Can bettas have heart attacks?

[sunnymui]

Just wondering whether it was possible for bettas to have a heart attack.

He was happily building a bubble nest when I looked over my shoulder, next second I look over, and he's shaking and dead within the minute...

Have no idea what happened. Tank was regulated PH, heat and filtered.

[Oldfishlady]

Fish have a closed circulatory system-the heart pumps blood in a single loop-blood goes from the heart to the gill then from the gills to the rest of the body and back to the heart-the thick walled ventricle is what does the pumping....and so I guess they can have a heart attack of sorts.....

What else is going on with him? how long have you had him and any changes in behavior before the sudden death, when was the last water change or anything thing new in the tank

My first thought with sudden death-some type of toxin fell in the water or in the air, cracked heater and stray volt, esophagus damage of some sort, shock, air emboli or parasite.

[sunnymui]

There was a lid on the tank, so I'm not sure anything fell into the tank. Sadly, I only had my betta for 6 weeks, and he was just settling in.

He was in a 5 gallon tank with 2 silk plants, 1 marimo and some gravel, with filter and heated at 77 degrees, PH 7. Water change had been the day before, no new plants or anything. Was feeding fine earlier that day on betta pellets, happily building a bubble nest, next moment shaking his head and sunk to bottom of tank.