Abstract
Introduction
To date, no study in published literature has investigated the prevalence of patients with QRS ≥120 ms (ESC/EHRA Guidelines) and QRS ≥150 ms (ACC/AHA/HRS Guidelines) from patients with left ventricular ejection fraction (LVEF) ≤35% in sinus rhythm (SR) with left bundle branch block (LBBB) morphology, both said QRS durations were included in the criteria of Class I indication for cardiac resynchronization therapy (CRT) implantation.
Purpose
To determine the prevalence of patients with QRS 120-150 ms and QRS ≥150 ms from patients with LVEF ≤35% in SR and LBBB, to classify these patients to ischaemic cardiomyopathy (ICM) and nonischaemic cardiomyopathy (NICM), and to determine their demographics in terms of age, sex, and comorbidities
Methods
This is a cross-sectional study performed from January to September 2016. Data collection was performed which consists of 2-D echocardiogram with LVEF ≤35% in SR and LBBB, from which 2 groups of QRS 120-150 ms and ≥150 ms with their demographic profiles such as age, sex, and comorbidities will be identified and analyzed using percentage or proportion.
Results
The sample size in the study period was composed of 10,113 patients, of whom 1% (135) had LVEF ≤35% in SR. From 135 patients, 11% (15) had LBBB with QRS ≥120 ms. From 135 patients, 7% (9) had QRS 120-150 ms and also 7% (9) had QRS ≥150 ms. All patients who had QRS 120-150 ms were ICM while those with QRS ≥150 ms, 56% (5) were ICM and 44% (4) were NICM. Among patients with QRS 120-150 ms, youngest age was 50, median age was 67, and oldest age was 84, while among patients with QRS ≥150 ms, youngest age was 50, median age was 66, and oldest age was 82. Among those with QRS 120-150 ms, 67% (6) were males and 33% (3) were females whereas those with QRS ≥150 ms, 78% (7) were males and 22% (2) were females. Both groups of QRS 120-150 ms and ≥150 ms had the same identified comorbidities: coronary artery disease (CAD), hypertension (HTN), diabetes mellitus (DM), dyslipidemia and end stage renal disease (ESRD). Those with QRS 120-150 ms, 67% (6) had both CAD and DM, 56% (5) had HTN, 22% (2) had dyslipidemia and 11% (1) had ESRD, whereas those with QRS ≥150 ms, 78% (7) had CAD, 56% (5) had HTN, 44% (4) had DM, and 11% (1) had both dyslipidemia and ESRD.
Conclusions
There was both 7% prevalence of patients with QRS 120-150 ms and QRS ≥150 ms from patients with LVEF ≤35% in SR and LBBB. All patients with QRS 120-150 ms were ICM while majority of those with QRS ≥150 ms were ICM. In both groups of QRS duration, youngest age was 50; median age of QRS 120-150 ms was 67 whereas QRS ≥150 ms was 66; and with QRS 120-150 ms, patients who were affected were older (84 years old vs 82 years old). Both QRS 120-150 ms and ≥150 ms were predominantly males with CAD, HTN, and DM as identified important risk factors.
Predictors and implications of early left ventricular ejection fraction improvement in new-onset idiopathic nonischemic cardiomyopathy with narrow QRS complex: A NEOLITH substudy
