A citywide system used in Ottawa, Canada has dramatically cut the time heart attack patients have to wait to receive artery-opening procedures and may be helping to save lives. The system involves paramedics performing electrocardiograms in the field to diagnose heart attacks and then calling the results into a specialized heart center where a heart attack team is put on alert. The patient then is taken directly to a catheter lab where he or she undergoes a balloon angioplasty procedure....