[Value of heart rate recordings in selecting the initial treatment of hypertension]

60 patients with mild arterial hypertension are studied, divided into three groups according to their heart rate (HR): 20 with heart rate below 70 b.p.m.; 20 with heart rate between 70 and 80 b.p.m., and 20 with heart rate above 80 b.p.m. In every group, 10 patients were treated with atenolol and the other 10 patients with chlorthalidone. The cases of bad tolerance or bad response to any of these drugs were included in the other subgroup, so that a total number of 71 responses to drugs were studied. It has been found that the hypertension in patients having HR above 80 b.p.m. has a better response to atenolol. On the other hand, in patients having HR below 70 b.p.m. the response is better to chlorthalidone. In those patients with HR between 71 and 79 a similar response to both drugs is observed, nevertheless the decrease of the diastolic pressure is significantly bigger with atenolol. We arrive at the conclusion that when the HR is above 70 b.p.m. and especially above 80 b.p.m., better results are obtained using atenolol than chlorthalidone.