adults

Background: We evaluated classification accuracy of ECG criteria at varying levels of left ventricular hypertrophy (LVH) severity according to echocardiographically measured left ventricular mass (LVM) adjusted to body size. Methods: The test population was derived from the Cardiovascular Health Study (CHS), a population-based sample of 5201 men and women aged 65 and older, and consisted of 1844 women and 1119 men with adequate quality ECGs and echocardiograms for LVM determination. The criteria evaluated were Sokolow-Lyon, Cornell voltage, Cornell product, Framingham modification of the Cornell voltage, and the left ventricular mass index (LVMI) of the Novacode ECG program. Results: With LVH thresholds at upper 95% normal limit for weight adjusted LVM for the CHS population and ECG thresholds adjusted for 95% specificity in normal weight and overweight subgroups, the sensitivity of ECG criteria for LVH was relatively low. It was highest (40.8%) for the Novacode LVMI in normal weight men and for the Framingham criteria (30.9%) in normal weight women, but it deteriorated for both of these criteria in the presence of obesity. The overall performance of the Cornell product and Cornell voltage criteria was least influenced by obesity. The Framingham adjustment for the Cornell voltage criteria for obesity substantially reduced their sensitivity. Conclusion: The choice of echocardiographic standard, LVH severity level and overweight in the test groups have a strong influence on ECG evaluation results.     

Race- and sex-specific ECG models for left ventricular mass in older populations. Factors influencing overestimation of left ventricular hypertrophy prevalence by ECG criteria in African-Americans

The validity of the reported high prevalence of left ventricular hypertrophy (LVH) among African-American men and women has been questioned owing to conflicting echocardiographic evidence. We used echocardiographic left ventricular mass (LVM) from M-mode measurements to evaluate associations between LVM, body size, and electrocardiographic (ECG) variables in 3,627 white and African-American men and women 65 years of age and older who were participants of the Cardiovascular Health Study (CHS), a multicenter cohort study of risk factors for coronary heart disease and stroke. ECG amplitudes used in LVH criteria were substantially higher in African-Americans, with apparent LVH prevalence 2 to 3 times higher in African American men and women than in white men and women, although there was no significant racial difference in echocardiographic LVM. The higher apparent LVH prevalence by Sokolow-Lyon criteria in African-American men is in part owing to smaller lateral chest diameter. In women, reasons for racial differences in ECG LVH prevalence remain largely unexplained although a small part of the excess LVH in African-American women by the Sokolow-Lyon criteria appears to be owing to a larger lateral chest semidiameter in white women. ECG variables alone were too inaccurate for LVM prediction, and it was necessary to incorporate in all ECG models body weight that was properly adjusted for race and sex. This resulted in modest LVM prediction accuracy, with R-square values ranging from .22 to .36. Race- and sex-specific ECG models introduced for LVM estimation with an appropriate adjustment for body size differences are expected to facilitate evaluation of LVH status in contrasting racial population groups.     

高血压左心室肥厚的简易心电图电压标准

目的　寻找心电图 (ECG)诊断左心室肥厚 (LVH)的较好电压标准。方法　以高血压患者为研究对象 ,将目前ECG诊断LVH的各种电压标准与超声心动图左心室心肌重量 (LVM )及左心室心肌重量指数 (LVMI)进行统计分析比较。结果　一项新的电压指标 ,即胸导联最大QRS电压 (简称Vmax)与超声心动图LVMI相关最为密切 (r =0 5 45 ,P <0 0 0 1)。结论　Vmax有希望成为ECG诊断LVH的有效实用的新指标     

Performance of conventional orthogonal and multiple-dipole electrocardiograms in estimating left ventricular muscle mass.

For estimating left ventricular mass (LVM), ECG criteria for left ventricular hypertrophy (LVH) were selected from conventional 12-lead ECGs, orthogonal three-lead ECGs, and multiple-dipole ECGs (MDECG). The three cardiograms were recorded in 139 patients for whom the degree of LVH was independently determined from biplane ventriculograms. Tested ECG criteria included Sokolow-Lyon measurements for the 12-lead ECG; for the orthogonal ECG, maximal QRS magnitude in the horizontal plane, R duration in the z-lead and Jxyz (spatial magnitude of point J); and for the 126 leads of the MDECG, the dipole activity (DA) of the septum and the free left ventricular wall. Correlation coefficients between LVM and the 12-lead ECG, three-lead ECG and MDECG were 0.61, 0.78 and 0.89, respectively, with corresponding errors of estimated LVM of 103, 82 and 60 g. More complex recording and analytic methods clearly led to increased accuracy in LVM estimates. However, the large error of estimate may limit practical applicability of such correlations. For classification of subjects into normal and above-normal categories, a likelihood ratio was also used and led to a maximum performance index of 86% with MDECG measurements.     

