Jim McKenny, a well-known television personality and former defenceman with the Toronto Maple Leafs, was in stable condition yesterday in South Miami Hospital after suffering a heart attack while on vacation in Montego Bay, Jamaica. "I spoke to him on the telephone [yesterday morning]and he was in good spirits -- it was almost like I was standing on the first tee with him," said Stephen Hurlbut, vice-president of news programming for CITY-TV. According to Hurlbut, McKenny, a sportscaster on CITY Pulse at 6,who will turn 56 on Dec. 1, was transported by air ambulance to Miami from Montego Bay on Thursday night after suffering chest pains and collapsing after a workout. He underwent an angioplasty early yesterday morning and will stay in hospital for observation before returning to Toronto within a week. Hurlbut said doctors have told McKenny he will need six weeks off work to recover.