advertisement
11 March 2013

Heart attack - from Natural Standard

A heart attack, or myocardial infarction (MI), occurs when the supply of blood and oxygen to an area of heart muscle is blocked.

0

BACKGROUND

A heart attack, or myocardial infarction (MI), occurs when the supply of blood and oxygen to an area of heart muscle is blocked.

A clot (or thrombus) is the final product of the blood coagulation (thickening). Specifically, a thrombus is a blood clot in an intact blood vessel. A thrombus in a large blood vessel will decrease blood flow through that vessel. In a small blood vessel, blood flow may be completely cut-off resulting in the death of tissue supplied by that vessel (as in a heart attack). If a thrombus dislodges and becomes free-floating, it is an embolus.

The clot can partially block the flow of blood in the arteries of the heart, causing a lack of oxygen to the heart muscle tissue (called ischemia). If the clot completely stops the blood flow in an artery in the heart (called coronary artery), then a heart attack develops. If treatment is not started quickly, the affected area of heart muscle begins to die. This injury to the heart muscle can lead to serious complications, and can even be fatal. It is possible to survive a heart attack, but part of the heart muscle may be damaged, causing shortness of breath, chest pain on exertion or at rest, and increases the potential to have another heart attack. It is very important if an individual has had a heart attack in the past to follow doctor's advice in preventing another one.

The survival rate for US patients hospitalized with a heart attack is approximately 90 to 95%. This represents a significant improvement in survival and is related to improvements in emergency medical response and treatment strategies.

In general, a heart attack can occur at any age, but its incidence rises with age and depends on pre-disposing risk factors. Approximately 50% of all heart attacks in the United States occur in people younger than 65 years of age, but as the baby boomers age, this percentage will probably lean toward over 65.

Sudden death from a heart attack can occur due to an arrhythmia (irregular heartbeat or rhythm) called ventricular fibrillation. If an individual survives a heart attack, the injured area of the heart muscle is replaced by scar tissue. This weakens the pumping action of the heart and can lead to heart failure (inability of the heart to pump blood throughout the body) and other complications including fatigue (tiredness), fluid buildup in the feet, ankles, or around the lungs (which makes it hard to breathe).

Heart attack is the leading cause of death in the United States (U.S.) as well as in most industrialized nations throughout the world. Approximately 800,000 people in the U.S. are affected annually, and 250,000 die prior to arrival to a hospital. Approximately every 65 seconds, an American dies of a heart related medical emergency. The World Health Organization (WHO) estimated that in 2002, 12.6% of deaths worldwide were from ischemic heart disease (lack of oxygen to the heart).

There are several types of heart attacks. Acute coronary syndrome is a name given to three types of coronary artery disease that are associated with sudden rupture of plaque inside the coronary artery: unstable angina, non-ST segment elevation myocardial infarction (NSTEMI), or ST segment elevation myocardial infarction (STEMI). The location of the blockage, the length of time that blood flow is blocked, and the amount of damage that occurs determines the type of acute coronary syndrome.

Unstable angina: Unstable angina (chest pain) can occur more frequently, occur more easily at rest, feel more severe, or last longer than stable angina. Although this angina can often be relieved with oral medications, it is unstable and may progress to a heart attack. Usually more intense medical treatment or a procedure is required. Unstable angina is an acute coronary syndrome and should be treated as a medical emergency.

Non-ST segment elevation myocardial infarction (NSTEMI): This heart attack (myocardial infarction) does not cause changes on an electrocardiogram (ECG). However, chemical markers in the blood indicate that damage has occurred to the heart muscle (including c-reactive protein, creatine kinase-MB (CK-MB) and troponin). In NSTEMI, the blockage may be partial or temporary, and so the extent of the damage to the heart is relatively minimal.

ST segment elevation myocardial infarction (STEMI): This heart attack is caused by a prolonged period of blocked blood supply (ischemia). It affects a large area of the heart muscle, and so causes changes on the ECG as well as in blood levels of the key chemical markers.

Atherosclerosis: Atherosclerosis is the hardening and narrowing of the arteries. It is caused by the slow buildup of plaque on the inside of walls of the arteries. Arteries are blood vessels that carry oxygen-rich blood from the heart to other parts of the body. Plaque is made up of fat, cholesterol, calcium, and other substances found in the blood. As it grows, the buildup of plaque narrows the inside of the artery and, in time, may restrict blood flow.

