In patients referred to a pediatric cardiologist for evaluation of chest pain, the most common serious causes of cardiac chest pain are myocarditis and pericarditis. Myocarditis usually follows a febrile viral illness. Patients typically present with symptoms of shortness of breath, nonspecific chest pain, anorexia, or malaise. A physical examination may reveal the presence of an S3 gallop rhythm. The CXR typically reveals cardiomegaly, although early in the illness it may reveal normal heart size. The ECG may reveal ST segment depression and T-wave abnormalities, especially in the inferior or lateral leads (II, III, AVF, V6, and V7). In these patients, the myocardium is inflamed and ventricular dysfunction and congestive heart failure is common. Myocardial inflammation may also affect the conduction system, and patients with myocarditis may present with arrhythmias. These arrhythmias tend to improve when the inflammation resolves. In patients who develop a chronic cardiomyopathy, arrhythmias may persist. Pericarditis more frequently presents with acute onset of sharp chest pain, which is lessened by leaning forward. Pericarditis results from inflammation of the pericardium and may result from infections, uremia, neoplasm, trauma, or autoimmune disorders. In patients with a small pericardial fluid collection, the physical examination may reveal a friction rub. In patients with a large pericardial fluid collection around the heart, pericardial tamponade may be present, resulting in distended neck veins, diminished heart sounds, and pulsus paradoxus. In the presence of a large pericardial effusion, the ECG may reveal low-voltage QRS complexes. In patients with pericarditis, the CXR usually demonstrates cardiomegaly. Myocarditis and pericarditis occur after a viral inflammatory process (e.g., coxsackievirus, adenovirus, echovirus, and parvovirus). A viral polymerase chain reaction test on a sample of blood may help determine the specific cause. Since Lyme disease may cause myocarditis, Lyme titers should be obtained for a patient who presents with chest pain and a history of a tick bite in an endemic area. Other inflammatory causes of pericarditis include autoimmune disorders, such as lupus erythematosus.

A history of chest pain in a child who also has a significant murmur may suggest left ventricular outflow tract obstruction caused by aortic stenosis or subaortic stenosis. In these patients, chest pain may indicate ischemic pain. Pain occurs during exercise because the ability to increase cardiac output is limited by the left ventricular outflow obstruction. The limited cardiac output, coupled with a fall in systemic vascular resistance during exercise, results in coronary hypoperfusion and subsequent myocardial ischemia.

Physical findings in patients with aortic stenosis can include a systolic ejection click, a harsh systolic ejection murmur over the base of the heart that radiates to the carotid arteries, and frequently a palpable thrill in the suprasternal notch. These patients may have a normal ECG or an ECG that suggests left ventricular hypertrophy. A patient with a significant murmur and chest pain should be referred to a cardiologist for an echocardiogram.