Does a Dual-Chamber Demand (DDD) pacemaker have a pacing spike?

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DS

Dainyal Siddiqui, MD

Internal Medicine

MJ

Manuel Jimenez, MD

Cardiology

FP

Franz Pierre-Louis, MD

Infectious Disease

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Last updated: March 5, 2025 • View editorial policy

From the Guidelines

A DDD pacemaker does produce pacing spikes on an electrocardiogram (ECG). A DDD pacemaker is a dual-chamber device that can sense and pace both the atrium and ventricle, as recommended by the expert consensus statement on pacemaker device and mode selection 1. When the pacemaker delivers an electrical impulse to stimulate either chamber, it creates a visible sharp, narrow, vertical deflection on the ECG called a pacing spike. These spikes appear immediately before the P wave (atrial pacing) or QRS complex (ventricular pacing). The "DDD" designation indicates that the pacemaker can pace both chambers, sense electrical activity in both chambers, and respond to sensed events with either triggering or inhibiting pacing as needed. Some key features of DDD pacemakers include:

  • Dual-chamber pacing capability
  • Ability to sense electrical activity in both atrium and ventricle
  • Production of pacing spikes on ECG to confirm proper function
  • Recommendation over single-chamber ventricular pacing (VVI) in patients with SND and intact AV conduction, as stated in the expert consensus statement 1. The presence of these pacing spikes on an ECG is an important diagnostic feature that helps clinicians confirm proper pacemaker function and identify which chambers are being paced during cardiac cycles.

From the Research

Pacing Spike in DDD Pacemakers

  • A DDD pacemaker can deliver an atrial spike that is superimposed upon the spontaneous premature QRS complex, resulting in a phenomenon known as pseudo-pseudofusion 2.
  • Under certain circumstances, the atrial spike is followed by a ventricular spike that falls on the extrasystolic T wave apex, known as competitive ventricular pacing 2.
  • The ventricular spike can occur on top of the T wave during episodes of junctional rhythm, which may appear as a lack of sensing of QRS complexes but is actually due to physiologic blanking 3.
  • The presence of a pacing spike in a DDD pacemaker is influenced by various factors, including the coupling interval of premature beats, post-atrial ventricular blanking (PAVB), and ventricular safety pacing 2.
  • Proper programming of the AV interval is crucial to ensure optimal pacing and avoid complications such as competitive pacing and sensing malfunctions 4, 3.

References

1
Guideline

hrs/accf expert consensus statement on pacemaker device and mode selection.

Journal of the American College of Cardiology, 2012

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This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.

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