Atrial = N/A
Ventricular = 37 min-1
Atrial fibrillation or slow idioventricular rhythm
Duration = 142 ms
Axis = -30° + 105°
R wave progression:
LV Hypertrophy [Sokolow; SV1 + (RV5 or RV6) > 35mm) or RI + SIII > 25mm]?
RV Hypertrophy [R/S ratio V5 or V6 < 1 or R/S ratio V1 > 1 or S1S2S3 pattern]?
Duration = 200 ms
Morphology = sagging depression II, III, aVF, V3-6
Duration = 240 ms
Morphology = inverted V1-3
QT duration = 664 ms
QTc duration = 519 ms
Interpretation: This is very tricky! The QRS complexes are regular but of two distinct types: one has a very clear RBBB pattern, which gives a QRS axis of 105° (beats 2, 4, and 5 on the rhythm strip). The other has a different RBBB pattern (borderline complete) with an axis of -30°. There are no P waves, so the underlying rhythm is atrial fibrillation. One explanation could be a fusion ventricular escape on a low nodal ventricular rhythm. It is likely that this is a result of chronic ischaemia rather than a complication of acute MI. Check for drug effects and electrolyte disturbances, but the patient will almost certainly require a permanent pacemaker.