Case
Hi, I’m calling from the ER. We have a 12 year old boy who sees cardiology for hypertrophic cardiomyopathy (HCM). He fainted today at school during recess. He looks OK now and all vitals are stable. Do I need to do anything else or can I discharge him with a plan to be seen back by cardiology?
What am I thinking?
I am very worried about this patient. This patient needs to be admitted for further workup and observation. He has an underlying condition with a risk for lethal arrhythmias and sudden death and now he presents with fainting. Although vasovagal syncope (simple fainting) is common in kids, any fainting in a child with an underlying heart disease should be taken very seriously. In fact, in teenagers and young adults, HCM is the commonest cause of sudden death. In any patient with an underlying heart problem who presents with fainting, vasovagal syncope should only be considered after every effort has been taken to make sure the patient could not have had a lethal arrhythmia that aborted. In fact, just as arrhythmias can begin suddenly for inexplicable reasons, they can also stop suddenly and inexplicably.
Since this patient has already been seeing a cardiologist and has a diagnosis of HCM, presumably we already have some history. It would be important to review the previous notes of this child. It would also be important to ask the family if the child has been sick recently or had an intercurrent illness. HCM is characterized by abnormal thickening of the ventricles, which, in turn, makes them less compliant (stiff), and thereby can limit their cardiac output. An intercurrent illness associated with diarrhea, vomiting, or poor oral intake and associated dehydration can be very poorly tolerated by such patients. The fact that the child went to school suggests there was no intercurrent illness, but it would be important to be sure.
It is also important to try to tease out what the child was doing when he passed out. Was he running in the playground or playing with friends? Syncope associated with physical exertion generally suggests a lethal arrhythmia, while syncope at rest or standing still is less suggestive. It is also important to ask whether any onlookers who observed the fainting noted seizure-like activity or whether there was incontinence of the bladder/bowels. The presence of any of these features would be highly concerning for a serious arrhythmia in this patient.
A thorough, cardiovascular-focused, examination in patients with HCM includes listening carefully for any murmurs. Additionally, it is important to listen with the patient standing, squatting, and while standing after having been squatting. The last maneuver can help “unmask” a dynamic left ventricular outflow tract obstruction, if present.
If the child was on a cardiac monitor while being observed in the ER, it is important to see if he has been having any premature ventricular complexes (PVCs) or even small runs of any arrhythmia. If not already done, the most critical tests to order are an ECG (see Fig. 25.1 ) and an echocardiogram. However, even if they are unchanged from previous studies, it is important to not be falsely reassured.