Coronary artery disease (CAD): Coronary artery disease (CAD), also known as coronary heart disease (CHD), occurs when the coronary arteries gradually become narrowed or blocked by plaque deposits. This can lead to a heart attack.

Unfortunately, sometimes a heart attack is the first sign of coronary artery disease (CAD). According to the Framingham Heart Study, over 50% of men and 63% of women who died suddenly of CAD (mostly from heart attack) had no previous symptoms of this disease.

Some individuals who have CAD and insufficient blood flow to the heart muscle (ischemia) do not have any symptoms. This is called "silent ischemia." In rare instances a patient may have a "silent heart attack," which is a heart attack without symptoms.

RISK FACTORS

High Blood Cholesterol: Cholesterol is a major component of the atherosclerotic plaque (particles of blood, cholesterol, and protein that "clump") that leads to blocked arteries in the heart. These blockages may lead to a heart attack. An elevated level of total cholesterol is associated with an increased risk of coronary atherosclerosis (hardening of the arteries) and heart attack. Laboratory testing provides a measure of certain types of circulating fat particles. Elevated levels of low-density lipoprotein (LDL or bad cholesterol) are also associated with an increased incidence of both atherosclerosis and heart attack. Total cholesterol levels should be below 200mg/dl.

Diabetes Mellitus: Individuals with diabetes have a substantially greater risk of a heart attack because it adversely affects blood cholesterol levels and increases the rate of plaque buildup.

Hypertension: High blood pressure, or hypertension, has consistently been associated with an increased risk of heart attack.

Smoking: Certain chemicals present in tobacco, or that are inhaled after lighting tobacco, are known to damage blood vessel walls. The body's response to this type of injury elicits the formation of coronary artery disease (CAD). CAD causes less oxygen to get to heart muscle tissue (ischemia) and eventually will lead to a heart attack.

Male Gender: The incidence of coronary artery disease (CAD) and heart attack is higher in men than women in all age groups. This gender difference in heart attack incidence, however, narrows with increasing age. Risks for heart attack increase in men over the age of 45 and women over the age of 55. The natural estrogen produced by the body protects women from heart disease before menopause. As levels of estrogen decline, the incidence of heart disease increases.

Family History: A family history of coronary artery disease (CAD) increases an individual's risk of a heart attack.

Age: Age may also increase the risk of having a heart attack. Statistics point to the fact that 83% of people who die from heart disease are 65 years of age or older.

Previous history: Having a previous history of angina (chest pain), a previous heart attack, or a surgical procedure such as angioplasty (the insertion of a catheter into the blood vessels and to the heart) may increase the risk of having a heart attack.

Obesity: A high body mass index (BMI), or a high amount of body fat, increases the chances of developing high blood pressure, heart disease, atherosclerosis (hardening of the arteries), and diabetes, all of which increase risk factors associated with a heart attack.

Elevated homocysteine and C-reactive protein: The amino acid homocysteine occurs naturally in the body, but elevated levels have been linked with a high risk of heart disease and heart attack. When atherosclerosis (hardening of the arteries) damages arteries around the heart, they become inflamed, which triggers C-reactive protein production.

Medications: Certain medications may increase the risk of developing a heart attack, such as hormonal replacement therapy (HRT) that contains estrogen. For a long time, it was thought that HRT reduced the risk of heart disease. However, research has found that women who have had a recent heart attack or a stroke are more likely to have a second heart attack or stroke (lack of blood supply to the brain) if they start taking HRT. For this reason, starting HRT is not recommended for women with cardiovascular disease. In addition, even healthy women who begin HRT (at least with Prempro©, an estrogen/progesterone combination) may have a slightly increased risk of heart attack or stroke in the first year or two of therapy.

CAUSES

The World Health Organization (WHO) states that 49% of heart attacks worldwide are caused by high blood pressure.

