A previously healthy 18-year-old high school wrestler with no known prior medical history collapses during a school match. He is unresponsive, pulseless, and apneic. Bystanders initiate CPR and quickly bring an automated external defibrillator to him. The device shows ventricular fibrillation and delivers a successful defibrillating shock. Sinus rhythm is restored, and he regains a pulse but remains unresponsive.
EMS personnel arrive, intubate the patient, and transport him to a local hospital, where he recovers gradually, including making a full neurologic recovery. His course is notable for aspiration pneumonia, methicillin-resistant Staphlococcus aureus infection, and a newly noted left bundle branch block. Exercise stress testing revealed no inducible ischemia or arrhythmias. Cardiac catheterization showed normal coronary artery anatomy without evidence of myocardial bridging, anomalous vessels, or obstructive atherosclerotic disease. Cardiac MRI revealed moderate global LV hypokinesis (LVEF 40%) with a small area of apical enhancement interpreted as consistent with sarcoidosis. He has been in the hospital for the past two weeks and is now referred to you for further management.
The patient's family reveals that his paternal uncle was an illicit drug user who died suddenly at the age of 35. The family history is otherwise completely unremarkable. Physical examination is normal.
The patient is resting comfortably, eager to go home.
At this point, you would advise:
Show Answer
The correct answer is: C. Implantable defibrillator placement now.
The AVID trial is the most relevant clinical reference for this case, which is an example of primary ventricular fibrillation in the absence of an obviously reversible cause. ICD therapy in these patients reduces mortality.1,2
The MRI findings suggestive of sarcoid do not change the fundamental need to protect this young man from subsequent VF and sudden death. Similarly, a biopsy would not alter the indication for ICD therapy. (Moreover, given the small area of enhancement on the MRI, the yield of a biopsy might be limited). This eliminates choices A and B. Cardiac sarcoidosis associated with young people is rare, but it has been reported in this age group and associated with malignant ventricular arrhythmias.3 While sarcoid is a treatable condition, there is no evidence that treatment will completely eliminate the risk of a subsequent sudden cardiac death event in this patient.
While choice D (BiV ICD therapy) might be considered in light of the left bundle branch block, this choice is not consistent with current guidelines for Cardiac Resynchronization Therapy.2 The LV dysfunction is relatively mild, and there is no history of heart failure symptoms or heart failure therapy. Myocardial stunning after the arrest may be an explanation for the reduced ejection fraction, which would be predicted to improve over time.
Choice E (a wearable defibrillator) might be considered, but in the absence of a reversible etiology for the VF, it would be an inferior choice to an implantable defibrillator. Wearable ICDs are a bridge to definitive therapy. They are only indicated when an ICD will be implanted subsequently but not immediately (e.g., because of infection concerns) or to protect a patient during a temporary waiting period until recovery from the SCD risk is expected. Neither of those conditions is present in this case. This patient needs lifelong SCD protection.
This patient highlights the widely recognized and difficult problem of sudden cardiac death in young athletes.4,5,6 Structural disease, including arrhythmogenic right ventricular dysplasia (ARVD) and hypertrophic cardiomyopathy, are known etiologies in this population group. Cardiac sarcoidosis, although not typically associated with young people or athletes, can clinically mimic ARVD and may be the source of the VF in this patient.3 Heritable channelopathies such as Brugada syndrome, congenital long QT syndrome, and catacholaminergic polymorphic ventricular tachycardia (CPVT), are additional potential causes and commonly present in patients with family members who have a history of syncope or sudden death. Genetic screening for these known conditions may be appropriate in this patient, particularly if the diagnosis of sarcoid is not firm and in the context of his young uncle's prior sudden death. A positive finding would have screening implications for other first-degree relatives, none of whom reported a history of arrhythmia, syncope, or sudden death.
The tragedy of sudden cardiac death is particularly compelling in young, robust athletes. While the value and logistics of large-scale SCD screening strategies remain controversial,6 this case is an elegant example of the value of automated external defibrillators (AEDs) in public places, an application of this technology that has been shown to have a significant mortality benefit.8
References
The Antiarrhythmics Versus Implantable Defibrillators (AVID) Investigators. A comparison of antiarrhythmic-drug therapy with implantable defibrillators in patients resuscitated from near-fatal ventricular arrhythmias. N Engl J Med 1997; 337:1576–1583.
Epstein, AE, DiMarco JP, et al,; ACC/AHA/HRS 2008 Guidelines for Device-Based Therapy of Cardiac Rhythm Abnormalities. Heart Rhythm 2008; 5:e1-62.
Vasiawala, S., et al. J Cardiovasc Electrophysiol 2009; 20:473–476.
Drezner J.A., Rogers K.J.: Sudden cardiac arrest in intercollegiate athletes: detailed analysis and outcomes of resuscitation in nine cases. Heart Rhythm 2006; 3:755-759.
Drezner J.A., Rogers K.J., Zimmer R.R., Sennet BJ.: Use of Automated External Defibrillators at NCAA Division I Universities. Medicine and Science in Sports & Exercise 2005; 37:1487-1492.
Link M.S., Estes , 3rd , 3rdN.A.: Sudden Cardiac Death in the Athlete: Bridging the Gaps Between Evidence, Policy, and Practice. Circulation 2012; 125:2511-2516.
Rho R.W., Page R.L. The automated external defibrillator. Journal of Cardiovascular Electrophysiology 2007; 18:896–899.
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