Prevalence and significance of fragmented QRS complex in lead V1 on the surface electrocardiogram of healthy athletes

Abstract

Aims Limited data exist concerning fragmented QRS complexes (fQRSs) on the surface electrocardiogram (ECG) of apparently healthy athletes. We aimed to study the prevalence and significance of fQRS in lead V1 (fQRSV1), representing right ventricular (RV) activation, regarding training-induced RV morphological remodelling. Methods and results Between January 2017 and August 2019, 434 consecutive non-sedentary subjects underwent preparticipation cardiovascular screening, including a 12-lead ECG. Three hundred and ninety-three apparently healthy subjects were included, 119 of them were athletes (defined as performing ≥8 h/week for the last 6 months) and 274 were non-athletes. All athletes underwent two-dimensional transthoracic echocardiography. Fragmented QRS complex in lead V1 pattern was defined as a narrow (<120 ms) and quadriphasic QRS complex in lead V1. Fragmented QRS complex in lead V1 was more frequent in athletes compared with non-athletes (22% vs. 5.1%, P < 0.001) and was independently associated with the athlete status [adjusted odds ratio (aOR) = 4.693, 95% confidence interval (95% CI) 2.299—9.583; P < 0.001], the endurance category (aOR = 2.522, 95% CI 1.176—5.408; P = 0.017), and age (aOR = 0.962, 95% CI 0.934–0.989; P = 0.007) in multivariate analysis. In the subgroup of athletes, fQRSV1 was independently associated with mean RV outflow tract diameter (aOR = 1.458, 95% CI 1.105–1.923; P = 0.008) and age (aOR = 0.941, 95% CI 0.894–0.989; P = 0.017) in multivariate analysis. Conclusion Fragmented QRS complex in lead V1 is a newly described, frequent, ECG pattern in young and apparently healthy athletes and is associated with training-induced RV remodelling.

The “V1 continuum” on the surface ECG of apparently healthy athletes

“…We recently described a new ECG pattern in apparently healthy athletes (Figure 1), corresponding to a fragmented QRS complex in lead V1 (fQRSV 1 ; also named RSR'S' pattern). 2 We found a prevalence of 22% for the fQRSV 1 pattern in athletes, compared with non-athletes (5.1%; P < .001). Using a systematic echocardiographic assessment in our 119 athletes, we also found that athletes with the fQRSV 1 pattern were younger and had a significantly larger RV outflow tract diameter, compared with athletes without such ECG pattern.…”

“…We recently described a new ECG pattern in apparently healthy athletes (Figure 1), corresponding to a fragmented QRS complex in lead V1 (fQRSV 1 ; also named RSR’S’ pattern) 2 . We found a prevalence of 22% for the fQRSV 1 pattern in athletes, compared with non‐athletes (5.1%; P < .001).…”

The “V1 continuum” in the athletes’ ECG

“…These authors recently reported the presence of fQRSV1 in healthy athletes. 2 In their pioneer study, an RSR'S' pattern was a prevalent ECG feature in athletes (~22%) compared to non-athletic controls (~5%). This finding was suggested to reflect exercise-induced right ventricle (RV) remodeling and was independently associated with RV outflow tract dilation.…”

“…These authors recently reported the presence of fQRSV1 in healthy athletes 2 . In their pioneer study, an RSR’S’ pattern was a prevalent ECG feature in athletes (~22%) compared to non‐athletic controls (~5%).…”

“…Remodeling of contiguous areas of the RV (such as the subpulmonic or outflow tract region) might indeed be among the numerous cardiac electromechanical adaptations to sports participation, which in turn can be reflected in ECG tracings as CSP or RSR’S’ patterns. In this regard, the fact that the athletic cohorts of both studies 2,3 showed a very narrow QRS ( ie , <100 ms) largely rules out the presence of a conduction delay in the His‐Purkinje network as the pathophysiologic substrate—instead of RV remodeling—for these two patterns.…”