Both mRNA Covid vaccines (Moderna and Pfizer) penetrate heart muscle cells and cause them to produce the spike protein – with measurable consequences for cell function: Moderna disrupted the cells’ calcium balance so severely that they beat arrhythmically and uncontrollably, whilst Pfizer put the cells into a permanently overstimulated state, comparable to a sustained adrenaline rush. Key Results:

https://bpspubs.onlinelibrary.wiley.com/doi/10.1111/bph.16262

Key Results
In the first 24 h after application, both mRNA-1273 and BNT162b2 caused neither functional disturbances nor morphological abnormalities. After 48 h, expression of the encoded spike protein was detected in ventricular cardiomyocytes for both mRNAs. At this point in time, mRNA-1273 induced arrhythmic as well as completely irregular contractions associated with irregular as well as localized calcium transients, which provide indications of significant dysfunction of the cardiac ryanodine receptor (RyR2). In contrast, BNT162b2 increased cardiomyocyte contraction via significantly increased protein kinase A (PKA) activity at the cellular level.

Conclusion and Implications
Here, we demonstrated for the first time, that in isolated cardiomyocytes, both mRNA-1273 and BNT162b2 induce specific dysfunctions that correlate pathophysiologically to cardiomyopathy. Both RyR2 impairment and sustained PKA activation may significantly increase the risk of acute cardiac events.