Cardiac asystole following cannabis (marijuana) usage--additional mechanism for sudden death?

A 21 year old university student previously operated during infancy for an unobstructed total anomalous pulmonary venous drainage with an excellent result, was noted on a routine follow up 24 h Holter monitor to have multiple pauses related to cardiac asystole, the longest lasting 5.8 s and temporally related to marijuana inhalation. A repeat Holter was normal following a two week cessation of marijuana usage and again when carried out 3 months later. The documented periods of asystole may be a precursor of sudden death seen in addicts even without evidence of ischaemic heart disease.