Does QRS Voltage Correction by Body Mass Index Improve the Accuracy of Electrocardiography in Detecting Left Ventricular Hypertrophy and Predicting Cardiovascular Events in a General Population?

Relating QRS voltages to left ventricular mass and body composition in elite endurance athletes

PURPOSE

Electrocardiogram (ECG) QRS voltages correlate poorly with left ventricular mass (LVM). Body composition explains some of the QRS voltage variability. The relation between QRS voltages, LVM and body composition in endurance athletes is unknown.

METHODS

Elite endurance athletes from the Pro@Heart trial were evaluated with 12-lead ECG for Cornell and Sokolow-Lyon voltage and product. Cardiac magnetic resonance imaging assessed LVM. Dual energy x-ray absorptiometry assessed fat mass (FM) and lean mass of the trunk and whole body (LBM). The determinants of QRS voltages and LVM were identified by multivariable linear regression. Models combining ECG, demographics, DEXA and exercise capacity to predict LVM were developed.

RESULTS

In 122 athletes (19 years, 71.3% male) LVM was a determinant of the Sokolow-Lyon voltage and product (β = 0.334 and 0.477, p < 0.001) but not of the Cornell criteria. FM of the trunk (β = - 0.186 and - 0.180, p < 0.05) negatively influenced the Cornell voltage and product but not the Sokolow-Lyon criteria. DEXA marginally improved the prediction of LVM by ECG (r = 0.773 vs 0.510, p < 0.001; RMSE = 18.9 ± 13.8 vs 25.5 ± 18.7 g, p > 0.05) with LBM as the strongest predictor (β = 0.664, p < 0.001). DEXA did not improve the prediction of LVM by ECG and demographics combined and LVM was best predicted by including VO₂max (r = 0.845, RMSE = 15.9 ± 11.6 g).

CONCLUSION

LVM correlates poorly with QRS voltages with adipose tissue as a minor determinant in elite endurance athletes. LBM is the strongest single predictor of LVM but only marginally improves LVM prediction beyond ECG variables. In endurance athletes, LVM is best predicted by combining ECG, demographics and VO₂max.

Visceral fat level correction of the left ventricular hypertrophy electrocardiographic criteria

Background

Left ventricular hypertrophy (LVH) is a well‐known risk factor for cardiovascular events. Even though there are many electrocardiographic (ECG) criteria for LVH, they still provide poor performance, especially among obese patients. The aim of this study was to examine whether adding visceral fat to ECG LVH criteria improves accuracy in the diagnosis.

Methods

One thousand seven hundred twenty two patients were included in the study. All patients underwent a complete physical examination, office blood pressure measurement, analysis of body composition, 12‐lead ECG, and M‐mode two‐dimensional echocardiography. Four standard ECG criteria for LVH were analyzed, including Cornell voltage criteria, Cornell duration criteria, Sokolow–Lyon voltage criteria, and Sokolow–Lyon product criteria. Adjustments of ECG LVH criteria were performed using visceral fat level (VFATL) and BMI. Transthoracic echocardiography was used as a reference method to compare the quality of ECG LVH criteria.

Results

Multivariate logistic regression models were created and revealed a significant increase of area under curve (AUC) after VFATL and BMI addition to ECG LVH criteria. Improvement of sensitivity at 90% specificity was observed in all created models. The odds ratio (OR) of the analyzed ECG criteria increased after adding VFATL and BMI to the models. Furthermore, ROC curves analysis exposed better characteristics in detecting LVH of VFATL‐adjusted criteria than BMI‐adjusted and unadjusted criteria.

Conclusions

Adjusting ECG indexes to BMI or VFATL improves the sensitivity of LVH detection. VFATL‐corrected indexes are more sufficiently than BMI‐corrected. After advancements in indexes, both lean and morbidly obese individuals outcomes show a greater prevalence of correct LVH diagnosis.

Diagnostic utility of the electrocardiographic left ventricular hypertrophy criteria in specific populations

BACKGROUND

Several electrocardiographic (ECG) criteria have been validated for the diagnosis of left ventricular hypertrophy (LVH); the majority in Caucasian subjects from Europe and North America. Diagnostic utility of ECG criteria to detect LVH has never been established in our population; nonetheless they are frequently used.

OBJECTIVE

To evaluate the diagnostic utility of different LVH ECG criteria in a Northern Mexican population and to determine the effect of gender, age, body mass index (BMI), hypertension and ischaemic heart disease (IHD) on their performance.

