The risk of sudden death in sickle cell trait: noninvasive assessmanet of cardiac response to exercise.

The effect of symptom-limited maximal treadmill exercise was evaluated in 34 patients with sickle cell trait (SCT) and 43 controls. Systolic time intervals were measured before and after exercise in 15 of the sickle cell trait subjects, and in 11 controls. Rate pressure product, degree of ST segment depression and incidence of ventricular arrhythmias in subjects with SCT were not significantly different from similar measurements in the control group. No significant difference in electromechanical systole QS2, left ventricular ejection time (LVET), pre-ejection period (PEP)/LVET or ejection fraction (EF) were found between the groups. These data indicate that healthy subjects with SCT do not have an increased incidence of exercise-induced ventricular arrhythmias, myocardial ischemia, or diminished ventricular function compared to normals. Further studies are indicated to elucidate factors that may be operative in sudden death syndrome.