COCAINE-INDUCED COMPLETE HEART BLOCK THAT WAS REVERSED BY NALOXONE

Abstract

TOPIC: Critical Care TYPE: Medical Student/Resident Case Reports INTRODUCTION: Cocaine is largely known for its abuse potential and its toxicity. We present a unique case of cocaine induced complete heart block (CHB) that resolved with IV naloxone administration. CASE PRESENTATION: 49-year-old woman with history of coronary artery disease, mechanical mitral valve, heart failure, anxiety, and depression on aspirin, warfarin, furosemide, gabapentin, citalopram, quetiapine, and clonazepampresented with 3 days history of abdominal pain, diarrhea, and vomiting. The initial vital signs showed heart rate of 32 bpm and blood pressure of 133/69 mmHg. Examination remarkable for epigastric tenderness. Initial labs were significant for WBC of 13.6 x10(3)/mcL, hemoglobin of 8.3 gm/dL, elevated creatinine of 1.24 mg/dL, BUN of 40.6 mg/dL, AST of 206 IU/L, ALT of 280 IU/L and lactic acid 3.7 mmol/L. EKG showed CHB. Urine toxicology was positive for cocaine and benzodiazepines. CT scan of abdomen and pelvis showed mild colitis. Patient was started on IV fluids, IV antibiotics for acute colitis and morphine for pain. Transvenous pacing and dopamine infusion were initiated for bradycardia and hypotension. Patient underwent permanent pacemaker placement due to persistent CHB and during the procedure, patient received fentanyl. Post procedure patient became lethargic, IV naloxone 0.4 mg was given for opioid toxicity with observed conversion of heart rhythm to normal sinus rhythm. Narcotics were discontinued. Patient was discharged in stable condition after 13 days of hospitalization. On follow up visits her EKG recordings showed normal sinus rhythm with no dependency on pacemaker. DISCUSSION: One of the very detrimental effects of cocaine toxicity is cardiovascular sequalae including tachyarrhythmias as well as bradyarrhythmias. Cocaine blocks the fast sodium current and reduces sinus node automaticity and leads to bradycardia. The treatment of tachyarrhythmia related to cocaine intoxication includes benzodiazepine which blunts the hyper sympathetic state mediated by cocaine. From literature review there is no clear guidelines in the management of cocaine induced bradyarrhythmia.Naloxone is used for opioid intoxication, thought to be competitive antagonist at opioid receptors. Our patient received IV naloxone with immediate resolution of CHB. From literature review, we found a case report on perindoprilintoxication inducing severe bradycardia and profound hypotension completely resolved with naloxone infusion. This is the first case of cocaine induced bradycardia that was treated with IV naloxone. We are not sure of the exact mechanism, but administration of naloxone has been associated with increase heart rate, cardiac output, and arterial blood pressure due to increased catecholamines. CONCLUSIONS: In conclusion, naloxone might be a possible treatment for cocaine induced CHB, but further studies are required to further elicit this observed effect. REFERENCE #1: Kariyanna PT, Jayarangaiah A, Al-Sadawi M, Ahmed R, Green J, Dubson I, McFarlane SI. A Rare Case of Second Degree Mobitz Type II AV Block Associated with Cocaine Use. Am J Med Case Rep. 2018;6(7):146-148. doi: 10.12691/ajmcr-6-7-7. Epub 2018 Aug 21. PMID: 30294672; PMCID: PMC6173318. REFERENCE #2: Robert M, De Bels D, Chaumont M, Honoré PM, Gottignies P. Angiotensin converting enzyme inhibitor intoxication: Naloxone to the rescue? Naloxone for ACE inhibitor intoxication. Am J Emerg Med. 2019 Jun;37(6):1217.e1-1217.e2. doi: 10.1016/j.ajem.2019.03.046. Epub 2019 Mar 28. PMID: 30952604. REFERENCE #3: Franklin SM, Thihalolipavan S, Fontaine JM. Sinus Bradycardia in Habitual Cocaine Users. Am J Cardiol. 2017 May 15;119(10):1611-1615. doi: 10.1016/j.amjcard.2017.02.018. Epub 2017 Mar 1. PMID: 28341362. DISCLOSURES: No relevant relationships by Oluwafemi Ajibola, source=Web Response No relevant relationships by Matthew Apedo, source=Web Response No relevant relationships by Susan Collins, source=Web Response No relevant relationships by Ayesha Iqbal, source=Web Response No relevant relationships by Pang Lam, source=Web Response