Chapter 430 Sudden Death
Sudden death other than sudden infant death syndrome (SIDS; Chapter 367) is rare in children younger than 18 yr. Sudden death can be divided into either traumatic or nontraumatic origin. Traumatic causes of sudden death are the most common in children; these include motor vehicle crashes, violent deaths, recreational deaths, and occupational deaths. Nontraumatic sudden deaths are often due to specific cardiac causes. The incidence of sudden death varies from 0.8 to 6.2 per 100,000 per year in children and adolescents as opposed to the higher incidence of sudden cardiac death in adults of 1 per 1,000. Approximately 65% of sudden deaths are due to heart-related problems in patients with either normal or congenitally (corrected, palliated, or unoperated) abnormal hearts. Competitive high-school sports (basketball, football) are high-risk environmental factors. The most common cause of death in competitive athletes is hypertrophic cardiomyopathy, with or without obstruction to left ventricular outflow. Other potential causes are listed in Table 430-1. These can be classified as structural abnormalities, including aortic stenosis and coronary artery abnormalities; myocardial disease, such as myocarditis; conduction system disease, including long Q-T syndrome (LQTS); and miscellaneous causes, including pulmonary hypertension and commotio cordis. Symptoms may be absent before the event but, if present, include syncope, chest pain, dyspnea, and palpitations. Patients may have a family history of heart disease (dilated or hypertrophic cardiomyopathy, long Q-T interval, arrhythmogenic right ventricular dysplasia, Marfan syndrome) or sudden death. Death often follows exertion or exercise.
Table 430-1 POTENTIAL CAUSES OF SUDDEN DEATH IN INFANTS, CHILDREN, AND ADOLESCENTS
SIDS AND SIDS “MIMICS”
CORRECTED OR UNOPERATED CONGENITAL HEART DISEASE
CORONARY ARTERIAL DISEASE
MYOCARDIAL DISEASE
CONDUCTION SYSTEM ABNORMALITY/ARRHYTHMIA
MISCELLANEOUS
SIDS, sudden infant death syndrome.
Mechanism of Sudden Death
There are 3 mechanisms of sudden death: arrhythmic, nonarrhythmic cardiac (circulatory and vascular causes), and noncardiac. Ventricular fibrillation (VF), while the most common final cause of sudden death in adults, is only the final cause in 10-20% of children with sudden cardiac death. More commonly, bradycardia leads either to VF or asystole (Chapter 429).
Congenital Heart Disease
Valvar aortic stenosis is the congenital defect most commonly associated with sudden death in children. Historically, approximately 5% of children with this disease die. A history of syncope, chest pain, and evidence of severe obstruction and left ventricular hypertrophy are risk factors (Chapter 421.5).
Cardiomyopathy
All 3 major types of cardiomyopathy (hypertrophic, dilated, and restrictive) are associated with sudden death in the pediatric population; sudden death may be the initial manifestation of the cardiomyopathy (Chapter 433).
