High Grade Atrioventricular Block Presenting with Cardiac Arrest

摘要

Introduction: Atrioventricular block usually does not cause cardiac arrest because of the development of an escape rhythm which maintains cardiac output. We report a case of high grade AV block presenting with cardiac arrest. Case Description: A 74-year-old man with past medical history of hypertension, dyslipidemia and a recent stroke was brought to the emergency room after a cardiac arrest, with pulseless electrical activity as the initial rhythm. Cardiopulmonary resuscitation was performed with return of spontaneous circulation after five minutes. On examination, he was unresponsive, with heart rate of 33 beats per minute, blood pressure of 108/51mmHg, normal heart sounds and clear lungs. He was given a total of 2mg of atropine, following which he was started on dopamine infusion, with no significant increase in heart rate. His electrocardiogram showed high grade AV block with ventricular rate of 30 beats per minute. An assessment of cardiac arrest due to severe conduction disease, with no evidence of acute coronary syndrome was made. A trans-venous pacemaker was inserted with improvement in the patient’s blood pressure and mental status. EKG revealed demand ventricular pacing with 100% ventricular capture. By the third day of admission, he was fully awake and following simple commands, but he remained pacemaker-dependent with no subsidiary rhythm. He had a dual chamber permanent pacemaker inserted without complication. Discussion: In advanced (high grade) second degree AV block, there is failure of conduction of two or more consecutive P waves. High grade AV block may be asymptomatic, or it may present with symptoms of hypoperfusion due to reduced cardiac output. Conclusion: This case describes a not previously reported presentation of high grade AV block with cardiac arrest and is in agreement with the 2008 American College of Cardiology/American Heart Association/Heart Rhythm Society (ACC/AHA/HRS) device guidelines recommendations for permanent pacemaker insertion.