METHODS

We conducted an observational, case-control study in patients divided according to the presence of LVH in an echocardiogram (Echo). We calculated the accuracy, sensitivity (Se), specificity (Sp), positive predictive value (PPV) and negative predictive value (NPV) of 22 ECG criteria.

RESULTS

Four hundred thirty-two patients were studied (202 had LVH). The Dalfó criterion (ECG18. SV3 + RaVL) had the best diagnostic performance with a Se of 56%, Sp of 71.3%, PPV 62.9%, NPV 65% and a diagnostic accuracy (95%CI) of 64.1% (59.5-68.6). This criterion had the highest accuracy in both genders, in all BMI, in older patients (>60 years) and in those with positive Echo ischaemic heart disease (IHD); it also performed well in patients with history of IHD and in hypertensive patients. VDP Cornell had the best accuracy in patients less than 60 years old, and in patients with non-ischaemic findings by Echo.

CONCLUSIONS

The Dalfó criteria had the overall best accuracy in the detection of LVH, and specific populations.

The pressioni arteriose monitorate e loro associazioni (PAMELA) research project: a 25-year long journey

INTRODUCTION

Among the observational studies performed in the area of blood pressure measurements in the population the Pressioni Arteriose Monitorate E Loro Associazioni (PAMELA) investigation represents an unique research for a number of reasons.

EVIDENCE ACQUISITION AND SYNTHESIS

The PAMELA study combines clinic, home and 24-hour blood pressure measurements in all partiicipants, which were representative of the general population. Examination included metabolic variables, allowing us to determine the interrelationships between bood pressure and metabolic profile. The protocol also included evaluation of organ damage, such as left ventricular hypertrophy, left ventricular diastolic dysfunction, left atrial dimensions and aortic root diameters. Finally, PAMELA represents one of the few studies with a prolonged follow-up, the last survey being completed three years ago and data collected are actually under analysis. This will allow to update the information related to cardiovascular morbidity and mortality in the study cohort.

CONCLUSIONS

The present paper will provide an overview of the various scientific contributions of the PAMELA study to the epidemiology, pathophysiology and clinical aspects of hypertension and hypertension related cardiovascular risk.

Prognostic significance of body mass index-adjusted criteria for left ventricular hypertrophy

Electrocardiographic left ventricular hypertrophy (ECG-LVH) is associated with both cardiovascular and all-cause mortality. Obesity attenuates the sensitivity of several ECG-LVH criteria, so body mass index (BMI) adjusted criteria have been developed. However, the prognostic significance of BMI-adjusted ECG-LVH criteria is not known. This analysis included 7812 participants (59.8 ± 13.4 years, 53% women, 50% non-Hispanic-whites) from the Third National Health and Nutrition Examination Survey. The Cornell criteria (R in aVL + S in V3 ≥ 2800 µV in men or ≥2200 µV in women) and Sokolow-Lyon criteria (S in V1 + R in V5 or R in V6 ≥ 3500 µV) criteria were used for LVH. To account for the effects of obesity, the BMI-adjusted Cornell criteria (product of R in aVL + S in V3 and BMI > 60 400 µV kg m^-2 ) and the BMI-adjusted Sokolow-Lyon criteria (add 400 µV if overweight, add 800 µV if obese) were used. Compared to traditional ECG-LVH criteria, more participants met criteria for ECG-LVH with BMI-adjusted Cornell voltage (9.9% vs 2.9%) and BMI-adjusted Sokolow-Lyon (13.1% vs 6.4%) criteria. In multivariable-adjusted Cox proportional hazards models, the BMI-adjusted Sokolow-Lyon criteria performed no better than traditional criteria (HR 1.18, 95% CI 1.06-1.32 for all-cause, HR 1.38, 95% CI 1.17-1.62 for cardiovascular mortality) and the BMI-adjusted Cornell voltage criteria attenuated the association with all-cause (HR 1.16, 95% CI 1.03-1.32) and cardiovascular mortality (HR 1.34, 95% CI 1.13-1.60). Despite potential improvements in the detection of LVH using BMI-adjusted ECG-LVH criteria, adjusting for BMI may result in the loss of prognostic information.

Predictive value of electrocardiographic left ventricular hypertrophy in the general population: A meta-analysis

BACKGROUND

Conflicting results have been reported on the predictive value of the electrocardiographic left ventricular hypertrophy (LVH) in the general population. This meta-analysis sought to compare the predictive value of different electrocardiographic criteria of LVH in the general population.

