eng Science and Education Publishing American Journal of Medical Case Reports 2374-216X 2019-07-16 7 9 193 196 10.12691/ajmcr-7-9-3 AJMCR2019793 article Pramod Theetha Kariyanna 1 Apoorva Jayarangaiah 2 Oleg Yurevich 2 Jonathan Francois 3 Denis Yusupov 3 Angelina Zhyvotovska 3 Louis Salciccioli 3 Sudhanva Hegde 3 Samy I. McFarlane Samy.mcfarlane@downstate.edu 3 Division of Cardiovascular Disease, Department of Internal Medicine, State University of New York, Downstate Medical Center, Brooklyn, N.Y, U.S.A-11203 Department of Internal Medicine, NYC Health and Hospitals/Jacobi Medical Center, Bronx, N.Y., U.S.A- 10461 Department of Internal Medicine, State University of New York, Downstate Medical Center, Brooklyn, N.Y, U.S.A-11203 Marijuana is the most commonly abused recreational substance. With the increasing legalization of marijuana, its use is expected to rise. Delta-9-tetrahydrocannabinol (THC) is the psychotropic component of marijuana, acting via CB1 and CB2 G-protein coupled cannabinoid receptors. Marijuana has serious cardiovascular effects including tachycardia, orthostatic hypotension, angina and myocardial infarction to name a few. Previous reports by our group and others documented various arrhythmias other than atrioventricular nodal reentrant tachycardia (AVNRT) that are associated with marijuana use. In this report, we present a case of AVNRT associated with marijuana use. Marijuana in high doses stimulates parasympathetic nerves. While parasympathetic stimulation can increase the refractory period of the fast conduction pathway, it has no effect on the slow and retrograde pathways, therefore its use creates an ideal milieu for AVNRT initiation and maintenance. Our case report highlights the importance of including marijuana use in the differential diagnosis, as a possible trigger, for patients presenting with AVNRT that is otherwise unexplainable. http://pubs.sciepub.com/ajmcr/7/9/3/ajmcr-7-9-3.pdf marijuana arrhythmia avnrt