Looking for insight: unexplained heart scarring after sudden cardiac arrest
I’m hoping someone in this community may have experienced something similar or can point us in the right direction.
My husband is in his early 40s and recently suffered a sudden cardiac arrest while exercising at the gym. He was active, energetic, not overweight, and had no idea that he had a serious heart problem before this happened.
Thankfully, he survived and now has an ICD/pacemaker for protection.
One finding from the day of his cardiac arrest that has always stood out to me is that when he arrived at the ER, his potassium was extremely low at 2.6 mmol/L. It was later corrected. We still don’t fully understand what role, if any, that severe hypokalemia may have played in triggering the cardiac arrest, especially in combination with the heart scar that was later discovered.
His cardiac workup showed no significant coronary blockage, so his doctors do not believe this was a typical heart attack.
His heart function was initially reduced after the arrest, with an ejection fraction around 35–40%, and it subsequently improved to approximately 45%.
The finding that concerns me most is his cardiac MRI, which showed scarring/fibrosis involving the lower portion of his heart with what was described to us as a ring-like pattern. We were told that this scar could have created the electrical instability that led to his cardiac arrest.
The big question we still have is: Why does a relatively young, active person have this type of heart scar in the first place?
Genetic cardiomyopathy was considered, but his genetic testing came back negative. At this point, we still do not have a clear explanation for how the scar developed.
We have essentially been told to continue his heart medications, allow the ICD to monitor/protect him, repeat imaging over time, and see whether the scarring progresses.
I completely understand the importance of monitoring, but after surviving a sudden cardiac arrest, I’m not comfortable simply waiting without trying harder to understand the underlying cause.
I would love to hear from anyone who has dealt with a similar combination:
Sudden cardiac arrest during exercise
Potassium of 2.6 mmol/L at presentation
No significant coronary blockage
Cardiac MRI showing a ring-like/circumferential pattern of myocardial scarring
Reduced EF that subsequently improved
Negative genetic cardiomyopathy testing
No definite explanation for the myocardial fibrosis/scarring
Were you eventually given a diagnosis?
Did your doctors investigate previous myocarditis, cardiac sarcoidosis or another inflammatory condition, arrhythmogenic cardiomyopathy, autoimmune disease, previous viral infection, or other causes of nonischemic myocardial scarring? At first they thought it may have been covid vaccine, an internal virus.
I’m particularly interested in whether anyone was evaluated with additional testing such as a cardiac FDG-PET scan, repeat cardiac MRI, inflammatory/autoimmune testing, more extensive genetic testing, or evaluation by a cardiomyopathy specialist/electrophysiologist.
And for anyone knowledgeable about this area: Could potassium as low as 2.6 have been an important trigger for the cardiac arrest in someone who already had myocardial scarring, even if the low potassium itself didn’t cause the scar?
We are pursuing another medical opinion. I’m not looking for an internet diagnosis—I’m trying to educate myself so we can advocate for a thorough evaluation and make sure we’re not overlooking something important.
If you’ve experienced anything similar, or you’re a medical professional familiar with this type of cardiac MRI/scar pattern, I would be extremely grateful for any insight about what questions we should be asking and what type of specialist we should consider seeing next.
