The Fragmented QRS Complex in Lead V1: Time for an Update of the Athlete's ECG?

Differentiating between ECG patterns related to athletes' heart remodeling and pathological findings is a challenge in sports cardiology. As the significance of fragmented complex in athletes remains uncertain, this study aimed to assess the presence of fragmented QRS in lead V1 (fQRSV1) among young athletes and its association with heart adaptations and arrhythmias. Young athletes referred for annual pre-participation screening receiving a maximal exercise testing and transthoracic echocardiography from January 2015 to March 2021 were included. The study included 684 young athletes. The prevalence of fQRSV1 was 33%. Subjects with fQRSV1 had higher exercise capacity and indexes of right ventricular function and remodeling. Among highly trained athletes, the fQRSV1 group demonstrated also increased left ventricular wall thickness. No significant association existed between fQRSV1 and exercise-induced arrhythmias, even in highly trained athletes. The high prevalence of fQRSV1 in young athletes is associated with training-induced heart adaptations but not exercise-induced ventricular arrhythmias.

Early atrial fibrillation detection is associated with higher arrhythmic burden in patients with loop recorder after an embolic stroke of undetermined source.

Background: After an embolic stroke of undetermined source (ESUS), long-term monitoring is recommended to start an anticoagulation therapy in patients with documented atrial fibrillation (AF). Literature is sparse about the AF burden following an ESUS, although this might have significant implications in terms of clinical management and therapeutic strategy. Our primary aim was to evaluate a possible association between early detection of AF (within 90 days from the ILR implantation) and higher AF burden. Methods: This is a retrospective single-center study of 129 consecutive patients who received implantable loop recorders (ILRs) after an ESUS for detection of subclinical AF and their AF burden. Results: Mean age was 70.3 ± 10.4 years old (males: 51.9%). Atrial fibrillation was found in 40.3% of patients. Patients with AF were older, presented a higher CHAD2S2-Vasc Score and greater left atrial volume compared with patients without AF. The median AF burden was 1.2%; 59% of patients had the first AF episode within 90 days from the ILR implant while 41% experienced the first episode later than 90 days. The AF burden was significantly higher in the former group. Of note, the univariate analysis showed that only early AF detection was significantly associated with AF burden >1% (OR 20.0; 95% CI 1.68-238.6, p = 0.01). Conclusions: The early AF detection was found to be significantly associated with a higher burden of AF.

Burden of ventricular arrhythmias at 12-lead 24-hour ambulatory ECG monitoring in middle-aged endurance athletes versus sedentary controls.

BACKGROUND: Whether prolonged and intense exercise increases the incidence of ventricular arrhythmias in middle-aged athletes remains to be established. DESIGN: Prospective, case-control. METHODS: We studied 134 healthy competitive athletes >30 years old (median age 45 (39-51) years, 83% males) who had been engaged in 9 ± 2 h per week of endurance sports activity (running, cycling, triathlon) for 13 ± 4 consecutive years. One hundred and thirty-four age- and gender-matched individuals served as controls. Both groups underwent 12-lead 24-h ambulatory electrocardiogram monitoring, which included a training session in athletes. Ventricular arrhythmias were evaluated in terms of number, complexity (i.e. couplet, triplet or non-sustained ventricular tachycardia), exercise-inducibility and morphology. RESULTS: Thirty-five (26%) athletes and 31 (23%) controls showed >10 isolated premature ventricular beats or ≥1 complex ventricular arrhythmia ( p = 0.53). Athletes with ventricular arrhythmias were older (median 48 versus 43 years old, p = 0.03) but did not differ with regard to hours of training and years of activity compared with athletes without ventricular arrhythmias. Ten (7%) athletes and six (5%) controls showed >500 premature ventricular beats/24 h ( p = 0.30): the most common ventricular arrhythmia morphologies were infundibular (six athletes and five controls) and fascicular (two athletes and one control). CONCLUSIONS: The prevalence of ventricular arrhythmias at 24-hour ambulatory electrocardiogram monitoring did not differ between middle-aged athletes and sedentary controls and was unrelated to the amount and duration of exercise. These findings do not support the hypothesis that endurance sports activity increases the burden of ventricular arrhythmias. Among individuals with frequent premature ventricular beats, the predominant ectopic QRS morphologies were consistent with the idiopathic and benign nature of the arrhythmia.

Ventricular Arrhythmias in Young Competitive Athletes: Prevalence, Determinants, and Underlying Substrate.

BACKGROUND: Whether ventricular arrhythmias (VAs) represent a feature of the adaptive changes of the athlete's heart remains elusive. We aimed to assess the prevalence, determinants, and underlying substrates of VAs in young competitive athletes. METHOD AND RESULTS: We studied 288 competitive athletes (age range, 16-35 years; median age, 21 years) and 144 sedentary individuals matched for age and sex who underwent 12-lead 24-hour ambulatory electrocardiographic monitoring. VAs were evaluated in terms of number, complexity (ie, couplet, triplet, or nonsustained ventricular tachycardia), exercise inducibility, and morphologic features. Twenty-eight athletes (10%) and 13 sedentary individuals (11%) showed >10 isolated premature ventricular beats (PVBs) or ≥1 complex VA (P=0.81). Athletes with >10 isolated PVBs or ≥1 complex VA were older (median age, 26 versus 20 years; P=0.008) but did not differ with regard to type of sport, hours of training, and years of activity compared with the remaining athletes. All athletes with >10 isolated PVBs or ≥1 complex VA had a normal echocardiographic examination; 17 of them showing >500 isolated PVBs, exercise-induced PVBs, and/or complex VA underwent additional cardiac magnetic resonance, which demonstrated nonischemic left ventricular late gadolinium enhancement in 3 athletes with right bundle branch block PVBs morphologic features. CONCLUSIONS: The prevalence of >10 isolated PVBs or ≥1 complex VA at 24-hour ambulatory electrocardiographic monitoring did not differ between young competitive athletes and sedentary individuals and was unrelated to type, intensity, and years of sports practice. An underlying myocardial substrate was uncommon and distinctively associated with right bundle branch block VA morphologic features.