[en] Severe congestive heart failure developed in an acromegalic patient, and was successfully treated with octreotide followed by trans-sphenoidal surgery. Clinical, hormonal echocardiographic and haemodynamic findings as well as histological heart examination before and after treatment revealed that over-production of growth hormone may induce the myocardial cell degeneration responsible for mechanical heart dysfunction. In addition, this unique example demonstrates the reversibility of myocardial damage following octreotide and trans-sphenoidal surgery, leading to significant improvement in cardiac function with minimal diastolic dysfunction and moderate interstitial fibrosis.