NEWLY DEVELOPED ST-T ABNORMALITIES ON THE ELECTROCARDIOGRAM AND CHRONOLOGICAL CHANGES IN CARDIOVASCULAR RISK-FACTORS

An ST-T abnormality on an electrocardiogram (ECG) is known to independ ently predict subsequent morbidity and mortality from cardiovascular d iseases. But how ST-T abnormality develops in relation to chronologic changes in cardiovascular risk factors has not been fully discussed. S ixty-eight men whose ECG had been initially normal but who exhibited S T-T abnormality later (ST-T subjects) were identified among 21,579 app arently healthy adults who had undergone comprehensive health examinat ions for >10 years. Echocardiography proved that 26 of 29 examinees am ong ST-T subjects had left ventricular hypertrophy. Antihypertensive d rugs were given to 26 of the ST-T subjects. Their cardiovascular risk factors were chronologically reviewed from 10 years before the onset o f definite ST-T abnormality, and were compared with those of 68 men wh ose ECG had remained consistently normal for 10 years (controls). Mean values of systolic and diastolic blood pressure gradually increased o ver 10 years (from 127/78 to 144/84 mm Hg) among ST-T subjects, but sh owed little change (from 122/76 to 124/77 mm Hg) during the same perio d in controls. The time course of blood pressure over 10 years was sim ilar in ST-T subjects, irrespective of final blood pressure level. Mea n serum cholesterol and glucose increased over 10 years in both ST-T a nd control subjects. Uric acid decreased over 10 years (from 6.1 to 5. 6 mg/dl) only in ST-T subjects. Multivariate analysis revealed that bl ood pressure and uric acid before onset of ST-T abnormality were chron ologically changed independent of other risk factors. The time course of risk factors may be of great importance in the development of cardi ovascular disorders.