QT alterations and cardiodynamic parameters in old myocardial infarction.

: Prolonged QT interval in patients with old myocardial infarction was noticed as a marker of poor prognosis. The sensitivity of this functional electrocardiographic scar was augmented in 82 patients with old myocardial infarction by recording the recumbent and orthostatic electrocardiogram, phonocardiogram and carotid piezogram. The incidence of abnormally prolonged QT intervals and increased QT ratios was three times higher in orthostatic posture than in patients lying down. Abnormal QT intervals in standing position correlate also with abnormal PEP/L VET ratio and severe electrocardiographic alterations and may become a useful tool for a more accurate prognosis in patients with old myocardial infarction.