Atrial Fibrillation and Metabolic Syndrome

This article gives a brief overview of atrial fibrillation and how reversible risk factors can prevent them.

Electrical Conduction in the Heart

For the heart to work correctly, there should be a well-coordinated movement between the heart’s chambers.

There should be a point source of an electrical signal coming from the right atrium and then to the left atrium. Then the electrical signal spreads out to the ventricles, which are the main pumping chambers of the heart.

The flow of the blood is as follows: The blood coming back to the heart goes to the right atrium, which pumps it to the right ventricle.

The right ventricle pumps the blood to the lungs, and then the blood goes to the left atrium, which pumps it to the left ventricle, which pumps it to the rest of the body. Well-Coordinated electrical conduction gives the heart its regularity when pumping.

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Blood flow thru the heart

The  Abnormal Electrical conduction in AF

In atrial fibrillation, the single-point source of an electrical signal coming from the atrium is replaced by multiple sources, and all of them beat at different times such that the ventricles lose their regular rhythm and it starts to beat irregularly.

The patient can sense the irregular heart rhythm as palpitations in the chest.  This can be heard when listening to the chest using a stethoscope and confirmed by an EKG.

Sometimes the AF is on and off (Paroxysmal AF) and undetectable to the patient and doctors until the complications happen.

Not all palpitations are atrial fibrillation. Some palpitations or cardiac irregularities are normal variants and do not need treatment. The only way to know is to get an EKG.

 

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Normal EKG tracing on top, Atrial Fibrillation below

Heart Complications of AF

Sometimes, atrial fibrillation can beat very fast. Up to 150 heartbeats per minute. The normal heart rate is 60 to 100 per minute.

This rapid heart rate can lead to a heart attack (Myocardial Infarction) if there is an underlying blockage to the coronaries (blood vessels of the heart).

The rapid heartbeat also makes the pumping function of the heart ineffective, such that the pump will fail and blood will back up in the lungs resulting in Congestive Heart Failure (CHF).

Once fluid builds up in the lungs, it occupies the space reserved for air exchange. Leaving less room for inspired air. and then the oxygen level in the blood gets lower.

Low oxygen or hypoxia manifests as shortness of breath. A patient may present with both myocardial infarction and congestive heart failure at the same time. I have seen many.

Medications can be used for these situations, and the patients can be stabilized, admitted to the hospital, and later discharged home with drugs to control the heart rate and thin the blood.

If the patient is unstable, electrical paddles are applied to the chest andcardioversion is done. A rapid-acting intravenous sedative is administered if there is time to remove anxiety.

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Typical Path of Electrical Conduction in the Heart

Blood Clot in AF Can Go Anywhere and Wreak Havoc

In atrial fibrillation, a clot can form inside the heart.  The formed blood clot may break off in small pieces and travel all over the body. Blood clot that travels down the arteries can potentially block the blood supply to an organ.

If the clot goes to the brain, you have a stroke or cerebrovascular accident). In the kidneys, acute kidney failure.

If the clot goes to the legs and arm, and completely blocks the blood supply, it will need emergency treatment.

If the arteries to the intestines get involved, the bowels can become gangrenous and require immediate surgery, even in the middle of the night.

The problem with ischemic guts (intestines) is that an inexperienced physician can easily miss them because the abdominal findings do not present as a surgical abdomen. If undiagnosed, the patient can die.

Medications for Blood Clot Prophylaxis have Bad Side Effects.

To prevent clot formation in a patient with AF, a  patient will be prescribed a blood thinner.

The choices will be warfarin, wherein you need to have regular blood work done on a weekly and then monthly basis to make sure that you get the correct dose. There is no “one dose fits all” prescription for warfarin.

Aside from that inconvenience, you have to avoid fruits like grapefruit and a lot of antibiotics because they can make your blood too thin and cause you to hemorrhage spontaneously from your nose, gut, and brain.

It can be a problem if you have an accident and a skin cut because it will bleed longer than usual. Some foods like asparagus, avocados, green peas, green tea, and olive oil, to name a few can counter the blood-thinning effect of warfarin. The problem is, the foods that I mentioned are all good for you.

