What is the pattern of QRS complexes in rhythm strip of this ecg? Regular or iregular? If irregular is it regularly irregular or irregularly irregular? It can be seen that QRS complexes are clumped into groups, each comprising of three complexes. So its regularly irregular as marked in the following figure: Main differential of such a rhythm would be sinus arrhythmia, Mobitz type II block, Atrial premature beats, Sinus arrhythmia is unlikely because, in sinus arrhythmia, the rate usually gradually slows and then gradually speeds up. There is no prolongation of PR interval as in mobitz type II block. Now have a look at p wave morphology of three beats in every group and the compensatory pause after it: Are you thinking Atrial Trigeminy? YES, you nailed it. If we notice the p wave morphology of every third beat its slightly different from the preceding p waves, and also its occurring earlier, compensatory pause after it and then restoration of sinus ...
Cardiology Notes: Clinical Cases including ECG, Echocardiography, Cath, and MOCK Exams to sharpen your cardiology data interpretation skills. Healthcare is stressful!!! Learning cardiology shouldn't be !!!