Prognostic Significance of Electrocardiographic Voltages and Their Serial Changes in Elderly With Systolic Hypertension

Searching for the Best Machine Learning Algorithm for the Detection of Left Ventricular Hypertrophy from the ECG: A Review

Background: Left ventricular hypertrophy (LVH) is a powerful predictor of future cardiovascular events. Objectives: The objectives of this study were to conduct a systematic review of machine learning (ML) algorithms for the identification of LVH and compare them with respect to the classical features of test sensitivity, specificity, accuracy, ROC and the traditional ECG criteria for LVH. Methods: A search string was constructed with the operators "left ventricular hypertrophy, electrocardiogram" AND machine learning; then, Medline and PubMed were systematically searched. Results: There were 14 studies that examined the detection of LVH utilizing the ECG and utilized at least one ML approach. ML approaches encompassed support vector machines, logistic regression, Random Forest, GLMNet, Gradient Boosting Machine, XGBoost, AdaBoost, ensemble neural networks, convolutional neural networks, deep neural networks and a back-propagation neural network. Sensitivity ranged from 0.29 to 0.966 and specificity ranged from 0.53 to 0.99. A comparison with the classical ECG criteria for LVH was performed in nine studies. ML algorithms were universally more sensitive than the Cornell voltage, Cornell product, Sokolow-Lyons or Romhilt-Estes criteria. However, none of the ML algorithms had meaningfully better specificity, and four were worse. Many of the ML algorithms included a large number of clinical (age, sex, height, weight), laboratory and detailed ECG waveform data (P, QRS and T wave), making them difficult to utilize in a clinical screening situation. Conclusions: There are over a dozen different ML algorithms for the detection of LVH on a 12-lead ECG that use various ECG signal analyses and/or the inclusion of clinical and laboratory variables. Most improved in terms of sensitivity, but most also failed to outperform specificity compared to the classic ECG criteria. ML algorithms should be compared or tested on the same (standard) database.

Estimating Left Ventricular Mass from the Electrocardiogram across the Spectrum of LV Mass from Normal to Increased LV Mass in an Older Age Group

Objectives

To examine the relationship of QRS voltages and left ventricular (LV) mass across the spectrum of individuals with different LV mass.

Methods

Twenty QRS voltage measurements or combinations were determined in a consecutive series of 159 adults with an ECG and echocardiogram without previous myocardial infarction, left or right bundle branch block, pre-excitation, or electronic pacemaker.

Results

The four strongest and significant correlations between QRS and LV mass were S in V4, deepest S wave in any precordial lead plus S in V4, S in V3, and S in V3 plus R in AVL times QRS duration. For men, the strength of the relationships were S in V3 (F = 33.8), deepest S wave in any precordial lead plus S V4 (F = 33.7), S in V3 plus R aVL (F = 29.9), S in V4 (F = 29.79), and deepest S in precordial leads (F = 17.9). The R wave in AVL alone did not correlate with LV mass. Criteria using the R wave in lateral precordial leads did not correlate as strongly with LV mass. For women, only S in V4 significantly correlated with LV mass. Overall, the R wave voltage in limb leads (AVL I or II) did not correlate with precordial S wave amplitudes. Univariate and multivariate analysis showed that some but not all QRS voltages correlated with each other. In multivariate analysis, using only single variables and not combination of QRS variables, the only significant relationship between QRS voltage and left ventricular mass was for men the S in V3 (p = 0.04) and for women S in V4 (p = 0.016) and R in V6 (p = 0.04).

Conclusion

The S wave in V3 and V4 correlate most strongly with LV mass while the R wave in limb leads, including AVL, do not correlate.

First-line diuretics versus other classes of antihypertensive drugs for hypertension

BACKGROUND

Different first-line drug classes for patients with hypertension are often assumed to have similar effectiveness with respect to reducing mortality and morbidity outcomes, and lowering blood pressure. First-line low-dose thiazide diuretics have been previously shown to have the best mortality and morbidity evidence when compared with placebo or no treatment. Head-to-head comparisons of thiazides with other blood pressure-lowering drug classes would demonstrate whether there are important differences.

OBJECTIVES

To compare the effects of first-line diuretic drugs with other individual first-line classes of antihypertensive drugs on mortality, morbidity, and withdrawals due to adverse effects in patients with hypertension. Secondary objectives included assessments of the need for added drugs, drug switching, and blood pressure-lowering.

SEARCH METHODS

Cochrane Hypertension's Information Specialist searched the Cochrane Hypertension Specialized Register, CENTRAL, MEDLINE, Embase, and trials registers to March 2021. We also checked references and contacted study authors to identify additional studies. A top-up search of the Specialized Register was carried out in June 2022.

SELECTION CRITERIA

Randomized active comparator trials of at least one year's duration were included. Trials had a clearly defined intervention arm of a first-line diuretic (thiazide, thiazide-like, or loop diuretic) compared to another first-line drug class: beta-blockers, calcium channel blockers, alpha adrenergic blockers, angiotensin converting enzyme (ACE) inhibitors, angiotensin II receptor blockers, direct renin inhibitors, or other antihypertensive drug classes. Studies had to include clearly defined mortality and morbidity outcomes (serious adverse events, total cardiovascular events, stroke, coronary heart disease (CHD), congestive heart failure, and withdrawals due to adverse effects).

DATA COLLECTION AND ANALYSIS

We used standard Cochrane methodological procedures.

