Cardiac Arrest Following Cannabis Use

A 39-year-old woman with a history of daily tobacco and cannabis use and no prior cardiac history presented from home following an asystole cardiac arrest. The arrest lasted for 4 minutes and return of spontaneous circulation was achieved with compressions without administration of shocks or medications. Electrocardiogram revealed ST-segment elevation in leads V2-V5 and depression in III and aVF. She was immediately taken for coronary angiography, which revealed normal coronary arteries. Echocardiogram revealed an ejection fraction of 55% and no wall motion abnormalities.Further evaluation included monitoring troponin levels, which peaked at 0.130 ng/ml (normal: <0.032 ng/ml) 2 days after admission. The patient had no further cardiac arrests or other cardiac complications. Urine toxicology using mass spectrometry was collected approximately 4 hours after the arrest and was analysed to determine any acute ingestion as a possible aetiology for the patient's presentation. It was significant for the presence of tetrahydrocannabinol, hydrocodone, hydromorphone and fentanyl. The patient used hydrocodone for chronic pain at home and she was administered fentanyl in the hospital. Toxicology specialists were consulted, and it was determined that acute intoxication was not likely since these drugs were at subclinical levels. Once extubated, the patient had no recollection of the event and denied any preceding symptoms, prior episodes, increase in her cannabis use or the use of any illicit drugs. She did not require any medical therapies beyond sedation while intubated. In the absence of other aetiologies and with the evidence of normal coronary arteries on coronary angiography, cannabis use was attributed as the aetiology for her cardiac arrest. Following the cardiac arrest, she gradually recovered without any complications. The patient was recommended to abstain from cannabis use; however, she dismissed cannabis as the cause of her cardiac arrest, stating `it is harmless'.