Association Of QRS Duration Research Articles

Association of QRS Duration with Echocardiographic Left Ventricular Dimensions

Background: QRS duration (QRSd) is used to diagnose left bundle branch block (LBBB) and is important for determining cardiac resynchronization therapy eligibility. Others have reported associations of left bundle branch block (LBBB) and interventricular conduction delay with left ventricular (LV) systolic and diastolic dysfunction in patients without clinical HF. Individualized QRSd thresholds may improve diagnosis and intervention strategies. The goal of this study was to assess the relations of QRS duration to echocardiographic left ventricular (LV) dimensions in individuals. Methods: This was a hospital-based cross-sectional analytical study. A total of 134 purposively selected respondents were included in the study from the patients attending the outpatient or inpatient department of cardiology, Dhaka Medical College Hospital, advised for an echocardiogram. They were divided into two groups depending on their QRS complex duration (Group I≤100 ms and Group II>100 ms). After taking informed written consent, a case record form was filled and Echo measurements were taken following standard procedure with confidentiality. Results: Among the respondents, the mean age was found 52.68 ± 14.24 years. The majority were male (68%), and around 1/3rd of the respondents were overweight or obese. Males were found to have less QRS duration than females (p<0.001) but there was no difference in age (p=0.814) between the groups. All the risk factors considering obesity, diabetes mellitus, hypertension, family history, smoking status, and dyslipidemia were found in similar proportions in both groups (p>0.05). The study found that the interventricular septum thickness and inferolateral wall thickness were higher among those having a QRS duration of more than 100 ms (Group II), but this difference was not significant (p > 0.05). On the other hand, left ventricular diastolic dimension, systolic dimension, and left ventricular mass were found to be increased significantly (p<0.05) with a reduction in ejection fraction in Group II (p<0.05). Conclusion: Left ventricular diastolic and systolic dimensions along with left ventricular mass significantly increase according to QRS duration among the patients. Meanwhile, a reduction in ejection fraction was also evident. (Bangladesh Heart Journal 2024; 39(2): 144-150

Abstract 12957: Delay in Qrs Interval Predicts Risk of Heart Failure and In-hospital Mortality in Patients Admitted With Atrial Fibrillation With Rapid Ventricular Response

Introduction: Atrial fibrillation is associated with increased risk of heart failure and mortality. The association of QRS duration (QRSd) with morbidity and mortality is understudied in patient with atrial fibrillation (AF) Hypothesis: We sought to investigate the association of prolonged QRSd (≥120 ms) and risk of heart failure and in-hospital death in patients admitted for AF with rapid ventricular response (RVR) Methods: A retrospective study in a community hospital using EPIC database analyzed 1637 patients from 2013-2018 with admission codes of AF with RVR. The cohort was then stratified based on QRSd ≥120ms vs <120ms. A p-value of <0.05 was considered significant Results: Among the 1637 patients who were admitted with AF with RVR, 233 (14%) had QRS ≥120ms. Patient’s characteristics with QRSd≥120 compared to those with QRSd<120ms were mean age [75.9 (11.8) vs 70.9 (13.6), (P<.0001)], history of CAD [41% vs 28%, odds ratio (OR)= 1.78, 95% confidence interval (CI): 1.3-2.3 (P<.0001)], history of PVD [15% vs 7%, OR=2.38, 95% CI: 1.58-3.59 (P<.0001)], history of acute MI [50% vs 33%, OR=1.99, 95% CI:1.5-2.6 (P<.0001)] and CHA2DS2Vasc score [median (IQR) 5(3, 6) vs 4(3, 5) (P<0.001). QRSd≥120ms was associated with higher BNP value [median (IQR) 537(305, 862) vs 371(186, 655) (P<0.001)] and an increased risk of heart failure [(70% vs 55%, OR=1.93, 95% CI:1.43-2.6 (P<.0001)]. Additionally, higher in-hospital mortality rate was observed in patients with QRSd≥120ms [4.3% vs 1.3%, OR=3.11, 95% CI:1.44-6.75 (P=0.006)] Conclusions: In patients who were admitted with AF with RVR, QRSd≥120ms was associated with a higher burden of cardiovascular disease, CHA2DS2Vasc score and an increased risk of heart failure resulting in worse clinical outcomes. Higher median BNP values suggest that worsening heart failure contributed to higher in-hospital mortality. Heart failure associated mortality could be alleviated with medical management or cardiac resynchronization therapy.