MAIN RESULTS

We included 20 trials with 26 comparator arms randomizing over 90,000 participants. The findings are relevant to first-line use of drug classes in older male and female hypertensive patients (aged 50 to 75) with multiple co-morbidities, including type 2 diabetes. First-line thiazide and thiazide-like diuretics were compared with beta-blockers (six trials), calcium channel blockers (eight trials), ACE inhibitors (five trials), and alpha-adrenergic blockers (three trials); other comparators included angiotensin II receptor blockers, aliskiren (a direct renin inhibitor), and clonidine (a centrally acting drug). Only three studies reported data for total serious adverse events: two studies compared diuretics with calcium channel blockers and one with a direct renin inhibitor. Compared to first-line beta-blockers, first-line thiazides probably result in little to no difference in total mortality (risk ratio (RR) 0.96, 95% confidence interval (CI) 0.84 to 1.10; 5 trials, 18,241 participants; moderate-certainty), probably reduce total cardiovascular events (5.4% versus 4.8%; RR 0.88, 95% CI 0.78 to 1.00; 4 trials, 18,135 participants; absolute risk reduction (ARR) 0.6%, moderate-certainty), may result in little to no difference in stroke (RR 0.85, 95% CI 0.66 to 1.09; 4 trials, 18,135 participants; low-certainty), CHD (RR 0.91, 95% CI 0.78 to 1.07; 4 trials, 18,135 participants; low-certainty), or heart failure (RR 0.69, 95% CI 0.40 to 1.19; 1 trial, 6569 participants; low-certainty), and probably reduce withdrawals due to adverse effects (10.1% versus 7.9%; RR 0.78, 95% CI 0.71 to 0.85; 5 trials, 18,501 participants; ARR 2.2%; moderate-certainty). Compared to first-line calcium channel blockers, first-line thiazides probably result in little to no difference in total mortality (RR 1.02, 95% CI 0.96 to 1.08; 7 trials, 35,417 participants; moderate-certainty), may result in little to no difference in serious adverse events (RR 1.09, 95% CI 0.97 to 1.24; 2 trials, 7204 participants; low-certainty), probably reduce total cardiovascular events (14.3% versus 13.3%; RR 0.93, 95% CI 0.89 to 0.98; 6 trials, 35,217 participants; ARR 1.0%; moderate-certainty), probably result in little to no difference in stroke (RR 1.06, 95% CI 0.95 to 1.18; 6 trials, 35,217 participants; moderate-certainty) or CHD (RR 1.00, 95% CI 0.93 to 1.08; 6 trials, 35,217 participants; moderate-certainty), probably reduce heart failure (4.4% versus 3.2%; RR 0.74, 95% CI 0.66 to 0.82; 6 trials, 35,217 participants; ARR 1.2%; moderate-certainty), and may reduce withdrawals due to adverse effects (7.6% versus 6.2%; RR 0.81, 95% CI 0.75 to 0.88; 7 trials, 33,908 participants; ARR 1.4%; low-certainty). Compared to first-line ACE inhibitors, first-line thiazides probably result in little to no difference in total mortality (RR 1.00, 95% CI 0.95 to 1.07; 3 trials, 30,961 participants; moderate-certainty), may result in little to no difference in total cardiovascular events (RR 0.97, 95% CI 0.92 to 1.02; 3 trials, 30,900 participants; low-certainty), probably reduce stroke slightly (4.7% versus 4.1%; RR 0.89, 95% CI 0.80 to 0.99; 3 trials, 30,900 participants; ARR 0.6%; moderate-certainty), probably result in little to no difference in CHD (RR 1.03, 95% CI 0.96 to 1.12; 3 trials, 30,900 participants; moderate-certainty) or heart failure (RR 0.94, 95% CI 0.84 to 1.04; 2 trials, 30,392 participants; moderate-certainty), and probably reduce withdrawals due to adverse effects (3.9% versus 2.9%; RR 0.73, 95% CI 0.64 to 0.84; 3 trials, 25,254 participants; ARR 1.0%; moderate-certainty). Compared to first-line alpha-blockers, first-line thiazides probably result in little to no difference in total mortality (RR 0.98, 95% CI 0.88 to 1.09; 1 trial, 24,316 participants; moderate-certainty), probably reduce total cardiovascular events (12.1% versus 9.0%; RR 0.74, 95% CI 0.69 to 0.80; 2 trials, 24,396 participants; ARR 3.1%; moderate-certainty) and stroke (2.7% versus 2.3%; RR 0.86, 95% CI 0.73 to 1.01; 2 trials, 24,396 participants; ARR 0.4%; moderate-certainty), may result in little to no difference in CHD (RR 0.98, 95% CI 0.86 to 1.11; 2 trials, 24,396 participants; low-certainty), probably reduce heart failure (5.4% versus 2.8%; RR 0.51, 95% CI 0.45 to 0.58; 1 trial, 24,316 participants; ARR 2.6%; moderate-certainty), and may reduce withdrawals due to adverse effects (1.3% versus 0.9%; RR 0.70, 95% CI 0.54 to 0.89; 3 trials, 24,772 participants; ARR 0.4%; low-certainty). For the other drug classes, data were insufficient. No antihypertensive drug class demonstrated any clinically important advantages over first-line thiazides.

AUTHORS' CONCLUSIONS

When used as first-line agents for the treatment of hypertension, thiazides and thiazide-like drugs likely do not change total mortality and likely decrease some morbidity outcomes such as cardiovascular events and withdrawals due to adverse effects, when compared to beta-blockers, calcium channel blockers, ACE inhibitors, and alpha-blockers.

Performance of a novel ECG criterion for improving detection of left ventricular hypertrophy: a cross-sectional study in a general Chinese population

OBJECTIVES

The sensitivity of ECG for detecting left ventricular hypertrophy (LVH) is low. The aim of this study was to explore a better ECG criterion for screening LVH in a large general Chinese population.

DESIGN

Case-control study.

