A reevaluation of the hemodynamics of pheochromocytoma.

Abstract

We examined the hemodynamic features of 24 untreated patients with surgically proven pheochromocytoma during steady-state periods and compared them with 24 untreated essential hypertensive patients individually matched for sex, age, body surface area, and arterial blood pressure. We found that, despite having 10-fold higher levels of circulating catecholamines, pheochromocytoma patients have hemodynamic characteristics similar to patients with essential hypertension and that, in individual patients, the ratio of circulating norepinephrine to epinephrine had no relation to the hemodynamic profile. In both groups, increased total peripheral resistance is primarily responsible for maintenance of hypertension. These results suggest that, unlike the acute administration of catecholamines, long-term exposure to high levels of circulating catecholamines does not produce hemodynamic responses characteristic of this group of compounds. This might be due in part to desensitizatlon of the cardiovascular system to catecholamines and might explain the clinical observation that some patients can be completely asymptomatic despite harboring an actively catecholamine-secreting pheochromocytoma. (Hypertension 1990;15(suppl I):M28-I-131)

Increased blood pressure variability in pheochromocytoma compared to essential hypertension patients

“…Higher HR values in subjects with pheochromocytoma in comparison with EH were also reported in other studies [16,26]. In the pheochromocytoma group without treatment with a 1 -receptor blockers, a significantly higher coefficient of daytime HR variation was found.…”

“…One explanation of these results can be the differential desensitization of adrenergic receptors as a result of the chronic excess of norepinephrine or epinephrine [16][17][18].…”

Autoimmune Hypertensive Syndrome

“…We did not have detailed hemodynamic studies other than the initial cardiac catheterization and measurements of cardiac function estimated from echocardiographic studies. Because even pheochromocytomas do not present with unique hemodynamic studies, 28 we are unable to demonstrate any unique characteristics that might differentiate either type of adrenergic agonist presentation. Because the AA␤ARs do not change concentrations in a short frame of time and appear to not interact with the ␣ 1 receptor, one would not anticipate blanching.…”

Präoperative α-Rezeptoren-Blockade beim asymptomatischen Phäochromozytom? Pro

“…Nicht alle Phäochromozytome manifestieren sich jedoch durch diese typischen Symptome, sondern bleiben klinisch asymptomatisch [3,6,9,11,16,20,24].…”

“…Dies resultiert mög-licherweise aus einer bereits ausgepräg-ten Desensibilisierung des kardiovaskulä-ren Systems gegenüber Katecholaminen, sodass selbst deutlich erhöhte Katecholaminspiegel keine adäquaten Blutdruckanstiege mehr auslösen [6,13,28].…”