THALLIUM PERFUSION AND MYOCARDIAL HYPERTROPHY IN TRANSPLANTED HEART RECIPIENTS WITH NORMAL OR NEAR-NORMAL CORONARY ARTERIOGRAMS

In patients with hypertrophic cardiomyopathy or systemic hypertension, exercise thallium perfusion defects have been observed but without significant angiographic stenoses. Hypertension and myocardial hypertrophy are common in transplanted heart recipients, and the aim of this study was to determine if exercise thallium scintigraphy false-positives are frequent in transplanted heart recipients.Thirty-four transplanted heart recipients were evaluated by exercise thallium single emission computed tomography and subsequently had a normal or near normal coronary arteriogram. At the time of the exercise, the patients (28 men and six women) had a mean age of 48.9 ± 12 years and 29 had been previously treated for systemic hypertension. The mean duration between transplantation and the exercise test was 31.6 ± 13 months. In all patients left ventricular mass was obtained by echocardiography within 3 months of thallium 201 SPECT and was ≧130g. m-2 in nine males and ≧ 110 g. m-2 in four females. M-mode septal+posterior end-diastolic thickness was >23 mm in 14 patients, all of whom had been previously treated for systemic hypertension. These patients were older and endured a longer period during which the heart was kept cold but ischaemic before being grafted ('cold ischaemia') but a shorter exercise duration than patients without left ventricular hypertrophy. During exercise testing, 26 of 34 patients achieved at least 80% of their maximal predicted heart rate and two developed significant ECG changes. Exercise and 4 h redistribution thallium perfusions were normal in 33 patients, but one patient with a left ventricular mass = 100 g. m-2 had a persistent apical defect.We conclude that in transplanted heart recipients with normal or near normal coronary arteriograms, myocardial perfusion evaluated with exercise thallium 201 SPECT is usually normal despite a high frequency of myocardial hypertrophy. © 1994 The European Society of Cardiology.