(P104) "The Old Kid Around the Block" - A Case Report of Complete Heart Block from Coxsackie Myocarditis

Chief Complaint : 72-year-old male with multiple co-morbidities presents from home via ambulance with worsening dyspnea.

History of Present Illness : 72-year-old male with a past medical history of end-stage renal disease on dialysis, coronary artery disease with percutaneous coronary intervention to the LAD, patent foramen ovale with aneurysmal atrial septum, diabetes mellitus, hyperlipidemia, hypertension, pulmonary sarcoidosis, and chronic obstructive pulmonary disease on supplemental oxygen presented to the emergency department with worsening dyspnea for two days. Patient reported dyspnea was unchanged with exertion, associated with generalized malaise and weakness without associated productive cough and minimally improved with home oxygen. He reported viral-like symptoms one week prior to symptom onset. Additionally, the patient stated he missed hemodialysis due to worsening symptoms. Patient denied any recent travel, tick exposure, or rashes. He denied starting any new medications and noted compliance with all home medications. Review of systems was negative for chest pain, back pain, nausea, vomiting, fevers, syncope, and headache. He had not received sarcoid treatment since his initial diagnosis ~20 years ago.

Pertinent Physical Exam: VS: BP: 103/88, HR: 35, SpO2 98% on NC
General appearance: Sitting up on 2L via NC, speaking in full sentences
Cardio: Bradycardia- HR 35, s/p 1mg atropine given by EMS
Respiratory: Bilateral rales in all fields with associated coarse breath sounds
Abdomen: Soft, Non-tender, non-distended
Extremities: Full ROM, no pedal edema bilaterally, distal pulses intact
Heme: cap refill 2-3 seconds, no petechiae or purpura
Neuro: AAOx3, no focal deficits
Skin: no rash or wounds

Pertinent Laboratory Data: Left / Right Heart Catheterization: No obstructive coronary artery disease in a co-dominant system. Transcutaneous pacing from ED stopped during catheterization; underlying rhythm noted to be complete heart block with ventricular escape at 30bpm.
PET/ CT Heart Sarcoid with Perfusion: No evidence of myocardial inflammation suggestive of active cardiac sarcoidosis. As an incidental finding, there was extensive myocardial calcification, suggestive of calcinosis.
TTE: Left ventricular ejection fraction ~45-50% with mild left ventricular hypertrophy, mildly decreased right ventricular function.

Case Discussion: Complete heart block can occur secondary to pathologic or iatrogenic causes. In this case report, we discuss the pragmatic approach taken in stabilizing and evaluating a medically complex patient. First, identifying reversible, life-threatening causes of this presentation such as acute MI, hyperkalemia, acute medication-induced toxicity such as beta-blocker toxicity were considered, prompting immediate intervention. On arrival, the patient was emergently treated for presumed hyperkalemia, based on the HPI obtained and initial EKG. He was found to have CHB, elevated troponin and emergently transcutaneous paced and taken for cardiac catheterization with concern for STEMI. A transvenous pacer (TVP) was placed and the patient was admitted to the cardiac ICU. After an unremarkable catheterization and decreased LVEF, there was increasing concern for myocarditis. Given his history of pulmonary sarcoidosis, cardiac sarcoidosis could also cause complete heart block. Similarly, given his recent viral illness, there was a possibility of viral myocarditis. Possible, but more rare causes of his presentation included Giant Cell or Lyme myocarditis. Given his medication history, AV-nodal blocking medications seemed less likely. With positive titers, the etiology was ultimately attributed to Coxsackie myocarditis, a rare inflammatory disorder resulting from direct injury to the myocardium.

Coxsackie myocarditis can be present within the umbrella of viral myocarditis in infants and adolescents, but it is rare to present as complete heart block and diagnose in older adults. There are generally three stages of progression in Coxsackie myocarditis – direct viral cytotoxicity to the myocardium, an increase in autoimmune injury with antibody, T and B cell production and diffuse myocardial fibrosis and cardiac dysfunction. Our patient prodromal viral URI was likely the inciting event leading to the development of the underlying cardiac dysfunction. This case exemplified the thinking model of resuscitation and team driven focus behind emergency medicine patient stabilization.

References and Acknowledgements (Optional): Leonard, EG. Viral myocarditis. Pediatric Infectious Disease Journal. 2004;23:665–666.
Tam, P. Coxsackievirus Myocarditis: Interplay between Virus and Host in the Pathogenesis of Heart Disease. 2006; 19(2):133-146.
Olejniczak M, Schwartz M, Webber E, Shaffer A, Perry T. Viral Myocarditis – Incidence, Diagnosis and Management. 2020; 34(6):1591-1601.
Ogunbaya G, Elayi S-C, Ha L, Olorunfemi O, Elbadawi A, Saheed D, Sorrell V. Outcomes of Heart Block in Myocarditis: A Review of 31,760 Patients. 2019; 28(2):272-276.