Myocardial Infarction and Reversible Left Ventricular Apical Ballooning Associated With Pheochromocytoma:

Coronary artery myointimal dysplasia in patients with pheochromocytoma-possible causal relationship: pathophysiology and clinical implication with reference to Takotsubo cardiomyopathy and spontaneous coronary dissection

Myocardial damage in catecholamine cardiomyopathy, characterized by patchy myocyte necrosis commonly with contraction band appearances, interstitial fibrosis, and varying degrees of inflammatory infiltrates, has been well documented. However, coronary vascular pathology has not been recognized. Autopsy of a 43-year-old housewife who died of acute apical anteroseptal myocardial infarction revealed the incidental finding of a left adrenal pheochromocytoma. The epicardial and intramyocardial median- and small-sized coronary arteries exhibited myointimal dysplasia in the form of fibroblastic proliferation in the intima and media, resulting in thickened dysplastic vessels with marked luminal narrowing, occasionally leading to near-total occlusion. The distal left anterior descending artery showed features of recanalization after prior embolic occlusion. The density and severity of vascular involvement revealed a decreasing gradient from apical to basal region, mainly affecting the left ventricle, but the proximal coronary arteries were minimally affected. Myointimal dysplasia was not seen in control cases of hypertensive heart, and despite its presence in hearts with hypertrophic cardiomyopathy, it lacked the distinctive pattern of distribution and the epicardial vessels are uninvolved. Myointimal dysplasia probably results from reactive fibroplasia in response to the vasoconstrictive effect of circulating or local neurosecretory catecholamine and appears crucial in the pathogenesis of various types of catecholamine cardiomyopathy, including Takotsubo or stress cardiomyopathy. Together with the direct catecholamine cardiotoxicity, they result in diffuse microscopic ischemic necrosis and fibrosis. Depending on the type of catecholamine overproduction and action, together with the characteristic anatomic distribution and density of the various types of adrenergic receptors in the ventricles, different regions of the heart are variously affected so that different patterns of ventricular dysfunction are produced, with the subsequent angiographic appearances ranging from apical through midventricular to basal ballooning. Additional complications from the myointimal dysplasia include spontaneous coronary dissection, acute myocardial infarction, and superimposed thrombus formation in the dysplastic vessels and dyskinetic ventricle, with the risk of further damage from embolic events.

Acute systolic heart failure and uncontrolled hypertension: what is the missing link?

Pheochromocytoma is a rare tumor in adults, with an estimated annual incidence of 0.8 per 100,000 persons. Cardiomyopathy is an uncommon presentation of such a rare disease. Serious cardiovascular complications of these tumors are related to potent effects of secreted catecholamines. The mechanism of pheochromocytoma-related cardiomyopathy is not well understood but it is likely due to the effect of excess catecholamines and their oxidation products which have been found to have a direct toxic effect on the myocardium. We describe below a case of a 70-year old female with uncontrolled hypertension and new onset acute systolic heart failure, who on further evaluation was noted to have pheochromocytoma-related cardiomyopathy. Pheochromocytoma should be strongly considered in the differential diagnosis of non-ischemic cardiomyopathy for a patient with elevated blood pressures relative to severity of cardiac dysfunction.

Takotsubo-like cardiomyopathy in pheochromocytoma

BACKGROUND

Takotsubo Cardiomyopathy (TTC) is commonly triggered by acute illness, physical or emotional stress and has been associated with elevated catecholamine levels. TTC has also been associated with pheochromocytoma (TTC-pheo).

METHODS

We performed a computer assisted search of the electronic databases Medline, Scopus and Google Scholar from 1965 to January 2011. All case reports with reported TTC-pheo were selected and compared to a recent review by Gianni et al. which examined primary TTC (TTC-primary).

STATISTICS

Data analysis was performed using SPSS version 18. Chi-square test of Fisher's exact test was used as appropriate to compare categorical data.

RESULTS

38 cases of TTC-pheo were retrieved from literature and compared to 254 cases of TTC-p. Chest pain was the most common presentation in both groups. The TTC-pheo patients were on average 18 years younger than patients with TTC-p (p<0.01). Only a minority of TTC-pheo patients presented with classical features of pheochromocytoma including hypertension (52.6%), headache (28.9%), palpitations (31.6 %), and diaphoresis (26.3%). In TTC-pheo complications rates were higher compared to TTC-p, including cardiogenic shock (34.2% vs. 4.2%, p<0.01) and heart failure (46.7% vs. 17.7%, p<0.01). Antecedent stressors were less common in TTC-pheo. About one-third of TTC-pheo patients presented with the inverted pattern, which compared to the apical pattern, was associated with higher complication rates, including, cardiogenic shock, heart failure, acute renal failure and arrhythmias.

CONCLUSIONS

Although rare, pheochromocytoma should be considered in the differential diagnosis of TTC especially in younger patients presenting without antecedent stressors and a high complication rate. The similarities in the clinical features and outcomes in patients with TTC-p and TTC-pheo point to a similar underlying cardiac pathophysiologic process at the time of the acute presentation.