jer5150's picture

Patient data:  62-year old man.

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I believe Sinus 1st degree av blk,  INF changes and pacemaker L side, maybe VVI not the Best at pacers.

Dave Richley's picture

This looks like a profound sinus bradycardia, atrial rate just under 30bpm, with VVI pacing at 65bpm. Unusually, there seems to be LV, rather than RV, pacing. The two narrow QRS complexes (beats 4 and 9) are conducted sinus beats: they each follow a P wave in the T wave of the preceding beat. There are also P waves before three of the paced QRS complexes (beats 2, 7 and 12) and these would almost certainly have conducted had the pacemaker not intervened first. Jason’s ECGs are usually fiendishly difficult and complicated so I fear I may have missed something!

Dave R

hassan's picture

RV pacing with Junctional beats due to no P wave before 4, 9...

Hassan Alsafi

 - Severe sinus bradycardia @ approx 30 bpm
 - LV(?) paced rhythm @ approx 49 bpm
 - AV-dissociation by default
 - #4 and 9 are capture beats
 - #2, 7, and 12 are fusion beats
 - RP/PR reciprocity as evidenced by the shorter PRi's on the fusion beats
 - T-wave inversions of the supraventricular beats in V3-V6, II, III, and probably I and III, uncertain origin (coinsider cardiac memory if no other cause found).
 - Poor R-wave progression of the supraventricular beats.

Probably a dual chambered Medtronic pacemaker that has reached Elective Replacement Indicator (BOL 85 ERI 65).  Hook up to a programmer to confirm and schedule revision.  Other possiblility would be a single chambered device that was previously set due to permanent Afib then converted back to sinus rhythm.  Need more info on this patient, definitely need a programmer. 

jer5150's picture

(1.)  Marked sinus bradycardia (rate about 41/min) dissociated from a . . .
(2.)  . . . biventricular pacemaker (rate about 65/min) in demand mode (VVI).
(3.)  Two ventricular capture beats (4th and 9th beats) with prolonged P-R intervals due to . . .
(4.)  . . . retrograde concealed conduction.
(5.)  R-P/P-R reciprocity.
(6.)  Three ventricular paced fusion beats (2nd, 7th, and 12th beats).

The pacemaker is recognized as biventricular (Bi-V) from the wholly-negative QS complex in lead I.  As Vince pointed out, there is poor r-wave progression on the sinus beat in leads V1-3 and the nonspecific T-wave inversions could be due to persistent ventricular pacing.  Based on the normal P-V intervals of the fusion beats, the patient's intrinsic P-R intervals are probably also normal during sinus rhythm.

Jason E. Roediger - Certified Cardiographic Technician (CCT)
[email protected]

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