Cardiac surgery, also called heart surgery, involves surgical operations performed on the heart under to correct life-threatening conditions. The surgery can be either open-heart surgery or minimally invasive surgery depending on the condition to be corrected.
The purpose of cardiac surgery is to improve the quality of life of the patient and to extend the patient's lifespan.
Cardiac surgery involves substantial risk and is only done when the benefits outweigh the risk. Risks are highest for infants under one year of age and adults over age 60. Risk increases with age and when the individual has other health problems such as diabetes, chronic kidney failure , chronic lung disease, pulmonary edema , congestive heart failure , electrolyte imbalances, alcoholism, and prior history of heart attack or stroke . Although few conditions absolutely rule out a cardiac procedure, the physician must judge the risks and benefits on an individual basis.
To understand how cardiac surgery works, it is helpful to know something about the anatomy of the heart. The heart is a muscle containing four compartments or chambers that separate oxygen-poor blood from oxygen-rich blood. The atria are the top chambers. They receive blood from the body. The ventricles are the bottom chambers. They pump blood out to the body. Oxygen-poor blood enters the right atrium, then moves through a valve to the right ventricle. It is then pumped out of the right ventricle to the lungs where it picks up oxygen. The oxygen-rich blood returns to the left atrium of the through the pulmonary vein, flows through a valve to the left ventricle, and is then pumped into the aorta. The aorta is the only artery carrying blood out of the heart. Smaller arteries branch off and carry blood to the rest of the body from this very large, thick, long artery. The first arteries to branch off the aorta are the coronary arteries. These carry a continuous supply of oxygen-rich blood to the heart.
Cardiac surgery is done to correct many different types of heart conditions. The most common are:
- congenital heart defects
- coronary artery disease
- aneurysm repair
- heart valve defects
- end-stage heart failure requiring heart transplantation
In general, for open-heart surgery under general anesthesia , the surgeon makes a 6–8 inch (10–15 cm) incision in the chest and then breaks the breastbone (sternum) to gain access to the heart. During many cardiac operations operation (i.e., coronary artery bypass surgery), the heart must be still (not beating) in order for the surgeon to operate, so the patient is put on a cardiopulmonary bypass or heart-lung machine. This machine keeps oxygen-rich blood flowing through the body while the heart is not pumping.
The surgeon then proceeds with the specific repair or replacement procedure. Once the operation is complete, the patient is removed from the heart-lung machine, and the heart is started beating again.
However, the patient is kept on a ventilator to aid in breathing. Once the heart is beating strongly, drains are inserted in the chest, the sternum is wired back together, and the chest wall is closed.
Minimally invasive surgery involves a smaller incision, the breastbone is not broken, and a heart-lung machine may or may not be necessary. Many heart valve repairs and treatments for arrhythmia can be done with minimally invasive surgery, as can about 20% of coronary bypass surgeries.
Diagnosis begins with a complete physical examination and a health, medication, and lifestyle history. Before undergoing cardiac surgery, the individual also will undergo a battery of diagnostic tests. Common tests to aid in the diagnosis of cardiac problems and assist in developing a treatment plan include:
- angiogram: an x-ray (radiographic) study of the blood vessels. An angiogram uses a radiopaque substance, or contrast medium, to make the blood vessels visible under x ray
- blood tests: check for anemia (low iron) and chemical (electrolyte) imbalances in the blood
- chest x ray: non-invasive test shows if fluid is building up in the lungs or if the heart is enlarged
- echocardiogram: non-invasive imaging test that produces a picture of the heart in motion as it beats; extremely helpful in showing heart and valve damage
- electrocardiogram (EKG): non-invasive test helps detect abnormalities in heart rhythm and heart health by measuring the electrical activity of the heart
- electrophysiologic mapping: diagramming the electrical activity by using a catheter that measures the heart's electrical activity at many different spots
- kidney function tests: help pinpoint the cause of fluid retention
- multiple-gated acquisition (MUGA) scan: imaging test that uses radioactive dye injected in the veins to produce a picture of blood circulation in the heart
- stress test: an electrocardiogram done while exercising or, for people who cannot exercise, while the heart is stimulated by medication
- transesophageal echocardiography: a diagnostic test using an ultrasound device that is passed into the esophagus of the patient to create a clear image of the heart muscle and other parts of the heart
QUESTIONS TO ASK YOUR DOCTOR
- Why do I need this type of heart surgery? Are there any alternatives?
- How much experience do you have performing this operation?
- How many of these operations are performed at this hospital each year? Is there a more experienced or better equipped hospital where I should have this operation?
- What are the risks involved?
- What can my family and I expect in terms of a normal recovery?
- Can you refer me to social services that may help me and my family during my recovery?
- What costs associated with this operation are covered by my insurance?
