Introduction
Cannabis is globally the most commonly used psychoactive substance and
its use is increasing world over for both medicinal and recreational
purposes.Physicians can expect to encounter more patients who use or
abuse marijuana.Both acute and chronic adverse effects of cannabis on
cardiovascular system like myocardial infarction, cardiomyopathy,
tachyarrhythmias, stroke and cardiac arrest have been described and its
consumption is a risk factor for cardiovascular disease in young
adults.1The psychoactive constituent of marijuana,
Δ9-tetrahydrocannabinol (THC), is an agonist of both cannabinoid
receptors 1 and 2 (CB1R and CB2R), and exerts its psychoactive and
adverse cardiovascular effects through the activation of CB1R in the
central nervous and cardiovascular systems. There are several proposed
mechanisms for cannabis induced tachyarrhythmia but how it causes
bradyarrythmia is not very clear and mainly thought to be mediated by
increased vagal tone. 2 Few cases of bradyarrythmia
have been described previously 3-13 but reversible
high grade atrio-ventricular (AV) block with electrophysiologic
determination of site of conduction blockade is not reported to best of
our knowledge. Our Patient presented with high grade AV block. The
electro-physiological study revealed that the site of blockade was
supra-his(nodal) and AV conduction completely improved at follow up, all
of which support that cannabis induced bradyarrythmia are vagally
mediated.