Correlation between atrial electrocardiographic indexes and left atrial enlargement in competitive athletes. From the ALMUDAINA case-control study

Background

Left atrial (LA) remodelling and enlargement in athletes is a well-kown component of the athlete's heart. However, information about the correlation between of LA enlargement and atrial electrophysiological features in athletes is scarce.

Purpose

Our aim was to characterize LA enlargement, P-wave duration, and the prevalence of interatrial block (IAB) in competitive athletes (with and without LA enlargement) and in controls.

Methods

ALMUDAINA (Analysis of Left atrial Measurements of Ultrasound Dilation Among International and National Athletes) was a nationwide, cross-sectional study involving 9 hospitals and sport clinics across Spain. Cases fulfilled the international consensus definition of a competitive athlete and were currently engaged in skill, power, mixed or endurance disciplines at a national or international level. The following P-wave parameters were analysed: 1) duration 2) voltage in lead I and 3) the presence of interatrial block (IAB). LA enlargement was defined as an indexed volume by body surface area ≥34 ml/m2, measured by transthoracic echocardiography. A contemporary cohort of otherwise healthy and active controls was used as a comparison group.

Results

Baseline clinical and echocardiographic characteristics of both cohorts are summarised in table 1 whereas electrocardiographic characteristics are displayed in table 2, respectively. 356 subjects were included, 308 athletes (mean age: 36.4±11.6 years) and 48 controls (mean age: 49.3±16.1 years). Athletes showed a higher mean LA indexed volume (29.8±8.6 vs. 25.6±8.0 mL/m2, P=0.006) and higher prevalence of LA enlargement (113 [36.7%] vs. 5 [10.4%], P<0.001), but there were no relevant differences in P-wave duration (106.3±12.5 ms vs 108.2±7.7 ms; P=0.31), voltage in lead I (0.08±0.04 vs. 0.08±0,04 mV; P=0.79) and the prevalence of IAB (40 [13.0%] vs. 4 [8.3%], P=0.36). Only a case of advance IAB was detected, in an athlete without LA enlargement. Among athletes, those with LA enlargement (113, 36.7%) had higher P-wave duration (110.3±14.1 vs. 103.0±10.9 ms, P<0.001) and a higher prevalence of interatrial blockade (23 [20.4%] vs. 17 [8.8%], P=0.004), but similar voltage of P-wave in lead I (0.08±0.003 vs. 0.08±0.05 mV, P=0.689). In a multivariate analysis, competitive training was independently associated with LA enlargement (odds ratio [OR] 14.7, 95% confidence interval [CI] 4.7–44.0; P<0.001) but was not associated with P-wave duration (OR 1.02, 95% CI: 0.99–1.04; P=0.19) or IAB (OR 1.4, 95% CI 0.7–3.1; P=0.34).

Conclusions

LA enlargement is prevalent in adult competitive athletes. However, ECG indexes of atrial electrophysiology were not different from healthy controls. Our data suggest that LA enlargement and IAB are two different entities.

Funding Acknowledgement

Type of funding sources: None.

Effect of smoking on sudden and premature death

BACKGROUND

Smoking has been related to coronary heart disease, and, in men, to sudden death. The results of a case-control study designed to assess the relationship between smoking and all causes of sudden and premature death are reported.

METHODS

A questionnaire on the previous history and causes of death of all people buried in the Municipal Cemetery of Valencia (1986-1987) was administered to the relatives of the deceased. Among 4718 deaths, 284 victims of sudden death were identified, and 495 people who had not died suddenly were randomly sampled as controls.

RESULTS

The proportion of smokers among the women studied was extremely low in contrast to 58.9% of men in the sudden death study group and 59.2% of men in the non-sudden death study group who smoked. Smokers died on average 10 years younger than non-smokers in the sudden-death group (63.3 +/- 12.3 and 73.3 +/- 11.0 years respectively; P < 0.001), and 8 years earlier in the non-sudden death group (68.5 +/- 13.3 and 76.8 +/- 13.2 years, respectively; P < 0.001). A logistic regression model showed that smokers had an adjusted relative risk of 0.81 for sudden death compared with non-smokers (95% confidence interval [CI]: 0.45-1.46). Smokers 65 years of age or under had a 2.7 times greater risk (95% CI: 1.49-5.04) of premature death than non-smokers. Similar results were found in patients from the coronary- and cardiac-death subgroups.

CONCLUSIONS

Smoking is an independent risk factor for premature death but not for sudden death.