Treatment of Heart Attack
- First aid during a heart attack
- Treatment by paramedics
- Emergency therapy in hospital
- Treatment of patients with cardiogenic shock
- Treatment of arrhythmias
- Treatment after a heart attack
The extent of damage to the heart cells and the number of complications during a heart attack largely depend on how fast the patient is hospitalized and treated. This is the reason why it is very important to seek medical attention as soon as you suspect that you or someone close to you might be having a heart attack. Proper treatment can make the difference between life and death of the patient.
If you noticed that you or someone close to you is experiencing symptoms described above, you should call an ambulance immediately.
Your next actions should be:
- Provide more fresh air by opening a window;
- If the person wears a tie or has a tight collar, untie/unbutton it, in order to allow for easier breathing;
- Help the person position themselves comfortably (half-sitting or lying position with an elevated head);
- Tell them to take a tablet of nitroglycerin and chew a tablet of aspirin if the person isn’t allergic to it (chewing the tablet will allow for it to be absorbed much faster).
If the person’s heart has stopped beating (you can notice this by seeing that the person is either not breathing or has agonal respiration (agonal respiration is a gasping, labored breathing, with strange vocalizations and myoclonus (involuntary twitching of various muscles), immediately start cardiopulmonary resuscitation (CPR). By doing this, you are greatly increasing the person’s chances of survival.
Once a team of paramedics has arrived the treatment begins:
- The person is hooked up to a heart monitor in order to allow the health care team to monitor the function of the heart.
- Oxygen is given in order to increase in the concentration of oxygen in the blood and decrease the amount of tissue damage caused by hypoxia.
- An intravenous line is placed in order to provide the person with all the necessary medicines and fluids.
- In order to reduce the pain, nitroglycerin is given. If this doesn’t help, morphine is administered. Not only does the morphine reduce the pain, it also dilates the blood vessels within the heart just like nitroglycerin does, aiding in blood circulation and oxygenation of the heart. Moreover, morphine slows down the heart and decreases blood pressure. The last two facts should be considered since, if the patient has a low blood pressure and is going into shock, morphine is contraindicated.
- Aspirin is given (if the person didn’t take one before the arrival of the ambulance).
- If the patient develops a life-threatening arrhythmia, it is immediately treated using antiarrhythmic drugs and a defibrillator.
- If the patient has a sudden cardiac arrest (the heart stops beating), a defibrillator should be used immediately. It can provide the necessary shock to make the heart start beating again. Use of defibrillator is combined with CPR until the patient’s heart starts beating again (this could take half an hour or even more, unlike what you see in the movies where they give up after a minute).
A heart attack occurs when a blood clot blocks the passage of blood through one of the coronary arteries. Removing this obstruction is the number one priority as it decreases cell damage and improves survival of the patient.
Angioplasty is the first and foremost choice for treating a heart attack. Also known as percutaneous coronary intervention (PCI), this technique should be performed in the first 90 minutes of arriving at the hospital (this is the time it takes for muscle tissues to die due to lack of oxygen) in order to achieve optimal results. The technique shouldn’t be performed if more than 12 hours have passed since the onset of the heart attack as it will not yield any results.
Angioplasty is performed in several steps:
First, a narrow catheter is threaded through the artery until it reaches the affected vessel.
- In order to open up the blocked vessel, the cardiologist inflates a balloon located on the end of the catheter. The pressure applied by the balloon on the walls of the artery open it up allowing for the blood to flow freely.
- In the majority of cases, a stent is then inserted into the affected region in order to keep the artery open. To clarify, a stent is a metal mesh tube that expands inside a coronary artery, helping to prevent it from closing up again.
In about 10% of the cases, this procedure is followed by complications, which usually appear within the first 24 hours.
Reclosure of the artery is the most common complication. Restenosis (reclosure) of the artery often occurs during or right after angioplasty. Sometimes it might occur after more than a year. This requires a repeated angioplasty. Drug-eluting stents coated with paclitaxel or sirolimus help prevent restenosis. However, if a person has a drug-eluting stent, an anticoagulant (aspirin or clopidogrel) should also be taken to reduce the risk of blood clots. If the patient cannot use aspirin and clopidogrel due to an allergy, then a bare-metal stent should be used instead of a drug-eluting one.
Thrombolytics are a class of drugs used to dissolve the clot. Therapy using these drugs should be done within the first 3 hours; however, ideally, they should be given within the first 30 minutes after arriving at the hospital if angioplasty is contraindicated. Other situations which call for the use of thrombolytics are:
- The patient cannot be brought to hospital immediately in order to perform PCI.
- PCI procedure is unsuccessful or too difficult to perform.
However, there are a number of conditions which can prevent the doctors from using thrombolytics:
- The patient is older than 75 years;
- The first symptoms of the heart attack appeared more than 12 hours ago;
- If the woman experiencing a heart attack is pregnant;
- The patient recently went through invasive surgery or experienced head trauma;
- The patient has active peptic ulcers;
- If the patient was receiving cardiopulmonary resuscitation (CPR) for a long period of time;
- If the patient recently had a major bleeding for any reason;
- If the ECG shows that ST segment is low;
- If the patient has an unmanaged high blood pressure, especially if the systolic blood pressure exceeds 180 mm Hg.
The most serious complication of thrombolytic therapy is hemorrhagic stroke. Fortunately, this condition is quite rare.
Coronary artery bypass graft surgery
This is a surgery that is occasionally used as a substitute for angioplasty. This operation is usually performed when the patient has 2 or more blocked arteries. This is a very invasive procedure:
- The chest cavity is opened
- During this operation the blood has to be rerouted to the lung-heart machine.
