Encyclopedia of Health and Medicine

heredity and heart disease 63
People who have transplanted hearts are vulnerable
to rapidly progressive CAD, HYPERTENSION,
and arrhythmias. The transplanted heart is denervated—though
it contains its own conductive
NERVE network to convey electrical pacing
impulses, it does not have nerves connecting it to
the body’s sympathetic nerve pathways. Normal
NERVOUS SYSTEM mechanisms (the sympathetic
nerve pathways) that typically regulate HEART RATE
and cardiac workload are not functional in the
transplanted heart, though in some people reinnervation
occurs over time. The absence of sympathetic
nerve pathways also means the person
does not experience angina pectoris, a primary
symptom of CAD and ISCHEMIC HEART DISEASE (IHD).
This increases the risk for silent HEART ATTACK. Cardiologists
closely monitor the transplanted heart
for any signs of CAD, and also routinely prescribe
lipid-lowering medications to help prevent CAD
from developing.
Other long-term risks include an increased risk
for cancer, most commonly skin and lymphatic,
because of the IMMUNOSUPPRESSIVE THERAPY. Infection
and rejection remain risks as well. Rejection
can be acute (come on suddenly and severely) or
chronic (persist in a low-grade fashion over time,
or come and go). Many cardiologists believe the
accelerated CAD process also results from immunosuppression
rather than the conventional factors.
Outlook and Lifestyle Modifications
Most people remain hospitalized for 5 to 10 days
after the transplant operation, while the new
heart stabilizes and the surgical wounds start to
heal. During this time doctors initiate IMMUNOSUP-
PRESSIVE THERAPY, ANTICOAGULATION THERAPY, and
various medications to support the heart’s function
during early HEALING. All transplant recipients
will need to take IMMUNOSUPPRESSIVE MEDICATIONS
for the remainder of their lives to prevent their
bodies from rejecting the donor organ.
Most heart transplant recipients will continue
taking other cardiovascular medications to support
cardiovascular efficiency. The transplanted heart’s
denervation affects its ability to adjust to changing
cardiovascular needs in the body, such as with
exercise. Many people require a PACEMAKER after
transplantation to maintain an adequate heart rate
and appropriate heart rhythm. Heart transplantation
requires lifetime medical follow-up, usually
annual CARDIAC CATHETERIZATION and other diagnostic
procedures to assess the heart’s function.
Most heart transplant recipients return to their
regular work and leisure activities, including sexual
activity, gradually over two to three months.
The cardiologist may restrict certain kinds of strenuous
physical activity depending on the heart’s
ability to respond to the body’s increased oxygen
needs. The healing process is generally quite rapid
as full cardiovascular function returns the body to
its normal function. CARDIAC REHABILITATION helps
restore the body to a level of physical STRENGTH
and AEROBIC FITNESS that further supports cardiovascular
health. Moderate daily physical exercise
(such as walking), nutritious eating habits, and
total abstinence from smoking are essential.
See also CARDIOVASCULAR DISEASE PREVENTION;
MEDICATIONS TO TREAT CARDIOVASCULAR DISEASE; OPEN
HEART SURGERY; PHYSICAL EXERCISE AND CARDIOVASCU-
LAR HEALTH; QUALITY OF LIFE; SEXUAL ACTIVITY AND CAR-
DIOVASCULAR DISEASE; TRANSMYOCARDIAL LASER
REVASCULARIZATION (TMLR); VENTRICULAR ASSIST
DEVICES (VADS).
heredity and heart disease The genetic variables
that influence the development of CARDIOVASCULAR
DISEASE (CVD). Some forms of cardiovascular disease
are entirely hereditary and develop without
influence of lifestyle factors. Among them are
hypertrophic CARDIOMYOPATHY, LONG QT SYNDROME
(LQTS), WOLFF-PARKINSON-WHITE SYNDROME, and
familial HYPERLIPIDEMIA. There appear to be few
interventions, medical or lifestyle, that can prevent
these conditions. Early diagnosis allows for
optimal medical management. Researchers suspect
that undiagnosed hereditary conditions, notably
ARRHYTHMIA disorders, account for up to 25 percent
of SUDDEN CARDIAC DEATH in the United States.
Congenital malformations of the HEART often
accompany GENETIC DISORDERS or CHROMOSOMAL DIS-
ORDERS. Septal defect is common in children who
have DOWN SYNDROME (trisomy 21), for example.
Most people who have MARFAN SYNDROME, a
hereditary connective tissue disorder, have cardiovascular
abnormalities including malformed heart
valves and arterial walls that lack connective tissue,
weakening them and making them vulnerable
to ANEURYSM.