Response to Nitro has No Predictive Value BUT use it to relieve symptoms
Test of Treatment or Therapeutic Challenge although imprecise is often used and is helpful in clinical practice. However, in their example of common tests of treatment, the authors gave an example of response to nitroglycerin as a test of Angina with 69-71% specificity. However, at least 2 studies [1-2] that evaluated the discriminatory value of nitroglycerin in patients presenting with chest pain, failed to show its usefulness in differentiating cardiac from non-cardiac chest pain, and response to nitroglycerin should not be used to guide the diagnosis. I think it is important to correct this myth that a chest pain relieved by nitroglycerin is angina and it incorrectly reinforces the patient and the physician. This unnecessarily results in further testing in most patients with atypical symptoms. I often tell patients that nitroglycerin is helpful in relieving symptoms by relaxing smooth muscles and discomfort causes by irritation or spasm of any smooth muscle in the body - whether in the heart (angina), oesopahgus (oesophageal spasm) or uterus (uterine contractions) would be relieved with nitroglycerin. In addition, there is always a possibility of placebo effect. It is important to advise patients to use nitroglycerin to relieve chest pain symptoms, keeping in mind that it doesn’t differentiate between the two common causes of chest pain.
References:
1. Henrikson CA, Howell EE, Bush DE, Miles JS, Meininger GR, Friedlander T, Bushnell AC, Chandra-Strobos N. Chest pain relief by nitroglycerin does not predict active coronary artery disease. Ann Intern Med. 2003 Dec 16;139(12):979-86. PMID: 14678917
2. Steele R, McNaughton T, McConahy M, Lam J. Chest pain in emergency department patients: if the pain is relieved by nitroglycerin, is it more likely to be cardiac chest pain? CJEM. 2006 May;8(3):164-9. PMID: 17320010
Competing interests:
None declared
Competing interests:
No competing interests
22 May 2009
Malvinder S. Parmar
Associate Professor, Northern Ontario School of Medicine
Rapid Response:
Response to Nitro has No Predictive Value BUT use it to relieve symptoms
Test of Treatment or Therapeutic Challenge although imprecise is often used and is helpful in clinical practice. However, in their example of common tests of treatment, the authors gave an example of response to nitroglycerin as a test of Angina with 69-71% specificity. However, at least 2 studies [1-2] that evaluated the discriminatory value of nitroglycerin in patients presenting with chest pain, failed to show its usefulness in differentiating cardiac from non-cardiac chest pain, and response to nitroglycerin should not be used to guide the diagnosis. I think it is important to correct this myth that a chest pain relieved by nitroglycerin is angina and it incorrectly reinforces the patient and the physician. This unnecessarily results in further testing in most patients with atypical symptoms. I often tell patients that nitroglycerin is helpful in relieving symptoms by relaxing smooth muscles and discomfort causes by irritation or spasm of any smooth muscle in the body - whether in the heart (angina), oesopahgus (oesophageal spasm) or uterus (uterine contractions) would be relieved with nitroglycerin. In addition, there is always a possibility of placebo effect. It is important to advise patients to use nitroglycerin to relieve chest pain symptoms, keeping in mind that it doesn’t differentiate between the two common causes of chest pain.
References:
1. Henrikson CA, Howell EE, Bush DE, Miles JS, Meininger GR, Friedlander T, Bushnell AC, Chandra-Strobos N. Chest pain relief by nitroglycerin does not predict active coronary artery disease. Ann Intern Med. 2003 Dec 16;139(12):979-86. PMID: 14678917
2. Steele R, McNaughton T, McConahy M, Lam J. Chest pain in emergency department patients: if the pain is relieved by nitroglycerin, is it more likely to be cardiac chest pain? CJEM. 2006 May;8(3):164-9. PMID: 17320010
Competing interests:
None declared
Competing interests: No competing interests