Ventricular Standstill in Sinus Tachycardia

Report:

Sinus tachycardia 113/min

Second degree, mostly 2:1 AV block

Complete AV block – ventricular standstill

Intraventricular conduction delay (known LBBB)

Comment:

This is almost certainly Möbitz 2 AV block in view of the associated bundle branch block and sudden asystole. We do not see the transition from 1:1 to 2:1 conduction and the diagnosis of Möbitz 2 remains only presumptive.

Below is a strip obtained about 20 minutes later (Fig 46a), as the 2:1 conduction returned. By then the sinus rate accelerated to over 140/min. The CPR was not going well but the patient survived, at least temporarily.

Fig 46b is another strip taken during the CPR (or the lack of it). The appearance of rather slow ventricular escape rhythm (with dubious output) caused the treating team to stop the chest compressions and gaze at the monitor. The massage artefact reappears at the end of the second strip.

Fig.46a. Spontaneous resumption of 2:1 conduction.

Fig 46b. Slow irregular escape rhythm is clearly visible even during the chest compressions. Pausing the latter served no purpose except to hasten the inevitable end.

Fig 47. 76 year old lady with several days’ history of chest pains and grayouts. She was asymptomatic during the recording shown below.