Health conditions: Underlying health conditions can contribute to the development of a heart attack. These include emotional stress, anger, exposure to cold, exertion from exercise or sex, anemia (low iron and oxygen in the blood), coronary heart disease , atherosclerosis (hardening of the arteries), coronary thrombosis (blood clots), embolus (blood clot that comes loose and travels in the bloodstream) arrhythmias (irregular heart beat), Fabry's Disease (genetic disease leading to blood vessel damage), hyperlipidemia (high levels of fat in the blood), electrolyte imbalance (minerals such as potassium and sodium are off balance), shock, severe injury, sleep apnea (pauses in breathing during sleep), hemorrhage (blood loss), electrocution, anaphylactic shock (allergic reaction that affects the entire body), hypoxia (lack of oxygen such as in suffocation), and respiratory failure (not enough oxygen getting into the bloodstream from the lungs).

Medications: Certain medications may cause a heart attack, including high-dose oral contraceptives such as Necon 1/50©, Norinyl 1/50©,Ortho-Novum 1/50©, and Yasmin© (due to an increase of blood clots), short-acting nifedipine (Procardia©) a calcium channel blocker for high blood pressure that was found to increase risk of heart attack for some patients on high doses), ribavirin (Copegus©; Rebetol©; Ribasphere©; Vilona©, Virazole©, anti-viral drugs), and Pegatron© (combination of ribavirin and peginterferon alfa-2b - an immune system agent). Amphetamines, cocaine, methamphetamine, ecstasy, ephedra, and caffeine are stimulants and may also cause a heart attack.

SIGNS AND SYMPTOMS

Classical symptoms of a heart attack (myocardial infarction) in men include chest pain or pressure (heaviness), jaw pain, or extension of pain into the arms or shoulder, especially the left arm, unexplained shortness of breath, unexplained sweating, heartburn or feeling of indigestion, nausea or vomiting, back pain or upper abdominal pain, general lethargy (tiredness), heart palpitations (irregular heart beat), anxiety, and a sudden feeling of illness.

The most common symptoms of heart attack (myocardial infarction) in women include shortness of breath, weakness, and fatigue. A study found that many women reported warning symptoms one month before having a heart attack. Only 30% of women reported chest pain, which the majority of men report. Although women may not have the classical symptoms of a heart attack, they should call 911 immediately if symptoms are present.

Unfortunately, sometimes a heart attack is the first sign of coronary artery disease (CAD). According to the Framingham Heart Study, over 50% of men and 63% of women who died suddenly of coronary artery disease (mostly from heart attack) had no previous symptoms of this disease.

Approximately one fourth of all myocardial infarctions are silent, without chest pain or other symptoms. Silent heart attacks can occur more frequently in people with diabetes. Symptoms of a silent heart attack can include discomfort in the chest, arms or jaw that seems to go away after resting, shortness of breath and tiring easily. The most common complaints of visitors to the emergency room are chest pain (angina) and shortness of breath.

The symptoms of angina (chest pain) can be similar to the symptoms of a heart attack. Angina may lead to a heart attack.

A heart attack is a process that continues over several hours, unless death occurs.

DIAGNOSIS

What to do if a heart attack is happening: The most important thing to do if an individual thinks they are having heart attack symptoms is to call an ambulance (911) or get to a hospital emergency room as quickly as possible (someone other than the victim must drive). It is important to stop whatever is going on and sit or lie down. If nitroglycerin has been prescribed, place one tablet under the tongue as soon as possible. One tablet under the tongue every five minutes for three doses can be tried (if no relief with the first one). Also, crush or chew a full-strength aspirin (325 milligrams, swallow with a glass of water) to prevent further blood clotting.

Do not minimize the symptoms of a heart attack and do not delay calling for help (911). Waiting more than fifteen minutes to see if the pain goes away can result in permanent damage to the heart, and can even result in death. It is illegal for a hospital to refuse a person having a medical emergency, regardless of their ability to pay.

If a heart attack is in the middle of happening, the hospital staff will initiate medications described in the "Treatment" section below.

Diagnosis of a heart attack includes electrocardiogram (ECG), echocardiogram, blood tests, nuclear scan, or coronary angiography.

Electrocardiogram (ECG): The ECG test detects the electrical activity of the heart and records each heartbeat (called waves) on a graph. It is safe and painless, and it takes only a few minutes. An ECG is performed by taping electrodes on the arms, legs, and chest. The electrodes pick up the electrical impulses of the heart from different points of view in the chest. ECG abnormalities diagnostic of heart attack are sometimes seen early in a heart attack, but the ECG may be normal at first and need to be repeated. Sometimes existing ECG abnormalities may make the diagnosis difficult.