Association of QRS duration with left ventricular volume and ejection fraction after anterior myocardial infarction assessed by gated single photon emission computed tomography

Background: Even intermediate QRS prolongation without bundle branch block is associated with worse clinical outcome after myocardial infarction (MI). We assessed the association of QRS duration with left ventricular (LV) volume and ejection fraction after anterior MI by using quantitative gated single photon emission computed tomography (SPECT).Methods: Eighty-two patients with prior anterior MI were enrolled. Intermediate QRS prolongation was defined as QRS duration ≥100 ms without bundle branch block. Quantitative analysis of thallium SPECT was performed on the redistribution image. LV end-diastolic volume (LVEDV), end-systolic volume (LVESV) and ejection fraction (LVEF) were obtained.Results: There were 25 patients with intermediate QRS prolongation and 57 patients with normal QRS duation. Compared to patients with normal QRS duration, patients with intermediate QRS prolongation had larger LVEDV (137.4 ± 75.1 ml vs 87.9 ± 43.6 ml, p = .004), larger LVESV (89.9 ± 69.6 ml vs 49.2 ± 35.5 ml, p = .009) and lower LVEF (39.3 ± 14.6% vs 47.6 ± 12.0%, p = .02). QRS duration was positively associated with LVEDV (r = 0.49, p < .001) and LVESV (r = 0.47, p < .001), and was inversely associated with LVEF (r= −0.32, p < .001). Multivariate analysis showed that male sex (β = 0.22, p = .04), QRS duration (β = 0.34, p = .002) and number of abnormal Q waves (β = 0.37, p < .001) were associated with LVEDV. QRS duration (β= −0.32, p = .003) and number of abnormal Q waves (β = −0.40, p < .001) were associated with LVEF.Conclusions: Our results suggest that QRS duration as well as number of abnormal Q waves is independently associated with LV volume and ejection fraction after anterior MI.

The association of QRS duration with atrial fibrillation in a heart failure with preserved ejection fraction population: a pilot study.

Heart failure is a significant cause of morbidity and mortality, yet patient risk stratification may be difficult. Prevention or treatment of atrial fibrillation (AF) may be an important strategy in these patients that could positively affect their outcome. It has been demonstrated that in patients with systolic dysfunction, prolonged QRS duration (QRSd), an easily measured electrocardiographic parameter, is associated with AF. Prolonged QRSd is associated with an increase in prevalence of AF in patients with heart failure with preserved ejection fraction(HFPEF). Between February 2006 and February 2009, 718 patients were discharged with a diagnosis of HF from the Dartmouth-Hitchcock Medical Center. Of these, 206 had EF ≥50% by echocardiography performed within 72 hours of admission. After exclusions, 82 patients remained, of which 25 had AF and 57 had sinus rhythm. Characteristics of the AF and sinus-rhythm patients were compared in this pilot study. After adjustment for age, prior diagnosis of HF, and left atrial area, there was a nonsignificant trend (odds ratio: 2.2, 95% CI of 0.3-17.2) for a QRSd >120 ms to be associated with AF. Similar to results in patients with systolic dysfunction, patients with preserved EF may have an association between a prolonged QRSd and AF.

Ethnic differences in the association of QRS duration with ejection fraction and outcome in heart failure

BackgroundQRS duration (QRSd) criteria for device therapy in heart failure (HF) were derived from predominantly white populations and ethnic differences are poorly understood.MethodsWe compared the association of QRSd with ejection...

QRS duration predicts death and hospitalization among patients with atrial fibrillation irrespective of heart failure: evidence from the AFFIRM study

The association of QRS duration (QRSd) with morbidity and mortality is understudied in patients with atrial fibrillation (AF). We sought to assess any association of prolonged QRS with increased risk of death or hospitalization among patients with AF. QRS duration was retrieved from the baseline electrocardiograms of patients enroled in the Atrial Fibrillation Follow-Up Investigation of Rhythm Management (AFFIRM) study and divided into three categories: <90, 90-119, ≥120 ms. Cox models were applied relating the hazards of mortality and hospitalizations to QRSd. Among 3804 patients with AF, 593 died and 2305 were hospitalized. Compared with those with QRS < 90 ms, patients with QRS ≥ 120 ms, had an increased mortality [hazard ratio (HR) 1.61, 95% confidence interval (CI): 1.29-2.03, P < 0.001] and hospitalizations (HR 1.14, 95% CI: 1.07-1.34, P = 0.043) over an average follow-up of 3.5 years. Importantly, for patients with QRS 90-119 ms, mortality and hospitalization were also increased (HR 1.31, P = 0.005 and 1.11, P = 0.026, respectively). In subgroup analysis based on heart failure (HF) status (previously documented or ejection fraction <40%), mortality was increased for QRS ≥ 120 ms patients with (HR 1.87, P < 0.001) and without HF (HR 1.63, P = 0.02). In the QRS 90-119 ms group, mortality was increased (HR 1.38, P = 0.03) for those with HF, but not significantly among those without HF (HR 1.23, P = 0.14). Among patients with AF, QRSd ≥ 120 ms was associated with a substantially increased risk for mortality (all-cause, cardiovascular, and arrhythmic) and hospitalization. Interestingly, an increased mortality was also observed among those with QRS 90-119 ms and concomitant HF.

