Time domain heart rate variability measurements and echocardiographic studi
es were performed in 35 patients with carcinoid syndrome. Carcinoid heart d
isease was present in 18 patients (51%). Heart rate variability parameters
(standard deviation of all normal RR intervals, percentage of the number of
pairs of adjacent normal RR intervals differing by >50 ms) were significan
tly reduced in patients with than in those without carcinoid heart disease.