Zebrafish teach researchers more about atrial fibrillation (mitochondria issues)

University of Copenhagen/Science Daily ^ | January 21, 2020 | Michelle M. Collins, Gustav Ahlberg, Camilla Vestergaard Hansen, Stefan Guenther, Rubén Marín-Juez,

[ConservativeMind]

'It seems that we may also have to think of atrial fibrillation as an atrial cardiomyopathy -- that is, a challenged heart -- rather than as a purely electrical disorder', she says.

Defects in muscle fibres and mitochondria

Contrary to expectations, the researchers did not find any disturbances in the ion channels that spread electrical signals between the heart's muscle cells.

Instead, they found defects in the structure of the heart muscle itself and in the mitochondria that normally function as the cell's power plant. The defects already occurred in the foetal stage of the fish and deteriorated exponentially with age.

'At the same time, we can see in our pictures that there are too many mitochondria. So, it seems that the heart is trying to compensate for the defective muscle fibres. This indicates that there is a structural defect in the heart which over time will cause a rhythm defect'.

Antioxidant prevents defects

According to the research study, the increased number of mitochondria appears to aggravate the negative spiral, the reason being that also the mitochondria are defective and gradually increase the level of so-called oxidative stress.

At the same time, however, the researchers found that early and ongoing treatment with the antioxidant NAC seemed to counteract the defect and in the long term prevent atrial fibrillation in the fish.

[ConservativeMind]

Atrial fibrillation may actually be a mitochondrial issue, meaning treatment could be CoQ10, MitoQ, PQQ, Ergothioneine (mushrooms), and Glutathione.

These are all readily available for use to try out.

[Norski]

Top 9 Benefits of NAC (N-Acetyl Cysteine)

1. Essential for Making the Powerful Antioxidant Glutathione
2. Helps With Detoxification to Prevent or Diminish Kidney and Liver Damage
3. May Improve Psychiatric Disorders and Addictive Behavior
4. Helps Relieve Symptoms of Respiratory Conditions
. . .
8. May Reduce Heart Disease Risk by Preventing Oxidative Damage
. . . see link.

https://www.healthline.com/nutrition/nac-benefits

[Moonman62]

Atrial fibrillation may actually be a mitochondrial issue,

...

Yet ablation works so well to cure it.

[neverevergiveup]

Probably an interesting study, from a molecular biology perspective, but the relevance to human atrial fibrillation is likely tenuous, at best. First, zebrafish have very different physiological parameters as compared to humans. Second, atrial fibrillation in humans is a complex entity, and has many different potential causes - including atrial dilation and fibrosis (developing over time in response to hypertension, valvular disease, or other contributors). There are also genetic causes. In short, atrial fibrillation is a consequence of many potential contributing factors, and can be very different in causation in different people. Even binge drinking can cause it. The bottom line is that it is highly unlikely that an atrial fibrillation model in a zebrafish will be predictive of pharmacological success in humans.
Just sayin..

[aquila48]

bookmark

[Wm F Buckley Republican]

A fib bump

[zeestephen]

I agree.

It's not clear to me what relevance this has for humans.

Life long runners, like me, have 3-4 times the rate of A-Fib compared to non-runners.

Yet, most of us have no other cardio-pathology.

But, one thing did catch my attention in this article.

I had A-Fib symptoms in my early teens. USA doctors are very skeptical when they hear that.

It will be interesting to see if the requisite physiology for A-Fib is present in human children.

[JohnnyP]

Runners are usually on a high carb diet. Could have some relation.