Complete Heart Block?

 This case is from the great ECG aficionado, Dave Richley. @DaveRichley

 

 

Regular QRS. Regular P waves. Are they dissociated?

His ladder diagram hypothesis:

 

In his words:

1. Atrial tachycardia (flat P waves I & V1; atrial rate 112/min). 

2. Wenckebach AV block and dual AVN pathways with conduction switching from fast to slow pathway explaining big jump in PR from beat 5 to 6 and beat 9 to 10.

Dual AVN Physiology

 Fantastic case from @AThomazAndrade

 

Here is Dr. Antonio's ladder diagram:

Read the full case report here:

https://jafib-ep.com/wp-content/uploads/2023/09/ECG-Challenge-Accelerated-Junctional-Rhythm-or.pdf

Ventricular Escape

 Twitter case from @ecgandrhythmRoe

 Seems to be some manner of escape rhythm, punctuated by Sinus capture.

 Hypothesis:

 The long horizontal lines demarcate zones of Atrium (A), AV node (AV), and Ventricles (V). 

The blue dots suggest a primary ventricular escape with successful retrograde conduction through the AV node, and into the Atrium. 

Suddenly, there is Sinus capture (green dot) with antegrade conduction into the ventricles. This Sinus impulse attempts to control the pace (orange dots), but is impeded because of restoration of the ventricular escape.

Atrial Flutter with Variable Block

 ECG posted to Twitter from @DanielSukmadja

 

 

Atrial Flutter with variable block. What sort of relationship is taking place between Atrium and Ventricles? My hypothesis is based on:

Multilevel Atrioventricular Block. Kosowsky, B. D., et al. Circulation, Vol 54, No 6, 1976.

 

 

The AV node (AVN) is physiologically divided into upper-level (UL) and lower-level (LL) components, each of which can influence antegrade conduction from Atrium to Ventricles.

I conceptualize it like this: 

 

Each colorized arrow is an antegrade impulse. The green impulse is blocked at the UL. The orange arrow is blocked at the LL. The black arrow successfully reaches the ventricles. Sometimes this behavior, collectively, manifests in a predictable pattern.

 

 

The alternating green and blue is to suggest that the UL has a 2:1 block. So, for every 2 impulses that enter the UL, 1 is blocked and does not proceed.

 

The alternating yellow and orange is to suggest that the LL has a 3:2 block. For every 3 impulses that enter the LL, only 2 proceed into the ventricles. Moreover, the shaded secondary impulse is to suggest that, at this level, the block is particularly Wenckebach.