Comparison of the combination of nifedipine and atenolol with the combination of nitroglycerine and atenolol in patients with angina pectoris

Patients exhibiting-severe exercise angina and significant coronary artery stenosis performed seven symptom limited exercise tests under the following conditions: control (C), 12 h after atenolol 100 mg (A 100) and A100 plus tri nitroglycerine (TNT), 12 h after atenolol 200 mg (A200) and A200 plus TNT and finally A200 plus 20 mg of sublingual nifedipine (A200 $ NIF) given just after A200 plus TNT. The tests were scheduled at 0900,0915 and 1130 h on three successive days. Maximal and submaximal values of the heart rate blood pressure product, the extent of ST segment depression, exercise capacity and their relationships were compared by means of the Student paired t-test. The results indicate that when nifedipine or nitroglycerine are added to a β-blocker such as atenolol, they provide further improvement in terms of exercise capacity, the extent of relief of ST segment depression, the maximal heart rate and the onset of symptoms. In patients, who are on β-blockers, 20 mgm of nifedipine sublingually taken 3 h before the exercise test gave as much improvement as that which was obtained with 0.75 mg of nitroglycerine sublingually. We conclude that the addition of nifedipine to β-blocker treatment is safe and that it leads to further suppression of exercise-induced angina pectoris in most of these patients. On the other hand the combination should be avoided in patients with only mild angina and in those who are in excellent physical condition. When signs of increased ragal tone such as significant bradycardia exist or when patients are hypotensive or have symptoms of cardiac failure the combination should probably also not be prescribed.