Electrocardiographic criteria for diagnosis of left ventricular hypertrophy in the presence of complete right bundle branch block

On-Treatment Blood Pressure and Cardiovascular Outcomes in Adults With Hypertension and Left Ventricular Hypertrophy

BACKGROUND

Benefits of intensive blood pressure lowering on health outcomes have been demonstrated in high-risk patients. However, little is known about such benefits in patients with left ventricular hypertrophy (LVH).

OBJECTIVES

This study sought to investigate the association of on-treatment blood pressure with cardiovascular disease (CVD) risk in adults with hypertension and LVH.

METHODS

From a nationwide health examination database, this study identified 95,545 participants aged 40-79 years who were taking antihypertensive medication and had LVH on baseline electrocardiography. Using Cox models, HRs and 95% CIs for CVD events were calculated according to systolic blood pressure (SBP) or diastolic blood pressure (DBP).

RESULTS

Over a median follow-up of 11.5 years, 12,035 new CVD events occurred. An SBP of <130 mm Hg and DBP of <80 mm Hg were associated with the lowest risk for CVD events in cubic spline models. When the group with SBP of 120-129 mm Hg was the reference, multivariable-adjusted HRs were 1.31 (95% CI: 1.24-1.38) in the ≥140 mm Hg group, 1.08 (95% CI: 1.02-1.15) in the 130-139 mm Hg group, and 1.03 (95% CI: 0.93-1.15) in the <120 mm Hg group. Likewise, when the group with DBP of 70-79 mm Hg was the reference, multivariable-adjusted HRs were 1.30 (95% CI: 1.24-1.37) in the ≥90 mm Hg group, 1.06 (95% CI: 1.01-1.12) in the 80-89 mm Hg group, and 1.08 (95% CI: 0.96 to 1.20) in the <70 mm Hg group.

CONCLUSIONS

In adults with hypertension and LVH, the risk for CVD events was the lowest at SBP <130 mm Hg and DBP <80 mm Hg. Further randomized trials are warranted to establish optimal blood pressure-lowering strategies for these patients.

Positive T wave in lead aVR as an independent predictor for 1-year major adverse cardiac events in patients with first anterior wall ST-segment elevation myocardial infarction

BACKGROUND

Positive T wave in lead aVR has been shown to predict an adverse in-hospital outcome in patients with anterior wall ST-segment elevation myocardial infarction (STEMI). However, the prognostic value of positive T wave in lead aVR on a long-term outcome has not been fully explored.

METHODS

We performed a retrospective analysis of 190 consecutive patients with first anterior wall STEMI who underwent an emergent coronary angiogram. Patients were divided into those with positive T wave > 0 mV and those with negative T wave ≦ 0 mV in lead aVR. Baseline and angiographic characteristics, and in-hospital revascularization procedures were recorded. In addition, in-hospital and 1-year major adverse cardiac events (MACE) including death, recurrent myocardial infarction, and target vessel revascularization were recorded.

RESULTS

Among 190 patients, 37 patients (19%) had positive T wave and 153 patients (81%) had negative T wave in lead aVR. Patients with positive T wave had higher rate of left main disease defined as stenosis ≥50% (11% vs. 2%, p = .028) than those with negative T wave. Patients with positive T wave had higher rate of 1-year MACE (38% vs. 13%, p < .001) driven by higher all-cause mortality (27% vs. 5%, p < .001). Positive T wave was an independent predictor for 1-year MACE (OR 2.74; 95% CI 1.04-7.15; p = .04).

CONCLUSION

Positive T wave in lead aVR was an independent predictor for 1-year MACE in patients with first anterior wall STEMI.

