“…However, some authors find that, while f3-blocking agents have little influence on the electrocardiographic pat tern typical of coronary insufficiency (159,160,164), the combination of propranolol and isosorbid dinitrate, apart from alleviating pain and improv ing exercise capacity, notably modifies the ischemic electrocardiographic pattern of selected patients with severe and refractory forms of angina ( 177). This combination of propranolol and isosorbid dinitrate produced persistent relief of symptoms in 109 of 115 patients including some with re fractory angina (178). In twelve other cases of angina evaluated in a blind crossover study the combination of the two drugs produced a greater overall improvement than either drug alone (179).…”