Cannabis induced cardiac arrhythmias: a case series

Abstract

Introduction Cannabis use is known to be associated with significant cardiovascular morbidity. We describe three cases of cannabis-related malignant arrhythmias, who presented to the cardiac department at our institution within the last 2 years. All three patients were known to smoke cannabis on daily basis. Case summaries Case 1: A 30-year-old male, presented with recent onset of palpitations. A 12-lead electrocardiogram (ECG), transthoracic echocardiogram (TTE), and blood tests were all normal. During an inpatient exercise treadmill test (ETT) he developed polymorphic ventricular tachycardia (VT), which converted spontaneously to supraventricular tachycardia (SVT) in the recovery phase of the test. Subsequent risk stratification with cardiac magnetic resonance imaging and coronary angiography showed no abnormalities and an electrophysiological study was negative for sustained VT, however, SVT was easily induced with rapid conversion to atrial fibrillation. The patient successfully stopped smoking all tobacco products including cannabis and was treated with beta-blockers, with no further episodes of arrhythmia. Case 2: A 30-year-old male presented to the Emergency Department with palpitations, chest pain, and dizziness that improved during exertion. His initial ECG demonstrated complete atrioventricular block (AVB). Subsequent traces showed Mobitz Type I and second-degree AVB, which converted to atrial flutter after exertion. Routine blood tests, TTE, and an ETT were all normal and he was discharged home with no conduction abnormalities. Case 3: A 24-year-old male presented with two episodes of syncope. Baseline examination was normal, with an ECG showing a low atrial rhythm. Interrogation of his implantable loop recorder showed episodes of early morning bradycardia episodes with no associated symptoms. Discussion Cannabis-related arrhythmia can be multiform regarding their presentation. Therefore, ambiguous combinations of arrhythmia should raise suspicion of underlying cannabis abuse, where clinically appropriate. Although causality with regards to cannabis use cannot be proven definitively in these cases, the temporal relationship between drug use and the onset of symptoms suggests a strong association.

The Old and the New: Cardiovascular and Respiratory Alterations Induced by Acute JWH-018 Administration Compared to Δ9-THC—A Preclinical Study in Mice

“…Arrhythmias can be induced not only by CB-dependent mechanisms, but also by acting on other targets in a CB-independent manner [ 34 , 35 ]. Similarly, Δ 9 -THC-induced tachycardia is related to biphasic and dose-dependent effects, and low or moderate doses cause a direct sympathetic stimulation, leading to tachycardia, hypertension, and increased cardiac output, and a higher dose a Δ 9 -THC-induced parasympathetic vasodilatation with bradycardia and hypotension [ 57 , 106 ]. The autonomic dysregulation results in increased cardiac output and workload, thus increasing the myocardial oxygen demand induced by Δ 9 -THC, coupled with microvascular/coronary artery spasm and the prothrombotic state arising from Δ 9 -THC use, which has been associated with an increased risk of acute coronary syndrome, even in the absence of an atherosclerotic coronary artery disease [ 107 ].…”

Cannabis Use and the Risk of Cardiovascular Diseases: A Mendelian Randomization Study

“…Previous studies found that cannabis use independently predicted the risk of acute ischemic stroke among younger adults (adjusted OR, 1.17; 95% CI 1.15-1.20; p < 0.0001) (3) and HF in 18-to 55-year-old individuals (OR, 1.1; 95% CI 1.03-1.18; p < 0.01) (4) compared to non-users using data of the Nationwide Inpatient Sample (NIS) database. Several case reports have described the occurrence of AF following cannabis consumption, suggesting that cannabis use could be a cause of AF (5)(6)(7).…”

Accidental Ingestion of Tetrahydrocannabinol-Laced Gummies Causing Bradycardia and First-Degree Atrioventricular Block in a Pediatric Patient: A Case Report

“…In the pediatric population, tachycardia is the most common cardiovascular symptom [4,5]. Tachycardia results from sympathetic stimulation and can also be due to reflex tachycardia from vasodilation secondary to parasympathetic stimulation [11,12]. Bradycardia, which was observed in this case, is an uncommon cardiovascular manifestation in children with marijuana exposure.…”

“…Incidence is not well established but from the studies reviewed, it can be estimated to range from 0.4% to 4% [19]. Both bradycardia and hypotension can result from increased cardiac vagal tone, especially with higher doses of exposure [11]. This could mean that the child in this case must have ingested a high dose of THC to elicit a parasympathetic response.…”

“…While the psychoactive effects of cannabis are well known, the cardiovascular effects are not fully understood, especially in children. Heart rate, rhythm, and blood pressure abnormalities are some of the reported signs of toxicity [4,5,9], which were thought to be brought about by the activation of cannabinoid receptors in the cardiovascular system and autonomic nervous system [10][11][12]. Tachycardia is the most common cardiac manifestation of cannabis exposure but there are very few cases of bradycardia and arrhythmia reported in the literature [4,5,9].…”