#258 – AMA #48: Blood pressure—how to measure, manage, and treat high blood pressure

In this “Ask Me Anything” (AMA) episode, Peter delves into the critical subject of blood pressure, which is one of the three primary causes of atherosclerosis, along with high apoB and smoking. He begins by unraveling the nature of high blood pressure, its prevalence, and why it often goes undiagnosed. Peter describes in detail the proper way to accurately measure blood pressure and what determines a diagnosis. Next, Peter discusses the actionable steps one can take in response to high blood pressure, shedding light on the extent to which factors like weight loss, exercise, and nutrition can make an impact. He also explores the pharmacological options available and offers valuable insights on how to approach them.

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We discuss:

• Blood pressure and other risk factors for cardiovascular disease [2:30];
• Defining blood pressure and the purpose and meaning of a blood pressure measurement [5:45];
• The implications of high blood pressure and the importance of maintaining an optimal level [10:30];
• The importance of accurate measurements of blood pressure and how Peter approaches the care of patients at the very top range of “normal” [21:45];
• The prevalence of high blood pressure—a hidden epidemic? [24:30];
• The consequences of high blood pressure on cardiovascular health, brain health, kidneys, and more [24:45];
• Low blood pressure: symptoms and consequences [35:30];
• How to properly measure blood pressure [37:45];
• Daily variance in blood pressure and the transient changes in blood pressure during exercise [48:00];
• Primary hypertension vs. secondary hypertension: what to look for [51:45];
• Lifestyle factors impacting blood pressure: weight loss, exercise, and sodium [57:45];
• Impact of insulin resistance and type 2 diabetes on blood pressure [1:04:45];
• How sleep impacts blood pressure [1:06:45];
• Pharmacologic options for managing blood pressure [1:08:00]; and
• More.

Blood pressure and other risk factors for cardiovascular disease [2:30]

If you look at cardiovascular disease, three main risk factors: 

• 1) Smoking
• 2) ApoB
• 3) Blood pressure

Today’s discussion:

• So far, we hadn’t done as much of a deep dive on blood pressure
• Answering questions like: what is high blood pressure, low blood pressure, why should someone care, what does it affect, because it goes beyond just the risk of cardiovascular disease as well as how do you know where you’re at?
• Unlike apoB, you can’t give yourself an at-home blood test, but you can check your blood pressure and you can understand how it changes throughout the day

We will also discuss:

• The common terminology about blood pressure
• What can you do to control your blood pressure?
• What are the lifestyle factors that you can do to lower it? How well do those work?
• What are the most common drugs? What do we know about them? Are there factors that would make one “better” than the other?

Defining blood pressure and the purpose and meaning of a blood pressure measurement [5:45]

What does a blood pressure measurement actually mean, what is it actually doing and measuring?

• The heart is pumping and what you’re feeling is the pulsatile sensation of the pressure difference in the arteries as the heart contracts
• There’s two phases of the cardiac contraction: systole and diastole 

Systole

• The first is called systole—when the ventricles are contracting
• The ventricles are the larger chambers, the left one being the muscular one because it has to pump the blood against the systemic resistance of the whole body, and it’s the one that’s responsible for getting blood out to the body

*Side note:

• Today, we’re going to talk about the systemic circulation and we’re NOT going to talk is a different blood pressure, which is pulmonary blood pressure
• It turns out that when people hear 120 over 80 is their blood pressure, that is talking about the blood pressure in their circulatory system of the periphery
• but if you wanted to know the blood pressure in your lungs, which is controlled by the right ventricle, those would be pulmonary pressures, and those would be significantly lower 

Back to systole: 

• So, when your left ventricle contracts, your in systole
• blood is leaving the heart through the aortic valve, goes out the aorta at the ascending part of the aorta, and then it immediately just starts moving to the rest of the body
• This is happening really quickly, even if your heart is beating as slow as one beat per second/60 beats per minute
• There’s a pressure in the artery that is experienced by literally the blood pushing against the walls of the artery during that phase 

Diastole

• It’s important to remember that there is a second equally important phase of the heart, which is the relaxation of the ventricle, and that’s how they fill—that’s called diastole
• So after the heart squeezes and blood leaves the heart, the heart has to relax to have blood come back into the ventricles through the atria
• This is when the heart itself receives its blood supply, whereas all the other organs are receiving their blood supply during systole
• Even though the pressure in the arteries is lower during diastole, there is still a tonic amount of pressure within the artery wall

So when you have your blood pressure checked and it spits out two numbers like, 125 over 79, what that means is…

• when your heart is doing the squeeze and there’s the greater force as blood is leaving the left ventricle via the aorta, the pressure is 125 millimeters of mercury
• And when that ventricle relaxes and begins to fill through the left atrium, the pressure drops to 79 millimeters per mercury

The implications of high blood pressure and the importance of maintaining an optimal level [10:30]

when we say high blood pressure, what are the two numbers that we’re referring to so people can, as they look back at their own blood pressure results, can kind of know where they fit?

• This has changed a little bit

{end of show notes preview}