Association of QRS duration with left ventricular structure and function and risk of heart failure in middle‐aged and older adults: the Multi‐Ethnic Study of Atherosclerosis (MESA)

Prolonged QRS duration (QRSd) on the electrocardiogram (ECG) has been associated with cardiac structural and functional abnormalities by echocardiography and an increased risk of heart failure (HF). Data are sparse on these relationships in middle-aged and elderly individuals free of baseline cardiovascular disease with respect to cardiac magnetic resonance imaging (MRI). We sought to determine whether QRSd is associated with incident HF and measures of cardiac structure and function by cardiac MRI. We analysed baseline ECGs in the Multi-Ethnic Study of Atherosclerosis (MESA) to determine whether QRSd >100 ms was associated with incident HF. We adjusted for demographic and clinical risk factors, as well as MRI measures of left ventricular (LV) structure and function. Among 4591 eligible participants (51% women; 39% white; mean age 61 years), 75 developed incident HF over a mean follow-up of 7.1 years. QRSd >100 ms was significantly associated with MRI measures of cardiac structure and function, as well as incident HF, even after adjustment for demographic covariates [hazard ratio (HR) 2.10, 95% confidence interval (CI) 1.29-3.42; P = 0.003] and clinical risk factors (HR 1.86, 95% CI 1.14-3.03; P = 0.01). With further adjustment for individual LV structural measures, findings were attenuated to non-significance. Separate adjustment for LV functional measures yielded only mild attenuation. In middle-aged and older adults without cardiovascular disease, a QRSd >100 ms was significantly associated with incident HF. After adjustment for LV structural measures, the association was attenuated to non-significance, suggesting that prolonged QRSd is potentially a useful marker of LV structure that may predispose to HF risk.

Duration of QRS Complex in Resting Electrocardiogram Is a Predictor of Sudden Cardiac Death in Men

Previous studies indicate that increased QRS duration in ECG is related to the risk of all-cause death. However, the association of QRS duration with the risk of sudden cardiac death (SCD) is not well documented in large population-based studies. Our aim was to examine the relation of QRS duration with SCD in a population-based sample of men. This prospective study was based on a cohort of 2049 men aged 42 to 60 years at baseline with a 19-year follow-up, during which a total of 156 SCDs occurred. As a continuous variable, each 10-ms increase in QRS duration was associated with a 27% higher risk for SCD (relative risk, 1.27; 95% confidence interval, 1.14-1.40; P<0.001). Subjects with QRS duration of >110 ms (highest quintile) had a 2.50-fold risk for SCD (relative risk, 2.50; 95% confidence interval, 1.38-4.55; P=0.002) compared with those with QRS duration of <96 ms (lowest quintile), after adjustment for established key demographic and clinical risk factors (age, alcohol consumption, previous myocardial infarction, smoking, serum low- and high-density lipoprotein cholesterol, C-reactive protein, type 2 diabetes mellitus, body mass index, systolic blood pressure, and cardiorespiratory fitness). In addition to QRS duration, smoking, previous myocardial infarction, type 2 diabetes mellitus, cardiorespiratory fitness, body mass index, systolic blood pressure, and C-reactive protein were independently associated with the risk of SCD. QRS duration is an independent predictor of the risk of SCD and may have utility in estimating SCD risk in the general population.

Abstract 9749: Impact of QRS Duration and Morphology on The Risk of Sudden Cardiac Death in Asymptomatic Patients with Aortic Stenosis: The Simvastatin and Ezetimibe in Aortic Stenosis Study