SETTING

China Medical University in Shenyang, China.

PARTICIPANTS

All permanent residents in Dawa, Zhangwu and Liaoyang aged 35 years or older were invited. Participants with unqualified data, pacemaker rhythm, frequent premature ventricular beats, Wolff-Parkinson-White syndrome, complete bundle branch block, myocardial infarction or hypertrophic cardiomyopathy were excluded. A total of 10 360 subjects (4630 males) were recruited.

INTERVENTIONS

A novel ECG criterion (Northeast China Rural Cardiovascular Health Study (NCRCHS)) composed of different ratios of maximum R wave in lead V₅ or V₆ (R_V5/V6), S wave in lead V₃ (S_V3) and R wave in lead aVL (R_aVL) was proposed and validated using multiple linear regression. Receiver-operating characteristic curves were used to compare the NCRCHS criterion with traditional criteria for LVH detection.

RESULTS

An optimised model (15^*R_aVL+8^*S_V3+7^*R_V5/V6) was constructed (R² 0.192, p<0.001) with the cut-off values of 36.8 mV for males and 26.1 mV for females. The maximum area under the curve was obtained using the NCRCHS criterion (male 0.74, 95% CI 0.73 to 0.75; female 0.73, 95% CI 0.72 to 0.75), followed by Cornell voltage criterion, Sokolow-Lyon criterion, Peguero-Lo Presti criterion, multi-ethnic study of atherosclerosis (MESA)-specific criterion and Syst-Eur voltage criterion. Compared with the Cornell voltage criterion, the NCRCHS criterion had a significantly higher sensitivity for detecting LVH at the same level of specificity (p<0.05).

CONCLUSIONS

The NCRCHS criterion significantly improved sensitivity for LVH detection in a general Chinese population, with cut-off values of 36.8 and 26.1 mV for males and females, respectively. This criterion can detect LVH earlier and better and may prevent subsequent cardiovascular diseases.

Relationship between QRS measurements and left ventricular morphology and function in asymptomatic individuals

BACKGROUND AND AIM

QRS amplitude and duration are associated with increased left ventricular (LV) volume, mass and dysfunction. However, the diagnostic concordance between QRS measurements and LV morphology and function, as shown by Doppler echocardiography, is not well established. We investigated the relationships of QRS duration and amplitude with echocardiographic measurements of LV morphology and systolic and diastolic function in normal individuals.

METHODS

Individuals without signs or symptoms of coronary artery disease or heart failure, who underwent clinical examination as a part of a cross-sectional survey for the prevalence of coronary risk factors, randomly selected from the population list in Caltanissetta, Italy, were included in the study. QRS duration and amplitude were automatically measured using inbuilt software. LV ejection and filling patterns were studied using Doppler echocardiography.

RESULTS

We studied 184 individuals (96 men and 88 women), mean age 55.9 (11.3). QRS duration increased by 5.4 ms for every 100 g increase in LV mass, and by 4.6 ms for each 10 mm increase in LV end-diastolic diameter. The amplitude increased by 0.8 mm for every 100 g increase in LV mass. There was no relationship with LV dimensions. A nonlinear correlation was found between QRS amplitude and indexes of global dyssynchrony. The time-voltage QRS area correlated with LV mass, dimensions and indexes of dyssynchrony. There was no relationship between QRS measurements and ejection fraction.

CONCLUSIONS

QRS prolongation and increase in amplitude are strongly influenced by LV increased mass and volume, as well as by dyssynchrony, independently of ejection fraction.

Office and Home Blood Pressures as Determinants of Electrocardiographic Left Ventricular Hypertrophy Among Black Nigerians Compared With White Flemish

BACKGROUND

The association of electrocardiographic left ventricular hypertrophy (ECG-LVH) with blood pressure (BP) in Blacks living in sub-Saharan Africa remains poorly documented.

METHODS

In 225 Black Nigerians and 729 White Flemish, we analyzed QRS voltages and voltage-duration products and 12 criteria diagnostic of ECG-LVH in relation to office BP (mean of 5 consecutive readings) and home BP (duplicate morning and evening readings averaged over 1 week).

RESULTS

In multivariable analyses, QRS voltage and voltage-duration indexes were generally higher in Blacks than Whites. By using any of 12 criteria, ECG-LVH was more prevalent among Black than White men (54.4% vs. 36.0%) with no ethnic difference among women (17.1%). Precordial voltages and voltage-duration products increased with office and home systolic BP (SBP), and increases were up to 3-fold steeper in Blacks. In Blacks vs. Whites, increases in the Sokolow–Lyon voltage associated with a 10-mm Hg higher SBP were 0.18 mV (95% confidence interval [CI], 0.09–0.26) vs. 0.06 mV (0.02–0.09) and 0.17 mV (0.07–0.28) vs. 0.11 mV (CI, 0.07–0.15) for office and home BP, respectively, with a significant ethnic gradient (P < 0.05). The risk of ECG-LVH increased more with office and home BP in Blacks than Whites.

CONCLUSIONS

Associations of ECG voltages and voltage-duration products and risk of ECG-LVH with BP are steeper in Black Nigerians compared with a White reference population. In resource-poor settings of sub-Saharan Africa, the ECG in combination with office and home BP is an essential instrument in risk stratification across the entire BP range.

Cohort Study of ECG Left Ventricular Hypertrophy Trajectories: Ethnic Disparities, Associations With Cardiovascular Outcomes, and Clinical Utility

Background

ECG left ventricular hypertrophy (LVH) is a well‐known predictor of cardiovascular disease. However, no prior study has characterized patterns of presence/absence of ECG LVH (“ECG LVH trajectories”) across the adult lifespan in both sexes and across ethnicities. We examined: (1) correlates of ECG LVH trajectories; (2) the association of ECG LVH trajectories with incident coronary heart disease, transient ischemic attack, ischemic stroke, hemorrhagic stroke, and heart failure; and (3) reclassification of cardiovascular disease risk using ECG LVH trajectories.