Prevalence and Prognostic Implications of Bundle Branch Block in Comatose Survivors of Out-of-Hospital Cardiac Arrest

This study reports the prevalence and prognostic impact of right bundle branch block (RBBB) and left bundle branch block (LBBB) in the admission electrocardiogram (ECG) of comatose survivors of out-of-hospital cardiac arrest (OHCA). The present study is part of the predefined electrocardiographic substudy of the prospective randomized target temperature management trial, which found no benefit of targeting 33°C over 36°C in terms of outcome. Six-hundred eighty-two patients were included in the substudy. An admission ECG, which defined the present study population, was available in 602 patients (88%). These ECGs were stratified by the presence of LBBB, RBBB, or no-BBB (reference) on admission. End points were mortality and neurologic outcome 6 months after OHCA. RBBB was present in 79 patients (13%) and LBBB in 65 patients (11%), and the majority of BBBs (92%) had resolved 4 hours after admission. RBBB was associated with significantly higher 6 months mortality (RBBB: hazard ratio [HR]_unadjusted 1.78, 95% confidence interval [CI] 1.30 to 2.43; LBBB: HR_unadjusted 1.26, 95% CI 0.87 to 1.81), but this did not reach a level of significance in the adjusted model (HR_adjusted 1.33, 95% CI 0.94 to 1.87). Similar findings were seen for neurologic outcome in the unadjusted and adjusted analyses. RBBB was further independently associated with higher odds of unfavorable neurologic outcome (RBBB: adjusted odds ratio 1.97, 95% CI 1.05 to 3.71). In conclusion, BBBs after OHCA were transient in most patients, and RBBB was directly associated with higher mortality and independently associated with higher odds of unfavorable neurologic outcome. RBBB is seemingly an early indicator of an unfavorable prognosis after OHCA.

R Wave in aVL Lead is a Robust Index of Left Ventricular Hypertrophy: A Cardiac MRI Study

BACKGROUND

In patients free from overt cardiac disease, R wave in aVL lead (RaVL) is strongly correlated with left ventricular mass index (LVMI) assessed by transthoracic echocardiography. The aim of the present study was to extend this finding to other settings (cardiomyopathy or conduction disorders), by comparing ECG criteria of left ventricular hypertrophy (LVH) to cardiac MRI (CMR).

METHODS

In 501 patients, CMR and ECG were performed within a median-period of 5 days. CMR LVH cut-offs used were 83 g/m2 in men and 67 g/m2 in women.

RESULTS

RaVL was independently correlated with LVMI in patients with or without myocardial infarction (MI) (N = 300 and N = 201, respectively). SV3 was independently correlated with LVMI and LV enlargement only in patients without MI. In the whole cohort, RaVL had area under receiver-operating characteristic curve of 0.729 (specificity 98.3%, sensitivity 19.6%, optimal cut-off 1.1 mV). The performance of RaVL was remarkable in women, in Caucasians, and in the presence of right bundle branch block. It decreased in case of MI. Overall, it is proposed that below 0.5 mV and above 1.0 mV, RaVL is sufficient to exclude or establish LVH. Between 0.5 and 1 mV, composite indices (Cornell voltage or product) should be used. Using this algorithm allowed classifying appropriately 85% of the patients.

CONCLUSIONS

Our results showed that RaVL is a good index of LVH with a univocal threshold of 1.0 mV in various clinical conditions. SV3 may be combined to RaVL in some conditions, namely LV enlargement to increase its performance.

Electrocardiographic Left Ventricular Hypertrophy as a Predictor for Nonsignificant Coronary Artery Disease in Patients With Non-ST-Segment Elevation Myocardial Infarction

