What is unstable angina?
Unstable angina refers to a new pattern of anginal symptoms for a patient. This new pattern may be the recent onset of chest pain in a patient who never had chest pain before, or a worsening of chest pain in a patient with a history of chronic and stable chest pain. This new pattern of angina is often due to new blockage in a coronary artery or progression of an existing blockage. Unstable angina is now generally referred to as “Acute coronary syndrome.”
What causes unstable angina?
Unstable angina occurs in patients with coronary artery disease who have a piece of plaque break off on of their blockages. This leaves a raw surface on the plaque that becomes covered with a blood clot. In patients with unstable angina, the clot does not completely occlude the coronary artery as it does in patients who experience a heart attack. Instead, the blood clot in patients with unstable angina acts to intermittently impair the blood flow down that artery. While this may cause only a small amount of initial damage to the patient’s heart, patients with unstable angina are at high risk of experiencing a major heart attack.
What are the symptoms of unstable angina?
Patients with unstable angina often experience the typical symptoms of angina including chest pressure, shortness of breath, sweatiness, or nausea. However, patients with unstable angina may report that their chest pain is new or is occurring in an accelerating fashion. In the latter situation, a patient with a previously stable pattern of anginal symptoms may now present with an increase in the frequency or intensity of anginal episodes or a reduced threshold of exertion to trigger episodes of angina. Often patients will present with episodes of angina occurring at rest or of prolonged duration.
What are the dangers of unstable angina?
Patients presenting with unstable angina are at risk for suddenly having a significant myocardial infarction with progression of partial to complete occlusion of the coronary artery. They may also be at risk for potential life threatening heart rhythm abnormalities known as ventricular arrhythmias.
What are the treatments for unstable angina?
As a general rule, an aggressive approach is taken in patients presenting with unstable angina. In view of the significant risk these patients have for going on to having an acute myocardial infarction, physicians will generally approach these patients with urgent diagnostic cardiac catheterization, often followed by a procedure to treat the unstable plaque such as a coronary angioplasty or coronary bypass surgery. Occasionally, diagnostic coronary angiograms will diagnose a coronary problem that can be treated with medicines alone.