Holt R G, Gross R, Carlsson E
Radiology. 1978 Jun;127(3):601-5. doi: 10.1148/127.3.601.
Cineangiocardiograms from 2 patients with carcinoid syndrome and cardiac involvement were reviewed. Gross and microscopic pathology specimens were available for 1 case. Both patients exhibited tricuspid valvar stenosis and insufficiency. The area of the pulmonic valve was similar in both with narrowing of the annulus and tapering toward the valve of the proximal pulmonary artery and the subvalvar right ventricular outflow tract, producing an hourglass appearance, which the authors feel is characteristic of this disease.