It's Not the Pulse, It's the Perfusion

     Attack One responds to a report of a man having a heart attack. The call arrives in the late afternoon from a business address. The crew is guided by an anxious security guard to an upstairs office, where they are told "the boss" is having a heart attack. They find a 58-year-old man lying on an office couch, a pillow propping up his legs.

     Crew members address the man quickly. His assistant tells them the patient complained of chest discomfort and light-headedness. He is not responding verbally. He has a cold washcloth on his forehead, but beyond that, his skin is warm and dry. The pulse oximeter counts a very rapid pulse rate, with saturation at 95%. His breathing is regular at 28 times a minute. His blood pressure is palpated at about 110.

     Since the patient is not communicating with them, the paramedics pull out the big patches. They also place the leads for the cardiac monitor. The patient reacts by wincing when the intravenous line is started at his elbow, but continues to be quiet. The assistant chimes in again, reporting that the man has had a recent history of heart problems and recently underwent some tests. He was told he may need some type of surgery, and that had concerned him a great deal. It has been stressful at the office, and all the staff have been putting in long hours. The patient had an abrupt onset of his symptoms just prior to the call for help.

     The cardiac monitor shows a fast heart rhythm, with a rate of almost 190 beats a minute. At that rate, it's hard to determine whether it's a regular or irregular rhythm on the small monitor screen, so crew members utilize the print function to produce a 10-second paper recording. On the paper, it's obvious that this is a regular, narrow-complex rhythm, with a rate of about 190 beats.

     The paramedics weigh their options. Should they shock the patient or attempt to use medication? One decides to include the patient in the decision-making. Noting that the patient has skin that's perfusing well and capillary fill sufficient to produce a good reading on the pulse oximeter, he has reason to believe the patient's brain is also perfusing sufficiently.

     "Sir, your heart is beating very fast, and we need to get it to slow down to make you feel better," he firmly tells the man. "We're trying to decide whether to give you medicine in your vein or apply a big shock across your chest to stop your heart temporarily and then have it return to its normal rhythm."

     The man's eyes open quickly. "You're going to do what?!" he asks.

     With that comment, the victim complied with a decision rule I refer to as Augustine's Law. This rule is derived from an observation that if a patient doesn't refuse the electricity, then he probably needs it.

Prehospital Treatment
     The crew is then able to discuss with the patient the need to correct his fast heart rhythm.

     The patient says he was quite upset about his recent diagnosis of a heart valve problem and having to contemplate corrective surgery for it. Work had been very stressful, and he was drinking more caffeine than usual. With the onset of the fast heart rate, he felt uncomfortable and a little short of breath. He denies having any pain. He says he was so distressed that he doesn't remember what happened until the crew asked him about "getting shocked."

     The paramedics explain they could likely convert the fast, narrow complex and regular rhythm with one or two doses of a medicine that's given in a vein and momentarily stops his heart. The patient remembers having that occur the last time he was in the hospital, and the first dose of the medicine corrected his rhythm. He tells them to proceed.

     The medics prepare the patient for administration of the medication (adenosine), then quickly give the dose in the antecubital vein. The patient's heart rhythm stops for a moment, then returns with a regular sinus rhythm at a rate of about 90 beats a minute. The patient reports feeling much better.