New research to be published in the Annals of Emergency Medicine has found that the often-used method of determining the cause of chest pain by placing a nitroglycerin tablet under a patient's tongue is unreliable.
According to the published report, physicians in emergency departments have used the test when a patient arrives complaining of chest pains: If the pain subsides within a few minutes, the likely diagnosis is coronary artery disease, the report explains.
The researchers consisted of emergency physicians and cardiologists from the University of California, Davis Medical Center in Sacramento. They tested 664 patients who arrived at an emergency department complaining of chest pain, using an 11-point pain-intensity scale to measure the patients' perceptions of the reduction of chest pain. The researchers found no relationship between the reduction of chest pain among patients who were later diagnosed with heart disease and those who were not.
The study says that nitroglycerin works to relieve chest pain caused by coronary artery disease by relaxing the blood vessels to the heart, causing blood flow and oxygen supply to the heart to increase. For patients without heart disease whose chest pain was reduced by nitroglycerin, researchers suspect the drug may have relieved muscle spasms in the esophagus, the researchers said.