Tissue Doppler echocardiography in patients with thalassaemia detects early myocardial dysfunction related to myocardial iron overload.

Abstract

To compare an echocardiographic method for detecting abnormal cardiac function before development of overt cardiomyopathy with a recently validated technique of quantifying myocardial iron load. We examined thalassaemia patients whose myocardial iron load had been evaluated with magnetic resonance imaging (MRI). By tissue Doppler echocardiography, myocardial velocities were sampled continuously from base to apex in the RV and LV free wall, and the septum in 52 patients aged 29.2 (14.2-43.1) years and 52 age-matched controls. Ninety-six percent of patients had normal LV ejection fraction by MRI. Thirty-eight (73%) had abnormal iron loading of the myocardium, and 33 of those had regional wall motion abnormalities detected in the septum (n=29), LV (n=2), RV (n=1), and septum plus LV (n=1). The incidence of wall motion abnormalities was significantly higher (P<0.04) in patients with myocardial iron overload (87%) than in the 14 without (35%). Furthermore, myocardial iron overload was suggested by a low T2(*)(15.1+/-15.8 ms) in patients with wall motion abnormalities vs those with normal wall motion (T2(*): 30+/-19 ms) (P<0.007). Wall motion abnormalities may represent an early sign of cardiac disease despite preserved global function. The regional abnormalities are related to iron overload and easily detectable with tissue Doppler echocardiography.