Prevalence and clinical significance of isolated low QRS voltages in young athletes.

AIMS: Low QRS voltages (peak to peak <0.5 mV) in limb leads (LQRSV) on the athlete's electrocardiogram (ECG) may reflect an underlying cardiomyopathy, mostly arrhythmogenic cardiomyopathy (ACM) or non-ischaemic left ventricular scar (NILVS). We studied the prevalence and clinical meaning of isolated LQRSV in a large cohort of competitive athletes. METHODS AND RESULTS: The index group included 2229 Italian competitive athletes [median age 18 years (16-25), 67% males, 97% Caucasian] without major ECG abnormalities at pre-participation screening. Three control groups included Black athletes (N = 1115), general population (N = 1115), and patients with ACM or NILVS (N = 58). Echocardiogram was performed in all athletes with isolated LQRSV and cardiac magnetic resonance (CMR) in those with ventricular arrhythmias or echocardiographic abnormalities. The isolated LQRSV pattern was found in 1.1% index athletes and was associated with increasing age (median age 28 vs. 18 years; P < 0.001), elite status (71% vs. 34%; P < 0.001), body surface area, and body mass index but not with sex, type of sport, and echocardiographic left ventricular mass. The prevalence of isolated LQRSV was 0.2% in Black athletes and 0.3% in young individuals from the general population. Cardiomyopathy patients had a significantly greater prevalence of isolated LQRSV (12%) than index athletes, Black athletes, and general population. Five index athletes with isolated LQSRV and exercise-induced ventricular arrhythmias underwent CMR showing biventricular ACM in 1 and idiopathic NILVS in 1. CONCLUSIONS: Unlike cardiomyopathy patients, the ECG pattern of isolated LQRSV was rarely observed in athletes. This ECG sign should prompt clinical work-up for exclusion of an underlying cardiomyopathy.

Anomalous origin of coronary arteries from the "wrong" sinus in athletes: Diagnosis and management strategies.

AIMS: Although anomalous origin of left (AOLCA) and right coronary artery (AORCA) from the wrong sinus may cause sudden death (SD) in athletes, early diagnosis and management of these anomalies are still challenging. We analysed clinical/instrumental profiles of athletes identified with AOLCA/AORCA focusing our attention on diagnosis, management and follow-up. METHODS AND RESULTS: We report 23 athletes (17 males, mean age 27±17yrs.), 6 with AOLCA and 17 with AORCA. Diagnosis was made by trans-thoracic echocardiography (TTE) in 21/23(91%). Symptoms were present only in 10(41%). Only 3 had an abnormal rest-ECG and 9(39%) an abnormal stress test ECG (3 ST-depression, 4 ventricular arrhythmias, 1 supraventricular arrhythmias, 1 rate-dependent left-bundle-branch-block). Anatomy of the anomalous coronary artery showed no significant correlation with clinical presentation, except for a tendency to higher occurrence of proximal hypoplasia in symptomatic athletes (83% vs 40%, p=0.09). All athletes were disqualified from competitive-sports and advised to avoid strenuous effort. Surgery was recommended to all athletes with AOLCA and 6 with AORCA, but only 6 underwent surgery. No major cardiac events or ischemic symptoms/signs occurred during a mean follow-up of 65±70months. CONCLUSIONS: Early diagnosis of AOLCA/AORCA in athletes is feasible by TTE. Typical symptoms/signs of myocardial ischemia are present only in one third of cases thus underlying the need of a high index of clinical suspicion to achieve the diagnosis. After exercise restriction, none had major cardiac events or ischemia symptoms/signs recurrence. There was no correlation between anatomical characteristics and clinical presentation with the possible exception of coronary hypoplasia.

Nonischemic left ventricular scar and cardiac sudden death in the young.

Nonischemic left ventricular scar (NLVS) is a pattern of myocardial injury characterized by midventricular and/or subepicardial gadolinium hyperenhancement at cardiac magnetic resonance, in absence of significant coronary artery disease. We aimed to evaluate the prevalence of NLVS in juvenile sudden cardiac death and to ascertain its etiology at autopsy. We examined 281 consecutive cases of sudden death of subjects aged 1 to 35 years. NLVS was defined as a thin, gray rim of subepicardial and/or midmyocardial scar in the left ventricular free wall and/or the septum, in absence of significant stenosis of coronary arteries. NLVS was the most frequent finding (25%) in sudden deaths occurring during sports. Myocardial scar was localized most frequently within the left ventricular posterior wall and affected the subepicardial myocardium, often extending to the midventricular layer. On histology, it consisted of fibrous or fibroadipose tissue. Right ventricular involvement was always present. Patchy lymphocytic infiltrates were frequent. Genetic and molecular analyses clarified the etiology of NLVS in a subset of cases. Electrocardiographic (ECG) recordings were available in more than half of subjects. The most frequent abnormality was the presence of low QRS voltages (<0.5 mV) in limb leads. In serial ECG tracings, the decrease in QRS voltages appeared, in some way, progressive. NLVS is the most frequent morphologic substrate of juvenile cardiac sudden death in sports. It can be suspected based on ECG findings. Autopsy study and clinical screening of family members are required to differentiate between arrhythmogenic right ventricular cardiomyopathy/dysplasia and chronic acquired myocarditis.