Methods and Results

We performed a cohort study among 75 412 men and 107 954 women in the Northern California Kaiser Permanente Medical Care Program who had available longitudinal exposures of ECG LVH and covariates, followed for a median of 4.8 (range <1–9.3) years. ECG LVH was measured by Cornell voltage‐duration product. Adverse trajectories of ECG LVH (persistent, new development, or variable pattern) were more common among blacks and Native American men and were independently related to incident cardiovascular disease with hazard ratios ranging from 1.2 for ECG LVH variable pattern and transient ischemic attack in women to 2.8 for persistent ECG LVH and heart failure in men. ECG LVH trajectories reclassified 4% and 7% of men and women with intermediate coronary heart disease risk, respectively.

Conclusions

ECG LVH trajectories were significant indicators of coronary heart disease, stroke, and heart failure risk, independently of level and change in cardiovascular disease risk factors, and may have clinical utility.

Uncontrolled hypertension is associated with coronary artery calcification and electrocardiographic left ventricular hypertrophy: a case-control study

We conducted a 1:2 matched case-control study in order to evaluate whether the prevalence of coronary artery calcium (CAC) and electrocardiographic left ventricular hypertrophy (LVH) or strain was higher in patients with uncontrolled hypertension than in subjects from the general population, and evaluate the association between CAC and LVH in patients with uncontrolled hypertension. Cases were patients with uncontrolled hypertension, whereas the controls were random individuals from the general population without cardiovascular disease. CAC score was assessed using a non-contrast computed tomographic scan. LVH was evaluated using the Sokolow-Lyon voltage combination and Cornell voltage-duration product, respectively. Associations between CAC, LVH and traditional cardiovascular risk factors were tested by means of ordinal, conditional and classic binary logistic regression models. We found that uncontrolled hypertension was independently associated with both an ordinal CAC score category (odds ratio (OR) 3.9 (95% CI, 1.6-9.1), P = 0.002), the presence of CAC score>99 (OR 4.5 (95% CI, 1.4-14.7), P = 0.01) and electrocardiographic LVH (OR 10.1 (95% CI, 3.4-30.2), P < 0.001) on both univariate and multivariable analyses. There was, however, no correlation between CAC and LVH. The lack of an association between CAC and LVH suggests that they are markers of different complications of hypertension and may have independent predictive values. Patients with both CAC and LVH may be at higher risk than those in whom only one of these markers is present.

Differential value of left ventricular mass index and wall thickness in predicting cardiovascular prognosis: data from the PAMELA population

BACKGROUND

Data on the prognostic value of echocardiographic left ventricular (LV) hypertrophy (LVH) as defined by LV wall thickness rather than LV mass estimate are scarce and not univocal. Thus, we investigated the value of LV mass index, wall thickness, and relative wall thickness (RWT) in predicting cardiovascular events in the PAMELA population.

METHODS

At entry 1,716 subjects underwent diagnostic tests, including laboratory investigations, 24-hour ambulatory blood pressure (BP) monitoring, and echocardiography. For the purpose of this analysis, all subjects were divided into quintiles of LV mass, LV mass/ body surface area (BSA), LV mass/height(2.7), interventricular septum (IVS), posterior wall (PW) thickness, IVS+PW thickness, and RWT.

RESULTS

Over a follow-up of 148 months, 139 nonfatal or fatal cardiovascular events were documented. After adjustment for age, sex, BP, fasting blood glucose, total cholesterol, and use of antihypertensive drugs, only the subjects stratified in the highest quintiles of LV mass indexed to body surface area (BSA) or height(2.7) exhibited a greater likelihood of incident cardiovascular disease (relative risk (RR) = 2.72, 95% confidence interval (CI) = 1.05-7.00, P = 0.03; RR = 4.83, 95% CI = 1.45-16.13, P = 0.01, respectively) as compared with the first quintile (reference group). The same was not true for the highest quintiles of IVS, PW thickness, IVS+PW thickness, and RWT. Similar findings were found when echocardiographic parameters were expressed as continuous variables.

CONCLUSIONS

This study indicates that LV wall thickness, different from LV mass index, does not provide a reliable estimate of cardiovascular risk associated with LVH in a general population. From these data it is recommended that echocardiographic laboratories should provide a systematic estimate of LV mass index, which is a strong, independent predictor of incident cardiovascular disease.

Clinical significance of subclinical carotid atherosclerosis and its relationship with echocardiographic parameters in non-diabetic chronic kidney disease patients

Background

Non-diabetic chronic kidney disease (CKD) patients are a heterogeneous group with a variety of prognosis. We investigated the role of subclinical carotid atherosclerosis for the prediction of adverse cardiovascular (CV) outcomes in these patients, and tried to identify clinical and echocardiographic parameters associated with subclinical carotid atherosclerosis.

Methods

As a prospective design, 182 asymptomatic non-diabetic CKD patients underwent carotid ultrasonography and Doppler echocardiography. Carotid atherosclerosis was defined as a carotid intima-media thickness ≥1.0 mm and/or the presence of plaque.

