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Repetitive Nonreentrant Ventriculoatrial synchrony (RNRVAS) - ECG

Repetitive nonreentrant ventriculoatrial synchrony (RNRVAS)

Dual-Chamber Pacemaker

Upload & Analyze Your ECG Now ⚡🫀 (Watch or 12-Lead)

Dual-Chamber Pacemaker

Dual chamber pacemekar, Repetitive nonreentrant ventriculoatrial synchrony (RNRVAS)

Dual-chamber pacemaker

Has two electrodes (in the atrium and the ventricle)

Repetitive Non-Reentrant VA Synchronization (RNRVAS)

Can occur in a dual-chamber pacemaker (DDD, DDDR)
Ventricular pacing causes retrograde conduction through the AV node
Retrograde P wave occurs during the PVARP interval

Therefore, the pacemaker ignores it

Subsequent retrograde P waves are ignored due to

the refractory period of atrial myocardium

If a retrograde P wave occurs after the PVARP interval

It results in a pacemaker-mediated tachycardia

ECG mechanism, Repetitive nonreentrant ventriculoatrial synchrony (RNRVAS)

Repetitive Non-Reentry Ventriculo-Atrial Synchronization (RNRVAS)

VAC (VA Conduction)

This is the time of retrograde conduction through the AV node (350ms)

KES (Ventricular Extrasystole)

Depolarizes the ventricles (QRS) and the impulse travels retrograde through the AV node to the atria
A retrograde P wave is generated but during the PVARP interval (400ms)

During the PVARP interval, the pacemaker ignores the retrograde P wave

AEI (Atrial Escape Interval)

This is the interval between ventricular pacing and atrial pacing (525ms)
If within 525ms after ventricular pacing (sensing) no spontaneous P wave occurs

then the pacemaker activates atrial pacing (Ap)

However, Ap occurs during the refractory period of the atrial myocardium (MyoRP)

Thus, the pacemaker-generated P wave (Ap) is blocked

However, the pacemaker counts the AV interval (225ms) from the blocked P wave (Ap)

It then initiates ventricular pacing
The cycle then repeats

Repetitive non-reentry VA synchronization is most commonly triggered by

Ventricular Extrasystole (KES)

ECG pacemaker, Initiation Repetitive nonreentrant ventriculoatrial synchrony (RNRVAS), Ventricular premature complex (VPC), ventriular safety pacing (VSP), VPC with retrograde VA conduction

Repetitive Non-Reentry VA Synchronization (Trigger)

The patient has a DDD pacemaker
The first two beats have effective pacing of the atria and ventricles (ApVp)
The third beat is ventricular safety pacing (VSP)

The pacemaker responds to a ventricular extrasystole with VSP

This is a protective mechanism of the pacemaker against cross-talk

The fourth beat is a ventricular extrasystole (KES) with retrograde (VA) conduction

The retrograde P wave is not visible

This is followed by ineffective atrial pacing

No P waves follow
Because the atrial pacing occurs during the refractory period of the atrial myocardium (MyoRP)

After ineffective atrial pacing

There is effective ventricular pacing

ECG pacemaker, termination Repetitive nonreentrant ventriculoatrial synchrony (RNRVAS), atrial capture, VPC without retrograde VA conduction

Repetitive Non-Reentry VA Synchronization (Termination)

The patient has a DDD pacemaker
The fourth beat is a ventricular extrasystole (KES)

With retrograde conduction

The fifth beat is a ventricular extrasystole

With retrograde VA block

This is followed by effective atrial pacing (Ap) because Ap occurs:

Outside the PVARP
Outside the refractory period of the atrial myocardium

Sources

ECG from Basics to Essentials Step by Step
litfl.com
ecgwaves.com
metealpaslan.com
medmastery.com
uptodate.com
ecgpedia.org
wikipedia.org
Strong Medicine
Understanding Pacemakers

Repetitive Nonreentrant Ventriculoatrial synchrony (RNRVAS) - ECG

Repetitive nonreentrant ventriculoatrial synchrony (RNRVAS)

Dual-Chamber Pacemaker

Upload & Analyze Your ECG Now ⚡🫀 (Watch or 12-Lead)

Dual-Chamber Pacemaker

Dual-chamber pacemaker

Has two electrodes (in the atrium and the ventricle)

Repetitive Non-Reentrant VA Synchronization (RNRVAS)

Can occur in a dual-chamber pacemaker (DDD, DDDR)
Ventricular pacing causes retrograde conduction through the AV node
Retrograde P wave occurs during the PVARP interval

Therefore, the pacemaker ignores it

Subsequent retrograde P waves are ignored due to

the refractory period of atrial myocardium

If a retrograde P wave occurs after the PVARP interval

It results in a pacemaker-mediated tachycardia

Dual chamber pacemekar, Repetitive nonreentrant ventriculoatrial synchrony (RNRVAS)

ECG mechanism, Repetitive nonreentrant ventriculoatrial synchrony (RNRVAS)

Repetitive Non-Reentry Ventriculo-Atrial Synchronization (RNRVAS)

VAC (VA Conduction)

This is the time of retrograde conduction through the AV node (350ms)

KES (Ventricular Extrasystole)

Depolarizes the ventricles (QRS) and the impulse travels retrograde through the AV node to the atria
A retrograde P wave is generated but during the PVARP interval (400ms)

During the PVARP interval, the pacemaker ignores the retrograde P wave

AEI (Atrial Escape Interval)

This is the interval between ventricular pacing and atrial pacing (525ms)
If within 525ms after ventricular pacing (sensing) no spontaneous P wave occurs

then the pacemaker activates atrial pacing (Ap)

However, Ap occurs during the refractory period of the atrial myocardium (MyoRP)

Thus, the pacemaker-generated P wave (Ap) is blocked

However, the pacemaker counts the AV interval (225ms) from the blocked P wave (Ap)

It then initiates ventricular pacing
The cycle then repeats

Repetitive non-reentry VA synchronization is most commonly triggered by

Ventricular Extrasystole (KES)

ECG pacemaker, Initiation Repetitive nonreentrant ventriculoatrial synchrony (RNRVAS), Ventricular premature complex (VPC), ventriular safety pacing (VSP), VPC with retrograde VA conduction

Repetitive Non-Reentry VA Synchronization (Trigger)

The patient has a DDD pacemaker
The first two beats have effective pacing of the atria and ventricles (ApVp)
The third beat is ventricular safety pacing (VSP)

The pacemaker responds to a ventricular extrasystole with VSP

This is a protective mechanism of the pacemaker against cross-talk

The fourth beat is a ventricular extrasystole (KES) with retrograde (VA) conduction

The retrograde P wave is not visible

This is followed by ineffective atrial pacing

No P waves follow
Because the atrial pacing occurs during the refractory period of the atrial myocardium (MyoRP)

After ineffective atrial pacing

There is effective ventricular pacing

ECG pacemaker, termination Repetitive nonreentrant ventriculoatrial synchrony (RNRVAS), atrial capture, VPC without retrograde VA conduction

Repetitive Non-Reentry VA Synchronization (Termination)

The patient has a DDD pacemaker
The fourth beat is a ventricular extrasystole (KES)

With retrograde conduction

The fifth beat is a ventricular extrasystole

With retrograde VA block

This is followed by effective atrial pacing (Ap) because Ap occurs:

Outside the PVARP
Outside the refractory period of the atrial myocardium

Sources

ECG from Basics to Essentials Step by Step
litfl.com
ecgwaves.com
metealpaslan.com
medmastery.com
uptodate.com
ecgpedia.org
wikipedia.org
Strong Medicine
Understanding Pacemakers