What are the cardiac-related causes of syncope?
• Cardiac causes can be secondary to obstruction to blood flow (aortic valvar stenosis, hypertrophic cardiomyopathy, primary pulmonary hypertension, Eisenmenger’s syndrome) • Heart rhythm abnormalities (ventricular tachycardia, Wolff-Parkinson-White syndrome, long QT syndrome, sinus node dysfunction, atrioventricular block, arrhythmogenic right ventricular dysplasia) • Diminished heart function (ventricular dysfunction from a variety of causes including dilated cardiomyopathy; inflammatory diseases such as acute myocarditis and Kawasaki disease; and ischemic heart disease secondary to an anomalous coronary artery, Kawasaki’s disease, or hypercholesterolemia) It is the job of the cardiologist to determine whether one of these serious causes of syncope exists. By far the most common cause of syncope during childhood, accounting for more than 90 percent of syncope in children, is • Secondary to irregularities in a normal involuntary (autonomic) reflex resulting in an inappropriate relaxat