Results

During the mean follow-up period of 28.8 ± 16.1 months, 23 adverse CV events occurred. Patients with carotid atherosclerosis (99, 54.4%) showed significantly higher rates of annual CV events than those without (8.6 vs. 1.5%, p <0.001). Particularly, the presence of carotid plaque was a powerful predictor of adverse CV outcomes (OR 7.80, 95% CI 1.45-45.97). Clinical parameters associated with the presence of subclinical carotid atherosclerosis were old age, previous history of hypertension, increased pulse pressure, and higher high-sensitivity C-reactive protein (hs-CRP) level. By echocardiography, early diastolic mitral annular velocity (E’) and the ratio of early peak transmitral inflow velocity (E) to E’ (E/E’) were closely related with the presence of carotid atherosclerosis. A multivariate analysis showed that age, hs-CRP, and E/E’ were significant determinants of carotid atherosclerosis.

Conclusions

Carotid plaque, even subclinical, was closely associated with a poor prognosis in non-diabetic CKD patients. Increased age, hs-CRP level, and E/E’ ratio may be useful markers suggesting the presence of carotid atherosclerosis in these patients.

Prevalence of electrocardiographic left ventricular hypertrophy in human hypertension: an updated review

AIM

Left ventricular hypertrophy (LVH) is a strong predictor of cardiovascular events in different clinical settings. We reviewed recent studies on the prevalence of hypertensive LVH, as assessed by ECG, in order to update our knowledge about this marker of cardiac organ damage in human hypertension.

DESIGN

A MEDLINE search using the key words ' LVH ', 'hypertension', 'ECG', 'cardiac organ damage' and 'cardiac hypertrophy' was performed in order to identify relevant articles. Full articles published in English language in the last decade (1 January 2000 to 31 December 2010) reporting studies in adult or elderly individuals, were considered.

RESULTS

A total of 26 studies, including 40 444 untreated and treated individuals (85% whites, 47% men, 32% obese, 28% diabetics and 22% patients with cardiovascular disease) were considered. LVH was defined by 15 criteria (seven studies used two or more criteria, range 2-7); LVH prevalence consistently varied among studies (0.6-40.0%) with an average of 18% in the pooled population. A sex-based analysis in five out of 26 studies (12 084 patients) showed an average prevalence of LVH of 24% in men and 16% in women (odds ratio 1.38, 95% CI 0.91-2.09, P  =  0.11).

CONCLUSION

Our analysis shows that LVH, as assessed by ECG, is present in a relevant fraction of the hypertensive population; these data highlight the role of ECG as a first-line examination for identifying subclinical organ damage and optimizing blood pressure control in hypertensive patients.

Prognostic factors in resistant hypertension: implications for cardiovascular risk stratification and therapeutic management

Resistant hypertension (RH) is defined as uncontrolled office blood pressure (BP) in spite of the use of at least three antihypertensive medications. Although its condition has a high prevalence, it is still understudied, and its prognosis is not well established. Some prospective studies evaluated the prognostic value of ambulatory BP monitoring, ECG and renal parameters. They pointed out that ambulatory BPs are important predictors of cardiovascular morbidity and mortality, whereas office BP has no prognostic value. The diagnosis of true RH and the nondipping pattern are also valuable predictors of cardiovascular outcomes. Moreover, several ECG (prolonged ventricular repolarization, serial changes in the strain pattern and left ventricular hypertrophy) and renal parameters (albuminuria and reduced glomerular filtration rate) are also powerful cardiovascular risk markers in RH. These markers and others yet unexplored, such as arterial stiffness and serum biomarkers, may improve cardiovascular risk stratification in these very high-risk patients.

Prevalence of left-ventricular hypertrophy by multiple electrocardiographic criteria in general population: Hermex study

OBJECTIVES

To determine the prevalence of left-ventricular hypertrophy (LVH) in the general population by means of multiple electrocardiographic criteria and those variables independently associated.

METHODS

Random-sample cross-sectional study of the general population aged between 25 and 79 years, representative of a health area, was conducted. An electrocardiogram was recorded 'on line' in the Electropres project website; 17 LVH criteria together with two combined criteria were used. By multivariate analysis we examined those variables independently associated with the presence of electrocardiographic LVH.

RESULTS

We recruited 2564 individuals, mean age 50.9 [standard deviation (SD) 14.7] years, 45.7% men. The criteria more prevalent were: Dalfó 19.4%, RV6/V5 14.5%, Perugia 10.9%, any combination with at least three positive criteria (Combined 3) 9.4%, Romhilt 7.5%, Lewis 6.2% and the recommended criteria of the European Society of Hypertension 4%. The best prevalence ratio between hypertensive and normotensive individuals was achieved with Lewis, Dalfó and Perugia criteria. The least prevalence was Sokolow 0.7%. The variables that were independently associated with the presence of LVH by Combined 3 criterion were pulse pressure at least 50 [odds ratio (OR) 2.13, 95% confidence interval (CI) 1.47-3.09], arterial hypertension (OR 1.75, 95% CI 1.21-2.53) and smoking (OR 0.69, 95% CI 0.50-0.95).

CONCLUSIONS

The detection ability of the electrocardiogram with regard to the LVH may improve with the use of other criteria than those currently recommended by the guidelines. The presence of LVH is positively associated with hypertension and elevated pulse pressure and negatively with a history of smoking.

Regression of ECG-LVH is associated with lower risk of new-onset heart failure and mortality in patients with isolated systolic hypertension; The LIFE study

BACKGROUND

Hypertension and electrocardiographic left ventricular hypertrophy (ECG-LVH) are strong predictors of heart failure (HF). It is unclear whether regression of ECG-LVH during treatment predicts less new-onset HF in patients with isolated systolic hypertension (ISH).

METHODS

A total of 9,027 patients with hypertension and ECG-LVH and without a history of HF were randomized to losartan- or atenolol-based treatment in the Losartan Intervention For Endpoint reduction in hypertension study. Incident HF and the combined endpoint of HF and death were evaluated in 1,280 ISH patients and as compared with 7,747 patients with systolic-diastolic hypertension or isolated diastolic hypertension (non-ISH) during mean 4.8 ± 0.9 years follow-up.

