Pain sensitivity in silent myocardial ischemia.
Although the cause of silent myocardial ischemia (SMI) is unknown, several theories have been advanced to explain the disorder. Most prominent among these are the suggestions that attribute the condition to generalized impaired pain sensitivity and/or enhanced endorphin activity. The present study examined both hypotheses. It was carried out in 33 patients with myocardial ischemia: 13 with silent myocardial ischemia (silents) and 20 with symptomatic ischemia (symptomatics). Pain sensitivity was determined with thermal, electrical, and ischemic pain tests using signal detection theory (SDT) and conventional threshold procedures. To evaluate the significance of endorphin mechanisms naloxone (6 mg i.v.) and placebo were administered on alternate days in a double-blind, cross-over procedure before the pain tests and again before a treadmill exercise test (TET). Somatic pain sensitivity was found not to be impaired in patients with SMI, and no evidence was found to support a causal role for endorphins in the disorder.
Glusman
Murray
M
Departments of Behavioral Physiology and Biopsychology, New York State Psychiatric Institute, New York, NY, USA Department of Psychiatry, Columbia University College of Physicians and Surgeons and Department of Medicine, Division of Cardiology, College of Physicians and Surgeons, Columbia University, New York, NY, USA.
Coromilas
James
J
Clark
Crawford W
CW
Janal
Malvin N
MN
Blood
David K
DK
Kuhl
John P
JP
Burns
Kathleen
K
D000787:Angina Pectoris / Q000150:complications / Q000523:psychology; D001290:Attitude; D018592:Cross-Over Studies; D004192:Discrimination, Psychological / Q000502:physiology; D004311:Double-Blind Method; D005080:Exercise Test; D006358:Hot Temperature; D006801:Humans; D017202:Myocardial Ischemia / Q000503:physiopathology* / Q000523:psychology; D009270:Naloxone; D009292:Narcotic Antagonists; D010147:Pain Measurement / Q000295:instrumentation / Q000379:methods*; D017288:Pain Threshold / Q000502:physiology; D017603:Signal Detection, Psychological
D009292:Narcotic Antagonists; D009270:Naloxone