Myocardial hypertrophy due to volume and pressure overload is common in hemodialysis patients because renal failure is usually responsible for arterial hypertension. The left ventricular filling pattern often exhibits abnormalities denoting a relaxation disorder. These abnormalities increase after hemodialysis sessions, which are sometimes followed by severe hypotension. This sequence of left ventricular hypertrophy, altered relaxation, and severe postdialysis hypotension sometimes associated with severe ventricular rhythm disorders deserves to be studied in detail. The data gathered would help to determine the prognosis in this situation, which often depends on cardiac function.