Page 762 - Cardiac Nursing

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CHAPTER Adult Congenital Heart Disease

Philip Moons / Mary M. Canobbio

Congenital heart disease is defined as gross structural abnor-
malities of the heart or intrathoracic great vessels that have ac- CATEGORIZATION OF
1
tual or potential functional significance. They include a wide CONGENITAL HEART DEFECTS
spectrum of simple, moderate, and complex severity lesions. 2,3
Over the past five decades, advances in diagnosis and therapy, A variety of methods have been developed to classify congenital
including palliative or corrective surgery, have resulted in in- heart defects. 14–16 Some are based on the direction and magnitude
creased survival of adults with congenital heart disease of pulmonary blood flow or on a distinction between cyanotic and
(ACHD). Surgical interventions have not only increased life ex- acyanotic heart defects. For the purpose of this discussion, we use
pectancy of patients with defects that allow natural long-term a classification described by Jordan and Scott, which is illustrated
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survival but have also permitted survival of a large number of in Figure 31-1. A detailed review of all congenital heart defects is
those with disorders previously fatal in childhood. Appropriate beyond the scope of this chapter; therefore, selected defects that
long-term management of this population requires an under- commonly present in adult congenital heart disease practice are
standing of the anomalies and the residual effects of the surgi- discussed here.
cal repair.

ACYANOTIC HEART DEFECTS
INCIDENCE AND PREVALENCE WITH LEFT-TO-RIGHT SHUNT

The generally accepted incidence of congenital heart disease is This group of heart defects is characterized by a continuous flow
0.8%, although large variations in incidence data occur across of saturated blood from the left heart circulation to the right side
4
studies. Overall rates of congenital heart disease incidence in var- of the heart. This left-to-right shunting is associated with an
ious studies have ranged from 4/1,000 to 75/1,000 live births, 4 increased pulmonary blood flow.
depending on which heart defects are included in the assessment,
the patient’s age at diagnosis, and the study design (population Patent Ductus Arteriosus
studies or patient referral studies). Regardless, congenital heart de-
fects do represent the most frequently occurring congenital disor- Description
der in newborns. 5–7 It is argued that the incidence of congenital The ductus arteriosus is a vascular connection, which during fetal
heart disease remains stable over time. 4,8 However, some authors life directs blood flow from the pulmonary artery to the aorta, by-
have found temporal trends in the occurrence of some heart de- passing the lungs (Fig. 31-2). Functional closure of the ductus oc-
9
fects or in congenital heart disease overall. 5,10,11 curs within hours or days after birth, in some cases taking
Since the first surgical procedure for the “blue baby” was per- 6 months to several years to close. If the ductus remains patent, the
formed over 50 years ago, the number of children surviving into direction of blood flow is reversed to left-to-right, because of high
adulthood has steadily increased. Today, because of the dramatic ad- systemic pressure in the aorta. A patent ductus arteriosus (PDA),
vances in diagnosis and medical therapies, including interventional which can escape recognition until adulthood, accounts for about
procedures as well as cardiac surgical procedures, it is generally ac- 10% of all cases of congenital heart disease and predominates in
knowledged that at least 85% of infants born with cardiovascular women. The incidence of PDA is higher at high altitude than at sea
3
anomalies can expect to reach adulthood. As a consequence of level. It is reported that the risk for PDA in individuals residing be-
higher survival rates, the prevalence of ACHD has increased as well. tween 4,500 and 5,000 m is 30 times higher than in counterparts
The number of ACHD patients in the population has been esti- living at sea level. This increased risk is due to a postnatal persist-
18
mated to be about 5,000 patients per million inhabitants. 2,12 For ence of pulmonary hypertension. There is reversal of pulmonary hy-
the first time in history, there are now more adults than children liv- pertension after prolonged residence at sea level. 18
ing with congenital heart defects, and this population is growing by The hemodynamic changes and clinical manifestations depend
approximately 5% per year. 13 on the magnitude of the pulmonary blood flow. The amount of
These data are important in that they are predictive of the in- left-to-right shunt is related to the size of the ductal lumen and
creasing number of ACHD that will be presenting for care in the resistance in the pulmonary vascular bed. When the ductus is
adult health care settings. Unfortunately, the adult health care set- small, the pulmonary artery pressure remains normal; when larger,
ting is neither well informed nor prepared to manage this growing aortic pressure is transmitted into the pulmonary trunk.
subspecialty of cardiology. In future, nurses are required not only
to provide care for the primary defect but also for the postopera- Pathophysiology
tive residua, sequelae, and complications, many of which become A PDA functions as an arteriovenous fistula, increasing the work of
apparent in adulthood. the left ventricle. The major complications are ventricular failure
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