I saw scientific research on this perhaps 25 years ago when they linked gingivitis to pericarditis and to infections of the myocardium. Periodontal disease has long been suspected of causing multiple heart issues. In fact, as I believe I reported here several years back, there were fears by one Professor of nursing science at a UK university, now retired, stating that he felt that too many COVID vaccines were being improperly administered and that there was a high risk of pericarditis from that. All blood flows back to the heart, and if it carries bacteria, viruses, pollutants, etc, the heart will eventually suffer in part.