A heart attack means that part of the heart muscle has lost its blood supply, has died, and has been replaced by scar tissue. Injured heart muscle causes injured electrical systems and can lead to ventricular fibrillation, in which the heart jiggles instead of beats. No heart beat means no blood to the body, which leads to sudden cardiac death
Sudden cardiac death doesn't really care if the heart attack was mild or not. The most common reason people die in the midst of a heart attack is due to an electrical short circuit caused by heart muscle that has been irritated.
In Mr. Russert's case, bystanders were ready to use an automatic external defibrillator (AED), but the paramedics arrived at the same time to deliver electrical shocks to the heart to treat the ventricular fibrillation. The treatment failed, and they were unable to reverse Mr. Russert's death.
The heart is a muscle just like any other muscle in the body, and it has blood vessels that supply it with oxygen and nutrients to function. As opposed to arms and legs that can take a break when they get tired from lifting or running, the heart cannot take a break, it needs to keep beating.
Emergency departments have special plans to deal with patients having chest pain. The patient is descended upon by doctors, nurses, and technicians. Lots of things happen simultaneously (oxygen, monitors, EKGs, IVs, medications, people asking questions to access the patient's condition) until the diagnosis of an acute heart attack (myocardial infarction) is ruled out. Time is muscle. If part of the heart isn't getting blood supply, that muscle will die and be replaced with scar tissue, with the end result of a life-long weaker heart.
But the patient has to get to the hospital, and many people die because of fatal heart rhythms like ventricular fibrillation.
Classic television scripts are not real life.
Classic television: The monitor puts out a high pitched wail. The doctor reaches for the paddle. "Everybody clear, I'm ready to shock." The patient bucks on the table; the camera zooms onto the monitor screen waiting to see the telltale sign of a regular heart beat. The heart starts beating, everybody cheers, and the patient wakens almost immediately.
Real life: The electrical shocks are delivered with no change in the pattern on the heart monitor. Intravenous drugs are used to try to make the heart cells more likely to respond to defibrillation. More shocks, more drugs. All fail, and the patient is declared dead. Resuscitation from death is not a given. More often than not, the patient dies.
For those that survive, quality of life depends upon the length of time the brain was deprived of blood flow. The more potential damage to brain function will occur the longer the amount of time it was deprived of oxygen. The body cannot generate more brain cells, and when brain cells are lost, they are lost forever. It is a tragedy when the body lives, but the brain doesn't.
Kelsey Grammer is swimming in the ocean well away from any medical care and survives his heart attack. Tim Russert is sitting in the middle of a big city with an AED nearby and yet he dies. Philosophers try to explain life's mysteries and explain events in the world. The answer seems easy to many of us in the ER...life isn't fair.