Left ventricular hypertrophy (LVH) can lead to subendocardial ischemia by altering the coronary blood flow and its transmural myocardial distribution in the setting of increased oxygen demand. We hypothesized that electrocardiographic LVH predicts nonsignificant coronary artery disease (CAD) in patients with non-ST-segment elevation myocardial infarction (NSTEMI). We performed a retrospective analysis of 406 consecutive patients with NSTEMI who underwent coronary angiography. The LVH was diagnosed using Sokolow-Lyon and Cornell voltage criteria. Nonsignificant CAD was defined as stenosis less than 50% in the left main and 70% in any other coronary arteries. Of the 406 patients, 100 (25%) patients had electrocardiographic LVH and 99 (24%) patients had nonsignificant CAD. Patients with electrocardiographic LVH had a higher prevalence of nonsignificant CAD (32% vs 22%, P = .04) and a lower rate of in-hospital revascularization (45% vs 69%, P < .001) than those without LVH. On multivariate analysis, electrocardiographic LVH was an independent predictor of nonsignificant CAD (odds ratio 1.94; 95% confidence interval 1.12-3.35; P = .02). In conclusion, electrocardiographic LVH is an independent predictor of nonsignificant CAD and associated with a lower rate of in-hospital revascularization in patients with NSTEMI.

The electrocardiographic features associated with cardiac amyloidosis of variant transthyretin isoleucine 122 type in Afro-Caribbean patients

BACKGROUND

About 4% of African Americans possess the isoleucine 122 (V122I) variant of transthyretin, associated with cardiac amyloidosis beyond ages of 55 to 60 years. Transthyretin amyloidosis associated with variant V122I (ATTR V122I) is likely to be an important cause of heart failure in Afro-Caribbean populations, but the high prevalence of left ventricular hypertrophy (LVH) and lack of awareness of this genetic disorder pose diagnostic hurdles. We report the electrocardiographic (ECG) features of ATTR V122I in the largest clinical series to date.

METHODS

Patients with ATTR V122I were identified in collaboration with the UK National Amyloidosis Centre. The ECG at presentation was assessed for cardiac rhythm, axis, and voltage complex size.

RESULTS

We include 64 patients with ATTR V122I, with a median age of 74 years (range, 57-88 years). Normal or increased ECG voltage was present in 44.3% of patients, and overall 25% met the criteria for LVH. A significant negative correlation between voltage complex size and duration of illness was seen (P < .05). First-degree heart block was evident in 56% of patients in sinus rhythm. During follow-up (n = 17; median, 28 months), 50% of patients with initial first-degree heart block required pacing.

CONCLUSION

Electrocardiographic voltages meet the criteria for LVH in one quarter of patients with ATTR V122I cardiac amyloidosis. The widely held belief that cardiac amyloidosis is associated with low-voltage complexes is likely to contribute to underdiagnosis of ATTR V122I. First-degree heart block is common at diagnosis and identifies patients at high risk for subsequent pacing requirement.

Usefulness of electrocardiographic and echocardiographic left ventricular hypertrophy to predict adverse events in patients with a first non-ST-elevation acute myocardial infarction

Left ventricular hypertrophy (LVH) portends a worse outcome after non-ST-elevation acute myocardial infarction (NSTEMI). However, its definition has varied and the incremental prognostic information provided by echocardiography has been unclear. Different electrocardiographic and echocardiographic criteria for LVH were compared for their ability to predict in-hospital complications in 451 consecutive patients with a first NSTEMI, 337 of whom had a reliable echocardiogram. Five to 8% had LVH using Sokolow-Lyon or Cornell (voltage or product) criteria on admission; 15%, using either electrocardiographic criteria; and 24%, using echocardiography. LVH predicted the occurrence of adverse events (death, reinfarction, or severe angina or heart failure), with the strongest association found for the Cornell product (50.0% vs 24.9% of patients meeting or not meeting this criterion had complications, respectively; p = 0.002). This association persisted after adjusting for baseline clinical predictors (odds ratio 2.52, 95% confidence interval 1.19 to 5.35), and considering echocardiographic LVH did not improve the prediction. LVH was more closely related to heart failure occurrence than to recurrent ischemic events. A progressive increase in the rate of complications was observed across quartiles of the components of all LVH criteria (17.1%, 23.7%, 31.7%, and 36.2% for Cornell product, respectively; p <0.001). In conclusion, LVH, especially an abnormal Cornell product, increased the risk of heart failure, but was weakly related to recurrent ischemia in patients with NSTEMI. Echocardiographic LVH did not appear to add prognostic information to the electrocardiogram. However, considering LVH criteria in a more quantitative manner may augment their ability to predict adverse events in this population.