RESULTS

New-onset HF and HF or death occurred in 57 (4.5%) and 179 (14.0%) ISH patients and 220 (2.8%) and 787 (10.2%) non-ISH patients. In Cox regression analyses adjusting for treatment and HF risk factors, time-varying Cornell product was associated with lower risk of new-onset HF in ISH (adjusted hazard ratio (HR) 0.79, 95% confidence interval (CI) 0.67-0.94, P = 0.008, per 1,050 mm × ms (1 SD) lower Cornell product) and in non-ISH (adjusted HR 0.67, 95% CI 0.61-0.72, P < 0.001, per SD lower Cornell product). In parallel analyses, time-varying Cornell product was associated with lower risk of new-onset HF or death in ISH and non-ISH (adjusted HR 0.83, 95% CI 0.75-0.93, P = 0.001 and 0.82, 95% CI 0.77-0.87, P < 0.001, per SD lower Cornell product).

CONCLUSIONS

Regression of time-varying Cornell product was associated with similar reductions in risk of new-onset HF and the combined endpoint of HF or death in ISH and non-ISH patients.

Association of heart failure hospitalizations with combined electrocardiography and echocardiography criteria for left ventricular hypertrophy

BACKGROUND

The value of performing echocardiography in hypertensive patients with electrocardiographic left ventricular hypertrophy (LVH) is uncertain.

METHODS

Baseline echo- and electrocardiographic data and cardiovascular events over 4.8 years study treatment were assessed in 922 hypertensive patients in the Losartan Intervention For Endpoint reduction in hypertension echocardiography substudy. Patients were grouped according to presence of LVH on both electrocardiogram (ECG) and echocardiogram (n = 515), only on ECG (n = 172), only on echocardiogram (n = 135), or on none tests (n = 100). LVH was diagnosed by Sokolow Lyon and Cornell product criteria by electrocardiography and as LV mass index >116 g/m(2) in men and >104 g/m(2) in women by echocardiography.

RESULTS

Patients with LVH on both tests were older, had higher systolic blood pressure and LV mass, lower LV systolic function, and included more patients with aortic regurgitation, albuminuria, and history of ischemic heart disease (all P < 0.05). Incidence of combined myocardial infarction, stroke, or cardiovascular death did not differ between groups. Incidence of hospitalization for heart failure was 5.3 and 2.6 times higher in patients with LVH on both tests compared to patients with LVH on ECG or echocardiogram only (P < 0.01). In Cox regression, LVH on both tests predicted hospitalization for heart failure (hazard ratio 4.29 (95% confidence interval 1.26-14.65), P = 0.020) independent of other covariates including study treatment allocation and history of ischemic heart disease.

CONCLUSIONS

Our results suggest that combining LVH assessment on a single ECG and echocardiogram provides a simple tool for additional heart failure risk stratification in asymptomatic high-risk hypertensive patients.

Second statement of the working group on electrocardiographic diagnosis of left ventricular hypertrophy

The Working Group on Electrocardiographic Diagnosis of Left Ventricular Hypertrophy, appointed by the Editor of the Journal of Electrocardiology, presents the alternative conceptual model for the ECG diagnosis of left ventricular hypertrophy (LVH). It is stressed that ECG is a record of electrical events, not of mechanical events and/ or anatomical characteristics. Considering the electrical characteristics of pathologically changed myocardium should lead to better understanding and improved clinical usefulness of the ECH in the clinical diagnosis of LVH.

Incidence of heart failure in relation to QRS duration during antihypertensive therapy: the LIFE study

BACKGROUND

Prolonged QRS duration (QRS) has been associated with left ventricular dyssynchrony and dysfunction and with the development of heart failure. However, whether persistence or development of increased QRS over time is associated with an increased incidence of heart failure in hypertensive patients, independent of blood pressure lowering and regression of electrocardiographic left ventricular hypertrophy (LVH) has not been examined.

METHODS AND RESULTS

The relation of QRS over time to incident heart failure was examined in 8945 hypertensive patients without history of heart failure who were randomly assigned to losartan-based or atenolol-based treatment. During 4.7 +/- 1.1 years follow-up, heart failure hospitalization occurred in 282 patients (3.2%): in 157 with in-treatment QRS less than 110 ms (4.6 per 1000 patient-years) and in 125 with persistence or development of QRS 110 ms or more (13.4 per 1000 patient-years). In univariate Cox analyses in which QRS during the study was entered as a time-varying covariate, in-treatment persistence or development of a QRS 110 ms or more was associated with a 153% increased risk of developing heart failure [hazard ratio 2.53, 95% confidence interval (CI) 2.00-3.20]. After adjusting for treatment, baseline risk factors for heart failure, incident myocardial infarction and for baseline and in-treatment electrocardiographic LVH and blood pressure, persistence or development of a QRS 110 ms or more remained associated with a 102% increased risk of new-onset heart failure (hazard ratio 2.02, 95% CI 1.49-2.74).

CONCLUSION

Persistence or development of a prolonged QRS during antihypertensive therapy is associated with an increased likelihood of new-onset heart failure, independent of blood pressure lowering, treatment modality and regression of electrocardiographic LVH in patients with essential hypertension. These findings suggest that serial assessment of QRS over time can be used to track the risk of heart failure in hypertensive patients.

Prognostic significance of baseline and serial changes in electrocardiographic strain pattern in resistant hypertension

OBJECTIVES

The prognostic importance of serial changes in electrocardiographic strain pattern of lateral ST-depression and T-wave inversion is unclear. The objective was to evaluate the significance of baseline and serial changes in strain pattern as predictors of cardiovascular morbidity and mortality in patients with resistant hypertension.

