NSR with monomorphic PACs
First Glance:
Normal sinus rhythm with a little light ectopy.
Discussion:
Beats 7 and 11 (and the last beat under the clip) are premature atrial contractions. The PR interval is normal, but they come early and the P morphology is wrong. This is lead II, yet the P deflections are negative. How would you get a negative deflection in II? II runs RA to LL. So this suggests an atrial ectopic focus near the AV node. When it fires the atrial myocardium depolarizes upwards and away from the positive lead II electrode, yielding the negative P.
Can you pick out the atrial waves on the CVP trace?
The PAC has its own A wave.
Final Impression?
NSR @ 80 bpm with two monomorphic PACs.
Management implications:
Nothing much. There are no hemodynamic implications with this kind of ectopy. It could answer the patient’s worries about palpitations, if they even feel them, and it could be treated with avoidance of common pro-arrhythmics or sympathomimetic drugs if symptomatic.
The Take-home Point:
If the P wave axis is off, it’s not a sinus beat. It’s ectopic atrial, or “P Prime” (denoted in shorthand as P’).
One star strip. Students should nail this.