Echocardiogram (echo): This is an ultrasound examination of the heart. The ultrasound device uses sound waves to create a detailed "picture" of the heart, which is then transmitted to a video monitor. This test is safe, noninvasive, and very helpful. A wand is used that is rubbed over the heart area. The chest is lubricated with petroleum jelly so the wand slides easily over the area. Echo may show problems in the heart structure, such as abnormalities in the movements of the heart wall (a heart attack damages the heart wall). It can show abnormal enlargement or pouching of the heart wall (aneurysm). Echo may also visualize complications of heart attack, such as valve problems, rupture of the heart muscle, or accumulation of fluid in the cardiac sac (pericardial effusion). The most important information obtained from the echo is the ejection fraction. This is a measurement of the strength of heart muscle. This information may be used to help predict outcome and to decide on treatment after a heart attack

Blood tests: Blood tests include blood cell counts, as well as measurements of electrolytes (sodium, potassium, calcium, magnesium, and other minerals), blood chemistry, homocysteine and/or C-reactive protein (both markers of inflammation), and coagulation (clotting) function (fibrinogen). A blood test will be done to check for enzymes (proteins that start chemical reactions in the body) or other proteins that are released when heart cells begin to die. These are "markers" of the amount of damage to the heart. The two most measured enzymes are creatine phosphokinase (CPK) and troponin.

Creatine phosphokinase, or creatine kinase (CK), is released from the heart muscle cells as they die and as their membranes dissolve. The level of the CPK enzyme (specifically the MB subform of the enzyme) takes a number of hours after the beginning of the heart attack to peak. It returns to normal by 24 hours after the beginning of the heart attack.

Troponin-I and troponin-T are also used to determine if a heart attack has occurred. The levels of these enzymes rise by 6 - 8 hours after the heart attack begins and remain elevated above normal for as long as a week. To some extent, the level of troponin can predict the likelihood of complications for an individual that has experienced a heart attack. The levels may also be helpful in deciding what treatments should be used.

Myoglobin test checks for the presence of myoglobin (a protein found in muscle tissue) in the blood. Myoglobin is released when the heart or other muscle is injured.

Cardiac stress test: A stress test determines how well the blood is flowing to the heart during exercise compared to resting. The patient either walks on a treadmill or is given IV medication that simulates exercise (usually dipyridamole or Persantine©) while connected to an electrocardiograph (ECG) machine. The exercise stress test is about 60-70% accurate in predicting increased risk of future heart attacks.

Nuclear scans: These tests shows areas of the heart that lack blood flow and are damaged. They also can reveal problems with the heart's pumping action. RVG's (radionuclide ventriculograms) also known as MUGA's (multiple gated acquisition) are the radionuclear tests (tests using radioactive materials) normally performed. A small amount of radioactive material (usually technetium-99m or Tc-99m) attached to a carrier (a substance that will travel to a particular organ, such as the heart) is injected into a vein, usually in the arm. The radioactivity and carrier then travels to the heart, and a scanning camera positioned over the heart records whether the nuclear material is taken up by the heart muscle or not. This determines if there are blockages in blood flow within the heart muscle. Like the exercise stress test, pictures are obtained with exercise on the treadmill and then with rest. The camera also can evaluate how well the heart muscle pumps blood. This test can be done during both rest and exercise, enhancing the usefulness of its results. This test is quite accurate in diagnosing coronary artery blockage. The small amount of radioactivity used in the test is not considered to be harmful.

Coronary angiography: A coronary angiography test is used to check blockages and narrowed areas inside coronary arteries. A fine tube is threaded through an artery of an arm or leg up into the heart. A dye that shows up on X ray is then injected into the blood vessel, and the vessels and heart are filmed as the heart pumps. The picture is called an angiogram or arteriogram. It often is performed for people with persistent pain and those who have not received "clot-busting" drugs to re-open their blocked artery. Coronary angiography is an invasive test with potentially serious complications, but when performed by an experienced doctor, the risk of complications is relatively small. An angiogram is the best test to determine what treatment is most appropriate: medication, angioplasty (the mechanical widening of a narrowed or totally obstructed blood vessel), stent (a wire mesh that expands inside a blood vessel - may contain anti-clotting drugs) placement, or bypass surgery.