Background: QRS duration and morphology are associated with poor prognosis in many different populations, but the predictive value, particularly of the risk of sudden cardiac death (SCD), in asymptomatic patients with aortic stenosis (AS) has not been well studied. Methods: Clinical examination, electrocardiography and echocardiography were obtained in 1,873 asymptomatic AS patients randomized to simvastatin/ezetimibe combination vs. placebo in the Simvastatin and Ezetimibe in Aortic Stenosis (SEAS) study. Association of QRS duration, evaluated as a categorical variable of &lt;85 msec vs. 85-99 msec and ≥100 msec (excluding bundle branch block [BBB]) and QRS morphology in those with BBB, with the risk of cardiovascular morbidity and mortality was assessed by adjusting for biomarkers, clinical- and echocardiographic covariates as well as randomized treatment. Results: QRS data were available in 1,542 patients; followed for a mean of 4.3±0.8 years (6,631 patients-years of follow-up). QRS duration was &lt;85 msec in 900 patients (58.4%), 85-99 msec in 396 (25.7%), ≥100 msec without BBB in 144 (9.3%) and 102 (6.6%) had BBB. In multivariable analyses, those with QRS duration ≥100 msec had, compared to those with QRS duration &lt;85 msec, a 4.9-fold higher risk of sudden cardiac death (95% confidence interval [CI], 1.4 to 16.9, p=0.01) and a 2.7-fold higher risk of cardiovascular death (CI, 1.3 to 5.8, p=0.01). In univariate analyses, left BBB (n=43) was, compared to QRS duration &lt;85 msec, associated with a 3.8-fold higher risk heart failure and right BBB combined with left anterior fascicular block (n=20) with a 4.6-fold higher risk of myocardial infarction (both p&lt;0.05). Conclusion: QRS duration and morphology in asymptomatic patients with AS are independently associated with poor prognosis, particularly the risk of SCD. Figure : Incidence of Sudden Cardiac Death According to Baseline QRS Duration and Morphology: During 4.3 Years of Follow-Up.

Association of QRS duration and survival in dogs with dilated cardiomyopathy: A retrospective study of 266 clinical cases

Objective The purpose of this study was to investigate the prognostic value of QRS duration in dogs with dilated cardiomyopathy (DCM) by studying its relationship with survival time. Methods The medical records of dogs diagnosed with DCM were retrospectively searched for good quality ECG tracings. The QRS duration was measured from the ECG tracing and two different models were used: binary variable (dogs were divided into 2 groups based on a QRS duration of <60 ms or ≥60 ms) and continuous variable. The survival times were analysed by the Kaplan-Meier method and Cox’s proportional hazard model. Results 266 dogs met the inclusion and exclusion criteria. A QRS duration ≥60 ms was associated with a reduced survival time compared to those with a QRS duration <60 ms (Hazard Ratio of 1.34, 95% CI 1.05–1.71, P = 0.02). When considered as a continuous variable the Hazard Ratio was 1.015 for each increase in QRS duration of 1 ms (95% CI 1.006–1.024, p = 0.001).Dogs with a QRS duration < 60 ms had a median survival time (IQ range) of 25 weeks (97-65) and dogs with a QRS duration ≥60 ms had a median survival time (IQ range) of 13 weeks (3–34). Conclusion The measurement of QRS duration is relatively simple to perform from a surface ECG recording. A duration ≥60 ms is associated with shorter survival times in dogs with DCM, which may provide practitioners with additional prognostic information.

On a Possible Mechanistic Association of QRS Duration and Atrial Fibrillation

On a Possible Mechanistic Association of QRS Duration and Atrial Fibrillation

Association of QRS duration and outcomes after myocardial infarction: the VALIANT trial

Prolongation of the QRS duration has been shown to be associated with adverse outcomes among heart failure (HF) patients. The association of QRS duration with clinical outcomes in the post-myocardial infarction (MI) setting is less well defined. To assess the prognostic significance of QRS duration prolongation on initial electrocardiogram after acute MI. QRS duration was measured in 403 patients with MI complicated by left ventricular dysfunction, signs or symptoms of HF, or both, who were enrolled in the Valsartan in Acute Myocardial Infarction (VALIANT) echo study. The cohort was divided into quartiles of QRS duration (<75 ms, 75-88 ms, 89-108 ms, >108 ms). The number of clinical events were determined and compared across the groups. Increasing QRS duration is associated with a higher incidence of HF, sudden death (SD), and cardiovascular (CV) death (P-trend <0.05) but not with stroke or recurrent MI. The univariate relative risks for HF, SD, and CV death with increasing QRS duration quartiles were 1.31 (95% CI, 1.06-1.64), 1.57 (95% CI, 1.03-2.40), and 1.31 (95% CI, 1.03-1.66), respectively, but QRS duration did not remain independently predictive of adverse outcome after adjusting for the 10 most predictive baseline covariates. Baseline end-diastolic and end-systolic volumes were larger and ejection fraction was lower in the higher QRS quartile groups. Prolonged QRS duration, even within the normal range, is associated with larger ventricular volumes, reduced systolic function, and an increased risk for development of HF, SD, and CV death after MI but appears to be a marker, rather than an independent predictor, for increased risk.

Is it possible to identify infrahissian cardiac conduction abnormalities in myotonic dystrophy by non-invasive methods?

OBJECTIVETo identify intracardiac conduction abnormalities in patients with myotonic dystrophy from their clinical, ECG, and genetic features.METHODS39 consecutive patients (mean (SD) age 42.9 (12.1) years; 16 female, 23 male) underwent...