Fragmented QRS and subclinical left ventricular dysfunction in individuals with preserved ejection fraction: A speckle‐tracking echocardiographic study

Abstract

Introduction Fragmented QRS (fQRS) complex on routine 12‐lead electrocardiogram (ECG) predicts adverse outcomes in patients with cardiovascular diseases. In addition, it has been found to be associated with subclinical myocardial dysfunction in chronic diseases. We sought to investigate the relationship between the presence of fQRS with the myocardial functions in individuals free from known systemic cardiovascular diseases. Methods In a case‐control study, we evaluated normal individuals from March 2017 to February 2018. All participants underwent a 2‐dimensional transthoracic echocardiographic examination using tissue Doppler imaging (TDI) and speckle‐tracking echocardiography. In addition, all participants were examined using a 12‐lead surface ECG, and patients with fQRS and a group of age‐ and sex‐matched controls without fQRS were enrolled in our study. Results The patients' mean age was 40.3 ± 10.7 and 35.4 ± 11.2 years in fQRS‐positive and fQRS‐negative groups, respectively (P = .110). Patients with fQRS had significantly lower values of apical left ventricular global longitudinal strain (LV GLS) in 2‐chamber (16.9 ± 2.5 vs. 20.5 ± 3.3, P < .001), 4‐chamber (16.9 ± 3.4 vs. 20.1 ± 3, P = .001), LAX views (17.7 ± 2.8 vs. 20.8 ± 3.5, P = .001), and averaged LV GLS (17 ± 2.6 vs. 20.4 ± 2.7, P < .001) values compared to patients without fQRS. In a multivariate analysis, averaged LV GLS and smoking history were independent predictors for positive fQRS. Conclusion The presence of fQRS on 12‐lead ECG in healthy population was associated with lower values of LV GLS compared to normal individuals without fQRS.

Left Ventricular Functions Assessment by Speckle Tracking in Comparison with The Two-Dimensional (2D) Echocardiography in Patients with Fragmented QRS

“…In our study, the mean age of sample was 52.9 ± 6.7 years and 54% was male. Clinical character of our participants showed that heart rate was 80.6 ± 12.4 beat per min, SBP was 116 ± 7.1 mm Hg and DBP was 75.1 ± 5.8 mm Hg in contrast with Dehghani et al, patients with fragmented QRS clinical characters were 76.5 ± 9.4 beat per min, SBP 118.5 ± 10.5 mm Hg and DBP was 70.4 ± 7.3 mm Hg (13) .…”

“…which supported by Bayramoğlu et al (3) , study whom found that patients with fQRS complex had EF of 58.9 ± 3.8%, LVESD was 3.3 ± 0.6 cm, LVEDD 4.5 ± 0.3 cm, intraventricular septum thickness 10.3 ± 0.6mm and posterior wall thickness was 10.6 ± 0.9 mm. And study of Dehghani et al (13) found that in patients with positive fQRS complex had EF of 59.6 ± 2.4%, LVEDD 4.8 ± 0.3cm, intraventricular septum thickness 1±0.1mm and posterior wall thickness was 0.9 ± 0.08 mm. In study of Yaman et al (12) , patients with fQRS complex had EF of 61.94± 2.18%, LVEDD 4.54±0.3 cm, LVESD was 3.14±0.28 cm, intraventricular septum thickness 0.94±0.18 mm and posterior wall thickness was 0.9 ± 0.11 mm.…”

“…In our study the early diastolic velocity was 7±0.9 cm/sec, late diastolic velocity was 6±0.1cm/sec and E/A ratio was 1.15±0.17. Dehghani et al (13) found that the early diastolic velocity was 0.7±0.06 cm/sec, late diastolic velocity was 0.5±0.7 cm/sec and E/A ratio was 1.2±0.1. In study of Yaman et al (12) , the early diastolic velocity was 0.67±0.14 cm/sec, late diastolic velocity was 0.65±0.15 cm/sec and E/A ratio was 1.10±0.37.…”

“…These complexes are shown to be linked to intraventricular systolic desynchrony and subendocardial fibrosis in nonischemic cardiomyopathy (1) . The study of Dehghani et al (13) , found that the existence of fQRS on standard 12-lead ECG in healthy individuals is significantly associated with the lower values of GLS compared to individuals without fQRS.…”

Editorial to QRS fragmentation as a potential new marker for subclinical myocardial dysfunction

“…Notably, almost all of these studies assessed patients with declined and reduced ejection fraction or impaired LV contractile function rather than healthy individuals or in those with relatively preserved ejection fraction. Dehghani et al reported in a case‐control study (age‐ and sex‐matched) of a healthy population that fQRS was associated with lower subclinical myocardial contractility marker of global ventricular longitudinal strain (GLS). By using speckle‐tracking, a highly sensitive marker for detecting systolic myocardial dysfunction even prior to overt chamber dilation.…”