Electrocardiography–left ventricular mass discrepancies in left ventricular hypertrophy: electrocardiography imperfection or beyond perfection?

The problem of discrepancies between left ventricular mass (LVM) and electrocardiography (ECG) findings in diagnosis of left ventricular hypertrophy (LVH) is approached from the perspective of the diagnostic ability of ECG. Contrary to current clinical understanding of LVH as an increase in LVM, the LVH is defined as the organ manifestation of the hypertrophic growth of cardiomyocytes accompanied by changes in interstitium. This complex understanding of the hypertrophic rebuilding of LV myocardium in LVH is the crucial requirement to understand the role of ECG in LVH diagnosis. The basic statements of the article are based on the fact that ECG provides information on the electrical field generated by the heart; therefore,

• ECG cannot be a surrogate method for the LVM estimation by its nature. The hypothesis that the ECG estimates LVM requires modification for the additional effects of myocardial tissue changes and conduction on the ECG.

• The added value of ECG in LVH diagnosis is given by its ability to register the electrical field of the heart and thus to estimate the electrical status of the myocardium.

Left ventricular hypertrophy: disagreements between increased left ventricular mass and ECG-LVH criteria: the effect of impaired electrical properties of myocardium

The classical paradigm of electrocardiographic diagnosis of left ventricular hypertrophy (LVH) is based on empirical finding of increased QRS voltage in cases of LVH and a continuous effort is devoted to finding ECG criteria that agree best with LVH classification according to an ECG-independent standard such as echocardiographic LVH (echo-LVH) based on increased left ventricular mass (LVM). Since there are more disagreements than agreements, this review is focused on discrepancies, i.e. false negative and false positive ECG findings. It summarizes the results of simulation studies on the effect of slowed conduction velocity and reduced intercellular coupling on the QRS pattern. The results from these simulation studies suggest that reduced myocardial conduction velocity which is either diffuse or regional, or reduced intracellular coupling, may account at least in part for the changes in the QRS patterns observed in patients with LVH.     

Indexation criteria of ventricular mass and predictive role of blood pressure and body composition

BACKGROUND: There is no definite consensus on which indexation of left ventricular mass (LVM) should be used to better identify left ventricular hypertrophy (LVH). Left ventricular mass has been adjusted to height, to height2.7(h2.7) and to body surface area (BSA). The aims of the present study were to evaluate the prevalence of LVH according to different indexations and different cut-offs and to identify the most useful indexation of LVM to detect hypertension-related LVH. METHODS: Echocardiographic LVH was defined as LVM to h2.7, LVM to BSA, LVM to height, LVM values in the upper 5th percentile of our gender-related LVM distribution, using different partition values suggested in previous population-based studies. RESULTS: Prevalence of LVH in the general population was 32% using the less restrictive criterion (LVH 49.2/46.7 g/m2.7), 15% with the criterion of LVH 116/104 g/m2, and 3.8% with the most restrictive one (LVH 134/110 g/m2). Prevalence of LVH in hypertensive subjects was almost twice than in normotensive subjects with all criteria. Only 20 subjects out of the 707 evaluated were found to have LVH with all six criteria. In multiple regression analysis SBP was independently associated with nonindexed LVM and was indexed to both BSA and h2.7. On the other hand, fat-free mass was a powerful predictor of nonindexed LVM or of LVM to BSA, whereas body mass index was the strongest predictor of LVM to h2.7. CONCLUSIONS: The indexation of LVM to BSA, possibly with the cut-off of LVH 116/104, is probably the best criterion for identifying blood pressure-related LVH.     

A study of the human heart as a multiple dipole source. IV. Left ventricular hypertrophy in the presence of right bundle branch block.

