Heart involvement in metastatic carcinoid disease.

Sixteen patients with metastatic carcinoid tumors of ileal or cecal origin were studied in order to evaluate the frequency and degree of cardiac involvement in a nonselected patient group. We have also studied the correlation between plasma hormone levels (e.g., 5-hydroxytryptamine (5-HT) and substance P) and the degree of cardiac involvement. The patients underwent physical examinations, electrocardiograms, chest x-rays, cardiac catheterization, and echocardiography. Plasma levels of 5-HT and substance P were analyzed. Carcinoid heart involvement was found in 3 of 16 patients (19%) but no patient had subjective symptoms associated with heart disease. Four patients (25%) had slight pulmonary hypertension. No left-sided heart lesions were seen. No correlation between blood levels of 5-HT or substance P and heart involvement was found. Eight patients died during the follow-up period, but in none of these was the cause of death cardiac failure. Carcinoid heart disease is not as common in our patients as in patients selected on a cardiological basis described in earlier studies. Echocardiography appears to be the most efficient technique for detection of even subclinical heart involvement and a useful tool for following its progress.