Cardiac performance in various stages of renal failure.

Cardiac catheterisation was performed to evaluate cardiac function in 12 patients with various stages of renal failure. All patients were studied at rest and during supine exercise to subjective exhaustion. Eight patients had a normal arteriovenous oxygen difference at rest and during exercise whereas three had a low arteriovenous oxygen difference and one a high arteriovenous oxygen difference. Left ventricular stroke work did not increase normally at transition from rest to exercise in most patients with serum creatinine concentrations greater than 500 mumol/l. The left ventricular end diastolic pressure was abnormally raised during exercise in all patients (range 20-42 mm Hg) and also at rest in most of them (range 8-36 mm Hg), indicating myocardial dysfunction. These observations suggest that patients have abnormal cardiac performance at a relatively early stage of renal failure.