A heart attack occurs when the flow of blood to the heart is blocked, most often by a build-up of fat, cholesterol and other substances, which form a plaque in the arteries that feed the heart (coronary arteries). The interrupted blood flow can damage or destroy part of the heart muscle.
A heart attack, also called a myocardial infarction, can be fatal, but treatment has improved dramatically over the years. It's crucial to call emergency medical help if you think you might be having a heart attack.
Common heart attack signs and symptoms include:
- Pressure, tightness, pain, or a squeezing or aching sensation in your chest or arms that may spread to your neck, jaw or back
- Nausea, indigestion, heartburn or abdominal pain
- Shortness of breath
- Cold sweat
- Lightheadedness or sudden dizziness
Heart attack symptoms vary
Not all people who have heart attacks have the same symptoms or have the same severity of symptoms. Some people have mild pain; others have more severe pain. Some people have no symptoms, while for others, the first sign may be sudden cardiac arrest. However, the more signs and symptoms you have, the greater the likelihood you're having a heart attack.
Some heart attacks strike suddenly, but many people have warning signs and symptoms hours, days or weeks in advance. The earliest warning may be recurrent chest pain (angina) that's triggered by exertion and relieved by rest. Angina is caused by a temporary decrease in blood flow to the heart.
A heart attack differs from a condition in which your heart suddenly stops (sudden cardiac arrest, which occurs when an electrical disturbance disrupts your heart's pumping action and causes blood to stop flowing to the rest of your body). A heart attack can cause cardiac arrest, but it's not the only cause.
A heart attack occurs when one or more of your coronary arteries become blocked. Over time, a coronary artery can narrow from the buildup of various substances, including cholesterol (atherosclerosis). This condition, known as coronary artery disease, causes most heart attacks.
During a heart attack, one of these plaques can rupture and spill cholesterol and other substances into the bloodstream. A blood clot forms at the site of the rupture. If large enough, the clot can completely block the flow of blood through the coronary artery.
Another cause of a heart attack is a spasm of a coronary artery that shuts down blood flow to part of the heart muscle. Use of tobacco and of illicit drugs, such as cocaine, can cause a life-threatening spasm. A heart attack can also occur due to a tear in the heart artery (spontaneous coronary artery dissection).
Certain factors contribute to the unwanted buildup of fatty deposits (atherosclerosis) that narrows arteries throughout your body. You can improve or eliminate many of these risk factors to reduce your chances of having a first or subsequent heart attack.
Heart attack risk factors include:
- Age - Men age 45 or older and women age 55 or older are more likely to have a heart attack than are younger men and women.
- Tobacco - Smoking and long-term exposure to secondhand smoke increase the risk of a heart attack.
- High blood pressure - Over time, high blood pressure can damage arteries that feed your heart by accelerating atherosclerosis. High blood pressure that occurs with obesity, smoking, high cholesterol or diabetes increases your risk even more.
- High blood cholesterol or triglyceride levels - A high level of low-density lipoprotein (LDL) cholesterol (the "bad" cholesterol) is most likely to narrow arteries. A high level of triglycerides, a type of blood fat related to your diet, also ups your risk of heart attack. However, a high level of high-density lipoprotein (HDL) cholesterol (the "good" cholesterol) lowers your risk of heart attack.
- Diabetes - Insulin, a hormone secreted by your pancreas, allows your body to use glucose, a form of sugar. Having diabetes — not producing enough insulin or not responding to insulin properly — causes your body's blood sugar levels to rise. Diabetes, especially uncontrolled, increases your risk of a heart attack.
- Family history of heart attack - If your siblings, parents or grandparents have had early heart attacks (by age 55 for male relatives and by age 65 for female relatives), you may be at increased risk.
- Lack of physical activity - An inactive lifestyle contributes to high blood cholesterol levels and obesity. People who get regular aerobic exercise have better cardiovascular fitness, which decreases their overall risk of heart attack. Exercise is also beneficial in lowering high blood pressure.
- Obesity - Obesity is associated with high blood cholesterol levels, high triglyceride levels, high blood pressure and diabetes. Losing just 10 percent of your body weight can lower this risk, however.