This report concerns the task of electrocardiographic (ECG) diagnosis and quantitation of left ventricular hypertrophy (LVH) in patients with right bundle branch block (RBBB). In 36 patients with RBBB the left ventricular mass (LVM) of each patient was independently known from quantitative biplane angiography. Two ECG techniques, standard 12-lead ECG and multiple dipole electrocardiography (MDECG), were evaluated. In diagnosing LVH, the best performance of the several standard ECG criteria was sensitivity = 29%, specificity = 100%, and that of the MDECG was sensitivity = 94%, specificity = 96%. In quantitating LVH, the standard ECG gave a correlation with LVM of r = 46% and a standard error of estimate of 98 g. The corresponding figures for the MDECG were r = 81% and the root mean square prediction error = 64 g. These results confirm other studies showing that the conventional ECG is of only marginal value in the task of diagnosing LVH in the presence of RBBB. In contrast, the MDECG performs well both in this task and that of quantitating LVH. The results provide further support of the accuracy of the model of the cardiac electrical generator and volume conductor used in the MDECG method.     

Echocardiographic definition of left ventricular hypertrophy in the hypertensive: which method of indexation of left ventricular mass?

OBJECTIVES: It has been suggested that hypertensives at high risk of cardiovascular complications can be identified on the basis of their left ventricular mass as determined echographically. However, there is as yet a lack of consensus on the mode of indexation (body surface area, height, height 2.7) of left ventricular mass (LVM), and on the cut-off values for definition of left ventricular hypertrophy (LVH). The main objective of this study is to test the influence of the different modes of indexation for LVM on the prevalence of LVH in a population of never treated hypertensive patients on the basis of cut-offs for LVM based upon its relationship with ambulatory blood pressure (BP) measurement. METHODS: A population of 363 untreated hypertensives was investigated using a standardised procedure. The men and women were analysed separately. We studied the relationship between mean daytime ambulatory systolic BP and LVM and calculated the LVM cut-off for a BP of 135 mm Hg using three different methods of indexation. On the basis of these criteria, the population was divided into those with and those without LVH. RESULTS: The prevalence of LVH was found to be higher when LVM was indexed to height2.7 (50.4%) or height (50.1%). Prevalence was lowest when LVM was indexed to body surface area (48.2%), which tended to minimise the hypertrophy in obese individuals. Only indexation by height 2.7 fully compensates for relationships between height and ventricular mass in this population. CONCLUSIONS: Indexing LVM to height 2.7 thus appeared to give a more sensitive estimate of LVH by eliminating the influence of growth. Cut-offs of 47 g/m2.7 in women and 53 g/m2.7 in men corresponded to a cardiovascular risk indicated by a daytime systolic BP >/=135 mm Hg.     

Left ventricular mass by 12-lead electrocardiogram in healthy subjects: comparison to cardiac magnetic resonance imaging

The ability to estimate left ventricular mass (LVM) from the standard 12-lead electrocardiogram (ECG) has been shown to be limited because there is a considerable variability of the normal 12-lead ECG due to demographic and anthropometric variables. We sought to study LVM in healthy subjects and its relationship with QRS duration, and established electrocardiographic criteria for left ventricular hypertrophy. Cardiac magnetic resonance imaging was used to measure LVM. Seventy-one healthy volunteers (36 men; age range, 21-82 years) were studied. All ECG criteria tested showed a statistically significant relationship with LVM. The highest R value was found between LVM and QRS duration, as well as the 12-lead voltage-duration product (R = 0.59, P < .001 for both). The lowest R value was found for the Sokolow-Lyon voltage criterion (R = 0.25, P = .033). Left ventricular mass differed significantly between sexes, as did all ECG criteria except the Sokolow-Lyon criterion. Thus, in healthy subjects, QRS duration alone is equally or more strongly correlated to LVM than are established electrocardiographic left ventricular hypertrophy criteria.     

