Controlled Activation for Interrogation of the Electrophysiological Substrate

Area of Science:

• Cardiovascular Electrophysiology
• Cardiac Arrhythmia Mechanisms
• Biomedical Engineering

Background:

• Arrhythmias can arise from ectopic activation in diseased myocardial substrates.
• Standard electrophysiological mapping during sinus rhythm may not detect all pro-arrhythmic substrates.
• Ectopic beats can trigger arrhythmias by revealing underlying substrate abnormalities.

Purpose of the Study:

• To investigate a novel method for interrogating myocardial substrates using variable activation patterns.
• To determine if this method can reveal electrophysiological features not detectable during sinus conduction.
• To assess the feasibility of using trackable loop catheters for detailed local tissue property mapping.

Main Methods:

• Utilized simulation and experimental models with trackable loop catheters.
• Stimulated and recorded myocardial regions using multiple activation patterns.
• Acquired longitudinal and traverse conduction velocities.
• Detected and removed artifacts caused by varying electrode-pacing distances.

Main Results:

• Demonstrated the feasibility of mapping local tissue properties with variable activation patterns.
• Successfully exposed features of the electrophysiological substrate not recovered during sinus conduction.
• Acquired reliable conduction velocity data and removed pacing artifacts.

Conclusions:

• Mapping local cardiac tissue properties with variable activation patterns is a viable technique.
• This approach can identify pro-arrhythmic substrates missed by conventional sinus rhythm mapping.
• The findings have implications for improving arrhythmia diagnosis and treatment strategies.