We report two observations of significant left heart involvement in patients 
with the carcinoid syndrome assessed by transthoracic and transoesophageal 
echocardiography. Echocardiographic lesions of this kind have only been reported 
twice. In the present cases, there was mitral involvement with mitral 
regurgitation in one case and a mitro-aortic involvement with mitral and aortic 
regurgitation in the other. The mechanism of left heart lesions is unclear since 
in both cases no right-to-left cardiac shunt was present, as attested by colour 
Doppler and saline contrast transoesophageal echocardiography. The location of 
the primary tumour was unknown in one case and ileal in the other; no pulmonary 
metastasis was detected. The use of transoesophageal echocardiography might make 
it possible to detect left-sided cardiac lesions more frequently since they were 
found in anatomical series, in 30% of patients with carcinoid syndrome.