Effect of irbesartan versus atenolol on left ventricular mass and voltage: results of the CardioVascular Irbesartan Project

Regression of hypertensive left ventricular hypertrophy (LVH) is associated with improved prognosis. The aim of this trial was to compare the effects of irbesartan versus atenolol on LVH in subjects with essential hypertension. Because electrocardiographic and echocardiographic parameters of LVH carry disparate prognostic information, both methods were applied in this trial. In the randomized, double-blind, multicenter trial CardioVascular Irbesartan Project, 240 patients with essential hypertension were treated with irbesartan or atenolol for 18 months. Voltage criteria used for LVH were Sokolow index, Cornell index, Cornell voltage x QRS duration product and Lewis index. In parallel, left ventricular mass (LVM) was determined by 2-dimensional guided M-mode echocardiography. After 6 and 18 months, reductions of LVM and voltage criteria for LVH were only found in subjects treated with irbesartan. However, a reduction of LVM was only detectable in subjects within the highest quartile of baseline LVM but not overall. In contrast, reductions of voltage criteria for LVH were detectable after 6 and 18 months even within commonly used normal limits. In conclusion, treatment of hypertension with irbesartan resulted in a significant reduction in the voltage criteria for LVH, although an effect on LVM was only seen in subjects with high baseline LVM. In contrast, atenolol did not lead to reductions in electrocardiographic or echocardiographic parameters of LVH. Because voltage criteria for LVH have been shown to predict cardiovascular outcome independently from LVM, we suggest that both methods should be used to accurately assess the benefits of antihypertensive treatment.     

Electrocardiographic left ventricular hypertrophy and the risk of adverse cardiovascular events: A critical appraisal

This review covers selected electrocardiographic left ventricular hypertrophy (ECG-LVH) studies which have evaluated their prognostic value for adverse cardiovascular (CVD) events. Most ECG-LVH studies have used echocardiographic left ventricular mass (Echo-LVM) as the gold standard for evaluating ECG-LVH criteria. More recently, LVM from magnetic resonance imaging (MRI-LVM) has evolved as the new gold standard. The reported risk of adverse CVD events is generally highest for ECG-LVH criteria which combine high amplitude QRS criteria with repolarization abnormalities such as in LV strain pattern. Evolving coronary heart disease (CHD) may account in part for the increased risk for ECG-LVH. However, one large coronary arteriography study found that 5-year survival was significantly lower in coronary artery disease (CAD) patients with ECG-LVH than without LVH regardless of CAD status. The utility of Echo-LVH as a standard is limited by the large intra- and inter-reader variability and the lack of standardization of allometric formulations for adjustment of LVM to body size. Newer evaluation data with MRI-LVM as the standard show that for most ECG criteria CVD event rates are significantly higher for study subgroups with ECG-LVH than those without ECG-LVH. However, the performance results differ when comparing the risk for CVD events from those for the overall LVH classification accuracy according to sensitivity and specificity. Large short-term variability of ECG amplitudes due to electrode placement variability is a common limiting factor for ECG-LVH criteria performance regardless of the gold standard. Clinical trials for hypertension control rely largely on monitoring Echo-LVH rather than ECG-LVH.     

The electrocardiogram in left ventricular hypertrophy: past and future

The electrocardiographic diagnosis of left ventricular hypertrophy (LVH) has been centered on improving the diagnostic sensitivity and specificity of the method, using criteria whose precise relationship to increased left ventricular mass are not established. Although the electrocardiogram (ECG) has been displaced to a secondary role in the prediction of left ventricular mass, ECG/LVH has been shown to be a strong predictor of morbidity and early mortality. There are strong clues that each of the parameters in ECG/LVH is related to cardiac contractility and ejection. It is suggested that research be redirected to an exploration of these relationships and predicted that this will lead to both a better understanding of this venerable tool and an improvement in its usefulness to the clinician and patient.     

Evaluation of the electrocardiographic criteria for left ventricular hypertrophy with use of three-dimensional echocardiography

BACKGROUND: Left ventricular hypertrophy (LVH) is a common condition that carries an increased risk of cardiovascular events. Use of ECG in detection of LVH is limited because of the reported low sensitivity. Conventional echocardiographic techniques used as the standard for estimating left ventricular (LV) mass have limitations related to the position of the image plane and shape of the ventricle. Three-dimensional echocardiography is free of these limitations and therefore is more accurate. We hypothesized that accuracy of ECG criteria for LVH would improve when LV mass was assessed by three-dimensional echocardiography. RESULTS: For most of the criteria, sensitivity, specificity and accuracy improved when LV mass was assessed by three-dimensional echocardiography. Two-dimensional echocardiography significantly overestimated LV mass as compared with the three-dimensional method. CONCLUSIONS: Sensitivity, specificity, and accuracy of the ECG criteria improved when LV mass was estimated by three-dimensional echocardiography. This improvement may be attributed at least in part to superior accuracy of three-dimensional measurements.     

