Before examining the heart itself, observe the infant carefully for any cyanosis. It is important to detect central cyanosis because it is always abnormal and because many congenital cardiac abnormalities, as well as respiratory diseases, present with cyanosis.

Recognizing minimal degrees of cyanosis requires care. Look inside the body (i.e., the inside of the mouth, the tongue, or the conjunctivae) in addition to assessing skin color. A true strawberry pink is normal, whereas any hint of raspberry red suggests desaturation and requires urgent evaluation. The distribution of the cyanosis should be evaluated. An oximetry reading will confirm desaturation.

Observe the infant for general signs of health. The infant's nutritional status, responsiveness, irritability, and fatigue are all clues that may be useful in evaluating cardiac disease. Note that noncardiac findings (see box on the next page) are often present in infants with cardiac disease.

Observe the respiratory rate and pattern to help distinguish the degree of illness and cardiac versus pulmonary diseases. An increase in respiratory effort is expected from pulmonary diseases, whereas in cardiac disease there may be tachypnea without increased work of breathing (called "peaceful tachypnea") until heart failure becomes significant.

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