What is a heart attack?
A heart attack occurs when the coronary arteries become blocked and a section of the heart muscle does not receive blood (including oxygen and nutrients).
In cases such as this, if blood flow is not adequately and promptly restored, the affected section of heart muscle will die, a condition called myocardial infarction (MI).
Patients suffering from a myocardial infarction can manifest symptoms such as chest discomfort (With or without difficulty of breathing), nausea, nausea, lightheadedness or sudden dizziness, fatigue without previous exertion, and diaphoresis (cold sweat).
What causes a heart attack?
Most heart attacks are due to ischemic heart disease, a condition where the coronary arteries are blocked and cannot provide oxygenated blood to sections of heart muscle. This is due to plaque build up within the inner lining of coronary arteries, a condition with the name of atherosclerosis, which may take several years to produce symptoms.
As time goes on, the plaque will harden and eventually rupture, causing blood clots to form at the site of injury. As a result, the artery narrows even further, thus reducing blood flow to the specific section of heart muscle.
Having atherosclerosis also predisposes coronary arteries to be hyper-reactive and this may lead to coronary artery spasms (a less common cause of heart attacks), which is a series of severe spasms (contractions or narrowing) of a coronary artery that may reduce or completely obstruct blood flow.
These usually occur at sites affected by atherosclerosis. Atherosclerotic arteries are usually prone to spasms. Coronary artery spasms usually triggered by certain drugs such as the stimulant cocaine, emotional stress or pain, tobacco use, and exposure to extremely cold environments.