Basics of Pacemaker Timing gCycles and Diagnostics: Uses and Interpretations

C W Israel M DC. W. Israel, M. D.J. W. Goethe University

Dept. of Medicine - Cardiology p gyFrankfurt, Germany

C.W.Israel@em.uni-frankfurt.de

VVI PacingTiming Cycles and Diagnostics

VVI Pacing

Lower rate interval

(Postventricular Ventricular) Blanking Period (Postventricular Ventricular) Refractory Period

VVI Pacing with HysteresisTiming Cycles and Diagnostics

VVI Pacing with Hysteresis

Hysteresis extension Lower rate interval

AAI PacingTiming Cycles and Diagnostics

AAI Pacing(Postatrial Atrial) Blanking Period (Postatrial Atrial) Refractory Period

Lower rate interval

AAI PacingTiming Cycles and Diagnostics

AAI Pacing

Oversensing of the QRS complex in the atrium(ventricular farfield oversensing)

AAI-StimulationTiming Cycles and Diagnostics

AAI-Stimulation

Lower rate intervalLower rate interval

→ Undersensing of atrial fibrillation (true undersensing)

AAI-StimulationTiming Cycles and Diagnostics

AAI-Stimulation

Refractory Sensed Signal„Blanked“ Signal (Functional Undersensing)

DDD PacingTiming Cycles and Diagnostics

DDD Pacing

AV sequential pacing AV synchronousAV sequential pacing (inhibited)

AV synchronous pacing (triggered)

AV i t l d AV i t l dAV interval paced- can be completely blanked- can be only partially blanked

AV interval sensed

DDD PacingTiming Cycles and Diagnostics

DDD Pacing

AV i t l l ti ll bl k d AV i t l dAV interval only partially blanked AV interval sensed

DDD PacingTiming Cycles and Diagnostics

DDD Pacing

P t t i l t i l bl ki P t t i l t i l f tPostventricular atrial blanking (PVAB, black)

Postventricular atrial refractory period (PVARP, white)

DDD WenckebachTiming Cycles and Diagnostics

DDD Wenckebach Upper Rate Behaviour

Timing Cycles and Diagnostics

Wenckebach Upper Rate BehaviourWenckebach Upper Rate Behaviour

Timing Cycles and Diagnostics

Automatic Mode SwitchingAutomatic Mode Switching

5 sec

→ fast and irregular tracking of AT

Endless-Loop-Tachycardia (ELT)Timing Cycles and Diagnostics

Endless-Loop-Tachycardia (ELT)

No Endless-Loop-Tachycardia (ELT)Timing Cycles and Diagnostics

No Endless-Loop-Tachycardia (ELT)

DDI PacingTiming Cycles and Diagnostics

DDI Pacing

DDI PacingTiming Cycles and Diagnostics

DDI Pacing

DDIR, LRL 60/min25 mm/s

VDD PacingTiming Cycles and Diagnostics

VDD Pacing

VDD Pacing with ELTTiming Cycles and Diagnostics

VDD Pacing with ELT

Timing Cycles and Diagnostics

Endless-Loop-Tachycardia:Endless-Loop-Tachycardia: Termination

After x cycles of VP-AS: automatic PVARP extension→ P wave no longer tracked, ELT stops

Noise ReactionTiming Cycles and Diagnostics

Noise Reaction

Timing Cycles and Diagnostics

Noise ReactionNoise Reaction

2:1 Lock-In of Atrial FlutterTiming Cycles and Diagnostics

2:1 Lock-In of Atrial Flutter

PVARPPVARP

PVABPVAB

25 mm/s5 /s

Atrial flutter with 2:1 undersensing (every 2nd flutter wave in PVAB) and 2:1 conduction by pacemakerPVAB) and 2:1 conduction by pacemaker

Safety Window Pacing

Timing Cycles and Diagnostics

Safety Window Pacing

Safety Window Pacing

Timing Cycles and Diagnostics

Safety Window Pacing

50 mm/s

Timing Cycles and Diagnostics

Safety Window Pacing (SP)Safety Window Pacing (SP)

False positive intervention dueFalse positive intervention due to a PVC

Appropriate intervention of SP due to cross-talk