Total QRS Voltage Research Articles

Amyloid Burden Correlates with Electrocardiographic Findings in Patients with Cardiac Amyloidosis-Insights from Histology and Cardiac Magnetic Resonance Imaging.

Cardiac amyloidosis (CA) is associated with several distinct electrocardiographic (ECG) changes. However, the impact of amyloid depositions on ECG parameters is not well investigated. We therefore aimed to assess the correlation of amyloid burden with ECG and test the prognostic power of ECG findings on outcomes in patients with CA. Consecutive CA patients underwent ECG assessment and cardiac magnetic resonance imaging (CMR), including the quantification of extracellular volume (ECV) with T1 mapping. Moreover, seven patients underwent additional amyloid quantification using immunohistochemistry staining of endomyocardial biopsies. A total of 105 CA patients (wild-type transthyretin: 74.3%, variant transthyretin: 8.6%, light chain: 17.1%) were analyzed for this study. We detected correlations of total QRS voltage with histologically quantified amyloid burden (r = -0.780, p = 0.039) and ECV (r = -0.266, p = 0.006). In patients above the ECV median (43.9%), PR intervals were significantly longer (p = 0.016) and left anterior fascicular blocks were more prevalent (p = 0.025). In our survival analysis, neither Kaplan-Meier curves (p = 0.996) nor Cox regression analysis detected associations of QRS voltage with adverse patient outcomes (hazard ratio: 0.995, p = 0.265). The present study demonstrated that an increased amyloid burden is associated with lower voltages in CA patients. However, baseline ECG findings, including QRS voltage, were not associated with adverse outcomes.

Electrocardiogram Criteria to Diagnose Cardiac Amyloidosis in Men With a Bundle Branch Block

Diagnosing cardiac amyloidosis is challenging and requires a high index of suspicion in patients with an increased left ventricular wall thickness (LVWT). Low QRS voltage on electrocardiogram (ECG) has been regarded as the hallmark ECG finding in cardiac amyloidosis; however, the presence of low voltage can range from 20-74% and the voltage/mass ratio carries a greater diagnostic accuracy than QRS voltage alone. Patients with cardiac amyloidosis can have conduction system infiltration and this may result in a BBB. Therefore, the ECG or mass/voltage criteria established for patients with a narrow QRS in the diagnosis of cardiac amyloidosis may not be applicable in patients with a BBB. We sought to identify criteria to aid in the diagnosis of cardiac amyloidosis in patients with increased LVWT on echocardiogram and with a BBB on ECG. We calculated the total QRS score/LVWT, limb lead QRS score/LVWT, R in lead aVL/LVWT, R in lead I/LVWT, and Sokolow index/LVWT. In patients with an increase in LVWT and BBB, total QRS voltage that is indexed to wall thickness can help distinguish between patients with increased wall thickness who have cardiac amyloidosis from those who have LVH related to a pressure overload state. A unique index of Total QRS Score/LVWT is the best predictor of cardiac amyloidosis with a cutoff value of 92.5 mV/cm which is 100% sensitive and 83% specific for the diagnosis of cardiac amyloidosis. This may be a useful screening tool in patients with an increased wall thickness to raise diagnostic suspicion for cardiac amyloidosis.

Electrocardiogram and echocardiographic study of left ventricular hypertrophy in patients with essential hypertension in a teaching medical college

Background: Left ventricular hypertrophy (LVH) is the adaptive mechanism for increased left ventricular (LV) stress and is associated with many adverse events. This study was undertaken to study LVH in patients of essential hypertension and to correlate between clinical, electrocardiogram (ECG), and echocardiography (ECHO) in the identification of LVH. Materials and Methods: One hundred patients attending the outpatient department and those who were admitted in our teaching institute from January 2013 to June 2014 were the study subjects. All cases of essential hypertension, irrespective of the duration of hypertension and type of treatment received were included in the study. Patients with secondary hypertension, ischemic heart disease/myocardial infarction, ischemic cardiomyopathy, congenital heart disease, and valvular heart disease were excluded. Conclusion: Out of the different ECG criteria, total QRS criteria showed a high sensitivity of 60%. ECG criteria have a high specificity but low sensitivity and hence, have limited use as a screening method. However, in a resource-poor country such as India where ECHO facilities are not available in all rural regions, improved ECG criteria such as total QRS voltage can be recommended as a routine investigation for LVH because of its cost-effectiveness and easy availability despite certain limitations.