Severe aortic stenosis without left ventricular hypertrophy: prevalence, predictors, and short-term follow up after aortic valve replacement.

OBJECTIVES: The purpose of the present study in patients with severe aortic stenosis was to assess the prevalence of absent left ventricular hypertrophy (LVH) (determined according to mass criteria), to identify predictors of absent LVH, and to assess short-term left ventricular adaptation and prognosis after aortic valve replacement. METHODS: Left ventricular mass (LVM) was determined by echocardiography in 109 men and 101 women with severe aortic stenosis (mean pressure gradient < or = 50 mm Hg). LVH was defined as LVM > or = 109 g/m2 in women and LVM > or = 134 g/m2 in men. RESULTS: One hundred and eighty nine patients showed LVH (group 1) (90%; mean (SD) age 65 (14) years), and 21 showed no LVH (group 2) (10%, age 57 (21) years P = 0.02 for difference in age). Twelve (6%) of those without LVH had increased relative wall thickness (that is, > or = 0.45 with LV concentric remodelling) and nine (4%) showed no macroscopically detectable hypertrophic adaptation. The following variables were associated with the absence of LVH: low body surface area, low body mass index, and increased cardiac index. 76/210 patients were followed up a mean of six months after aortic valve replacement. The frequency of adequate ventricular adaptation to the decreased afterload after aortic valve replacement was higher in patients with LVH than in those without. Mortality six months after aortic valve replacement was lower, but not significantly, in patients with LVH (7.6%) than in those without LVH (12.5%, P = 0.10). CONCLUSIONS: A tenth of patients with severe aortic stenosis did not develop LVH according to mass criteria; 4% of the patients did not have any macroscopic signs of myocardial adaptation to the pressure overload despite longstanding disease. Small body size was independently associated with lack of LVH according to mass criteria. Six months after aortic valve replacement, ventricular adaptation was more often adequate in patients with LVH than in those without.     

Effect of changes in left ventricular anatomy and conduction velocity on the QRS voltage and morphology in left ventricular hypertrophy: a model study

The increased QRS voltage is considered to be a specific electrocardiogram (ECG) sign of left ventricular hypertrophy (LVH), and it is expected that the QRS voltage reflects the increase in left ventricular mass (LVM). However, the increased QRS voltage is only one of QRS patterns observed in patients with LVH. According to the solid angle theory, the resultant QRS voltage is influenced not only by spatial (anatomic) but also by nonspatial (electrophysiologic) determinants. In this study, we used a computer model to evaluate the effect of changes in anatomy and conduction velocity of the left ventricle on QRS complex characteristics.

Material and Methods

The model defines the geometry of cardiac ventricles analytically as parts of ellipsoids and allows to change dimensions of the ventricles, as well as the conduction velocity in the individual layers of myocardium. Three types of anatomic changes were simulated: concentric hypertrophy, eccentric hypertrophy, and dilatation. The conduction velocity was slowed in the inner layer of the left ventricle representing the Purkinje fiber mesh and in the layers representing the working myocardium. The outcomes of the model are presented as the time course of the spatial QRS vector magnitude, the vectorcardiographic QRS loops (VCGs) in horizontal, left sagittal, and frontal planes, as well as derived 12-lead ECGs. The following indicators of the 12-lead ECG were evaluated: the left axis deviation, the intrinsicoid deflection in V6, Cornell voltage, Cornell voltage-duration product, and Sokolow-Lyon index.

Results

The increase in LVM did not affect the QRS voltage proportionally, and the LVM and type of hypertrophy were not the only determinants of the QRS patterns. The conduction velocity slowing resulted in a spectrum of QRS patterns including increased QRS voltage and duration, left axis deviation, prolonged intrinsicoid deflection, VCG patterns of left bundle branch block, as well as pseudo-normal VCG/ECG patterns. The anatomic changes and conduction velocity slowing affected differently Sokolow-Lyon index and Cornell criteria.