COMPLICATIONS

The lack of blood flow to the heart can lead to irreversible damage to the heart muscle. Invasive surgery may be required (coronary artery bypass graft surgery or CABG). Death that occurs suddenly after the onset of a heart attack is most often due to unstable electrical rhythms, specifically ventricular tachycardia and ventricular fibrillation, which do not allow the pumping chamber of the heart (ventricle) to pump efficiently and use up its supply of oxygen. This event can be rapidly reversed with the use of medications or shocks from a defibrillator.

Other complications from a heart attack include heart blocks, congestive heart failure (the inability of the heart to fill with or pump a sufficient amount of blood to the body), cardiogenic shock (inadequate circulation of blood due to primary failure of the ventricles of the heart to function effectively), infarct extension (an increase of the amount of affected heart tissue), pericarditis (inflammation around the lining of the heart), pulmonary embolism (blood clot in the lungs), valve problems, rupture of the heart muscle, or accumulation of fluid in the cardiac sac (pericardial effusion).

TREATMENT

A heart attack is a medical emergency that demands immediate attention. The faster an individual is treated in the acute phase of a heart attack, the greater the ability to prevent further complications. As time passes, the risk of damage to the heart muscle increases. If an individual thinks they are having a heart attack based on the symptoms described, call 911 emergency immediately. Not seeking medical attention can cause serious damage to the heart muscle and even death.

First line treatment: After a heart attack victim is brought to the hospital, oxygen will be started, 160 - 325 milligrams of aspirin will be given immediately, nitroglycerin (which dilates blood vessels and allows more oxygen to the tissue) will be given under the tongue or intravenously (in the veins), and analgesia (usually morphine) will be given intravenously. In many areas, first responders can be trained to administer these prior to arrival at the hospital.

Thrombolytic therapy: Thrombolytic therapy, also known as clot busting, is indicated for the treatment of ST segment elevation myocardial infarction (STEMI). Clot busting is used if the drug can be administered within 12 hours of the onset of symptoms, the patient is eligible based on exclusion criteria, and primary percutaneous coronary intervention (PCI) is not immediately available. The effectiveness of thombolytic therapy is highest in the first two hours after a heart attack. Twelve hours after a heart attack, the risk associated with thrombolytic therapy, such as bleeding and stroke, outweighs any benefit. Because irreversible injury to the heart muscle occurs within two to four hours of the heart attack due to a lack of blood flow and oxygen, there is a limited window of time available for reperfusion to work.

Thrombolytic drugs are not used for the treatment of unstable angina, NSTEMI, and for the treatment of individuals with evidence of cardiogenic shock (primary failure of the ventricles of the heart to function effectively).

Currently available thrombolytic agents include streptokinase, urokinase, and tissue plasminogen activator (tPA or Alteplase©). More recently, thrombolytic agents similar in structure to tPA such as reteplase (Retavase©) and tenecteplase (TNKase©) have been used. These newer agents are easier to administer than tPA. However, all these agents are very expensive. If tPA and related agents are used, other anticoagulation (blood thinning) with heparin or low molecular weight heparin is needed to keep the coronary artery open. Because urokinase and streptokinase have anticoagulant activity, heparin use is less necessary when using these thrombolytic agents.

Thrombolytic therapy is not always successful, and has a 10 - 20% failure rate. If the thrombolytic agent fails to open the infarct-related coronary artery, the patient is then either treated with anticoagulants or percutaneous coronary intervention (PCI) is then performed. Complications, particularly bleeding, are significantly higher with rescue PCI than with primary PCI due to the increase bleeding associated with the thrombolytic agent.

