Athlete Screening for Occult Cardiac Disease

Focused transthoracic echocardiography by sports medicine physicians: measurements relevant to hypertrophic cardiomyopathy

OBJECTIVES

The purpose of this study was to investigate whether sports medicine physicians can use portable echocardiography to obtain measurements pertinent to hypertrophic cardiomyopathy.

METHODS

Thirty male collegiate athletes, aged 18 to 21 years, were prospectively enrolled. Focused portable echocardiography was performed by a board-certified sports medicine physician and a resident physician, followed by comprehensive echocardiography within 2 weeks by a registered diagnostic cardiac sonographer. A left parasternal long-axis view was acquired to measure 3 dimensions: (1) end-diastolic interventricular septal thickness (IVSd), (2) end-diastolic left ventricular internal diameter (LVIDd), and (3) end-diastolic left ventricular posterior wall thickness (LVPWd).

RESULTS

Intraclass correlation coefficients between the sports medicine physician and the sonographer were strong: 0.77 for IVSd, 0.73 for LVIDd, and 0.64 for LVPWd. Intraclass correlation coefficients between measurements by the resident physician and sonographer were strong to moderate: 0.61 for IVSd, 0.62 for LVIDd, and 0.63 for LVPWd. Across all 3 readers, intraclass correlation coefficient calculations were 0.77 for IVSd, 0.81 LVIDd, and 0.75 for LVPWd, which indicated strong inter-rater reliability.

CONCLUSIONS

Sports medicine physicians are able to obtain measurements relevant to the diagnosis of hypertrophic cardiomyopathy with focused portable echocardiography that are consistent with comprehensive echocardiography by a registered sonographer.

Hypertrophic cardiomyopathy as a cause of sudden death

Hypertrophic cardiomyopathy (HCM) is the main cause of sudden unexpected death in the young and especially in young athletes with an incidence up to 2.3 per 100,000 athletes and year. Risk stratification models including patient history (syncope, familial risk of sudden death) and findings in noninvasive tests (nonsustained ventricular tachycardia, abnormal blood pressure response during exercise, maximum left ventricular wall thickness > or = 30 mm) have been developed in order to estimate the risk of individual patients. Echocardiographic parameters are helpful in distinguishing HCM from athlete's heart. Definitive diagnosis of HCM implicates disqualification from competitive sports resulting in a significant reduction of sudden cardiac death due to HCM during sports competition. This positive development should lead to a widespread preparticipation screening of athletes including historical, clinical, and electrocardiographic examination. At least in borderline findings and symptomatic athletes, an additional echocardiogram should be performed in order to minimize or better exclude the risk of sudden cardiac death.