METHODS

At baseline and during follow-up, 532 resistant hypertensive patients had the presence of strain pattern examined on 12-lead ECGs. Other clinical laboratory, echocardiographic and ambulatory blood pressure data were obtained. Primary endpoints were a composite of total cardiovascular events and mortality. Strokes and coronary heart disease events were secondary endpoints. Multiple Cox regression assessed the associations between strain pattern and subsequent endpoints.

RESULTS

At baseline, 115 patients (21.6%) presented the strain pattern and during follow-up, 17 patients regressed and 22 developed new strain pattern. After a median follow-up of 4.8 years, 69 patients died, 46 from cardiovascular causes; and 107 cardiovascular events occurred, 44 strokes and 42 coronary heart disease events. After adjustment for several cardiovascular risk factors, including time-varying ambulatory blood pressures and electrocardiographic voltage criteria of left ventricular hypertrophy, the persistence or development of strain during follow-up was a predictor of the composite endpoint (hazard ratio 1.97, 95% confidence interval 1.19-3.25), all-cause mortality (hazard ratio 1.99, 95% confidence interval 1.10-3.61) and of stroke (hazard ratio 3.09, 95% confidence interval 1.40-6.81). The combination of strain pattern and left ventricular hypertrophy voltage criteria improved stratification of cardiovascular risk.

CONCLUSION

Serial changes in electrocardiographic strain pattern during follow-up predict cardiovascular morbidity and mortality in resistant hypertensive patients. Regression or prevention of the strain pattern during antihypertensive treatment may be a therapeutic goal to improve prognosis.

Prognostic impact of baseline and serial changes in electrocardiographic left ventricular hypertrophy in resistant hypertension

BACKGROUND

The prognostic value of electrocardiographic left ventricular hypertrophy (ECG-LVH) in resistant hypertension (RH) is unknown. The aim was to evaluate the importance of baseline and serial changes in ECG-LVH as predictors of cardiovascular morbidity and mortality in patients with RH.

METHODS

At baseline and during follow-up, 552 resistant hypertensive patients had 3 ECG-LVH criteria obtained: Sokolow-Lyon, Cornell voltage, and Cornell voltage-duration product. Primary end points were a composite of fatal and nonfatal cardiovascular events and all-cause and cardiovascular mortalities. Total strokes and coronary heart disease (CHD) events were secondary end points. Multiple Cox regression assessed the associations between time-varying ECG-LVH and subsequent end points.

RESULTS

After a median follow-up of 4.8 years, 70 patients died, 46 from cardiovascular causes; and 109 total cardiovascular events occurred, 46 strokes, and 44 CHD events. After adjustment for several cardiovascular risk factors, baseline Cornell voltage and product, but not Sokolow-Lyon voltage, were independent predictors of the composite end point and of all-cause and cardiovascular mortalities. Reductions of all ECG-LVH criteria were protective factors for the composite end point: a 1-SD (1.1 mV) reduction in Sokolow-Lyon voltage was associated with a 35% lower risk (95% CI 10%-53%) of cardiovascular events, whereas prevention or regression of Cornell product LVH criterion implied a 40% lower risk (95% CI 11%-60%). Baseline and serial changes in Sokolow-Lyon voltage were independent predictors of strokes, whereas Cornell voltage was predictive of CHD events.

CONCLUSIONS

Baseline and serial changes in ECG-LVH predict cardiovascular morbidity and mortality in RH patients. Antihypertensive treatment targeted at regression or prevention of ECG-LVH may improve prognosis.

Regression of Left Ventricular Mass by Antihypertensive Treatment

Blood pressure–lowering therapy reduces left ventricular mass, but the question of whether differences exist among drug classes has not been fully resolved. Our aim was to compare the effects of diuretics, β-blockers, calcium channel blockers, angiotensin-converting enzyme inhibitors, and angiotensin receptor blockers on left ventricular mass regression in patients with hypertension on the basis of prospective, randomized comparative studies. We performed meta-analyses, involving pooled pairwise comparisons of the drug classes and of each class versus other classes statistically combined, and meta-regression analyses to identify the determinants of the regression. The 75 relevant publications involved 84 pairwise comparisons and 6001 patients. Regression of left ventricular mass was significantly less ( P =0.01) with β-blockers (9.8%) than with angiotensin receptor blockers (12.5%), but none of the other analyzable pairwise comparisons between drug classes revealed significant differences ( P >0.10). In addition, β-blockers showed less regression than the other 4 classes statistically combined ( P <0.01), and regression was more pronounced with angiotensin receptor blockers versus the others ( P <0.01). In multivariable meta-regression analysis on all of the treatment arms, β-blocker treatment was a significant and negative predictor of the regression (−3.6%; P <0.01), but this was not the case for the other drug classes, including angiotensin receptor blockers. In conclusion, β-blockers show less regression of left ventricular mass, whereas angiotensin receptor blockers may induce larger regression. The inferiority of β-blockers appears to be more convincing than the superiority of angiotensin receptor blockers.

Effects of Telmisartan, Ramipril, and Their Combination on Left Ventricular Hypertrophy in Individuals at High Vascular Risk in the Ongoing Telmisartan Alone and in Combination With Ramipril Global End Point Trial and the Telmisartan Randomized Assessment Study in ACE Intolerant Subjects With Cardiovascular Disease

Background— Angiotensin-converting enzyme (ACE) inhibitors and angiotensin receptor blockers reduce left ventricular hypertrophy (LVH). The effect of these drugs on LVH in high-risk patients without heart failure is unknown.

