By: THE CANADIAN PRESS

VANCOUVER - A heart specialist has told a public inquiry in Vancouver into the use of Tasers that a shock from the energy weapon can be deadly.

San Francisco cardiologist Zian Tseng says a Taser shock at a vulnerable period in the heartbeat can produce a fatal rhythm. He says the heart could be even more vulnerable if there is high adrenaline or drugs, such as cocaine, present in the person's system.

Tseng told the inquiry that just because someone dies minutes after a Taser application, it doesn't mean the two aren't connected.

He recommended more independent study of the electrical shock weapons, and that police be taught to avoid using the Taser more than once and avoid the chest area.

The initial phase of the inquiry is examining the general use of shock weapons by police and will later look specifically at the case of Robert Dziekanski, who died after being hit twice with an RCMP Taser at Vancouver airport last fall.