Percutaneous coronary intervention (PCI): The use of percutaneous coronary intervention as a therapy to stop a myocardial infarction (heart attack) is known as primary PCI. The goal of primary PCI is to open the artery as soon as possible, preferably within 90 minutes of the individual coming to the hospital. This time is referred to as the door-to-balloon time. Few hospitals can provide PCI within the 90 minute interval. The current guidelines in the United States restrict primary PCI to hospitals with available emergency bypass surgery as a backup, but this is not the case in other parts of the world. Primary PCI involves performing a coronary angiogram (injection of dye and then an X-ray to look at the blood vessels) to determine the location of the blocked vessel, followed by balloon angioplasty (the mechanical widening of a narrowed or totally obstructed blood vessel) and frequently deployment of a stent (an expandable wire mesh that is placed in a blocked coronary artery and opened - sometimes contains anticoagulant drugs). While the use of stents does not improve the short term outcomes in primary PCI, the use of stents is widespread because of the decreased rates of procedures to treat restenosis (re-clogging) compared to balloon angioplasty. Other therapies used during primary PCI include intravenous heparin, aspirin, or clopidogrel (Plavix©).

Glycoprotein IIb/IIIa inhibitors: Glycoprotein IIb/IIIa receptors on platelets (cells of the clotting system) bind to fibrinogen in the final common pathway of platelet aggregation. Antagonists (opposing) to glycoprotein IIb/IIIa receptors are potent inhibitors of platelet aggregation, and drugs include abciximab (ReoPro©), eptifibatide (Integrilin©), and tirofiban (Aggrastat©). The use of intravenous (IV) glycoprotein IIb/IIIa inhibitors during PCI and in patients with heart attack or acute coronary syndromes has been reported to reduce death and re-infarction (re-blockage). Side effects include an increase in bleeding.

Angiotensin converting enzyme inhibitors (ACEIs): Oral angiotensin converting enzyme inhibitors (ACEIs, such as lisinopril (Prinivil©, Zestril©)) dilate blood vessels and increase oxygen to the heart. ACE inhibitor therapy should be started 24 - 48 hours after a heart attack, particularly in patients with a history of heart attacks, diabetes mellitus, hypertension, anterior (front) location of infarct (blockage), and/or evidence of left ventricular dysfunction. ACEIs reduce mortality, the development of heart failure, and decrease ventricular remodeling (changes in size and shape of heart valves) after the heart attack. Contra-indications for ACEIs include hypotension (low blood pressure) and declining kidney function with ACEI use.

Coronary artery bypass graft surgery (CABG): Coronary artery bypass graft (CABG) surgery bypasses one or more blocked blood vessels by a blood vessel graft to restore normal blood flow to the heart. These grafts usually come from the patient's own arteries and veins located in the chest, leg, or arm. The graft goes around the clogged artery to create new pathways for oxygen-rich blood to flow to the heart. Some problems associated with CABG include a heart attack (occurs in 5% of patients), stroke (occurs in 5%, with the risk greatest in those over 70 years old), blood clots, death (occurs in 1-2% of individuals), and sternal wound infection (occurs in 1-4%). Infection is most often associated with obesity, diabetes, or having had a previous CABG. In about 30% of patients, "post-pericardiotomy syndrome" can occur anywhere from a few days to six months after surgery. The symptoms of this syndrome are fever and chest pain. This condition can be treated with medications. The incision in the chest or the graft site (if the graft was from the leg or arm) can be itchy, sore, numb, or bruised. Some individuals report memory loss and loss of mental clarity or "fuzzy thinking" following CABG.

Sometimes surgeons can perform open heart surgery without using a bypass pump and while the heart is beating (off-pump bypass surgery). The procedure causes fewer side effects than the standard procedure, but it is not practical in all situations. If just the front or right coronary arteries need bypass, a surgeon may replace the blocked artery with an artery from the chest via a small keyhole incision, without opening the chest, to detour the blockage (minimally invasive coronary bypass (MINI-CABS)). This procedure also decreases the many problems associated with conventional coronary artery bypass surgery.

Monitoring for arrhythmias: After a heart attack, monitoring for life-threatening arrhythmias (irregular heart beat) or conduction disturbances is performed in a coronary care unit in the hospital. The patient will be given a type of drug called an antiarrhythmic agent (such as amlodipine (Norvasc©) or diltiazem (Cardizem©)) if arrhythmias are found

Rehabilitation: Cardiac rehabilitation is a medically supervised program to help heart patients recover quickly and improve their overall physical and mental functioning. Cardiac rehabilitation is performed to optimize function and quality of life in those afflicted with a heart disease. This can be with the help of a physician, or in the form of a cardiac rehabilitation program. Physical exercise may have beneficial effects on cholesterol, blood pressure, weight, and stress and is an important part of rehabilitation after a heart attack. An exercise program will be given to the patient by their health care provider. Some individuals are afraid to have sex after a heart attack. Most people can resume sexual activities after three to four weeks. The amount of activity needs to be determined by the patient's healthcare provider.

