INCLUSION CRITERIA:
Criteria for entry of patients into the protocol include a strong clinical suspicion of pheochromocytoma, as indicated by a continuing history of two or more symptoms suggestive of pheochromocytoma (e.g., excessive truncal sweatiness, palpitations, headaches, pallor, dizziness, anxiety, panic), combined with either documented paroxysmal hypertension or increases in plasma or urinary catecholamines. Patients are screened and selected for further study, based on abnormal in-house test results for plasma catecholamines or metanephrines or an abnormal ABPM profile. Participation in this protocol is offered to adults independently of gender, race, age, ethnicity, religion, or any other demographic or sociopolitical classifications. Control subjects are either normal volunteers or patients previously diagnosed with essential hypertension, this confirmed by the intake evaluation.
Inclusion into the protocol of subjects in the comparison group of essential hypertensives requires evidence for lack coronary heart disease by stress echo cardiography or a thallium scan carried out within the previous year. Inclusion of subjects in the comparison group of patients with panic disorder requires a diagnosis based on the Structured Clinical Interview of DSM4.
EXCLUSION CRITERIA:
Minors younger that 18 years old are excluded. A candidate subject is excluded if, in the judgment of the Medically Responsible Investigator or Clinical Director, protocol participation would place the subject at substantially increased acute medical risk or where the medical risk appears to outweigh the potential scientific benefit. This includes risks associated with air travel to the NIH. Examples of disqualifying conditions include hepatic or renal failure, congestive heart failure, symptomatic coronary heart disease, uncontrolled grade III hypertension, refractory ventricular arrhythmias, cardiac arrhythmia associated with tachycardia, history of digitalis-induced tachycardia or heart block, severe anemia, degenerative central nervous system disease, stroke, psychosis, convulsive disorders, diabetes mellitus, respiratory insufficiency, and active gastric or duodenal ulcer disease.
Subjects with a known or suspected allergy or hypersensitivity to any of the test drugs or treatments are excluded. Patients in whom we feel it would be difficult to insert a catheter into a vein are excluded. Subjects who are not expected clinically to tolerate lying still during the procedures are excluded.
Advanced age, pregnancy, or a positive HIV test result do not constitute criteria for exclusion from the protocol, in particular the screening portions of the protocol; however, pregnant or lactating women are excluded from portions of the protocol that in the judgment of the Principal Investigator would entail undue risk to the subject or fetus (e.g., administration of radioactivity). More specifically, pregnant women are excluded from all tests involving radioactivity, imaging and administration of drugs. All women of childbearing potential must have a negative blood test for pregnancy done within 24 hours before any of the above tests.
Patients who must take medications daily in the following categories are excluded: anticoagulants, tricyclic antidepressants, barbiturates, aspirin, or acetaminophen. Patients unable to discontinue nicotine or alcohol temporarily are excluded. Subjects are excluded if clinical considerations require that the patient continue treatment with a drug likely to interfere with the scientific results. An example would be treatment with a tricyclic antidepressant. Patients are not to discontinue any medications before the patient or the patient's doctor discusses this with the Medically Responsible Investigator, or the Research Nurse.
Subjects in the initial and secondary evaluations are excluded from further participation if they have both a normal ABPM record and normal plasma levels of catecholamines and metanephrines. Subjects in whom abnormal ABPM records or plasma catecholamines are due to medications, renal artery stenosis, hyperaldosteronism, renal failure, baroreflex failure, obstructive sleep apnea, or melancholic depression are excluded from continuing in the protocol. Discovery of the above-noted disqualifying medical conditions during screening evaluations also exclude further participation.
Subjects at risk from injury from the MRI magnet due to implantable metal or who suffer from anxiety in enclosed spaces are excluded from parts of the study involving MRI.
Patients with an established diagnosis of pheochromocytoma are excluded from study under the protocol. However, where there is initial suspicion of pheochromocytoma, such patients may undergo initial testing of plasma free metanephrines and catecholamines under the protocol. Where this initial testing supports a possibility of pheochromocytoma, the patient will be referred to NICHD, for evaluation of pheochromocytoma under a separate protocol (00-CH-0093; Diagnosis, pathophysiology, and molecular biology of pheochromocytoma). Among these patients, those in whom pheochromocytoma is subsequently ruled out are invited back for further evaluation under the present protocol.
Warren Grant Magnuson Clinical Center (CC)