Case
I’m calling from the ER with a 16-year old male who was playing in a soccer tournament today and suddenly collapsed on the field. They say that just before he fell he was acting strange, a bit disoriented, and very unsteady on his feet. He was running the opposite direction of the ball and then he fell, face-first into the ground and has a pretty bad contusion to his forehead and may have broken his nose. An onlooker present at the game was a nurse and went to check on him when he wasn’t getting up. She says that she may have felt a pulse but he really wasn’t sure. She decided to start chest compressions and told people to call 9-1-1. After approximately 30 seconds of chest compressions the boy started to wake up and amazingly, wanted to get back in and play after paramedics had checked him out! He feels fine now except for his injuries to his face. I’m thinking that maybe he was just dehydrated but the “no pulse” thing kind of freaks me out. I’ll get an ECG on him now but wondering if he needs to see you before playing again?
What am I thinking?
I need to see this young man and his family before he is cleared for sports again. Any discussion of pulselessness requires further evaluation involving history, family history, full physical examination, and a battery of tests to ensure current and future cardiac functioning. There are a number of conditions that can present in this similar circumstance and the answer may be found through cardiac and genetic testing for inherited cardiac arrhythmia syndromes. The scenario presented is that of an aborted sudden cardiac arrest until proven otherwise. Taking a logical and comprehensive approach to the evaluation will be key in determining the risk of a repeat event.
| Differential diagnosis |
|---|
| Likely until excluded |
| Hypertrophic cardiomyopathy Anomalous coronary artery Wolff-Parkinson-White syndrome Aortic stenosis Myocarditis Long QT syndrome Catecholaminergic polymorphic ventricular tachycardia Arrhythmogenic right (or left) ventricular cardiomyopathy Brugada syndrome |
| Possible |
Neurocardiogenic or vasovagal syncope
Illicit drug use or prescription medication with side effect |
| Rare |
| Idiopathic ventricular fibrillation Short QT syndrome Early repolarization |
History and physical
As was described in the previous chapter, the history taking is critical to an investigation of a syncopal patient. A meticulous and detailed history (e.g., “crime scene investigation”) will lead to proper investigation and successful diagnosis. Such investigations take time and a significant amount of effort and should be conducted with the help of a pediatric cardiologist and/or electrophysiologist in cases such as the one described. Reaching out to eyewitnesses, first-responders, relatives often moves beyond the office visit and requires coordination. This chapter will focus on questions and answers that may lead the healthcare professional toward a structural or arrhythmic cardiac diagnosis.
Start with a history leading up to the event. On some occasions, victims of an aborted sudden cardiac arrest may have had a similar presentation earlier in their lives. Asking if the patient has ever suffered syncopal episodes in the past may lead to such discoveries. When asking about the minutes before the event, it is not uncommon for eyewitnesses to describe odd behavior. In patients experiencing arrhythmia, it is often reported that the patient was acting unusually before collapse; this is particularly true with sports participants (i.e., shooting an own goal, running the opposite way, standing in an awkward position). What does the patient recall about the fall: any prodrome of unusual heartbeats? Were any resuscitative measures used including the use of an automated external defibrillator? If so, were there any tracings from the defibrillator that could be obtained? Patients who have undergone a significant arrhythmia may not recall much of what happened before passing out and often awaken to discover that something had happened, but they feel ready to return to their previous activity. Those with arrhythmia who were unable to brace for a fall may result in significant facial injuries such as a broken nose, chipped teeth, and/or hematoma.
In a suspected aborted sudden cardiac arrest, the family history is critical to guiding toward a potential inherited diagnosis. Family history should focus on details of unexplained deaths in the family, unexplained drownings, unexplained seizures, and unexplained car accidents. Deaths related to physical activity or members of the family who have died of “heart conditions” before the age of 50 years. Specific conditions should be listed and asked for but the use of colloquial terms is encouraged for clear understanding (i.e., enlarged or thickened heart). Questions should also touch on possible aborted sudden cardiac arrest that usually manifests as syncope in specific situations. For example, asking about family members that pass out with loud noises (long QT syndrome) or with excitement such as roller coasters or being startled/surprised (catecholaminergic polymorphic ventricular tachycardia). Follow-up with relatives may be required for deaths in the family that may be unclear. The healthcare provider should be prepared to make additional phone calls that may involve difficult conversations with estranged family members.
The past medical history should investigate previous illness or syncopal episodes as well as recently taken medications. Genetic arrhythmia syndromes such as Long QT syndrome may be exacerbated by the use of prescribed or over the counter medications. Social history in the athlete should include determining the use of over the counter energy agents, performance-enhancing drugs, or illicit drug use.
Physical exam is focused on stigmata of cardiac disease that may manifest as unusual rhythm upon auscultation or a pathologic murmur. Generally, the physical examination is normal in patients with a condition that can lead to cardiac arrest making the history and additional testing so critical to diagnosis.
Diagnostic testing
A patient with this type of presentation will undergo a gamut of tests given the risk associated with aborted sudden cardiac arrest. In such cases, it is likely wise to admit the patient under cardiac monitoring for observation. Initial blood work should include cardiac enzymes (e.g., troponin I). Blood gas, chemistry panel, complete blood count, lactate, and toxicology screen should all be ordered to assess possible etiologies for the arrest and evaluation for end-organ damage. An ECG should be obtained to evaluate for a number of arrhythmic-related disease such as Wolff-Parkinson-White syndrome, Long QT syndrome, Brugada syndrome, or even myocarditis. It is recommended that serial ECGs be obtained given that some conditions may present with intermittently normal ECGs. An echocardiogram should be ordered to evaluate for structural heart disease including evaluation for anomalous origin or course of coronary arteries. An exercise stress test can act as a provocation test for arrhythmias in patients with catecholaminergic polymorphic ventricular tachycardia (see Fig. 18.1 ). Further testing may be required to elucidate the clinical, genetic, and anatomic factors that may have contributed to the cardiac arrest.
