On every practice exam this keeps showing up: apical pulse is a full minute — no 15×4 shortcut. Is that the only case, or do you also count a clearly irregular radial for the full 60 during 7 a.m. vitals?
If the radial feels irregular at 7 a.m., switch to an apical and give it the whole minute — “irregular rhythm = 60 sec,” same as for digoxin checks. Document it as irregular and let the nurse know if it’s new; some facilities also want a pulse deficit. Does your policy call that out?