Metoprolol only makes it take longer for the repolarization of myocytes between beats. This means, it slows down the heart....AND...makes the muscle beat less strenuously, which helps with low-grade hypertension. Metoprolol doesn't stop arrhythmias, including PACs. You need an ablation for that, possibly one of the myriad of anti-arrhythmic drugs. But not metoprolol. It's a 'rate' medicine, not a 'rhythm' medicine. It keeps the rate low if the heart goes into fibrillation or tachycardia. At least, that's the plan. Didn't work especially well for me as my AF evolved and began to come on more frequently. In fact, once back into NSR, I would go into bradycardia due to the higher dose prescribed to try to keep my rate low when I was in AF. I went from 12.5 mg BID (one tablet cut in two) to 75 mg BID inside of six months. It was too much, and I don't want to repeat the sensation I felt when I was getting pins and needles at the back of my neck, feeling I was about to pass out. This was at 100 kph on a local highway. Behind the wheel. And I was not unusual. A great many patients report that they get over-medicated and go into dangerous bradycardia with metoprolol. For most, the relief comes after a successful ablation.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8890474/

Isn't taurine an ingredient in dry cat food? It just sounded like it. Lol. I take metoprolol and might have a PVC once a week. I also take magnesium per my cardiologist