cardiovascular-agents and Pheochromocytoma

Pheochromocytoma in pregnancy is very rare but it is associated with very high maternal and fetal mortality. Therefore, it is important to include pheochromocytoma in the differential diagnosis of hypertension associated with pregnancy. It is difficult to make a diagnosis of pheochromocytoma in pregnancy before delivery. The characteristic symptoms of pheochromocytoma could be initiated during delivery because the process of delivery, general anesthesia, fetal movement, induce acute surge of catecholamine release, which could also induce cardiomyopathy. Early diagnosis and intensive care can affect the prognosis of cardiomyopathy induced by pheochromocytoma. Proper management with alpha-blockade, beta-blockade and angiotension converting enzyme inhibitor could acutely reverse the course of cardiomyopathy.

Topics: Adrenal Gland Neoplasms; Adult; Cardiomyopathies; Cardiovascular Agents; Disease-Free Survival; Echocardiography; Electrocardiography; Female; Humans; Pheochromocytoma; Postpartum Period; Pregnancy; Pregnancy Complications, Cardiovascular; Pregnancy Complications, Neoplastic; Pregnancy Outcome; Tomography, X-Ray Computed

Studies performed in experimental animals and in humans have documented that high blood pressure markedly impairs baroreceptor control of heart rate. Whether a similar impairment also characterizes baroreceptor control of sympathetic activity modulating peripheral vasomotor tone is still unknown. In 28 untreated essential hypertensive subjects [14 of moderate and 14 of more severe degree, age 51.6+/-2.4 and 52.6+/-2.1 years (mean+/-SEM)] and in 13 untreated secondary hypertensives (renovascular or pheochromocytoma, age 50.1+/-4.6 years), we measured beat-to-beat arterial blood pressure (finger photoplethysmographic device), heart rate (electrocardiogram), and efferent postganglionic muscle sympathetic nerve activity (microneurography) at rest and during baroreceptor stimulation and deactivation induced by stepwise intravenous infusions of phenylephrine and nitroprusside, respectively. Data were compared with those obtained in 15 age-matched normotensive control subjects. Muscle sympathetic nerve activity (bursts per 100 heart beats) showed a progressive and significant (P<.01) increase from normotension (40.3+/-3.3) to moderate (55.6+/-4.1) and more severe essential hypertension (68.2+/-4.1), paralleling the progressive increase in blood pressure values. In contrast, muscle sympathetic nerve activity was not increased in secondary hypertensives (40.5+/-6.7) despite blood pressure values similar to or even greater than those of severe essential hypertensives. In both essential and secondary hypertensives, baroreceptor-heart rate control was displaced toward elevated blood pressure values and markedly impaired compared with normotensive subjects (average reduction, 38.5%). In contrast, the sympathoinhibitory and sympathoexcitatory responses to baroreceptor stimulation and deactivation were displaced toward elevated blood pressure values but similar in all groups. Thus, sympathetic activation characterizes essential but not secondary hypertension. Regardless of its nature, however, hypertension is not accompanied by an impairment of baroreceptor modulation of sympathetic activity.

Topics: Blood Pressure; Cardiovascular Agents; Case-Control Studies; Female; Heart Rate; Humans; Hypertension; Hypertension, Renovascular; Male; Middle Aged; Muscle, Skeletal; Nitroprusside; Phenylephrine; Pheochromocytoma; Pressoreceptors; Sympathetic Nervous System

Topics: Cardiovascular Agents; Child; Diagnosis, Differential; Humans; Hypertension; Infant; Muscle Relaxants, Central; Paraganglioma; Pheochromocytoma