LYNN – The cause of 54-year-old former Mayor Patrick J. McManus’ death last Friday remains “pending,” according to his death certificate filed in the city clerk’s office.”Our assumption is it was a heart attack. Officially we don’t know,” said McManus’ brother, Garry, on Friday. “He hadn’t been feeling well; he thought he had kidney stones. At the same time, he was really energized by the campaign. He did 47 block parties for the Fourth of July.”Garry McManus said heart problems “run in the family” but stressed his brother did not show any signs of them.The state Chief Medical Examiner’s office declined Thursday to explain or provide details on why a specific cause of death for McManus is not listed on the document. The office’s Web site indicates cause of death is listed on a certificate as “pending” in cases where the examiner’s office is still reviewing the reason for a death.McManus’ death certificate also indicates that the manner of his death is classified as “pending investigation,” including the results of an autopsy.”My understanding is that autopsy final results may not come in for up to three months. The temporary certificate was issued to allow us to take care of whatever contractual things we can do,” Garry McManus said.Dr. Peter Cummings with the Medical Examiner’s office pronounced McManus dead at 9:40 a.m. on July 10 after he was reportedly stricken at the Baltimore Street home where McManus lived with his wife, Debra, and their four children.District Attorney spokeswoman Carrie Kimball Monahan on Friday said State Police officials told her that “pending” status on a death certificate “is a routine thing to write when you are waiting for toxicology – something in the system that played a role in the person’s death.”McManus served as mayor from 1992 to 2002 and was mounting another run for the city’s top office at the time of his death. A six-hour wake was held last Tuesday in his honor at St. Pius V Church and he was buried from St. Pius on Wednesday.”The family really wants people to know we are blown away with the support the community has shown,” Garry McManus said.