New Oral Anticoagulants like Pradaxa® do not need regular blood work. There is also less food interactions.

Sounds perfect right? Not so fast.

NOACs, unlike warfarin, cannot be reversed in an emergency. So if you get into an accident or are bleeding inside your head and need immediate life-saving surgery, the reversal is not as easy as in warfarin.

Furthermore, the reversing medications may not be readily available and are more expensive. Otherwise, you will have to wait for that surgery—at least 12 to 24 hours.

How To Avoid Atrial Fibrillation.

Paralysis, shortness of breath, heart attacks, amputations, bleeding problems, emergency bowel resection, and dialysis from AF can be prevented if you prevent AF from happening.   Each component of the Metabolic Syndrome can cause and contribute to atrial fibrillation development.

This excellent review from the Journal of Atrial Fibrillation, Atrial Fibrillation, and Metabolic Syndrome: Understanding the Connection discusses how obesity, diabetes, dyslipidemia, and hypertension can individually and together contribute to the formation of AF. [1]

This prospective cohort study published in the Circulation titled Metabolic Syndrome and Risk of Development of Atrial Fibrillation, The Niigata Preventive Medicine Study showed that metabolic syndrome predisposes to AF even in the absence of diabetes and hypertension. [2]

A study published in PLOS ONE, titled Obesity, Metabolic Syndrome and Risk of Atrial Fibrillation: A Swedish, Prospective Cohort Study [3] on 924 men and 2 097 women, concluded with:

Body mass index, waist circumference and sagittal abdominal diameter could similarly predict atrial fibrillation.

Obesity was associated with an increased atrial fibrillation risk regardless of metabolic syndrome, whereas overweight and elevated waist circumference was associated with increased atrial fibrillation risk only if metabolic syndrome was present.

Not all atrial fibrillation is from metabolic syndrome, but at least you can reduce your chances if the risk factors can be controlled or removed.

To prevent AF, talk to your doctor to know if you need to treatment for diabetes, dyslipidemia, and hypertension. Lose weight if needed.

Try intermittent fasting and exercises foron-drug prevention and possibly reversal of the metabolic syndrome, Related Readings:

  1. How to do Intermittent Fasting
  2. Intermittent fasting results in new and stress-resistant the blood cells
  3.  The Deadliest Diseases Associated with Metabolic Syndrome
  4. Atrial Fibrillation and Metabolic Syndrome
  5. How Effective are Drugs that Increase HDL?
  6. Can You Be in Heart Failure Now?
  7. What Starts Atherosclerosis?
  8. The Magical Endothelium
  9. Abnormal Blood Clots and Metabolic Syndrome

References:

  1. Kumar P, Gehi AK. Atrial Fibrillation and Metabolic Syndrome: Understanding the Connection. J Atr Fibrillation. 2012 Oct 6;5(3):647. doi: 10.4022/jafib.647. PMID: 28496775; PMCID: PMC5153215.
  2. Watanabe H, Tanabe N, Watanabe T, Darbar D, Roden DM, Sasaki S, Aizawa Y. Metabolic syndrome and risk of development of atrial fibrillation: the Niigata preventive medicine study. Circulation. 2008 Mar 11;117(10):1255-60. doi: 10.1161/CIRCULATIONAHA.107.744466. Epub 2008 Feb 19. Erratum in: Circulation. 2010 Aug 17;122(7):e433. PMID: 18285562; PMCID: PMC2637133.
  3. Nyström, P. K., Carlsson, A. C., Leander, K., Faire, U. D., Hellenius, L., & Gigante, B. (2015). Obesity, Metabolic Syndrome and Risk of Atrial Fibrillation: A Swedish, Prospective Cohort Study. PLOS ONE, 10(5), e0127111. https://doi.org/10.1371/journal.pone.0127111

Image Credits: Wikipedia and Wikimedia (Bruce Blaus) EKG, josiño (pumping heart), Madhero88 (electrical conduction)

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