Multiple Pathways Implicated in Arrhythmia Pathogenesis Among Cannabis Users

Multiple hypothesized pathways could lead to cardiac arrhythmias among cannabis users, according to study results published in the American Journal of Cardiology.

In this retrospective study using the 2016 Kids’ Inpatient Database, researchers investigated the prevalence of cardiac arrhythmias among teenagers ages 13 to 19 years using cannabis in the United States (N=68,793). Using the International Classification of Diseases, Tenth Revision, Clinical Modification codes, researchers identified cannabis use, dependence, and abuse; ventricular fibrillation; palpitation; atrial flutter; atrial fibrillation; pre-excitation syndrome; and long QT syndrome.

For every 100,000 cases of cannabis users, the mortality rate of teenagers with cannabis use, abuse, or dependence was 106.3 (73 cases). Long QT syndrome was the most common of the conditions studied, with 353 cases reported (513.1/100,000 cases), followed by 96 cases with palpitations (139.5/100,000 cases), 80 cases with atrial fibrillation (116.3/100,000 patients), 57 cases with pre-excitation syndrome (82.3/100,000 cases), 26 cases with ventricular fibrillation (37.8/100,000 cases), and 25 cases with atrial flutter (36.3/100,000 cases).

This study was limited by the use of the Kids’ Inpatient Database, which may have had coding errors and data entry errors. The use in assessing long-term follow-ups was restricted.

Despite the deleterious cardiac effects of marijuana, it remains a very popular drug among teenagers. Potential pathways leading to cardiac arrhythmias include adrenergic stimulation and atrial ischemia. Catecholamine surges have been linked with ventricular fibrillation. Because of the blocking of the hERG channels, long QT syndrome can also be seen in cannabis users.

Reference

Ramphul K, Joynauth J. Cardiac arrhythmias among teenagers using cannabis in the United States [published online September 27, 2019]. Am J Cardiol. doi: 10.1016/j.amjcard.2019.09.002