Head-to-head comparison between echocardiography and cardiac MRI in the evaluation of the athlete's heart

 

OBJECTIVE
Echocardiographic cut-off values are often used for cardiac MRI in athletic persons. This study investigates the difference between echocardiographic and cardiac MRI measurements of ventricular and atrial dimensions and ventricular wall thickness, and its effect on volume and wall mass prediction in athletic subjects compared with non-athletic controls.

METHODS
Healthy non-athletic (59), regular athletic (59) and elite athletic (63) persons, aged 18-39 years and training 2.5±1.9, 13.0±3.0 and 25.0±5.4 h/week, respectively (p<0.001), underwent echocardiography and cardiac MRI consecutively. Left ventricular (LV) and right ventricular (RV) dimensions were measured on both modalities. LV and RV end-diastolic and end-systolic volumes and LV wall mass were determined on cardiac MRI. Echocardiographic M-mode LV volumes (Teichholz formula) and LV wall mass (American Society of Echocardiography formula) were calculated.

RESULTS
LV and RV dimensions were smaller on echocardiography (p<0.001), and although the correlation with the cardiac MRI volume was good (p<0.01), the difference in volume was large (LV end-diastolic volume difference 93±32 g, p<0.001). LV wall thickness and calculated wall mass were significantly (p<0.001) larger on echocardiography (wall mass difference -101±34 g, p<0.001). Differences in absolute dimensions did not change significantly between non-athletic and athletic persons; however, the difference in echocardiographic estimations of LV volumes and wall mass did increase significantly with the larger athlete's heart, requiring possible correction of the standard echocardiographic formulas.

CONCLUSIONS
Echocardiography shows systematically smaller atrial and ventricular dimensions and volumes, and larger wall thickness and mass, compared with cardiac MRI. Correction for the echocardiographic formulas can facilitate better intertechnique comparability. These findings should be taken into account in the interpretation of cardiac MRI findings in athletic subjects in whom cardiomyopathy is suspected on echocardiography.

 

What is already known on this topic
 
Previous studies show that ventricular volumes and dimensions on two-dimensional echocardiography are signifi cantly lower, and left ventricular wall mass and wall thickness higher as compared with cardiac MRI measurements in healthy subjects and patients.

 

What this study adds 

 
The linear difference between echocardiographic and cardiac MRI values for physiological enlargement of the athlete’s heart and pathological left ventricular (LV) hypertrophy has been established using a head-to-head comparison. Correction factors are offered in order to achieve a 1:1 relation between echocardiographic and cardiac MRI estimation of LV volumes and wall mass.