Mechanical Dispersion by Strain Echocardiography: A Novel Tool to Diagnose Hypertrophic Cardiomyopathy in Athletes
Abstract
BACKGROUND: Previous studies have demonstrated that global longitudinal strain (GLS) is altered in patients with hypertrophic cardiomyopathy (HCM) in comparison with athletes. Nevertheless, these results rely on studies comparing sedentary patients with HCM with healthy athletes. The aims of this study were to confirm these findings in an appropriate group of athletes with HCM and to study the additive value of novel parameters (i.e., mechanical dispersion and exercise GLS). METHODS: Thirty-six athletes with HCM were prospectively included and were compared with 36 sedentary patients with HCM, 36 healthy athletes, and 36 sedentary control subjects of similar age. Athlete groups had similar training duration and HCM groups similar maximal wall thickness. All underwent echocardiography at rest and during submaximal exercise. GLS was assessed; the SD of time to maximal myocardial shortening of longitudinal strain was calculated as a parameter of mechanical dispersion. RESULTS: The HCM sedentary group showed the lowest resting and exercise GLS. Resting GLS was not different between athletes with HCM and the two control groups, but exercise GLS enabled the differentiation of athletes with HCM from healthy athletes. Mechanical dispersion was higher in both HCM groups compared with both control groups at rest and during exercise. Receiver operating characteristic analysis in the athlete groups demonstrated that resting mechanical dispersion (area under the curve = 0.949 ± 0.023) had better ability to identify HCM compared with GLS at rest (area under the curve = 0.644 ± 0.069) (P < .001) or during exercise (area under the curve = 0.706 ± 0.066) (P < .005). CONCLUSIONS: In athletes, normal resting GLS does not rule out the diagnosis of HCM. Mechanical dispersion of longitudinal strain seems to be a promising tool for the diagnosis of HCM in athletes.