- Stress - You may respond to stress in ways that can increase your risk of a heart attack.
- Illegal drug use - Using stimulant drugs, such as cocaine or amphetamines, can trigger a spasm of your coronary arteries that can cause a heart attack.
- A history of preeclampsia - This condition causes high blood pressure during pregnancy and increases the lifetime risk of heart disease.
- A history of an autoimmune condition, such as rheumatoid arthritis or lupus - Conditions such as rheumatoid arthritis, lupus and other autoimmune conditions can increase your risk of having a heart attack.
Heart attack complications are often related to the damage done to your heart during a heart attack. This damage can lead to the following conditions:
- Abnormal heart rhythms (arrhythmias) - If your heart muscle is damaged from a heart attack, electrical "short circuits" can develop, resulting in abnormal heart rhythms, some of which can be serious, even fatal.
- Heart failure - OThe amount of damaged tissue in your heart may be so great that the remaining heart muscle can't do an adequate job of pumping blood out of your heart. Heart failure may be a temporary problem that goes away after your heart, which has been stunned by a heart attack, recovers. However, it can also be a chronic condition resulting from extensive and permanent damage to your heart following your heart attack.
- Heart rupture - Areas of heart muscle weakened by a heart attack can rupture, leaving a hole in part of the heart. This rupture is often fatal.
- Valve problems - Heart valves damaged during a heart attack may develop severe, life-threatening leakage problems.
Iit's never too late to take steps to prevent a heart attack — even if you've already had one. Here are ways to prevent a heart attack.
- Medications - Taking medications can reduce your risk of a subsequent heart attack and help your damaged heart function better. Continue to take what your doctor prescribes, and ask your doctor how often you need to be monitored.
- Lifestyle factors - You know the drill: Maintain a healthy weight with a heart-healthy diet, don't smoke, exercise regularly, manage stress and control conditions that can lead to heart attack, such as high blood pressure, high cholesterol and diabetes.
7 tests to diagnose heart diseases
With an increase in diseases related to lifestyle, patients are quite often made to undergo tests that are unnecessary.
- Blood Test - It’s the simplest tool to screen a patient for blood parameters such as lipid level and cholesterol that increase heart risk. Cost Rs. 1,000- Rs. 2,000.
- Electrocardiogram - It checks heart’s electrical system and rhythm. Finds out if chest pain is caused by a heart attack or angina. Rs . 300- 500. Patients who are asymptomatic and do not have an emergency condition should be fi rst screened for blood parameters and ECG rather than putting them through costlier tests.
- Echocardiogram - Helps check heart’s pumping efficiency and functioning of the valve. It is reasonable for heart risk assessment in asymptomatic adults with hypertension or diabetes. It is not recommended for asymptomatic adults without the conditions Rs. 1,500- Rs. 2,000.
- Exercise Stress Test - It is a screening tool used to test the effect of exercise on the heart. Doctors often combine it with regular ECG monitoring to follow electrical activity of the heart during the test for better results. Cardiologists say this is the most cost-effective test to assess heart risk in patients who come with unexplained chest pain or breathing difficulty. It does not involve exposure to any radiation.
- Thalium Stress Test - It is a nuclear imaging method that shows how well blood flows into the heart muscle, both at rest and during activity. It involves injecting radioactive isotope. Rs. 12,000 to Rs. 15,000.
- CT Angiogram - It is a non-invasive technique that uses X-rays to provide detailed pictures of the heart and the blood vessels that go to heart, lung, kidneys and other organs. It can show whether a blood vessel is blocked, where the blockage is, and how big the blockage is Rs. 12,000 to Rs. 15,000 The test is costly and exposes a patient to radiation. Doctors advise it should not be used in cases where initial tests such blood parameters or exercise stress test show heart risk.
- Coronary Angiography - It is an invasive technique that uses a special dye (contrast material) and x-rays to see how blood flows through the arteries in your heart. Though costly, angiography is one of the most definite tests to rule out heart disease Rs. 16,000 to Rs. 20,000. It is one the costliest diagnostic tools with radiation exposure. It should be used with caution and never as the primary tool to detect heart risk unless the person has suffered from heart attack or preliminary tests show vulnerability for the same.