Second-degree AV block, Mobitz II pattern
MSP221 recording · 03
Clinical history not documented in this image source.
Original waveform retained; quiz cropping only removes off-tracing interpretation or a row containing an answer label. Some sources are rhythm strips rather than a full 12-lead ECG.
Look for
- Some P waves do not conduct.
- Constant conducted PR intervals in the 3:2 sequences.
Where to look. Follow P waves over several cycles and compare PR intervals around a nonconducted P; do not use only the 2:1 segment.
Mobitz II suggests His–Purkinje disease. Exclude a blocked atrial premature beat and do not apply this label to an isolated 2:1 block.
The source diagnosis is retained; no additional clinical cause is inferred.
References & provenance
John Hampton; Joanna Hampton. The ECG Made Easy, 9th ed. (2019), ch. 3, pages du PDF / PDF pp. 73-74.
Second-degree AV block, source-labelled Mobitz II with 3:2 and 2:1 conduction, RBBB
Jer5150; image credit Jason E. Roediger, CCT, CRAT. Second-degree AV block, source-labelled Mobitz II with 3:2 and 2:1 conduction, RBBB. https://commons.wikimedia.org/wiki/File:Sinus_rhythm_with_3-to-2_and_2-to-1_Type_II_A-V_block.png. CC BY-SA 3.0. Adaptation: lossless metadata removal/encoding; quiz crop removes off-tracing labels/interpretive panels where applicable. Derivative image retains the same license. CC BY-SA 3.0
Adaptation: cropping and removal of headers/annotations outside the tracing where applicable; metadata removed. Waveforms have not been redrawn.
Compared with the published source; no independent clinical validation is claimed.
Original annotations & limitations
Second-degree AV block, source-labelled Mobitz II with 3:2 and 2:1 conduction, RBBB
Second-degree AV block, source-labelled Mobitz II with 3:2 and 2:1 conduction, RBBB
Original source labels retained. Question wording limited to visible findings; no independent clinical validation claimed.