Origins

Tyler Meagher was once the leader of Humans Engaging All Racial Terrorism also know as H.E.A.R.T. along with Luz Delgado, Mei Fin, Fiona McCormick and Danita Trevoni. They were hired by the Cypress Hill who wanted the recent killings to stop, H.E.A.R.T. believed that Ghost Rider was the cause of this and they attacked him. The team hardly proved a match for Ghost Rider and upon returning from their failed mission their headquarters was assaulted by a shadow organization which killed all but Tyler Meagher, taking her hostage. It was then that this organization was revealed to be the Firm, a group of people who experimented on individuals with super powers and studied magic. While Tyler Meagher had none of these qualities she was a fearsome fighter. The then leader of the Firm ordered them to re-create her body enhancing it and giving her the abilities to bring Ghost Rider back for experimentation. From there on Tyler Meagher was no more and she became Heart Attack.
 

New Life, Old Rivals

Upon awakening in the facility of the Firm, Tyler was informed that she and her comrades had been attacked by Ghost Rider. With her memory still fuzzy she believed them so the Firm loaded her with guns and a special suit with which she could reap her vengeance. The hunt for Ghost Rider began immediately and upon confronting him, she was infuriated that he didn't recognized her under the armor setting her into a half-hazard rage until he overcame her, knocking off and revealing Tyler Meagher underneath. She fled swearing she would avenge her team members.
 
Sometime later Ghost Rider was attacking the Firm when he was confronted by Heart Attack. In the midis of the battle he revealed the mastermind that sent the shadow agents to kill H.E.A.R.T. had been none other then the leader of Firm, Stern. At the same time Stern was recuperating from Ghost Rider's panacea stare when he was killed by Centurious.

Powers & Abilities

As the leader of H.E.A.R.T. Tyler was trained in several forms of hand-to-hand combat techniques and firearms operations, where she excelled in knowledge of weaponry and battle tactics. After she was captured by the Firm all her previous abilities were augmented through implants and a mixture of basic magic. These abilities give her higher reflexes, strength, stamina and nearly perfect accuracy. She wore a special suit designed by the Firm that protected her from most blunt attacks and had razor sharp claws. This enhancement was done only for the express purpose of capturing Ghost Rider. She seems to use heavy weaponry with no problem and even several laser guns that dwarf her body.