OSBORN WAVES DURING TARGETED TEMPERATURE MANAGEMENT

Abstract

SESSION TITLE: Fellows Cardiovascular Disease Posters SESSION TYPE: Fellow Case Report Posters PRESENTED ON: October 18-21, 2020 INTRODUCTION: Osborn waves also known as current of injury, J waves, camel-hump waves, hypothermic waves, late delta wave; is a deflection with a dome/ hump at the J point (R-ST junction) on the EKG. First described in 1953 by Dr. John Osborn while studying effects of hypothermia in dogs and was considered a bad prognostic sign leading to ventricular fibrillation. Most commonly seen in hypothermia and other causes include hypercalcemia, brain injury, subarachnoid hemorrhage, cardiopulmonary arrest from oversedation, vasospastic angina or idiopathic ventricular fibrillation, early repolarization and Brugada syndrome. Osborn waves are usually seen in the inferior and lateral precordial leads while in Brugada syndrome the EKG changes are seen in the right precordial leads. CASE PRESENTATION: A 50 year old female with past medical history of schizoaffective disorder , diabetes mellitus, hypothyroidism, obesity, sleep apnea presented to the Emergency room s/p cardiac arrest secondary to aspiration and ROSC achieved after 25minutes. Initial arterial blood gas post intubation showed respiratory acidosis with arterial Ph of 7.18 which was appropriately corrected with ventilatory changes. Targeted temperature management (TTM) was initiated post ROSC. Patient was admitted to the Medical ICU. She was sedated and paralysed for shivering while on TTM. Initial Troponin was 0.06. Patient was hemodynamically stable. Initial EKG showed narrow complex tachycardia (figure1). She was cooled using arctic sun protocol with goal of 33 F (92C). 12hrs into TTM patient developed bradycardia with heart rate of 40bpm , QTc 574 with characteristic osborn waves on EKG (figure2). Blood pressure was stable. She was rewarmed with resolution of bradycardia and osborn waves (figure3). 2decho with ejection fraction of 36-40% and no valvular or wall motion abnormality. DISCUSSION: Hypothermia is defined as core body temperature <95°F (35°C), and causes EKG changes of diagnostic and prognostic significance. Sinus tachycardia develops initially as part of the general stress reaction, however sinus bradycardia with prolongation of PR, QRS and QTc intervals occurs at temperatures less than 90°F. Atrial ectopic activity leading to atrial fibrillation and ventricular fibrillation can occur when temperatures reach 86°F or lower. At this level of hypothermia, 80% of patients have Osborn waves that consist of an extra deflection at the end of the QRS complex. Asystole occurs at temperature <60°F. CONCLUSIONS: Osborn waves are known to result from the high potassium gradient within the epicardium relative to the endocardium during ventricular repolarization. The differential diagnosis of prominent Osborn waves including early repolarization, hypercalcemia, and the Brugada syndrome should be considered and risk of ventricular arrhythmias should be considered. Reference #1: Maruyama M, Kobayashi Y, Kodani E, et al. Osborn waves: history and significance. Indian Pacing Electrophysiol J. 2004;4(1):33-39. Published 2004 Jan 1. Reference #2: Imad A. Alhaddad, Mohammed Khalil, and Edward J. BrownJr. Osborn Waves of Hypothermia. Circulation. 2000;101:e233–e244 Reference #3: Mori J. Krantz, M.D., and Christopher M. Lowery, M.D. Giant Osborn Waves in Hypothermia. N Engl J Med 2005; 352:184. DOI: 10.1056/NEJMicm030851 DISCLOSURES: Speaker/Speaker's Bureau relationship with pfizer Please note: $1001 - $5000 Added 06/11/2020 by Yizhak Kupfer, source=Web Response, value=Consulting fee No relevant relationships by Ratnam Santoshi, source=Web Response