Systematic review and meta-analysis of training mode, imaging modality and body size influences on the morphology and function of the male athlete's heart.
Level 3 - non-randomized controlled study
Systematic review and meta-analysis of prospective observational imaging studies
PubMed 23474689 · doi:10.1136/heartjnl-2012-303465
What was done
Systematic review and meta-analysis of prospective echocardiography and cardiac magnetic resonance (CMR) studies identified via PubMed, Medline, Scopus, and ISI Web of Knowledge. Included studies assessed elite young male athletes across specified sports and passed a quality criteria checklist. Two reviewers independently extracted data on ventricular and atrial dimensions, training modality, imaging modality, and body surface area.
What was found
All left ventricular (LV) structural parameters were higher in athletes than in controls. Compared with resistance athletes, endurance athletes had significantly greater LV end-diastolic diameter (54.8 mm [95% CI 54.1 to 55.6] vs 52.4 mm [95% CI 51.2 to 53.6]; p<0.001) and LV end-diastolic volume (171 ml [95% CI 157 to 185] vs 131 ml [95% CI 120 to 142]; p<0.001). Right ventricular end-diastolic volume, mass, and left atrial diameter were also greater in endurance athletes than in controls. LV end-diastolic volume was larger when measured by CMR than by echocardiography (178 ml [95% CI 162 to 194] vs 135 ml [95% CI 128 to 142]; p<0.001). Meta-regression identified positive, significant associations between body surface area and LV mass, RV mass, and LA diameter. Concentric hypertrophy was not observed as a training-specific pattern in resistance athletes.
Why it matters
The findings challenge the traditional model that resistance training causes isolated concentric cardiac hypertrophy in elite male athletes. They also show that both the choice of imaging modality and body surface area scaling significantly influence measured cardiac dimensions.
Limits
The total number of included studies and aggregate participant count are not reported in the abstract. Findings are restricted to elite young male athletes and cannot be generalized to female athletes, masters athletes, or non-elite populations. Specific numeric values for tissue-Doppler functional measures are omitted from the abstract.
Cited by
- supports Resistance training and exercise induce thickening of the left ventricular heart wall as a common physiological adaptation.