Conclusion

We showed that the LVM is not the only determinant of the QRS complex changes in LVH, but it is rather a combination of anatomic and electric remodeling that creates the whole spectrum of the QRS complex changes seen in LVH patients. The slowed conduction velocity in the model heart produced QRS patterns consistent with changes described in LVH, even if the LVM was not changed.     

Relation between abdominal obesity, insulin resistance and left ventricular hypertrophy diagnosed by electrocardiogram and magnetic resonance imaging in hypertensive patients

Obesity is related to left ventricular hypertrophy (LVH). Whether LVH on electrocardiography (ECG-LVH) is a result of increased cardiac electrical activity or due to increased left ventricular mass (LVM) remains to be determined. The aims of the present study were to investigate the relation between obesity and ECG-LVH and LVM by magnetic resonance imaging (MRI-LVM) in patients with hypertension and to investigate the relation of insulin resistance (IR) and LVH. Patients with hypertension (n = 421) were evaluated using Sokolow-Lyon voltage, Cornell voltage, and cardiac magnetic resonance imaging. Waist circumference was used as a measure of abdominal obesity. Linear regression analysis revealed an inverse relation (adjusted β = -0.02, 95% confidence interval -0.02 to -0.01) between waist circumference and Sokolow-Lyon voltage, indicating a decrease of 0.02 mV per 1-cm increase in waist circumference. There was a positive relation between waist circumference and MRI-LVM (β = 0.49, 95% confidence interval 0.32 to 0.67). Patients in the highest quartile of LVM had a worse metabolic profile than patients with the Sokolow-Lyon voltage criterion. The relations of IR with ECG-LVH and MRI-LVM were similar to those of waist circumference in relation to ECG-LVH and MRI-LVM. In conclusion, there is an inverse relation between waist circumference and ECG-LVH and a positive relation between waist circumference and MRI-LVM. This study indicates that obesity has a different relation to voltage criteria for LVH compared to anatomic criteria for LVH, supporting the hypothesis that IR decreases electrocardiographic voltages, despite an increase in MRI-LVM. The clinical implication is that especially in patients with IR, Sokolow-Lyon voltage is low in contrast to high MRI-LVM.     

Excessive increase in left ventricular mass identifies hypertensive subjects with clustered geometric and functional abnormalities

BACKGROUND: Left ventricular mass (LVM) exceeding needs to sustain haemodynamic load has been termed 'inappropriate left ventricular mass'. We hypothesized that inappropriate LVM identifies hypertensive patients with clustered cardiac geometric and functional abnormalities. METHODS: For this purpose, 359 hypertensive individuals without prevalent cardiovascular disease underwent Doppler echocardiography. Observed LVM exceeding more than 28% of the value predicted for individual cardiac work, body size and sex was defined as inappropriate LVM. Concentric left ventricular geometry was defined as age-adjusted relative wall thickness (RWT) greater than 0.40. Systolic dysfunction was defined as ejection fraction less than 50% or midwall shortening less than 14.7%. Diastolic dysfunction was defined as isovolumic relaxation time (IVRT) greater than 100 ms, E-velocity deceleration time greater than 220 ms or age and heart rate-normalized early/late (E/A) ratio less than 0.66. Left ventricular hypertrophy (LVH) was defined as an LVM index greater than 49.2 g/m2.7 in men and 46.7 g/m2.7 in women. RESULTS: As expected, inappropriate LVM was associated with higher RWT, lower left ventricular systolic function, longer IVRT and prolonged E-deceleration time (all P < 0.05). Patients with inappropriate LVM had a higher prevalence of concentric geometry (65.5 versus 40.4%), systolic dysfunction (67.9 versus 47.4%) and diastolic dysfunction (46.4 versus 39%; all P < 0.001) than those with LVH. Inappropriate LVM had greater sensitivity (0.89 versus 0.54) and specificity (0.82 versus 0.62; both P < 0.01) than LVH in identifying patients with clustered left ventricular concentric geometry, systolic and diastolic dysfunction. CONCLUSIONS: Inappropriate LVM is associated with a cluster of concentric left ventricular geometry, delayed left ventricular relaxation and reduced systolic performance. Compared with LVH, inappropriate LVM is more accurate at identifying patients with clustered left ventricular geometric and functional abnormalities.