The left ventricular end-systolic pressure-dimension relation in patients with thalassemia major. A new noninvasive method for assessing contractile state.

Abstract

Transfusion-dependent patients with thalassemia major (TM) are at an extremely high risk for cardiomyopathy. Traditional tests of left ventricular (LV) systolic function performed in these patients do not distinguish derangements in loading conditions from abnormalities in contractile state. In this study, we used the LV end-systolic pressure dimension (PES-DEs) relation, which is independent of preload, incorporates afterload and is highly sensitive to contractile state, to assess LV performance in 20 asympto- matic, chronically transfused patients, ages 7-25 years, with TM. All patients had normal resting systolic time intervals and exercise duration on treadmill. Baseline resting percent fractional shortening (% AD) on M-mode echocardiography (echo) was normal in 14 patients (group 1) and abnormal in six patients (group 2). Echo and carotid pulse recordings were made at rest and during i.v. infusion of methoxamine to alter LV afterload. DE was measured directly from echo; PES was estimated from a calibrated carotid pulse tracing.