Usefulness of Electrocardiographic Voltage to Determine Myocardial Fibrosis in Hypertrophic Cardiomyopathy

Classic electrocardiographic (ECG) voltage indexes have been applied to screen for left ventricular (LV) hypertrophy in hypertrophic cardiomyopathy (HC). However, it is unclear whether low ECG voltage reflects deteriorated electrical forces because of replacement of the myocardium by fibrotic tissues in HC. We investigated correlations between classic ECG voltage indexes (Cornell, total QRS voltage, and Sokolow-Lyon) and cardiac magnetic resonance (CMR) parameters focusing on the impact of low ECG voltage on the LV ejection fraction (LVEF) and myocardial fibrosis in HC. We studied 108 consecutive patients with HC who underwent CMR imaging with late gadolinium enhancement (LGE). Nineteen patients with complete right or left bundle branch block were excluded, leaving 89 patients for analysis (age 61.0 ± 13.9 years; 58 men). Of the 3 voltage indexes, the total QRS voltage and Sokolow-Lyon indexes were positively correlated with LVEF. For discriminating patients with end-stage HC (LVEF <50%) from patients with HC and preserved LVEF (≥ 50%), receiver-operating characteristic analysis revealed an excellent area under the curve of 0.87 for the total QRS voltage index and 0.90 for the Sokolow-Lyon index, whereas the area under the curve for the Cornell index was only 0.54 (p <0.01). Moreover, these 2 voltage indexes were negatively correlated with the extent of LGE-determined myocardial fibrosis when adjusted by the LV maximal wall thickness. In conclusion, low ECG voltage indexes may reflect increased myocardial fibrosis in patients with HC.

Refinement of total 12-lead QRS voltage criteria for diagnosing left ventricular hypertrophy

Objective: We sought to test the hypothesis that the total QRS voltage without either set of the limb leads (I, II, III) or (R, L, F) may be a better indicator of LVH as compared to the total QRS voltage. Background: The total 12 lead QRS voltage has been a validated electrocardiographic criterion for left ventricular hypertrophy (LVH), with an upper limit of175 mm. However, there is some redundancy in this measurement as the output of the limb leads is repeated because leads I, II, III, and R, L, F use the same three electrodes. Methods: 43 unselected, consecutive echocardiograms were examined for evidence of LVH by wall thickness. Electrocardiogram (ECG) of these patients within a week of the echocardiogram were then examined for the total 12 leads QRS voltage, minus I, II, III and total minus R, L, F voltages. ECG findings were then compared with corresponding echocardiographic dimensions. Results: A total QRS voltage of123 mmon ECG yielded a sensitivity of 73% and specificity of 67% for diagnosing LVH with 95% CI = 0.59 - 0.89, p = 0.007. Total minus (R, L and F) value of110 mmon ECG appears to give the best sensitivity (73%), specificity (72%), and accuracy (64% negative predictive value and 82% positive predictive value) for LVH. Conclusion: It appears that total QRS voltage minus either set of the limb leads, especially the total minus R, L and F is a better criterion, with110 mmbeing the best specific, sensitive and accurate index for diagnosing LVH.

Electrocardiogram as prognostic and diagnostic parameter in follow up of patients with heart failure

IntroductionMost patients with HF due to systolic dysfunction have a significant abnormality on ECG. It is a widely available tool relatively inexpensive, simple to perform, and yields an instant result. AimTo determine whether heart failure (ECG) conveys prognostic and diagnostic information in patients with HF. MethodsThe study was carried out on 100 heart failure patients. All patients were subjected to history taking, clinical examination, standard 12 lead ECG (at admission, discharge, and 3month follow up) for assessment of the following: (QRS voltage amplitude: in limb leads and in chest leads, total QRS voltage and transthoracic echocardiography were done for all patients (at discharge and at 3month follow up (FU). ResultsThere were 75 males and 25 females, aged between 21 and 86years (mean=59.14±13.41years). Total QRS voltage, limb leads voltage and chest leads voltage; all significantly increased from admission values (98.54±20.64, 37.87±11.06, and 60.67±15.26mm) to (110.72±21.28, 43.01±11.92, and 67.71±15.22) at discharge (p<0.001 for all). Also there was a significant increase in voltage at FU (111.72±21.28, 43.30±11.96, and 68.61±16.61mm) (p<0.001 for all). There was a negative correlation found between left ventricular end diastolic and systolic dimensions (LVEDD and LVESD) with total QRS voltage, chest leads voltage and limb leads voltage, both at discharge and at FU. The total QRS Voltage was significantly higher in patients having no lower limb (LL) edema than those with edema on admission, at discharge and on FU (p<0.001). ConclusionVoltages of ECG are considered one of the most important parameters in diagnosis and FU of patients with heart failure. Voltage of chest leads well correlated with LVEDD and LVESD. Voltage of limb leads has important inverse correlation with LL edema.

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.

Detection of incipient left ventricular hypertrophy in mild to moderate arterial hypertension with normal electrocardiogram and echocardiogram: a new use for signal-averaged electrocardiography.

