Fundamentals of pacemakers ECG interpretation - Part 1

Area of Science:

• Cardiology
• Biomedical Engineering

Background:

• Cardiac implantable electronic devices are essential in cardiology.
• Surface electrocardiograms (ECGs) are crucial for assessing pacemaker function.
• Modern pacing techniques increase ECG complexity, posing interpretive challenges.

Purpose of the Study:

• To present a systematic framework for pacemaker ECG interpretation.
• To provide an approach applicable across various device platforms and pacing practices.

Main Methods:

• A three-step approach integrating timing assessment, morphological pattern recognition, and malfunction detection.
• Explanation of fundamental pacemaker timing logic (escape, inhibition, triggering).
• Description of QRS morphologies for different pacing sites (RV, biventricular, His-bundle, LBB area pacing).
• Outline of ECG recognition for basic malfunctions (failure to pace/capture, undersensing/oversensing).

Main Results:

• The proposed framework aids in understanding normal pacemaker function on ECG.
• The approach facilitates distinguishing appropriate device function from true malfunction.
• Applicable to single-chamber, dual-chamber, cardiac resynchronization therapy (CRT), and conduction system pacing.

Conclusions:

• Understanding pacemaker timing logic is fundamental for ECG interpretation.
• A systematic approach improves the recognition of normal device behavior and malfunction.
• This framework supports clinicians in managing complex paced ECGs.