METHODS

We comprehensively searched PubMed and Embase databases until May 9, 2020 to identify observational studies investigating the predictive value of different electrocardiographic criteria for LVH (Sokolow-Lyon voltage, Cornell voltage or Cornell product) in the general population. Outcome measures were major adverse cardiovascular events (MACEs), cardiovascular or all-cause mortality.

RESULTS

Ten studies enrolling 58,400 individuals were included. Comparison with and without electrocardiographic LVH, the pooled risk ratio (RR) of MACEs was 1.62 (95% confidence interval [CI] 1.40-1.89) for the Sokolow-Lyon voltage criteria, 1.70 (95% CI 1.27-2.29) for the Cornell voltage criteria, and 1.56 (95% CI 1.17-2) for the Cornell product criteria. The pooled RR of all-cause mortality was 1.47 (95% CI 1.10-1.97) for the Sokolow-Lyon voltage criteria and 1.87 (95% CI 1.29-2.71) for the Cornell voltage criteria. Furthermore, the pooled RR of cardiovascular mortality was 1.38 (95% CI 1.19-1.60) for the Sokolow-Lyon criteria, 1.66 (95% CI 1.24-2.33) for the Cornell voltage criteria, and 1.82 (95% CI 0.65-5.09) for the Cornell product criteria.

CONCLUSIONS

Different electrocardiographic criteria for evaluating LVH had a similar value in predicting MACEs among the general population. LVH detected by the Cornell voltage appeared to have a stronger predictive value in prediction of cardiovascular or all-cause mortality.

Correction of QRS voltage for body mass index does not improve the prediction of fatal and nonfatal cardiovascular events. The Moli-sani study

BACKGROUND AND AIMS

The diagnosis of LVH by ECG may particularly difficult in obese individuals. The aim of this study was to prospectively investigate whether the correction for body mass index (BMI) might improve the prognostic significance for cerebro and cardiovascular events of two electrocardiographic (ECG) criteria for left ventricular hypertrophy (LVH) in a large cohort of Italian adults.

METHODS AND RESULTS

In 18,330 adults (54 ± 11 years, 55% women) from the Moli-sani cohort, obesity was defined using the ATPIII criteria. The Sokolow-Lyon (SL) and Cornell Voltage (CV) criteria were used for ECG-LVH. In overweight and obese subjects, as compared with normal weight, the prevalence of ECG-LVH by the SL index was lower. During follow-up (median 4.3 yrs), 503 cerebro and cardiovascular events occurred. One standard deviation (1-SD) increment in uncorrected and in BMI-corrected SL index and CV was associated with an increased risk of events (HR 1.12, 95% CI 1.02-1.22 and HR 1.16, 95% CI 1.06-1.26 and HR 1.12, 95% CI 1.03-1.23 and HR 1.17, 95% CI 1.07-1.27, respectively for SL and CV). In obese subjects, 1-SD increment in uncorrected CV and in BMI-corrected CV was not associated to a significant risk of events (HR 1.05, 95% CI 0.910-1.22 and HR 1.08, 95% CI 0.95-1.23 respectively). Uncorrected SL index showed a significant association with events, which was marginally stronger with BMI-corrected SL voltage (HR 1.18, 95% CI 1.02-1.37 and HR 1.17, 95% CI 1.04-1.33 respectively, Akaike information criterion change from 3220 to 3218).

CONCLUSIONS

BMI correction of ECG LVH voltage criteria does not significantly improve the prediction of cerebro and cardiovascular events in obese patients in a large cohort at low cardiovascular risk.

Electrocardiographic Detection of Left Ventricular Hypertrophy; Adding Body Mass Index and Spatial QRS-T Angle: A Cross-Sectional Study

Introduction

We investigated improvement of electrocardiographic LVH detection by adding measures of adiposity and/or novel electrocardiographic measures. Left ventricular hypertrophy (LVH) is an important risk factor for adverse cardiovascular outcomes. Improvement of electrocardiographic criteria for LVH is desirable, since electrocardiography is widely used.

Methods

We included 1091 participants of the Netherlands Epidemiology of Obesity Study (NEO) who underwent cardiac magnetic resonance imaging (MRI). Performance of Sokolow–Lyon and Cornell voltage and product criteria was assessed. Stepwise regression analysis was performed with each conventional electrocardiographic criterion and age, sex, body mass index (BMI), waist circumference, and waist:hip ratio (p-entry < 0.05, p-removal > 0.10). T-wave abnormalities or the spatial QRS-T angle (SA) were added to the improved models.