Methods and Results— In the Ongoing Telmisartan Alone and in Combination With Ramipril Global End Point Trial (ONTARGET), patients at high vascular risk and tolerant of ACE inhibitors were randomly assigned to ramipril, telmisartan, or their combination (n=23 165). In the Telmisartan Randomized Assessment Study in ACE Intolerant Subjects With Cardiovascular Disease (TRANSCEND), patients intolerant of ACE inhibitors were randomized to telmisartan or placebo (n=5343). Prevalence of LVH at entry in TRANSCEND was 12.7%. It was reduced by telmisartan (10.5% and 9.9% after 2 and 5 years) compared with placebo (12.7% and 12.8% after 2 and 5 years) (overall odds ratio, 0.79; 95% confidence interval [CI], 0.68 to 0.91; P =0.0017). New-onset LVH occurred less frequently with telmisartan compared with placebo (overall odds ratio, 0.63; 95% CI, 0.51 to 0.79; P =0.0001). LVH regression was similar in the 2 groups. In ONTARGET, prevalence of LVH at entry was 12.4%. At follow-up, it occurred slightly less frequently with telmisartan (odds ratio, 0.92; 95% CI, 0.83 to 1.01; P =0.07) and the combination (odds ratio, 0.93; 95% CI, 0.84 to 1.02; P =0.12) than with ramipril, but differences between the groups were not significant. New-onset LVH was associated with a higher risk of primary outcome during follow-up (hazard ratio, 1.77; 95% CI, 1.50 to 2.07).

Conclusions— In patients at high vascular risk, telmisartan is more effective than placebo in reducing LVH. New-onset LVH is reduced by 37%. The effect of combination of the 2 drugs on LVH is similar to that of ramipril alone.

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.

Thresholds in the relationship between mortality and left ventricular hypertrophy defined by electrocardiography

BACKGROUND

Electrocardiographic criteria for the diagnosis of left ventricular hypertrophy in current use were defined using autopsy results or echocardiography; criteria defined using mortality might be more clinically meaningful.

METHODS

Using data from Third National Health and Nutrition Examination Survey (NHANES III), we selected electrocardiographic measures that best differentiated those surviving at 5 years from those who did not. We identified voltage thresholds using regression techniques and then compared survival for subjects above and below the thresholds.

RESULTS

Cornell voltage, Cornell product, and Novacode estimate of left ventricular mass index were discriminative for mortality and had identifiable thresholds present in their relationships with mortality. Independent of systolic blood pressure, there were significant associations with 5-year mortality for Novacode index above threshold; hazard ratios were 1.58 for women and 1.27 for men, and for 5-year cardiovascular mortality were 1.78 for women and 2.34 for men.

CONCLUSIONS

Electrocardiographic criteria for left ventricular hypertrophy validated against mortality might be clinically useful.

Left ventricular hypertrophy in patients with renal artery stenosis

Left ventricular hypertrophy (LVH) has been shown to be 3 times more prevalent in patients with renal artery stenosis (RAS) compared to essential hypertension, but factors that predict LVH in this population are not known. We identified 66 patients with unilateral renal artery stenosis and an interpretable electrocardiogram (ECG). LVH by either Cornell voltage-duration product or Sokolow-Lyon voltage criteria was present in 18 of the 66 patients (27%). The mean intra-aortic blood pressure was 100 +/- 14 mm Hg in patients with LVH, and 104 +/- 23 mm Hg in those without LVH (P = 0.37). The average stenosis by quantitative computerized angiography was 68 +/- 17% in patients with LVH, and 64 +/- 13% in those without LVH (P = 0.34). The mean translesional pressure gradient was 11 +/- 15 mm Hg in patients with LVH, and 13 +/- 20 mm Hg in those without LVH (P = 0.60). Using linear regression models, there was no correlation between intra-aortic blood pressure, percentage of stenosis, or translesional pressure gradient and either Cornell voltage-duration product or Sokolow-Lyon voltage criteria. In summary, LVH using ECG criteria was present in 27% of patients with unilateral RAS but was not associated with blood pressure at the time of the procedure or severity of renal artery stenosis.

Left ventricular hypertrophy determined by Sokolow–Lyon criteria: a different predictor in women than in men?

The clinical usefulness of the Sokolow-Lyon voltage criteria in the assessment of electrocardiographic left ventricular hypertrophy (ECG LVH) is addressed. We prospectively studied 3,338 women and 3,330 men referred with hypertension, with an average follow-up of 11.2 years. The voltage amplitude sum SV1+max (RV5 or RV6) was calculated and ECG LVH was defined as a sum >or=3.5 mV. We adjusted survival for age, treatment status before presentation and a previous myocardial infarction or cerebrovascular accident. The risk of stroke, coronary heart disease (CHD) and cardiovascular disease (CVD) mortality increased significantly for each quantitative 0.1 mV increase in baseline electrocardiogram (ECG) voltage, in women within the range of 1.6-3.9% and in men 1.4-3.0%. After further adjustments for race, body mass index, smoking and systolic blood pressure, increasing voltage independently predicted CVD mortality in both men and women. In women, both increasing voltage and the presence of left ventricular hypertrophy (LVH) were predictors of stroke mortality, whereas in men this risk was attenuated. In men, the adjusted association between increasing voltage and CHD mortality tended to be stronger than in women. The use of different thresholds for the two genders made little difference. For stroke and CHD mortality, the population attributable fractions associated with LVH were 15.2 and 5.4% in women and 12.8 and 8.5% in men, respectively. In conclusion, the greater the baseline ECG voltage sum, the greater the associated CVD mortality risk. Women tended to have a high risk of stroke mortality owing to LVH despite adjustments.