Intermittent claudication complicating beta-blockade.

Intermittent claudication is an occasional side effect of beta-adrenergic blockade' but clinical details are lacking. Beta-blocking agents may exacerbate intermittent claudication in patients with severe peripheral arterial insufficiency.2 The following cases suggest that they may also provoke claudication in patients with previouslv asymptomatic peripheral arterial disease. Case 1 A man aged 54 without previous cardiovascular symptoms was found to be hypertensive. He was treated with methyldopa and, because of probable paroxysmal nocturnal dyspnoea, with bendrofluazide. After six months propranolol 120 mg daily was substituted for methyldopa. Three weeks later he developed cold extremities and bilateral calf claudication at 150 yards. After eight weeks' treatment, during which the blood pressure fell from 220/125 to 200/120 mm Hg, propranolol was withdrawn. Claudication began to improve after three weeks and resolved within five. Seven weeks after stopping propranolol the patient could play golf. Although both feet were cool, all peripheral pulses were palpable. The resting Doppler pressure index3 was normal, but Doppler sonography4 indicated generalised atherosclerosis of the lower limbs without pronounced vessel narrowing. The electrocardiogram (ECG) showed left ventricular hypertrophy. There was no radiographic evidence of cardiac decompensation. Case 2 A woman aged 60 without previous cardiovascular symptoms had a transient hemiplegia. Her blood pressure was 220/120 mm Hg. She was treated with practolol 300 mg daily. Six months later she developed bilateral calf claudication at 100 yards; blood pressure was unchanged and there were clinical signs of widespread distal arterial disease. ECG and chest x-ray examination indicated mild left ventricular hypertrophy; there was no evidence of cardiac decompensation. Methyldopa and bendrofluazide were substituted for practolol. One month later the blood pressure was 180/100 mm Hg and right calf claudication had resolved. Left calf claudication and the peripheral pulses were, however, unchanged. Left phenol sympathectomy was performed. After three months severe left calf claudication persisted, but right-sided symptoms had not recurred. A man aged 59 without previous cardiovascular symptoms sustained an anterior myocardial infarction. Despite digoxin and frusemide, signs of cardiac decompensation persisted for three months. Four months after nfarction he developed angina, and propranolol 120 mg daily was added to his treatment. Two months later he had no angina but complained of cold feet. After a further three months he developed bilateral calf claudication: the clinical signs indicated bilateral superficial femoral artery occlusions with poor distal flow. Without a change in his drug therapy, a left phenol sym-pathectomy was performed. Six …