- If I do not have adequate insurance, are there any special programs to help me pay for this operation?
The level of aftercare depends on whether the procedure was open-heart or minimally invasive cardiac surgery. After open-heart surgery, the patient will spend a minimum of two days in the intensive care unit. Initially ventilator support is provided to help the patient breathe. Barring complications, the patient is usually able to breathe on his or her own about 24 hours after surgery. Complications will extend the stay in the ICU.
After leaving intensive care, most patients are moved to a special cardiac unit where heart monitoring continues. After heart function stabilizes (anywhere from several days to a week), the patient then moves to a regular hospital bed for a stay of anywhere from a few days to a few weeks. During this time, the patient is encouraged to walk and move, sees a physical therapist , a respiratory therapist, and is given information about the recovery process and necessary lifestyle changes such as quitting smoking , reducing stress , and eating a diet low in fats and high in fruits, vegetables and whole grains. The patient will also be prescribed drugs such as anticoagulants, beta-blockers, and statins that will most likely be taken long term.
After discharge from the hospital , barring complications, it takes one to three weeks to begin to feel better and two to three months to fully recover. The breastbone takes about 13 weeks to heal. During this time, activity may gradually be increased, and the patient is encouraged to participate in a structured cardiac rehabilitation program. The time period for recovery is roughly halved for minimally invasive surgery and doubled to tripled in the case of heart or heart-lung transplantation.
As with any surgery, there is a risk of excessive bleeding, infection, and a negative reaction to anesthesia. Other complications include the development of kidney failure, heart arrhythmias , heart attack, blood clot formation, and stroke during or soon after the procedure. Death is possible and occurs in about 3% of patients who have cardiac bypass surgery and valve replacement surgery. About half of people with ruptured aortic aneurysms do not survive even with emergency surgery. Death is rare in cardiac ablation . The risk of serious complication and death is higher in individuals with damaged heart muscle, diabetes, chronic lung disease, and chronic kidney failure.
Results vary with the type of cardiac surgery performed. Since cardiac surgery is usually done when conditions become life-threatening, most patients see an improvement in the quality of their life following recovery. For example, about 90% of people who have coronary artery bypass surgery feel complete relief from angina . The nine-year survival rate for people having mitral valve replacement is about 65% and 90% of people who have cardiac valve repair need no additional surgeries. Successful cardiac ablation can permanently cure a heart arrhythmia.
Cardiac surgery is performed a hospital, often in a special suite dedicated to cardiac surgery. Some hospitals such as the Cleveland Clinic in the United States specialize in open-heart surgery, technically difficult cardiac repair, and pioneering heart operations. The operating team usually consists of a lead cardiovascular or cardiothoracic surgeon, assisting surgeons, a cardiovascular anesthesiologist, a perfusion technologist to oversee the functioning of the heart-lung machine, and cardiovascular nurses. In addition, during the hospital stay, the patient may be cared for by ICU nurses, a respiratory therapist, physical therapist, occupational therapist, nutritionist , and cardiac rehabilitation educator, and a social worker.
Anticoagulant —Pharmaceuticals to prevent clotting proteins and platelets in the blood to be activated to form a blood clot.
Aorta —The main artery that carries blood from the heart to the rest of the body. The aorta is the largest artery in the body.
Atrium (plural Atria) —The right or left upper chamber of the heart.
Coronary arteries —These are the first arteries to branch off the aorta (the large artery leaving the heart). They take oxygen-rich blood to the heart muscle. Blockage of these arteries can cause atherosclerosis and heart attack.
Graft —To implant living tissue surgically. Also refers to the tissue that is transplanted.
Heart-lung or cardiopulmonary bypass machine —A machine that replaces the function of the heart and lungs during open heart surgery by diverting blood flow away from the right atrium, adding oxygen to the blood, and returning blood beyond the left ventricle, to bypass the heart and lungs. This allows the heart to stop beating during surgery.
Plaque —Fatty material that is deposited on the inside of the arterial wall.
Stent —A device made of expandable, metal mesh that is placed (by using a balloon catheter) at the site of a narrowing artery; the stent stays in place to keep the artery open.
Ventricle —Alower pumping chambers of the heart. There are two ventricles, right and left. The right ventricle pumps oxygen-poor blood to the lungs to be re-oxygenated. The left ventricle pumps oxygen-rich blood to the body.
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American Heart Association, 7272 Greenville Avenue, Dallas, TX, 75231, (800) 242-8721, http://www.americanheart.org.
National Heart Lung and Blood Institute Health Information Center, P.O. Box 30105, Bethesda, MD, 20824-0105, (301) 592-8573; TTY: (240) 629-3255, (240) 629-3246, [email protected], http://www.nhlbi.nih.gov.
Tish Davidson A. M.