Pediatric Cardiology for Practitioners (Hardcover)

Basic Tools in Routine Evaluation of Cardiac Patients

The initial office evaluation of a child with possible cardiac abnormalities is usually accomplished by history taking; physical examination that includes inspection, palpation, and auscultation; electrocardiography (ECG); and sometimes chest radiography.
The weight of the information gained from these different techniques varies with the type and severity of the disease. For example, if a mother had diabetes during her pregnancy, infants with macrosomia have an increased chance of having cardiac problems. In these infants, the prevalence of congenital heart disease (CHD) increases to three to four times that found in the general population.
Ventricular septal defect (VSD), transposition of the great arteries (TGA), and coarctation of the aorta (COA) are more common defects. Congenital malformations of all types are increased in these infants. Hypertrophic cardiomyopathy with or without obstruction of the left ventricular outflow tract occurs in 10precent to 20precent of these infants, and they also have an increased risk of per- sistent pulmonary hypertension of the newborn. The physician should look for these defects when examining the child.
Auscultation may be the most important source of information in the diagnosis of acyanotic heart disease such as VSD or PDA. However, auscultation is rarely diagnostic in cyanotic CHD such as TGA, in which heart murmur is often absent. Careful palpation of the peripheral pulses is more important than auscultation in the detection of COA. Measurement of blood pressure is the most important diagnostic tool in the detection of hypertension. ECG and chest radiography have strengths and weaknesses in their ability to assess the severity of heart disease. ECG detects hypertrophy well and therefore detects conditions of pressure overload, but it is less reliable at detecting dilatation from volume overload. Chest radiography is most reliable in establishing volume overload, but it poorly demonstrates hypertrophy without dilatation.