Observations on myocardial function during chronic catecholamine oversecretion

Encapsulated pheochromocytoma cells secrete potent noncatecholamine factors

Pheochromocytomas are widely believed to induce cardiomyopathy via hypersecretion of catecholamines, including norepinephrine (NE). NE can have direct cardiomyocyte toxicity and/or can stimulate myocardial remodeling secondary to the induction of hypertension. Yet, the development of cardiomyopathy is not entirely related to catecholamine dose or the extent of hypertension. To explore these effects, we engineered a polymeric encapsulation system to control PC12 cell kinetics and NE release in vitro and in vivo. Primary neonatal rat cardiomyocytes incubated with pheochromocytoma-conditioned media exhibited greater cytoskeletal changes than myocytes cultured with identical doses of NE alone, including more profound dose-dependent decreases in desmin, beta-tubulin, and vinculin and upregulation of dystrophin. Cardiomyocyte contractility was 29 +/- 6% greater at given levels of NE release. Agarose-encapsulated PC12 cells retain cell viability and structural integrity in vivo. These implants induce a 30% greater degree of cardiac enlargement as compared to pumps releasing equivalent doses of NE. Protein level alterations observed in vitro were mirrored in vivo after implantation of encapsulated cells or NE pumps for 28 days. Together, these data suggest that pheochromocytoma-induced cardiomyopathy is not solely a catecholamine-mediated event; rather, the pathogenesis of this dilated cardiomyopathy appears to be dependent upon secondary factors unexamined to date.

De novo multiple endocrine neoplasia type 2B with noncardiogenic pulmonary edema as the presenting symptom

Multiple endocrine neoplasia (MEN) type 2B is a rare hereditary disorder characterized by medullary thyroid carcinoma, pheochromocytoma, and neuroma. Early signs of MEN 2B are usually neuroma, gastrointestinal problems, and medullary thyroid carcinoma. Noncardiogenic pulmonary edema is rare as a presenting symptom. We report a 31-year-old male who was admitted to our hospital because of noncardiogenic pulmonary edema. He was 168 cm in height, weighed 55 kg, and had an arm span of 166 cm. No marfanoid habitus was evident, but thickened lips and tongue neuroma were present. Chronic constipation had been present since childhood, and the patient had a two-year history of untreated hypertension. Noncardiogenic pulmonary edema and toxic megacolon were noted, and abdominal computed tomography revealed bilateral adrenal tumors. Ultrasonography of the thyroid showed two mass lesions. Intubation and mechanical ventilation were performed because of severe hypoxemia. Endocrinological examinations showed high levels of serum and urinary fractionated catecholamines, serum calcitonin, serum carcinoembryonic antigen, and serum intact parathyroid hormone. It was suggested that the high level of catecholamine from pheochromocytoma had caused the pulmonary edema. RET gene analysis showed a codon 918 mutation in exon 16 resulting in an ATG (methionine) to ACG (threonine) substitution, but analysis of the patient's parents showed the wild type. Therefore, the patient was diagnosed as having de novo MEN 2B. He underwent laparoscopic bilateral adrenectomy and total thyroidectomy. However, the values of serum calcitonin and CEA did not decrease to the normal ranges. Patients with early-stage MEN 2B have distinct characteristics that can aid early detection of the disease, thus possibly allowing them to be saved.

Reversibility of myocardial dyskinaesia due to severe hypertension

Two cases of acute left ventricular failure associated with severe essential hypertension are presented. On admission echocardiography indicated severe dyskinaesia of all wall segments of the heart. Anti-hypertensive treatment resulted in significant improvement in clinical and echocardiographic findings.

Phaeochromocytoma and catecholamine induced cardiomyopathy presenting as heart failure

Phaeochromocytoma is rare and usually presents as paroxysmal or sustained hypertension; none the less, it can also cause severe acute pulmonary oedema in normotensive individuals. Six patients with phaeochromocytoma presenting in Cornwall and West Devon between 1982 and 1986 are described. Five of them died of pulmonary oedema within 24 hours of the onset of symptoms. At necropsy all five had normal sized hearts and in the four hearts examined by histology there was evidence of catecholamine induced heart disease in the form of focal myocardial necrosis. The sixth patient presented with arterial spasms and pulmonary oedema. Surgical removal of the causative tumour was successful in this patient.