- The heart has to be stopped during the operation.
- Parts of veins or arteries taken from other places in the body are used to make grafts that will be used to reroute the blood. These grafts are connected to the coronary arteries in such a way that the blood may bypass the necrotic region.
Mortality rate when this procedure is used after a heart attack is 6%. It is controversial whether this procedure should be used after a heart attack.
People with heart failure or who go into cardiogenic shock should be closely monitored and treated accordingly until they stabilize.
Cardiogenic shock involves a sudden drop in blood pressure which can lead to disseminated intravascular coagulation – a very serious life-threatening condition. In order to treat cardiogenic shock, various drugs that increase the blood pressure should be used immediately. Moreover, an intra-aortic balloon counterpulsation can be used. This technique involves threading a catheter which contains a balloon into aorta, which is then deflated during a systole (a phase of the heart cycle during which the heart pushes the blood into the aorta) and inflated during a diastole (when the heart relaxes). This technique reduces the stress on the heart and increases the blood flow within the coronary arteries, effectively decreasing myocardial oxygen demand.
An arrhythmia is an abnormal heart beat pattern which can be triggered by a heart attack.
Ventricular fibrillation – is a life-threatening arrhythmia during which the ventricles quiver rather than contract, which makes them unable to pump the blood. Intravenous beta blockers are used in order to slightly reduce the chances of ventricular fibrillation. Currently, however, there is no medicine which can prevent ventricular fibrillation completely.
Treatment of ventricular fibrillation:
- Defibrillators. In order to restore the normal heart beat, a strong electrical current is passed through the heart using a device called defibrillator. The electrical current depolarizes all the cells of the heart at once, making them function in sync once again. Sometimes people who had a heart attack may have recurrent cases of ventricular fibrillation. In such a case, an implantable cardioverter-defibrillator is implanted into the person’s body which essentially does the same thing as the defibrillator.
- Antiarrhythmic drugs. Antiarrhythmic drugs which are used to quickly treat arrhythmias caused by a heart attack or similar condition, include lidocaine, procainamide, or amiodarone.
It is important to mention that people who had atrial fibrillation as a result of a heart attack have increased chances of having a stroke afterwards, which is why these patients are treated using anticoagulants. Bradyarrhythmias (very slow rhythm) may also develop as a result of a heart attack. In such a case, atropine or pacemakers can be used.
Any person who had a heart attack should take a number of medicines to prevent it from happening again. Some of these medications will have to be taken for the rest of the patient’s life. Additionally, if the person, without consulting a doctor, decides to stop taking some medicines, it could have very negative consequences.
A number of lifestyle changes should also be made, including:
- Smoking cessation (if the person is a smoker)
- Regular exercise
- Follow a healthy diet, rich in nutrients and proteins and low in simple carbs.
- Limiting alcohol consumption
- Antiplatelet drugs including clopidogrel and/or aspirin should be used to prevent recurrent myocardial infarction. Antiplatelet drugs work by decreasing platelet aggregation which inhibits thrombus formation. Clopidogrel is usually reserved for patients with intolerance to aspirin, since aspirin is a cheaper alternative with good performance. Combining those two drugs may be beneficial in some cases; however, it also increases the risk of hemorrhage.
- Beta blockers. Beta blockers slow down the heart rhythm, increasing the ejection fraction, and affect the renin-angiotensin system, effectively lowering the blood pressure. These drugs are beneficial for people with left ventricular dysfunction and/or cardiac ischemia. Beta blockers reduce symptoms of cardiac ischemia. They are also particularly useful for preventing a second heart attack.
- ACE inhibitors. These drugs work by inhibiting the angiotensin-converting enzyme. This lowers the levels of angiotensin, lowering the blood pressure by decreasing the tension of blood vessels. These drugs are prescribed to patients with a history of heart attacks, hypertension, left ventricular dysfunction and diabetes mellitus.
- Statins. This is a class of drugs markedthat lowers levels of low-density lipoprotein (commonly referred to as “bad” cholesterol), These drugs also stabilize plaques which helps prevent the recurrence of myocardial infarction.
- Anticoagulants. Anticoagulants prevent the coagulation of blood and dissolve blood clots that have already formed. Heparin in the most widely used anticoagulant. This drug decreases the recurrence of a heart attack; however, this drug greatly increases the chances of bleeding.
- Nitrates, the most prominent member of which is nitroglycerine, are used as vasodilators by people who suffer from chronic heart failure and angina pectoris. They work by being converted into nitric oxide in the blood stream which is a potent vasodilator.
- Diuretics. Diuretics are substances which increase the production of urine. This lowers the blood volume reducing the stress on the heart. Loop diuretics (such as furosemide) are commonly used for this purpose. However, if the heart failure is accompanied by low blood pressure, diuretics are contraindicated.
- Polyunsaturated fats (omega-3 fatty acids). There is evidence that suggests that polyunsaturated fats have the ability to decrease coronary heart disease. This claim is still debatable since studies in high-risk people have yielded unclear results.
Prognosis largely depends on the person’s initial health, area of necrosis and the treatment that was given. Generally, with adequate treatment, 5-6% of people who had a heart attack die before leaving the hospital, while 7-18% die within the first year. Additionally, people with low-risk factors are a lot less likely to die than people with high-risk factors.
High-risk factors include:
- Old age
- Hemodynamic parameters including cardiac arrest on admission, heart failure and high systolic blood pressure.
- Deviation of ST-segment on ECG
- Elevated serum creatinine
- Peripheral vascular disease
- Elevated cardiac markers
Assessing the left ventricular ejection fraction can also have a predictive power on the outcome.