Heart to Heart Tom Petty's Death: a true Heartbreaker!

Tom Petty’s death has been masked by news of natural disasters and the  Las Vegas tragedy.  However, it is imperative that we examine the manner of death of such a prominent figure in American culture.  Additionally, I want to clarify some terms that we often read in the news reports.  His death was prematurely announced and then retracted…. Regardless, acknowledging initial reports that he had been found down and had prolonged period of likely lack of blood flow to his brain (which we term in medicine as "anoxia"), and the clue that he had been made a "DNR" (Do Not Resuscitate), I was sure it would be just a matter of time that he would expire.

He is reported as having had a "cardiac arrest."  Typically, a cardiac arrest is a term that we attribute to disruption of the normal cardiac rhythm or stopping of the heart.  In essence, cardiac arrest is the last thing that happens to us all, as our hearts stop and hence we begin to die.  This is often initially a reversible step.  We can with medications, CPR, and electrical cardioversion (defibrillation) restore the cardiac rhythm and maintain functionality.  This has to be achieved quickly (within minutes).  If prolonged, time is muscle and progressive injury would occur.   This is why immediate action is essential.  Calling 911 immediately is the only viable mechanism of survival for these patients.  Seconds count.  Driving oneself or loved one si laden with problems. Most importantly, the inability to administer life-saving medications and oxygen and appropriate resuscitation. 

While heart attacks can often lead to a cardiac arrest, not all cardiac arrests are related to a heart attack.  Sometimes, the heart rhythm is disrupted due to build up or changes in electrolytes (potassium, Ca++, Magnesium), build up of acid, ingestion of toxins, excessive drugs, and excessive alcohol to name a few.

What we term a heart attack is essentially the death of the cells of the heart which often ensues after a clot disrupts the flow of the blood through the coronary arteries-the first branches of the aorta that supply the muscle of the heart itself.  These clots are often a result of a atherosclerotic plaque rupturing and then clot forming.  The cells do not receive adequate nutrients (oxygen, glucose, etc) and this leads to change in the function of these myocytes (heart muscle cells). Once the coronary is occluded then lack of blood flow (given to lack of nutrient, "ischemia," and specifically lack of oxygen, "anoxia"),  the cells of the heart muscle no longer contract the same. Symptoms which are variable can develop. Some feel chest pain radiating to arm or neck.  Others sense pressure, tightness, burning, heart-burn, nausea, sweating, fatigue, lethargy.   These symptoms can varying women and diabetics.  When these cells are ischemic, they NO LONGER have the same capacity to maintain electrical rhythm.  This "arrhythmia" then results in changes in the ability of heart to keep up with the demands of the body and further leads to anoxia.  

Additionally, as the electrical activity and mechanical (pumping) ability is compromised the tissues (body) receive less nutrients and end up hav

ing low blood pressure (low perfusion).  This further leads to acid build up which then further compromises the heart’s ability to have normal electromechanical capacity. Once the tissues have had prolonged "anoxia" and acidosis (acid build up), then the process becomes essentially irreversible and what I as a physician-chemist term "the chemistry of death" develops.  This is irreversible and while some organs can recover, the brain is unforgiving and with brain death, chances of meaningful survival diminish. Hence the DNR order after discussion with family and loved ones.