Case
I have a 13 year old in my office who is here for a routine well child evaluation. She has had cardiac surgery to repair a tetralogy of Fallot when she was under a year of age. When I examined her, I could hear an irregular rhythm. So, we did an ECG and it shows two premature ventricular contractions (PVCs). I’d like her to come see you. How soon should she see you and are there any other tests or treatment she should have in the meantime? Also, she is a swimmer and has a swim competition this weekend. Can she be allowed to swim?
What am I thinking?
Tetralogy of Fallot is one of the most common cyanotic congenital heart diseases and is usually diagnosed in infancy. The key defects in the heart are a large ventricular septal defect and pulmonary stenosis. The pulmonary stenosis can be at multiple levels (valve, below the valve or above the valve, or a combination of these). Almost all children undergo corrective surgery that consists of closing the VSD and relief of the pulmonary stenosis. In the process of relieving the obstruction out of the right ventricle, the competency of the pulmonary valve can be affected resulting in significant pulmonary valve regurgitation, which leads to enlargement and stretching of the right ventricle. On the other hand, the pulmonary stenosis may be inadequately relieved leaving the patient with significant obstruction out of the right ventricle. Both these issues (pulmonary stenosis and or regurgitation) place stress on the right ventricle. The development of significant ventricular arrhythmias is an important long-term consequence of this right ventricular stress. In extreme cases, the patient may develop ventricular tachycardia or fibrillation leading to collapse and even sudden death. When a primary care physician tells me this child with tetralogy of Fallot repair has PVCs, I must decide: are these ectopic beats a benign and unrelated finding or is this child at significant risk of going into ventricular arrhythmias that could be potentially life-threatening?
Questions I would ask the pediatrician are: how is the child doing? Has she experienced any symptoms like syncope (especially during physical exercise), difficulty breathing or chest pain with exercise, or random episodes of the feeling that her heart is racing? A negative answer to these questions would be highly reassuring. A positive answer, especially to the fainting question, may prove highly concerning with the need for the child to be seen right away.
I would also ask for the ECG right away for review. I would pay particular attention to the rhythm and the QRS complexes as a longer QRS duration has been found to be associated with poor outcomes. I would also look at the PVCs to see if they are monomorphic (same appearance), which is more common, or multiform (differing appearance) potentially implying that the ectopic beats are arising from more than one spot and is more concerning for a diffuse disease process (see Figs. 26.1 and 26.2 ).
