On-line cardiac mapping: an analog approach using video and multiplexing techniques

Area of Science:

• Cardiovascular Physiology
• Biomedical Engineering
• Medical Imaging

Background:

• Ventricular arrhythmias pose significant clinical challenges.
• Accurate mapping of cardiac activation is crucial for understanding and treating these conditions.
• Existing computerized methods can be expensive and complex.

Purpose of the Study:

• To develop and evaluate a practical, inexpensive video multiplexing system for real-time ventricular activation mapping.
• To visualize the sequence and origin of ventricular activation in detail.
• To assess the system's utility in detecting ischemic regions and conduction abnormalities.

Main Methods:

• A video and multiplexing system was designed using a 112-dot matrix display representing a polar projection of the ventricles.
• An electrode array monitored myocardial activation, with dots brightening upon local cardiac activation.
• Experiments were conducted in in situ canine hearts, recording activation sequences at 8.3-ms intervals.

Main Results:

• The system provided real-time, slow-motion, and stop-frame visualization of ventricular activation.
• The origin of paced beats was located with sub-5 mm accuracy.
• Coronary occlusion effectively outlined ischemic areas and revealed delayed conduction on the display.

Conclusions:

• This system offers a practical and affordable alternative for ventricular mapping in research and intraoperative settings.
• It provides detailed, on-line visualization of cardiac activation patterns.
• The technology aids in the investigation of ventricular arrhythmias and myocardial ischemia.