Successful treatment of angina pectoris with liver transplantation and bilateral internal mammary bypass graft surgery in familial hypercholesterolemia.

sis. It is doubtful that inadequate alpha-receptor blockade was a significant factor, since the blood pressure was well controlled with phenoxybenzamine. Although T wave changes may occur in patients with mitral valve prolapse9 (a condition suggested by this patient's initial physical examination), it seems unlikely that this would explain the close association between ECG changes and specific interventions (i.e., drug therapy, tumor excision). Failure of the ECG to make a complete return to normal 4 months postoperatively suggests that minor irreversible subendocardial necrosis may have occurred, but these ECG changes may also be related to mitral valve prolapse.9 In conclusion, this case demonstrates that diverse ECG abnormalities of rhythm, conduction, and repolarization may occur in patients with pheochromocytoma. The paroxysmal nature and different degree of catecholamine secretion from this tumor probably accounts for the variability of these changes. Importantly, the ECG abnormalities may persist or worsen following adequate alphaadrenergic blockade. This may occur in the absence of obstructive coronary artery disease or other clinically detectable cardiac pathology. Although the mechanism for these changes is unclear, unopposed beta-adrenergic receptor stimulation may be a major factor. The nonspecificity and acute nature of the ECG changes associated with pheochromocytoma will often warrant coronary angiography prior to surgery. Although alpha-adrenergic blockade and blood pressure control are essential before any invasive procedure, complete alphaand beta-receptor blockade may be important for further myocardial protection, especially when ECG abnormalities are present initially.