Catecholamine-induced cardiopathy accompanied with pheochromocytoma

Catecholamine-induced cardiopathy accompanied with pheochromocytoma in a 28-year-old female including two other cases are reported and the relationship between pheochromocytoma and cardiac change was also discussed. In the first case, catecholamine in the tumor tissue showed extremely high values; 94.22 micrograms/g of adrenaline and 6,332.42 micrograms/g of noradrenaline. Histologically, myocardial degeneration and inflammatory cell infiltration between myocardial fibers were noted. In the second case, hypertrophied heart showed focal degeneration of myocardial fibers with a few inflammatory cells in the stroma. The third case showed increase of heart weight, but neither myocardial degeneration nor inflammatory infiltration was noted except for moderate myocardial hypertrophy. Although the cause of difference in degree of myocardial changes is not yet clear, it may be attributed to the blood catecholamine level and/or duration of disease and/or area examined. A relative hypoxia theory is accepted for the mechanism of catecholamine-induced cardiopathy. This theory is supported by more severe lesions being noted near to the cardiac apex corresponding to peripheral coronary circulation.

An etiologic basis for congestive heart failure on the molecular level

It is here proposed that disordered redox balance leads to congestive heart failure in a variety of diverse clinical situations. These conditions include those associated with an excess of reducing agents, such as catecholamines and thyroid hormone, or impaired oxidant defenses, such as in selenium deficiency. The clinical situations include hypertension, hyperthyroidism, progressive congestive heart failure, amphetamine overdose and hemochromatosis. The molecular damage to the cardiac muscle is postulated to be mediated via reaction oxygen radicals.

Clinical determinants and consequences of left ventricular hypertrophy

The left ventricle adapts to an increased afterload such as that produced by arterial hypertension with concentric left ventricular hypertrophy. However, this adaptive process can be modified by a variety of physiologic and pathophysiologic states. Progressive aging, black race, and perhaps disorders with an increased sympathetic outflow seem to accelerate left ventricular hypertrophy. Obesity and other high cardiac output states predominantly produce dilatation of the left ventricle, and their combination with arterial hypertension results in eccentric left ventricular hypertrophy. Similarly, endurance exercise increases left ventricular volume more than wall thickness, whereas isometric exercise produces an increase in wall thickness only. The presence or absence of some physiologic and pathogenetic factors has direct implication on the assessment of what constitutes a "normal" left ventricular structure and function. Left ventricular hypertrophy has been shown to increase ventricular ectopic impulse generation and to put patients at a high risk of sudden death. Moreover, the increase in myocardial mass lowers coronary reserve and enhances cardiac oxygen requirements. Thus, the presence of left ventricular hypertrophy has to be considered as an ominous sign rather than as a benign adaptive process.

Cardiomyopathy and phaeochromocytoma

A case is presented of phaeochromocytoma with catecholamine-induced cardiomyopathy. The difficulties in the management when left ventricular failure occurred are reported and the importance of monitoring pulmonary artery pressure during the anaesthetic procedure is stressed.

Unusual cardiovascular manifestations in a case of pheochromocytoma

A case of proven pheochromocytoma is reported of a patient who presented with attacks of apparent hypotension, pulmonary edema, and myocardial injury with typical ECG and enzyme change. In spite of unmeasurably low peripheral blood pressure recordings during the attack, central aortic pressure was well above 240/140 mmHg. A clinical shocklike state was in effect due to severe arterial vasoconstriction. The pulmonary artery pressure was 48/26 mmHg during attacks, wedge pressure was 26 mmHg, and cardiac index 1.8 liters/min/m2. The coronary angiogram showed abnormal pooling of dye in the myocardial capillary network. It is concluded that: (1) Apparent hypotensive episodes in pheochromocytoma may be misleading and central arterial measurements may be needed to demonstrate the hypertensive crisis. (2) The abnormal coronary angiogram in our patient may be due to myocardial necrosis and damage to the intact arteriolar and microvascular system of the myocardium.

Acute pulmonary oedema in a patient with phaeochromocytoma

A young patient with a phaeochromocytoma who presented as an acute non cardiogenic pulmonary oedema is described. Phaeochromocytoma should be considered as a possible cause of the "adult respiratory distress syndrome."