Effect of right bundle branch block on electrocardiographic amplitudes, including combined voltage criteria used for the detection of left ventricular hypertrophy

BACKGROUND

Although right bundle branch block (RBBB) delays right ventricular depolarization, its effect on cancellation of right and left ventricular forces within the QRS complex has not been quantified during stable temporal and physiological conditions. Systematic changes in QRS amplitude during transient RBBB bear directly on performance of standard ECG criteria for left ventricular hypertrophy (LVH), and these changes require quantification.

METHODS

We examined the instantaneous effect of RBBB on QRS amplitudes and LVH voltages in 40 patients who had intermittent complete RBBB during a single 10 sec standard 12-lead ECG recording, comprising 0.1% of approximately 400,000 consecutive ECGs in a university teaching hospital setting. Amplitudes were measured by magnifying graticule to the nearest 25 microvolts, averaged for up to 3 normal and 3 RBBB complexes, and compared by paired t test.

RESULTS

RBBB was associated with an increase in initial QRS forces (RV1, RV2, and QV6) but significant decreases in mean mid-QRS amplitudes that reflect left ventricular depolarization (RaVL [-75 microvolts], SV1 [-389 microvolts], SV3 [-617 microvolts], RV5 [-100 microvolts], and RV6 [-123 microvolts]). All late QRS forces were increased with RBBB (R'V1, SV5, SI). As a result, combined voltages used for LVH criteria were significantly reduced by RBBB: Sokolow-Lyon voltage decreased from 1520 +/- 739 to 1014 +/- 512 microvolts (p < 0.001), and Cornell voltage decreased from 1438 +/- 683 to 746 +/- 399 microvolts (p < 0.001).

CONCLUSIONS

RBBB is associated with significant reduction in "left ventricular" QRS amplitudes of the standard ECG, consistent with cancellation, rather than unmasking, of left ventricular mid-QRS forces by altered septal and delayed right ventricular depolarization. Because QRS voltages that are routinely combined for the detection of LVH are reduced in RBBB, standard LVH criteria will perform with lower sensitivity in patients with RBBB.

Distance correction in the electrocardiographic estimation of left ventricular mass

Assessment of the left ventricular mass (LVM) from electrocardiograms may be improved by the addition of clinical variables into a multivariate equation. As the heart-thorax distance may affect the results, its relationships with electrocardiographic and clinical data have been evaluated in a group of 220 subjects (53 +/- 15 years, 126 female, 175 without demonstrated heart disease) who were assessed for echocardiographic LVM and heart-thorax distance. Sokolow, Cornell, and total QRS voltage indexes were obtained. Multiple regression equations with LVM as the dependent variable were fit, with an ECG index, body mass index (BMI), age, and gender as the independent predictors. Each of the 3 ECG indexes, BMI, age, and sex was shown to be independent predictors of LVM, with the ECG and BMI contributing with most of the explanatory power. When added to the model, the distance from the interventricular septum to the precordium (septal-LVD) was not a predictor of LVM, but when BMI was withdrawn, septal-LVD became an independent predictor of LVM (P < .001). This was not observed when septal-LVD was substituted for any other clinical or ECG variable, thus suggesting that septal-LVD accounts for information contained in BMI but not in the remaining variables. In addition, the distance from the center of LV to the precordium (mid-LVD) achieved significance as an independent LVM predictor, although the coefficient of multiple determination (R) practically did not change. Almost identical results are obtained when LVM is indexed for body surface area. Body mass index supplies virtually all the information contained in the heart-thorax distance.

