Heart Attack (Myocardial Infraction)
Heart attack or myocardial infarction is the term used when the cardiac muscles are not receiving adequate oxygen. This can cause a wide range of symptoms, the most common of which is squeezing pain that feels like pounds of pressure felt on the left side. This would radiate to the left shoulder, neck and jaw. Numbness and tingling sensation may also be felt by some. However, one may suffer from a heart attack without having symptoms at all. This is referred to as ‘silent’ heart attack.
Heart attack is the leading cause of cardiovascular mortality rate in the United States for both genders. Around 1.5 million Americans suffer from the condition each year. Thirty percent of these incidents lead to death. A person who suffers from the disease will contract irreversible damage to the heart.
Angina pectoris is often mistaken to be a heart attack. Although both are caused by lack of oxygen in the heart muscles, angina is a much less serious condition than the latter as the damage caused is often temporary and symptoms can be treated with nitroglycerin and rest.
Normal Anatomy and Physiology
The heart is a fist sized muscular organ designed to pump blood throughout the body. Blood is carried by the arteries, veins and network of capillaries to the different parts of the body. This brings in nutrients, oxygen and immune system functions. All of these are needed for an organ to function properly.
Deoxygenated blood returns to the heart. This is then directed to the lungs to be oxygenated. As the blood enters the lungs, oxygen combines with hemoglobin. Hemoglobin is a spherical shaped blood cell that carries the oxygen to be diffused all throughout the body.
Hemoglobin moves through the blood vessels. Blood vessels are critical for almost all health conditions. They also have a muscular layer which can either constrict or dilate to adjust the blood flow and permeability.
Blockage of the blood vessels is the most common cause of cardiovascular problems. This can be due to inflammation, blood clot or plaque formation. Inflammation can be from trauma, infection or auto-immune diseases. Inflammation causes increased permeability thus letting blood seep through the vessels leading to hemorrhage.
Blot clot can either be called an embolus or thrombus. Embolus is used when the clot is still moving through the vessels. It is called thrombus when it has lodged in a specific part of the vessel. Blood is not able to pass through the clot. This would mean the body part after the clot would not be able to receive proper blood circulation.
Plaque formation or arteriosclerosis is the build-up of fats, calcium and other minerals in the blood. This can be a partial or complete obstruction. Severity of symptoms is directly dependent on this factor.
Heart attack can be mistaken for several other uncomplicated conditions because of its vague symptoms. Series of examinations should be undertaken to identify the proper treatment and medications to be used. Here are the most commonly done tests during admission:
• Complete medical and family history. Smoking, alcohol consumption, poor diet, stress and sedentary lifestyle are certain factors that lead to cardiovascular diseases. Family history and medical background can also be predisposing factors.
• Physical examination. This helps the physician assess the person’s current health status. Symptoms should be clearly defined and pinpointed to avoid misdiagnosis.
• Blood chemistry tests. Series of blood tests are drawn to determine the extent of cardiac muscle damage. Cardiac enzymes are released as damage is done. During a ‘true’ heart attack, troponin, creatine krinase and myglobin are significantly increased.
• Electrocadiogram. This device can measure the electric activities of the heart through a 12-lead external electrode. ECG has Q, R, S and T peak levels. A change from those could give a clue as to where the blockage is located. The most dangerous heart attacks are those with ST elevations.
• Echocardiogram. This makes use of ultrasound waves to visualize the heart structures. This can either be done externally or internally. Transesophageal scope is used to further assess the heart’s valve and other structures.
• Coronary Angiography. A catheter is introduced to the heart and dye is released. X-ray will then be used to assess the concentration and distribution of the heart. The dye will outline the blood vessels. An uneven concentration can mean blockage or change in structure.
• Exercise Stress Test. This test is done on a treadmill or bike. The patient is connected to an ECG at all times. The level of difficulty is gradually increased and heart responses are carefully monitored. This is also done prior to discharge to assess effectiveness of treatment therapy.
Treatments and Medications
Over the years, mortality rate has decreased due to extensive researches and medical breakthroughs. Treatments became more accessible to everyone. Depending on the current symptoms of the patient, treatment is highly personalized to improve full recovery from the condition.
Medications used include anti-platelet, anti-coagulant, clot-dissolving drug, nitrates, ACE inhibitors and Beta-blockers. Each would have a significant use to assist recovery from heart attack.
Anti-platelet and anti-coagulant drug therapy is to avoid further formation of blood clots anywhere in the body. If clots are already present, a clot-dissolving medication can be prescribed. Aspirin is commonly used as a drug of choice for myocardial infarction. This is a blood-thinning agent to promote ease of blood flow.
The other medications are used to control abnormal heart rhythms reflected in the ECG. The most common nitrates used are the nitroglycerin. It works by relaxing the muscles, including those of the heart, and cause vasodilatation. Its main aim is to lessen the severity of the heart attack. Vasodilatation opens and prevents spasm of the arteries, decreases heart workload and reduces oxygen consumption. All these greatly improve overall blood circulation.
ACE inhibitors and Beta-blockers are given to lessen heart workload. These also decrease low blood pressure and relieve stress. They are given to basically assist in fast healing of the heart muscles’ damages.
Surgeries that can be undertaken are Angioplasty, Stenting and Coronary Artery Bypass Grafting (CABG). The first two are done if blockage is minimal and can just be opened to let the blood pass through. CABG is rerouting the blood flow of the blocked artery. Patients are discharged after 5 to 7 days or when the condition stabilizes.
Switching to a healthier lifestyle and avoiding stress are the best ways to prevent suffering from another heart attack. Find out more information about heart surgery.