@osgilian I cannot be certain, but there's a hefty chance your lower resting HR is due to the influence of metoprolol. Your heart is calming, but so are YOU. Less anxiety, less adrenaline because you aren't fibrillating/getting so many triplets or runs of PACs [which can feel like AF], so your Vagal tone is better and your heart rate is lower on that account as well. It would be interesting to see if it climbs up nearer to your former 'normal rate' once your taper is over. Would you consider coming back and letting us know what it goes in general, but also if you notice that your RHR is pretty much back to the same level as before?