Results

The study population had a mean (SD) age of 56 (6) years, BMI of 26.1 (4.0) kg/m² and 46% were men. MRI-LVH was present in 10% of participants. The c-statistic for Sokolow–Lyon voltage was 0.58, R² was 0.02 and sensitivity at 90% specificity was 16%, for Sokolow–Lyon product this was 0.62, 0.02, and 21%, for Cornell voltage 0.65, 0.04, and 28% and for Cornell product 0.67, 0.04, and 25%. Best performing models were obtained by addition of both BMI and SA (Sokolow-Lyon voltage: c-statistic 0.74, R² 0.11, sensitivity of 41% at 90% specificity; Sokolow-Lyon product: 0.75, 0.12, 42%; Cornell voltage: c-statistic 0.70, R² 0.08, sensitivity of 38% at 90% specificity; Cornell product: c-statistic 0.72, R² 0.08, sensitivity of 44% at 90% specificity).

Conclusions

Electrocardiographic detection of LVH improved by adding BMI and SA to a model with conventional electrocardiographic criteria. This approach would require little extra effort and application in clinical practice is feasible. However, results should first be replicated in high-risk populations.

Electronic supplementary material

The online version of this article (10.1007/s40119-019-00151-9) contains supplementary material, which is available to authorized users.

QRS Complex Detection and Measurement Algorithms for Multichannel ECGs in Cardiac Resynchronization Therapy Patients

We developed an automated approach for QRS complex detection and QRS duration (QRSd) measurement that can effectively analyze multichannel electrocardiograms (MECGs) acquired during abnormal conduction and pacing in heart failure and cardiac resynchronization therapy (CRT) patients to enable the use of MECGs to characterize cardiac activation in such patients. The algorithms use MECGs acquired with a custom 53-electrode investigational body surface mapping system and were validated using previously collected data from 58 CRT patients. An expert cohort analyzed the same data to determine algorithm accuracy and error. The algorithms: 1) detect QRS complexes; 2) identify complexes of the most prevalent morphology and morphologic outliers; and 3) determine the array-specific (i.e., anterior and posterior) and global QRS complex onsets, offsets, and durations for the detected complexes. The QRS complex detection algorithm had a positive predictivity and sensitivity of ≥96% for complex detection and classification. The absolute QRSd error was 17 ± 14 ms, or 12%, for array-specific QRSd and 12 ± 10 ms, or 8%, for global QRSd. The absolute global QRSd error (12 ms) was less than the interobserver variation in that measurement (15 ± 10 ms). The sensitivity, positive predictivity, and error of the algorithms were similar to the values reported for current state-of-the-art algorithms designed for and limited to simpler data sets and conduction patterns and within the variation found in clinical 12-lead ECG QRSd measurement techniques. These new algorithms permit accurate, real-time analysis of QRS complex features in MECGs in patients with conduction disorders and/or pacing.

Novel Approach to the Detection of Left Ventricular Hypertrophy Using Body Mass Index-Corrected Electrocardiographic Voltage Criteria in a Group of African Ancestry

BACKGROUND

Electrocardiographic (ECG) QRS voltages used to generate criteria for left ventricular hypertrophy (LVH) detection are considerably attenuated by obesity. This effect renders the utility of ECG criteria to detect LVH in obese individuals of African ancestry to be of limited value.

HYPOTHESIS

A novel approach to correcting QRS voltages for the attenuating effect of body mass index (BMI) will improve the ability of ECG criteria to detect LVH in a group of African descent.

METHODS

Left ventricular mass was determined from echocardiography in 661 randomly selected participants (43.0% obese) of black African ancestry in South Africa.

RESULTS

As compared with Cornell and Sokolow-Lyon voltage criteria, BMI best correlated with RaVL , Gubner-Ungerleider, and Lewis QRS complex voltages, but these relations were noted only in those with BMI <29 kg/m(2) . Correcting RaVL and Lewis voltages by the difference in the slope of BMI-voltage relations in those with BMI <29 kg/m(2) vs those with BMI ≥29 kg/m(2) showed the greatest performance for LVH detection (uncorrected RaVL : 0.695 ± 0.025, corrected RaVL : 0.733 ± 0.022; P < 0.0001), and also increased the sensitivity (uncorrected RaVL : 30.6%, corrected RaVL : 42.4%; P < 0.0005) with no significant change in specificity (uncorrected RaVL : 86.3%, corrected RaVL : 83.0%; P = 0.28).

CONCLUSIONS

We offer a novel approach to correcting ECG voltages for the attenuating effects of obesity in individuals of African ancestry, and this improves the performance and sensitivity for LVH detection.