A 7-day-old boy was brought in by his mother for a well child evaluation. She said he had had some trouble latching on and needed some supplementation through a bottle. The mother noted a normal number of wet diapers and yellow stools.
The mother had been induced at 38 weeks because of abruption, and the baby weighed 7 pounds, 1 ounce. She was a little concerned about his feeding and said he was a little irritable.
He was afebrile and noted to have a heart rate of 182 bpm. No murmur was initially appreciated. Perioral duskiness was noted with crying. What should be done next to figure out his diagnosis?
Find the diagnosis and case discussion on the next page.
Diagnosis: Tetralogy of Fallot
Tetralogy of Fallot is a congenital heart condition characterized by four major features including right ventricular outflow tract obstruction, intraventricular communication, deviation of the origin of the aorta to the right, and concentric right ventricular hypertrophy. It is present in about four of every 10,000 live births in the United States. (MMWR Morb Mortal Wkly Rep. 2006;54:1301; http://bit.ly/2Jp2F6f.) Other papers note that it accounts for 3.5 percent of neonates born with congenital heart disease. (Heart. 2006;92:1353; http://bit.ly/2Crm0ht.)
These patients' presentation is dependent on the severity or degree of right ventricular outflow obstruction. The more significant that obstruction or atresia, the earlier and more cyanotic they present because the right to left shunt is more significant. The less severe often have a murmur picked up later or are noted to be more cyanotic during times of excitement, crying, or when hypovolemic. The ones with a less significant degree of right ventricular outflow tract obstruction are often referred to as pink tets.
These patients can appear comfortable and in no significant distress. If there is cyanosis, it can often be seen in the lips and nail beds. Peripheral pulses are usually normal. The murmur noted in these patients is usually a systolic, crescendo-decrescendo harsh ejection murmur. It can be heard best at the left mid to upper sternal border, and it radiates to the back.
The workup for these patients should include an ECG, a chest x-ray, and an echocardiogram. The ability to identify fetuses with this congenital abnormality has increased, but not all are found. Some studies show prenatal detection rates as low as 15-43 percent. (Ultrasound Obstet Gynecol. 2007;29:619; http://bit.ly/2Cs30iB.) It is important to remember that the only cardiac structures that will be visualized well are the four chambers in fetuses 11 weeks and younger. Tetralogy of Fallot is also reported as only “might be identified” during the early ultrasound period of 11-13 weeks. The sensitivity can increase, however, in the hands of an experienced sonographer who does four-chamber and outflow views. (Fetal Diagn Ther. 2017;42:161; http://bit.ly/2CsbR3Y.)
An echocardiogram is vital if there is concern once the baby is born, and this is how the diagnosis is most often made, although the chest x-ray and electrocardiogram can provide important clues. The two-dimensional echocardiogram with Doppler will be able to evaluate all the potential features of Tetralogy of Fallot. Usually this can be done as a transthoracic echocardiogram, but sometimes a transesophageal echocardiogram will be needed.
The electrocardiogram is another test that should be ordered. This usually shows right atrial and right ventricular enlargement. The chest x-ray can show a boot-shaped heart. Cardiac catheterization might be needed for evaluation and even therapeutic management before surgery to access the anatomy and even try to improve pulmonary flow through balloon valvuloplasty of the pulmonary valve. (J Am Coll Cardiol. 1991;18:159; http://bit.ly/2JpxhEX.)
When this patient was evaluated by cardiology, his heart was calmer, in the 140s, and we were able to hear a harsh systolic murmur across pericardium and radiating to the back. The patient received a chest x-ray and an ECG. The ECG had an inverted T wave in V1 indicative of right ventricular hypertrophy, and the chest x-ray showed a moderately enlarged heart that appeared to be shaped like a boot. The patient then had an echocardiogram that confirmed the diagnosis of Tetralogy of Fallot, specifically pink tet. None of the patient's prenatal ultrasounds showed any congenital concerns.
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Dr. Kaplanis an assistant professor of emergency medicine at the University of Colorado School of Medicine in Aurora. Read her past columns athttp://bit.ly/EMN-QuickConsult. This case was provided byAvery Teplinsky, MD, who made the amazing diagnosis and changed the course of this patient.