Mechanism of Anginal Pain: The Key Role of Adenosine

Anginal pain is the symptom that most often brings patients with ischemic heart disease to medical attention. However, transient myocardial ischemia and even necrosis can occur without pain, while severe anginalike pain can occur in the absence of detectable myocardial ischemia. Although the presence of cardiac ischemic pain serves the useful purpose of alerting the patient, it is unpleasant, alarming, and frequently disabling. Hence, as for other forms of response of the body to potentially noxious stimuli, pain can elicit a protective reaction. However, cardiac ischemic pain may become a major component of the disease when it is disproportionate to the severity of ischemia and bears no relation to the prognosis of the disease. A better understanding of the causes of cardiac ischemic pain and the factors that determine its occurrence and modulate its severity are important for understanding the causes of its elusive link to the severity of myocardial ischemia.