This video shows an example of something seen in trauma units around the world everyday; the last flicker of life!
That little piece of tissue you see quivering in this heart is the sinoatrial node (SA node or SAN) still firing, but, with no response or heart contraction. This is formally known as PEA or ‘pulseless electrical activity’. The SAN is the heart’s natural pace-maker, it is the initial spark that normally allows for an electrical impulse to travel down a conduction pathway which allows each of our heart muscles to contract in a specific order giving rise to the heart beat. For example, in a healthy heart, an increase firing rate of this node will increase the heart rate and cardiac output, allowing for an increase in oxygen and nutrient delivery to our muscles such as during exercise or the fight-or-flight response. Just as you cannot start a fire without a spark, we cannot have a normal physiologic heart beat without the intial spark of this SAN.
What you see here is the thoracic cavity after an open-thoracotomy or ‘clam shell.’ This procedure is a last resort to save a patient’s life. SAN dysfunction (SND) is common, but until recently the pathophysiology was incompletely understood. It was usually attributed to idiopathic age-related fibrosis and cell atrophy or ischemia. It is now evident that changes in the electrophysiology of the SAN, known as electrical remodelling, is an important process that has been demonstrated in SND associated with heart failure, aging, diabetes, atrial fibrillation and endurance exercise.
With this in our hearts, let’s make the intentions to appreciate the fact that our SA node is currently firing on our behalf right now. For if it weren’t, this day would cease to exist.
Written by: @mrs_angemi (on Instagram) & Navpreet Singh Badesha
©03/05/2018 All Rights Reserved.
Video credit: @thetraumaguy (on Instagram).
This research was published in The National Library of Medicine.
