CARDIOLOGY: Critical cardiac problems

Identifying “Critical Cardiac Problems Commonly Missed in Office Practice” involves recognizing red flags that indicate a need for greater scrutiny, said Kevin M. Shannon, MD, FAAP.

Among causes of nonfamilial sudden death, for example, coronary anomalies and myocarditis can both feature abdominal pain and nausea. However, symptoms of coronary anomalies can include syncope or near-syncope with exertion, and postexertional vomiting. Symptoms of myocarditis can include extreme malaise and tachycardia out of proportion to level of dehydration or that does not respond to a fluid bolus. Evaluation techniques for both conditions include echocardiogram, plus a computed tomography angiogram for coronary anomalies or an electrocardiogram (ECG) for myocarditis.

Long QT syndrome (LQTS) is a channelopathy often linked to familial sudden death. To uncover a family history of sudden or unexplained deaths, said Shannon, ask patients about any deaths in relatives aged younger than 30 years-especially single-vehicle car crashes and unusual drownings (eg, shallow water, good swimmer). Key symptoms include frequent stress-associated syncope. Appropriate evaluation techniques include resting ECG and genetic testing (3 genes account for more than 75% of LQTS cases).

Critical neonatal congenital heart diseases commonly missed by level 3 fetal screening and pulse oximetry include coarctation and total anomalous pulmonary venous return (TAPVR) without obstruction. The former presents at 5 to 14 days, with shock, congestive heart failure (progressively poorer feeding, emesis, tachypnea, and irritability), and absent femoral pulses with markedly reduced or undetectable blood pressure. Evaluation requires ECG for sinus tachycardia and right ventricular hypertrophy. Treatment strategies include resuscitation, prostaglandin E1, and surgical repair or transcatheter stent.

Kawasaki disease (KD), the most common form of acquired heart disease in children, can present with symptoms such as prolonged fever, nonpurulent conjunctivitis, cracked lips, and swollen or erythematous hands/feet. Typically self-limited, KD carries a 30% risk of coronary aneurysms if untreated versus an excellent prognosis with treatment. In the acute phase, treatment includes intravenous immunoglobulin (IVIG; 2 g/kg over 12 hours) and aspirin (100 mg/kg divided QID). If fever recurs more than 36 hours post-IVIG, he suggested repeating IVIG and considering intravenous corticosteroid pulse therapy, anti-tumor necrosis factor-alpha antibodies, or cytotoxic agents.

Atypical KD should be considered in any patient with prolonged fever and 2 or more criteria. The presence of supporting laboratory abnormalities might then prompt treatment with IVIG.

Kevin M. Shannon, MD, FAAP, is professor, pediatric cardiology, Mattel Children's Hospital, University of California Los Angeles.

Critical cardiac problems (not defined in Dr. Shannon's presentation, and no consensus definition exists) are often missed in the pediatrician’s office for the following reasons:

1. The signs and symptoms may be very nonspecific and mimic or overlap with much more common illnesses.

2. The relative rarity of these diseases is such that pediatricians don’t always include them in their differential diagnosis.

A careful history, including a family history of premature or sudden/unexplained deaths, may be the most valuable information that may prompt further testing for a potential cardiac etiology. A chest x-ray (CXR) and ECG are reasonable initial tests for children with suspected heart disease. However, these may be normal even in patients with significant disease, such as myocarditis or hypertrophic cardiomyopathy.

An echocardiogram can rule out the diagnosis of significant congenital heart disease in the vast majority of patients, but echo is not a cost-effective screening tool and should only be applied to patients with a high likelihood of a cardiac etiology for their symptoms (or an abnormal CXR or ECG).

Neonatal pulse oximetry screening should pick up most clinically significant (often ductal-dependent) aortic coarctations, and other ductal-dependent critical congenital heart lesions as well, but it won’t pick up many more mild forms of congenital heart diseases without right to left shunting (that often don’t require early intervention). A TAPVR without obstruction usually does not require early intervention.

The diagnostic accuracy of level 3 fetal ultrasound depends on the skill of the person performing the ultrasound. Many types of heart diseases can be detected, but some (such as an atrial septal defect, ventricular septal defect, or coarctation) can be difficult to diagnose, even for experienced imagers.

John R. Charpie, MD, PhD, FAAP, FACC, is professor and division director,pediatric cardiology, C.S. Mott Children’s Hospital, University of Michigan Health System, Ann Arbor.

Mr Jesitus is a medical writer based in Colorado. He has nothing to disclose in regard to affiliations with or financial interests in any organizations that may have an interest in any part of this article.