I heard Natalie Cole’s 1987 song “Jump Start” on the radio the other day. “Jump start my heart/ Charge me up when I’m runnin down/ Oh, jump start my heart/ Lift my feet up off the ground”. Of course, I would think about what that means in the ICU world. It means defibrillators, pacemakers, and medications; all to jump start the heart.
The heart has these incredible pacemaker cells which set the heart’s beat. They send an electrical impulse to the muscle cells and together, in sync, those muscle cells contract. Spontaneous synchronicity! We’re internally wired with electrical current in our heart. Internally wired. An electrical current sends a message to depolarize the muscles of the heart every single time your heart beats!
When the electrical system has a problem, the rhythm of the heart is affected. I remember one winter day I cared for a man who passed out in his car and hit a light pole. He sustained minor injuries but the paramedics found his heart rate would dip to only 28-30 beats a minute (normal is 70). He made an impression on me because he would say “Here I go again” and then his heart beat would slow way down and his eyes would start to roll back in his head and after jarring him and having him cough his heart beat would come back up. The cardiologist at the bedside snapped “Karen, pay attention! Pay attention!” because he was handing me wires to hook to the pacemaker box after he placed a temporary pacemaker. I was paying more attention to the heart rhythm and this man saying “Here I go again” than the task at hand. It was a first for me so I was a bit in awe of the entire situation and at the same time learning how to assist the cardiologist for the first time with a temporary pacemaker. Once I secured the temporary wires to the pacemaker box, his heart once again had an electrical signal saying “beat” at 70 times a minute. >Wow. He had a permanent pacemaker placed and was back on the road in a few days.
The electrical system can also go a little haywire in the lower chambers of the heart and cause a very fast irregular rhythm; when this happens, the heart cannot pump that fast or the cells are out of sync and not enough blood is pumped out to the brain and body. Back in the day when I first started nursing, I remember giving a “precordial thump”, basically taking my arm and dropping my fist onto a man’s chest for an irregular heart rhythm, to try and convert it back to normal. And by the way, he immediately said “Hey, what’d you do that for?”. If this irregular ventricular rhythm continues, a person can feel lightheaded or dizzy, and they might pass out or have a cardiac arrest. A defibrillator delivers a large enough shock that “resets” the electrical system and normal conduction returns. I remember caring for a woman who was admitted with episodes of nearly fainting. They were happening often enough that she went to her doctor who sent her to the hospital. It turns out she had an irregular rhythm. Luckily for her, the rhythm would correct itself. But for some folks, it doesn’t correct and they need to go home with a defibrillator. We use devices that combine a pacemaker and a defibrillator that are implanted under the skin in the chest, approximately 2.5 X 2 inches in size, with a battery life of 6-10 years. These devices definitely have the ability to jump start the heart.
What about medications? In a cardiac arrest situation, I.V. epinephrine (adrenaline) is given to increase the conduction of electrical impulses to the heart muscle, increase the heart rate, increase the strength of muscle contraction and raise blood pressure and blood flow to the brain and body. In a “code blue” situation, a flatline transforms into a heart rhythm with administration of straight adrenaline in the bloodstream. A few other medications are used to increase the heart rate, but a majority of the time, we use the defibrillator, I.V. epinephrine and sometimes a pacemaker to jump start the heart.
We’ll see what the next Top 40 list inspires…
“Electricity is really just organized lightning.”- George Carlin