The heart is the major organ of human circulatory system and hardest working organ of human body. It continuously pumps blood enriched with oxygen and vital nutrients through a network of arteries to all body tissues. It is a powerful pump, which has got no match; during peak exercise it can pump about 50 liters of blood in a single minute. To perform this arduous task of pumping blood to rest of the body, heart muscle itself requires a good supply of oxygen rich blood. A network of coronary arteries supplies this. There are 3 main coronaries- left anterior descending (LAD), left circumflex (LCx) arising from left side and one right coronary artery (RCA) from right side. If blood flow to the heart muscle is interrupted or blocked the heart muscle suffers injury, which is called myocardial infarction and is commonly known as heart attack.
Coronary artery disease:
The heart attack is the severest form of coronary artery disease. Coronary artery disease is said to be present when plaque starts accumulating inside the walls of coronary arteries. Plaque is an atherosclerotic chunk of fatty deposits causing hardening and narrowing of coronary arteries. There is slow accumulation of fatty deposits causing gradual narrowing of coronary arteries and progressively starving heart muscle of oxygen and nutrients. When heart muscle is deprived of proper blood supply and oxygen, it becomes ischaemic and pain occurs. This pain is called angina. This initially occurs during increased demand of the body when heart has to pump more blood to body mainly during exertional activities. So angina occurs when coronary arteries are unable to supply adequate amount of blood to heart muscle as is required by it.
The plaque can also rupture under certain circumstances, which causes sudden occlusion of coronary artery by the formation of thrombus or blood clot. This sudden occlusion totally stops the blood supply to heart muscle and it leads to heart attack or myocardial infarction.
Angina means chest pain; it is the primary symptom of heart disease and heart attack. It occurs when heart muscle doesn’t get as much blood (hence oxygen) as is required for a given level of work. It is usually referred to as one of the two states: stable and unstable. Anginal attacks can occur at any time during day, but a high proportion seems to take place in the early hours of the day. The unstable angina is often an intermediate stage between stable angina and a heart attack and its course is unpredictable and is a sign of more serious disease. It is usually diagnosed if one or more of following conditions occur.
- Pain awakens the patient or occurs at rest.
- A patient who has never experienced angina but is now having severe or moderate pain during mild exertion within last two months.
- Stable angina has progressed in severity, frequency and duration or medications are less effective in relieving pain.
Stable angina: It is extremely painful situation, more predictable course and less serious than unstable angina. It is usually relieved by rest and responds well to medical treatment especially nitrates which can be kept below the tongue. Any event that increases oxygen demand can cause an anginal attack. Some typical triggers include exercise, cold weather, emotional tension and heavy meals.
Unstable angina is usually described as part of a condition called acute coronary syndrome (ACS). It also includes patients with condition called NSTEMI (non ST-segment elevation myocardial infarction) also referred to non-Q - wave heart attack. In this ECG and blood tests suggest a developing heart attack. These conditions are less severe than heart attack but may develop into full-blown attacks without aggressive treatment. Full-blown heart attacks are usually called ST elevation myocardial infarction.
Indicators of heart attack:
Anyone who believes he or she is having heart attack should not hesitate to contact emergency medical services. People with known heart disease, any unusual chest pain or other symptoms of heart attack which are not clearing up with routine medications are warning signals to go to the hospital. The severity of pain and specific symptoms before heart attack vary greatly among individuals and onset may be abrupt, gradual or intermittent.
Chest pain is the most common indicator and clinical expression of heart disease. People with risk factors for heart disease or having heart disease should be very particular about any chest pain. It is usually precipitated with exercise or stress and interrupts normal activities and does not clear up after taking rest and routine heart medicine. It may be experienced as crushing weight against chest with profuse sweating. Pain may radiate to left shoulder, arm, neck or jaw. Some may have sense of fullness, squeezing or pressure over the chest. People may also experience nausea, vomiting, cold sweats, indigestion, heart burn, abdominal pain, fainting and a great fear of impending doom i.e. angor animi. Nearly half of the patients may not have chest pain, they may present with shortness of breath and cardiac arrest.
Some people with severe coronary artery disease may not experience angina, this condition is called silent ischaemia. It may be due to abnormal processing of heart pain by the brain. It is a dangerous condition because patient has no warning signs of heart disease.
Symptoms that are less likely to indicate a heart attack:
Sharp pain brought on by respiration/coughing. Pain mainly in lower or middle abdomen. Pain is pin pointed with tip of one finger, pain reproduced by moving or pressing on chest wall/ arms. Very brief pain lasting few seconds.
What actions need to be taken at onset of symptoms?
- Take nitroglycerin as spray or sublingual tablet and repeat after 5 minutes maximum upto 3 doses.
- Immediately call or reach emergency services, do not deceive yourself.
- Chew a tablet of aspirin
Dr TP SinghChief Consultant Cardiologist,SGHS Hospital, MohaliE-mail id: firstname.lastname@example.orgMobile No : 09872421946