Secondary prevention: The risk of a recurrent myocardial infarction decreases with blood pressure management and lifestyle changes, including stopping smoking, regular exercise, a sensible diet (more fresh fruits and vegetables and a decrease in red meats, junk food, saturated and trans fats), and limitation of alcohol intake (no more than two drinks daily). Medications including nitrates, antiplatelet drugs (aspirin), beta blockers, angiotensin converting enzyme inhibitors (ACEI), and statins are used commonly after a heart attack.

Nitroglycerin: Sublingual (under the tongue, tablets or spray), oral, or topical (on the skin) nitrates are given to individuals after suffering a heart attack. Nitrates dilate (expand) blood vessels and allow more blood and oxygen to flow to heart tissue. When taken sublingually or intravenously, nitroglycerin works rapidly. Clinical trial data support the initial use of nitroglycerin for up to 48 hours in heart attack. There is little evidence that nitroglycerin provides substantive benefit as a long-term post-MI (after a heart attack) therapy except when severe pump dysfunction or residual ischemia (lack of blood flow and oxygen) is present. Nitrate tolerance (when nitrates no longer work as well) can be overcome either by increasing the dose or by providing a daily nitrate-free interval of 8 - 12 hours. Side effects include hypotension (low blood pressure) and headache.

Antiplatelet drug therapy: Antiplatelet drugs such as aspirin and/or clopidogrel (Plavix©) should be continued to reduce the risk of plaque rupture and recurrent myocardial infarction. Aspirin is used for first-line treatment (meaning immediately) owing to its low cost and comparable efficacy (effectiveness), with clopidogrel reserved for patients intolerant of aspirin. The combination of clopidogrel and aspirin may further reduce risk of heart attack; however the risk of hemorrhage (bleeding) is increased. Side effects include many drug interactions and an increased risk of bleeding.

Beta blockers: Beta blocker therapy such as metoprolol (Lopressor©, Toprol©) or atenolol (Tenormin©) should be started. These have been particularly beneficial in high-risk patients such as those with left ventricular dysfunction and/or continuing cardiac ischemia (lack of blood flow and oxygen). They also improve symptoms of cardiac ischemia (lack of oxygen and blood flow to the heart) in non-ST segment elevation (NSTEMI, a type of arrhythmia). Side effects associated with beta blockers include insomnia, loss of sexual drive, and tiredness (fatigue).

Statin drugs (HMG-CoA reductase inhibitors): Statins, such as atorvastatin (Lipitor©) or lovastatin (Mevacor©), help lower cholesterol levels and have been reported to reduce mortality and morbidity after a heart attack. Statin use may cause liver problems or muscle pain, and can deplete coenzyme Q10 (CoQ10) levels.

Other medications: The aldosterone antagonist agent eplerenone (Inspra©) has been reported to further reduce risk of cardiovascular death after a heart attack in patients with heart failure and left ventricular dysfunction, when used in conjunction with standard therapies such as antiplatelet drugs and statins. Aldosterone is a hormone associated with sodium and potassium balance and fluid retention.

Fish oil: Omega-3 fatty acids, commonly found in cold water fish (such as salmon and halibut), have been reported to reduce death after a heart attack. However, further studies have not shown a clear-cut decrease in potentially fatal arrhythmias (irregular heart beat) due to omega-3 fatty acids. Fish oils may cause an increase in bleeding if taken with anti-platelet or anticoagulant medications.

Implantable cardiac defibrillators: Studies have found that Automatic Implantable Cardiac Defibrillators (AICD) in patients post-MI (after a heart attack) may be beneficial. A 31% risk reduction in all-cause mortality was found with the prophylactic (preventative) use of an AICD in patients post-MI with ejection fractions less than 30%. Cost therapy and benefits are weighed before a doctor uses this device.

Emerging therapies: Therapies in development for patients suffering from a heart attack include stem cell treatment and tissue engineering (growing healthy heart tissue).

