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The Beta Blocker and Clonidine Protocol


Lesson 4
Lesson 4 - Beta Blockers

22. Summary: A Thought Experiment

How can this be? How can a week of atenolol reduce two year mortality? Let's do a thought experiment. Suppose we take 200 people with really, really, bad coronary artery disease. It is a thought experiment, so I can get the sickest patients I want, enrollment is easy, consent is easy, and the paper work is minimal. We randomized the patients into two groups. 100 patients are sent to military boot camp: Twenty-four hours a day of exercise, stress, pain, tachycardia, poor or no sleep, etc. The other group of 100 patients gets catered meals in a hotel with a comfortable chair, TV, and pampering. What is going to happen?

Well, some of the people in the boot camp group are going to die from the forced exercise. Of the people who don't die, there is going to be episodes of myocardial ischemia, that ischemia is going to crack intracoronary plaque. Coronary ischemia damages the coronary endothelium. Once it is damaged, activated platelets cause vasoconstriction. In normal coronaries, activated platelets cause vasodilation, but in ischemia damaged coronaries, activated platelets cause vasoconstriction. So, ischemia begets more ischemia, begets infarction, which may lead to death. The stress leads to ischemia, which leads to infarction, which leads to death. Those deaths may occur during the forced exertion or in the next few weeks to months. The week of stress has set a chain of events going that leads to cardiac morbidity and mortality.

What about the people in the comfy chair group? Well, we never stressed them. We never started the vicious cycle. They just enjoyed themselves.

Thought Experiment

bullet 200 People with Coronary Artery Disease
bullet 100 sent to boot camp for a week of forced exercise
bullet
100 placed in comfortable chair with TV and catered meals
bullet Of those who don’t die during the week of forced exercise what will happen in next six months?

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Content by Art Wallace MD PhD
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