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it easier to connect the donated heart tissue. Before the recipient’s heart is removed, surgeons connect him or her to a heart-lung machine, which bypasses the blood flow to the lungs and heart. The machine temporarily takes over for the heart, pumping blood throughout the body, until the donor heart is implanted and attached to the blood vessels. As the donor heart gets warm, it begins to beat. If the heart does not start to beat, the surgeons stimulate it with an electric shock to trigger beating. All of the new connections in the blood vessels and heart chambers are checked for leaking before the heart-lung machine is disconnected.

Heart transplant recipients usually get out of bed a few days after the operation and can go home within 2 weeks if no problems arise. Eventually, about 85 percent of people with heart transplants go back to work or have the ability to do so, and many engage in swimming, running, or other physical activities.

Damaged heart ready for transplant

Heart transplant

Heart transplants

The first human heart transplant was performed in 1967. Since that time, the procedure has become an established treatment for advanced heart disease. Surgeons perform nearly 2,300 heart transplants nationwide each year. Doctors usually recommend a heart transplant only when a person has irreversible, long-term heart failure that cannot be controlled with other medical or surgical treatments. (The artificial hearts now available are still experimental and cannot offer a reliable, long-term solution to the problem of a diseased heart.) Heart transplants can be performed at any age, including infancy and childhood, but the procedure is usually not recommended for people over age 65. The most common causes of heart failure are:

• Coronary artery disease (blockage in the arteries leading to the heart)

• Cardiomyopathy (weakness of the heart muscle, affecting its ability to pump blood)

• Heart disease that is present at birth

• Damage to the heart muscle or valves

• Failure of an earlier transplant

After surgery, early symptoms of rejection (see page 821) of the donor heart are not always apparent, so doctors must regularly take tiny samples of the heart muscle and examine them under a microscope (a procedure called a biopsy) to check for signs of rejection. To obtain samples of the tissue, a doctor inserts a small tube into an incision in the neck, down the jugular vein, and into the heart. If the doctor finds signs of rejection, he or she will give the person higher doses of immune-suppressing drugs.

After the person goes home from the hospital for recovery, he or she will have to visit the doctor for regular follow-up visits and more biopsies. Some of the early complications (in addition to rejection) that can arise after heart transplant surgery include kidney failure (which is usually temporary), wound infection, pneumonia, and stroke. Irregular heartbeats called arrhythmias (see page 580) sometimes occur.

Heart transplants now have a high success rate: about 85 percent of those who receive a new heart are alive after 1 year, 79 percent after 3 years, and 74 percent after 5 years. These survival rates continue to improve. Without this lifesaving procedure, the vast majority of heart transplant recipients would have died within 2 years.

High Blood Pressure

Blood pressure is produced by the heart as it pumps blood through the arteries and as the arteries resist blood flow. It is measured in millimeters of mercury (mm Hg) with an instrument called a sphygmomanometer. Blood pressure is highest when the heart contracts (beats) and pumps blood into the arteries. This is the systolic pressure. Between beats, when the heart is resting, the pressure falls. This is the diastolic pressure. A blood pressure reading is given as a combination of these two pressures; the systolic pressure is written above or before the diastolic pressure. For example, if your blood pressure reading is 130 over 80, it is written as 130/80 mm Hg; 130 is the systolic pressure and 80 is the diastolic pressure.

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