PREVENTION

Control high blood pressure (hypertension): One of the most important things that can be done for prevention of a heart attack is to reduce high blood pressure. Blood pressure should be a systolic reading of 120, and a diastolic reading of 80 (120/80mmg Hg). Exercising, managing stress, maintaining a healthy weight, and limiting sodium (salt) and alcohol intake are all ways to keep blood pressure in check. Medications to treat hypertension, such as diuretics, angiotensin-converting enzyme (ACE) inhibitors and angiotensin receptor blockers may be used.

Lower cholesterol and saturated fat intake: Eating less cholesterol and fat, especially saturated fat, may reduce the amount of plaque (deposits) in the arteries. Most people should aim for a low density lipoprotein (LDL) level below 130mg/dL. If there are other risk factors for heart disease, the target LDL may be below 100mg/dL. If the individuals are at very high risk for heart disease, such as having a previous heart attack, an LDL level below 70mg/dL may be optimal. Statin drugs (HMG-CoA reductase inhibitors, such as lovastatin or Mevacor©) can be prescribed to help maintain healthy cholesterol levels.

Platetet inhibitors: Platelet inhibitors keep platelets from clumping together. In otherwise healthy men older than 50 years, aspirin 325 mg every other day prevents myocardial infarction (at a rate of 2 men per 1,000) but not stroke. In otherwise healthy women older than 45 years, aspirin 100mg every other day prevents ischemic stroke (at a rate of 3 women per 1 000) but not myocardial infarction. Aspirin may increase in the risk of gastrointestinal bleeding. Other platelet inhibitors include dipyridamole (Persantine©), ticlopidine (Ticlid©), and clopidogrel (Plavix©). A 15% relative risk reduction in vascular events (stroke, heart attack, and death) has been documented for aspirin compared with placebo.

Stop smoking: Smoking is a major risk factor for coronary artery disease and heart attack. Nicotine constricts blood vessels and forces the heart to pump harder. A buildup of carbon monoxide (CO) reduces oxygen in the blood and damages the lining of the blood vessels.

Control diabetes: Managing diabetes with diet, exercise, weight control and medication is essential. Strict control of blood sugar may reduce damage to the heart.

Flu shots: Flu shots for patients with chronic cardiovascular disease are now used routinely.

Weight control: Being overweight contributes to other risk factors of a heart attack, such as high blood pressure, cardiovascular disease, and diabetes. Weight loss of as little as 10 pounds may lower blood pressure and improve cholesterol levels.

Exercise: Exercise can lower blood pressure, increase the level of HDL cholesterol (good cholesterol), and improve the overall health of blood vessels and heart. It also helps control weight, control diabetes and reduce stress. Thirty minutes daily of exercise is normally recommended.

Manage stress: Stress can cause an increase in blood pressure along with increasing the blood's tendency to clot. Managing stress can be vital to keeping a heart healthy.

Diet: Eat healthy foods. A brain-healthy diet should include five or more daily servings of fruits and vegetables, foods rich in soluble fiber (such as oatmeal and beans), foods rich in calcium (dairy products, spinach), soy products (such as tempeh, miso, tofu and soy milk), and foods rich in omega-3 fatty acids, including cold-water fish, such as salmon, mackerel and tuna. However, pregnant women and women who plan to become pregnant in the next several years should limit their weekly intake of cold-water fish because of the potential for mercury contamination. The U.S. Food and Drug Administration (FDA) has announced that whole grain barley and barley-containing products are allowed to claim that they reduce the risk of coronary artery disease.

Copyright © 2011 Natural Standard (www.naturalstandard.com)

 
advertisement

Get a quote

advertisement

Read Health24’s Comments Policy

Comment on this story
0 comments
Add your comment
Comment 0 characters remaining

Live healthier

Strenghten your immunity »

Keep your immunity strong Immune system boosters Boost your family's immunity

5 immune boosters in your kitchen

You don’t need a handful of vitamins and supplements to keep your body healthy, check out these five immune boosting foods you probably already have in your kitchen.

Laugh a little »

Eat yourself happy Laugh more and live longer Laughing yoga the best medicine

The healing power of laughter

A good chuckle doesn't only make you feel happy for a moment, it's beneficial to your health too.