Clinical implication of left precordial T wave inversions in the presence of complete right bundle branch block

This study was designed to elucidate whether left precordial negative T waves are electrocardiographic indicators for the diagnosis of hypertrophic cardiomyopathy (HCM) even in the presence of complete right bundle branch block (CRBBB). In 7 consecutive patients with CRBBB accompanied by negative T waves in at least one of the left precordial leads (V4, V5, V6, maximal negativity; 1.06 +/- 0.40 mVol) (left precordial negative T wave group) and in 15 randomly selected CRBBB patients without left precordial T wave inversions (control group), echocardiography was performed to rule out underlying diseases causing left ventricular overload and to identify candidates for magnetic resonance (MR) imaging. None had anginal pain indicating ischemic heart disease. When 2-dimensional echocardiography indicated left ventricular hypertrophy with wall thickness > or = 15 mm, the magnitude and distribution of hypertrophy were scrutinized on contiguous left ventricular MR short-axis images. The diagnostic criterion of HCM was the demonstration of hypertrophy with a wall thickness of 20 mm or more on the left ventricular MR short-axis images. All patients in the left precordial negative T wave group had negative T waves in both I (negativity; 0.27 +/- 0.17 mVol) and aVL (negativity; 0.23 +/- 0.14 mVol), whereas none in the control group did. The diagnostic criterion for HCM was fulfilled in six patients in the left precordial negative T wave group. However there were no patients who fulfilled the criterion in the control group. Negative T waves were recorded in the I (negativity; 0.30 +/- 0.17 mVol), aVL (negativity; 0.25 +/- 0.14 mVol), V4 (negativity; 1.03 +/- 0.46 mVol), V5 (negativity; 0.83 +/- 0.37 mVol) and V6 leads (negativity; 0.31 +/- 0.31 mVol) in all patients with HCM, while they were recorded in only 6% of the patients without HCM. In conclusion, the existence of left precordial negative T waves in the presence of CRBBB strongly indicates HCM.

Body surface mapping criteria for diagnosis of left ventricular hypertrophy associated with complete right bundle branch block

The standard electrocardiographic (ECG) criteria for left ventricular hypertrophy are unreliable in patients with complete right bundle branch block. This study was undertaken to formulate criteria for diagnosing these patients by using body surface mapping. The echocardiographic left ventricular mass was calculated by the Penn method from M-mode measurements. Of 56 patients, 27 were defined as having left ventricular hypertrophy with a left ventricular mass of 215 g or more. Isopotential and isointegral maps of the QRS complex were observed. The QRS isointegral maps were separated into two parts at the end of the downstroke of the initial R wave of vector spatial magnitude. The body surface mapping criteria with the highest sensitivity were EPmax (maximum of early part of the QRS) 45 microV.s or greater (sensitivity 93%, specificity 90%), EPmax/d (EPmax averaged by EP duration) 0.8 mV or greater (sensitivity 93%, specificity 97%), and Max (initial maximum) 2.2 mV or greater (sensitivity 89%, specificity 90%). These results suggest that body surface mapping is a useful technique in diagnosing patients with left ventricular hypertrophy and right bundle branch block.

Diagnosis of right ventricular overload by body surface QRST isointegral maps in children with postoperative right bundle branch block

The utility of body surface QRST isointegral maps (QRST-Imaps) for the detection of right ventricular (RV) overload was examined in children with postoperative development of right bundle branch block. In healthy children with no evidence of bundle branch block (n = 31), the QRST-Imap demonstrated a maximum at the left anterior chest and a minimum near the right shoulder with a single dipole distribution. The positive areas extended from the left anterior chest to the left back, and negative areas extended from the right anterior chest to the right back. Children with complete right bundle branch block but without heart disease demonstrated a QRST-Imap that was similar to that seen in normal children. In patients with RV overload (n = 15; 8 with ventricular septal defect and complicated anomaly and 7 with tetralogy of Fallot), the QRST-Imaps were abnormal and demonstrated double maxima, a rightward shift of the maximum, and extension of positive areas to the right chest. In the 10 patients who developed postoperative complete right bundle branch block, 4 had no evidence of RV overload by hemodynamic or echocardiographic assessment and demonstrated a normal QRST-Imap. In the six children who had residual RV overload during hemodynamic assessment, the QRST-Imap was abnormal. These results suggest that the QRST-Imap is a useful method for the detection of RV overload in pediatric patients complicated with conduction disturbances.