To assess signal-averaged electrocardiogram (SAECG) for diagnosing incipient left ventricular hypertrophy (LVH). A study with 115 individuals was carried out. The individuals were divided as follows: GI - 38 healthy individuals; GII - 47 individuals with mild to moderate hypertension and normal findings on echocardiogram and ECG; and GIII - 30 individuals with hypertension and documented LVH. The magnitude vector of the SAECG was analyzed with the high-pass cutoff frequency of 40 Hz through the bidirectional four-pole Butterworth high-pass digital filter. The mean quadratic root of the total QRS voltage (RMST) and the two-dimensional integral of the QRS area of the spectro-temporal map were analyzed between 0 and 30 Hz for the frequency domain (Int FD), and between 40 and 250 Hz for the time domain (Int TD). The electrocardiographic criterion for LVH was based on the Cornell Product. Left ventricular mass was calculated with the Devereux formula. All parameters analyzed increased from GI to GIII, except for Int FD (GII vs GIII) and RMST log (GII vs GIII). Int TD showed greater accuracy for detecting LVH with an appropriate cutoff > 8 (sensitivity of 55%, specificity of 81%). Positive values (> 8) were found in 56.5% of the G II patients and in 18.4% of the GI patients (p< 0.0005). SAECG can be used in the early diagnosis of LVH in hypertensive patients with normal ECG and echocardiogram.

Non-endocrine late complications of bone marrow transplantation in childhood: part I.

Non-endocrine late complications of bone marrow transplantation in childhood: part I.

Altered cardiac hemodynamic and electrical state in normal sinus rhythm after chronic dual-chamber pacing for relief of left ventricular outflow obstruction in hypertrophic cardiomyopathy

Dual-chamber (DDD) pacing relieves left ventricular (LV) outflow tract obstruction in patients with hypertrophic cardiomyopathy. The reduction in LV outflow gradient persists in some patients after cessation of pacing. Twelve-lead and signal-averaged electrocardiograms were obtained before and after 12 weeks of DDD pacing in 18 patients with obstructive hypertrophic cardiomyopathy to determine whether the altered hemodynamic state after chronic pacing is accompanied by electrical changes. Hemodynamic studies were performed at baseline and at follow-up. Signal-averaged electrocardiograms were obtained using a Corazonix Predictor and bidirectional filters at 25 Hz to a noise level of <0.5 μV. At follow-up, LV outflow tract gradients were reduced significantly during DDD pacing and with cessation of pacing in sinus rhythm by 56 ± 10 and 47 ± 10 mm Hg, respectively (p < 0.001). There was no simple relation between changes in LV outflow tract gradient and in the electrocardiogram. For example, amplitude of the R wave in V 5,6 was reduced by ≥0.5 mv in 4 patients, unchanged in 12 and increased in 2. Similarly, the S wave in leads V 1,2 was reduced in 7 patients, unchanged in 7 and increased in 4. The T wave became more negative (≥0.1 mv) in leads II, III, aVF and V 5,6 in 13 patients and more positive in leads I and aVL in 12. The QRS was also altered by signal-averaged electrocardiographic criteria; duration of the total QRS and root-meansquare voltage of the QRS of the filtered Y axis increased (106 ± 12 to 112 ± 13 ms [p = 0.036] and 170 ± 82 to 195 ± 102 μV [p = 0.059], respectively). In conclusion, chronic DDD pacing significantly reduces obstruction to LV outflow, and after discontinuation of chronic DDD pacing, there is evidence of altered mechanical as well as electrical myocardial state.

Usefulness of total 12-lead QRS voltage for determining the presence of left ventricular hypertrophy in systemic hypertension

The total QRS voltage from all 12 electrocardiographic leads has been evaluated as a criterion for left ventricular (LV) hypertrophy in different disease states. 1,2 The upper limit of total QRS voltage has been established in adults free of cardiopulmonary disease by necropsy criteria. 3 Nevertheless, no study on the use of this criterion in essential hypertension has been performed. Such was the purpose of this study.

QRS voltage measurements in autopsied men free of cardiopulmonary disease: A basis for evaluating total QRS voltage as an index of left ventricular hypertrophy

Use of total 12-lead QRS electrocardiographic voltage as a criterion for left ventricular (LV) hypertrophy has been of recent interest. Although upper and lower limits of QRS voltage for individual electrocardiographic leads have been reported in clinically healthy men and women, the upper limit of total 12-lead QRS voltage has not been established in adults free of cardiopulmonary disease by clinical and necropsy criteria. Therefore, the total QRS voltage from all 12 electrocardiographic leads was determined in 30 autopsied men known to be free of cardiopulmonary disease by clinical assessment and by a special cardiac examination using postmortem coronary angiography and chamber partition determination of LV weight. Gross heart weight, LV weight and total QRS voltage are reported. Comparisons were made between disease-free patients and previously reported patients with aortic valve stenosis, aortic regurgitation and cardiac amyloidosis with respect to total QRS voltage and gross heart weight. Total QRS voltage and gross heart weight were significantly greater in patients with severe aortic stenosis (mean 245 mm) and severe aortic regurgitation (mean 274 mm) than in our patients (mean 127 mm). Total QRS voltage was significantly less, whereas gross heart weight was significantly greater in patients with cardiac amyloidosis (mean 101 mm) than in our normal subjects (mean 127 mm). These data provide a basis for evaluating the total 12-lead QRS voltage as a criterion for LV hypertrophy.