Spatial coherence: a new method of quantifying myocardial electrical organization using multichannel epicardial...

Area of Science:

• Cardiovascular Electrophysiology
• Biomedical Signal Processing

Background:

• Assessing myocardial electrical organization is crucial for understanding cardiac arrhythmias.
• Existing methods for analyzing electrograms can be complex and challenging, especially during fibrillation.

Purpose of the Study:

• To develop and validate a novel technique for quantifying the spatial organization of myocardial electrical activity.
• To introduce two new parameters, coherence length and coherence plateau, for characterizing cardiac rhythms.

Main Methods:

• Utilized magnitude-squared coherence (MSC) spectrum analysis on multichannel electrograms from canine epicardial mapping.
• Computed a 3D coherence surface and derived 2D graphs of coherence versus electrode separation.
• Fitted data to an exponentially decaying curve to extract coherence length and plateau parameters.

Main Results:

• Spatial coherence analysis revealed significantly longer coherence lengths and higher coherence plateau values for normal sinus rhythm compared to ventricular fibrillation (P < .0001).
• Ventricular tachycardia exhibited intermediate values, reflecting a degree of organization between NSR and VF.
• The technique successfully differentiated between various cardiac rhythms based on their electrical organization.

Conclusions:

• Spatial coherence is an effective method for quantifying the electrical organization of cardiac rhythms.
• This technique simplifies the analysis of vast electrogram data and bypasses the need for difficult activation time detection.
• The coherence length and coherence plateau parameters offer a robust measure of myocardial electrical organization.