Dear Dr. Mo: I’ve recently been diagnosed with a Prinz-Metal angina and I’ve been told this type is somewhat unusual – what does it mean? And what exactly is angina?
Dear reader: Angina is a clinical syndrome resulting from a transient reversible cardiac ischemia – this means that blood flow through the coronary artery to one part of the heart, carrying all important oxygen, temporarily and reversibly becomes dangerously low leaving that part of the heart undernourished and basically starving – we call that segment of the heart a vulnerable myocardium (myocardium means a heart muscle). Coronary arteries are the ones responsible for feeding the heart.
Clinical presentation of angina is a central chest discomfort or pain – less like a pain, much more like a weight or pressure at times also described as a burning sensation. This intense discomfort and/or pain may radiate to one or both arms, neck, jaw, epigastrium (upper part of the stomach), may not radiate at all or may be felt only in the area of radiation.
This anginal sensation occurs when current oxygen supply to the heart is less than the demand for it and the suffering undernourished (ischemic) heart muscle cries, which causes symptoms felt in angina.
We say that a tissue is ischemic when the blood supply to it drops below a minimum required level to provide oxygen and other nutrients necessary for normal function. If ischemia is prolonged, and depending on the type of tissue and its oxygen demand, cells die and in some tissues like in the heart or the brain, these cells cannot be replaced.
Duration of each episode of discomfort and/or pain typically shouldn’t last for longer than maximum 20 minutes and it usually spans from anywhere between 15 seconds to 15 minutes.
I am saying that 20 minutes of duration is maximum time within which we are talking about angina because longer ischemia causes myocardial infarction (death of heart cells which is irreversible as these cells are lost).
Your question is about one specific type of angina called Prinz-Metal angina.
This angina is clinically called ‘coronary vaso-spastic’ angina to describe its mechanism of onset because atherosclerotic lesions are not responsible for the symptoms like in the other two types of angina: the classical, stable angina and the unstable, variant angina.
Rather, in Prinz-Metal angina, the coronary artery has a fluctuating/unstable tone of its walls resulting in spasms (sudden narrowing of arterial walls), which momentarily lead to ischemia. Ischemia will occur throughout the wall of the heart and is called trans-mural ischemia. This mechanism is probably what they meant by saying it’s ‘unusual’.
Symptoms, which are typical angina symptoms may happen suddenly and at rest and this type is more common in females. It may also happen during exertion in which case oxygen demand by the working heart is higher and potential ischemia more dangerous.
This angina may be precipitated by cold air, as this air may stimulate blood vessels to narrow.
Typical treatment options involve dilation of the coronary arteries to increase blood perfusion of the affected parts of the heart. Dilators that are being used are mostly from the group of drugs called Calcium channel blockers as Calcium is involved in muscle contraction and by blocking its flow to the cell, contraction is inhibited or reduced, preventing spasms from occurring.
Other types of angina are Stable (classical) angina precipitated by exertion and Unstable (variant) angina, which is a pre-infarction condition that needs immediate management and stabilization. Both of these types involve atherosclerosis of the inside of the coronary artery, which creates obstruction to the blood flow, causing ischemia. Management of these two is short term via medicaments to relieve immediate symptoms and danger and long term via surgical intervention, medication, reduction/elimination of risk factors for atherosclerosis and life style changes.
Anginas are serious conditions but with proper life style and medical management, could be well under control with good long-term prognosis. So, start a healthy diet, reduce stress, eliminate sedentary living and talk to your doctor about ways to improve your overall health – your heart will follow suit.
Yours in health,