Electrocardiographic diagnosis of left ventricular hypertrophy in the presence of right bundle branch block in cases with essential hypertension

Right bundle branch block was diagnosed in electrocardiograms of 37 of 1085 patients with essential hypertension. Echocardiographically left ventricular hypertrophy was diagnosed in 14 of these 37 patients. Eighteen electrocardiographic (ECG) criteria, which were previously recommended, were determined in these 37 patients. The sensitivities of five criteria were found to be better than 50%. These are SV1 > or = 2 mm; RV6 > RV5; S III + (R+S) maximum precordial lead > or = 30 mm; P/PR > or = 1.6; R aVL > or = 11 mm. However, their specificities ranged from 56.5% to 95.6%. When the combination of RV6 > RV5 and S III + (R+S) maximum precordial lead > or = 30 mm was used, sensitivity was 57.1 and specificity was 100%. It is concluded that the presence of right bundle branch block these ECG criteria can be used for the diagnosis of left ventricular hypertrophy.

Limitations of the electrocardiographic diagnosis of left ventricular hypertrophy: the influence of left anterior hemiblock and right bundle branch block

We analysed the performance of the electrocardiogram in diagnosing left ventricular hypertrophy in 70 patients with isolated left anterior hemiblock and in 75 patients with right bundle branch block, either isolated (44 cases) or associated (31 cases) with left anterior hemiblock. Left ventricular hypertrophy defined as an echocardiographically determined left ventricular mass greater than 261 g in men and 172 g in women or left ventricular mass index greater than 125 g/m2 in men and 112 g/m2 in women was present in 48 subjects (57%) with isolated left anterior hemiblock and 33 subjects (44%) with right bundle branch block. In patients with isolated left anterior hemiblock the best results were obtained using the SV1 or SV2 + (RV6 + SV6) greater than 25 mm with 74% in sensitivity and 67% in specificity; the criterion SIII + (R + S) maximal in a precordial lead greater than or equal to 30 mm showed a sensitivity of 74% but a specificity of 47%. In the whole group of patients with right bundle branch block none of the criteria nor combination of criteria achieved an acceptable performance (sensitivities ranged from 17% to 41% and specificities ranged from 54% to 85%). When these patients were divided according to the presence or absence of concomitant left anterior hemiblock the electrocardiographic indexes mostly showed, in comparison to whole group, higher values in sensitivity and lower values in specificity in right bundle branch block plus left anterior hemiblock and an opposite behaviour in isolated right bundle branch block.(ABSTRACT TRUNCATED AT 250 WORDS)

Electrocardiographic diagnosis of left ventricular hypertrophy in the presence of bundle branch block

Autopsy and echocardiographic studies indicate that ECG criteria for LVH tend to maintain their sensitivity in the presence of LBBB, with the exception of left precordial lead criteria alone. With RBBB, ECG criteria for LVH using right precordial S waves and combination criteria of right precordial S waves and left precordial R waves have a marked reduction in sensitivity, whereas left precordial R wave criteria have modestly reduced sensitivity. Limb lead criteria for LVH have increased sensitivity in the presence of RBBB and, to a lesser extent, in the presence of LBBB. Acceptable sensitivity for the diagnosis of LVH in patients with bundle branch block requires a combination of limb and precordial lead voltage criteria and/or other nonvoltage ECG criteria, since the prevalence of LVH in the presence of RBBB or LBBB appears higher than the sensitivity of individual criteria.