Please keep Mrs. Clark in your thoughts

To all my blog fans, I have some bad news. Last week Mrs. Carolyn Clark went into cardiac arrest while speaking at a scholarship awards ceremony. Fortunately, two doctors in the audience resuscitated her and she was taken to the hospital. From my understanding, she underwent surgery to have an implantable cardioverter defibrillator (ICD) placed in her. After she was released from the hospital, she climbed the stars at her house and her new ICD sent a jolt of electricity thru her body! She is back in the hospital now.

For those of you who do not know Mrs. Clark, she is a wonderfully warm person who took it upon herself to graciously host the post funeral arrangements for my little brother last month. I am indebted to both the Prothro and Clark Families for their kindness and support over the past 30 years.

Please keep Mrs. Carolyn Clark in your thoughts.

HOW THE HEART WORKS: Follow the diagram, double click image to enlarge, (MOM) you might need to Ctrl N to put it in a new window so you can follow along!!! The numbers in the diagram show the path of blood flow in order thru the heart. Blue areas are without oxygen; red areas are with oxygen; R= right; L= left. Hearts work like this: blood comes from body in veins to the heart, to the R atrium, to the R ventricle, to the lungs to get oxygen, from the lungs with oxygen, to the L atrium, to the L ventricle, and out to the head and body in arteries. Cardiac nodes are basically large groups of nerves that control the heart. The SA node is of paramount importance because it triggers the heart to contract (beat), while the AV node causes the electrical signal sent from the SA node to slow down. This is WHY the atria and ventricles do NOT beat in unison and WHY we hear the slightly staggered “lub-dub” of a heartbeat.

ICD’s are designed for people that have a heart that beats dangerously fast, has ventricular tachycardia, or is prone to ventricular fibrillation. The ICD is implanted under the skin of the left shoulder and has two leads (paddles/sensors) inside the heart: one on the AV node and the other in the bottom of the R ventricle. ICD’s work by stimulating the AV node to slow the electrical signal sent by the SA node, thereby slowing the heart . ICD’s also function to maintain that both ventricles beat simultaneously AND after the simultaneous beat of both atria.

Have I lost anyone yet? The ound we hear is really from the heart's valves opening and shutting, but I'm trying to be simple. I could really go into specific details about depolarization, voltage gated ion channels, calcium release, cardiac and smooth muscle receptors, carrier proteins, etc, if anyone needs me to, thanks to my Aggie education!

Other devices: pacemakers are designed to speed up slow heartbeats (SA node), while cardiac resynchronization therapy (CRT’s) is aimed at treating heart failure. Also, cardiac arrest is slightly different from a heart attack. Usually a heart attack has warning signs like nausea, chest pain, numbness, and if all the symptoms are ignored, the patient goes into cardiac arrest, which is when the heart actually completely stops beating!

Disclaimer: I'm not a doctor YET, nor am I familiar with Mrs. Clark’s specific circumstances. I am going off hearsay (from my mother).