Effect of Treatment on Morbidity in Hypertension. Veterans Administration Cooperative Study on Antihypertensive Agents

Electrocardiographic (ECG) data are presented from the Veterans Administration Cooperative Study of 143 nontreated and 137 treated male patients with initial diastolic blood pressures averaging 90-114 mm Hg. Average follow-up was 2.9 years and longest follow-up was 5 years. Significant differences were observed with respect to the ECG signs of left ventricular hypertrophy (LVH). In the patients not meeting criteria for LVH prior to randomization, the incidence of abnormal QRS voltage, ST-segment depression or T wave flattening or inversion developing in the treated patients was approximately one-fourth that found in the control group. In the patients with ECG evidence of LVH prior to randomization, the reversion to normal of QRS voltage or ST-segment depression was approximately 2.5 times greater in the treated than in the control patients. Although no significant effect of treatment was observed on other ECG changes such as Q and QS patterns, A-V or ventricular conduction defects or arrhythmias, the incidence of such events was too low to make valid comparisons. However, the present results indicate that antihypertensive drug treatment markedly improved the ECG changes specifically related to hypertension.