[Recording of His potentials from surface chest leads using a computer]

Area of Science:

• Cardiology
• Electrophysiology
• Biomedical Engineering

Context:

• Recording His potentials, crucial for cardiac electrical activity, typically requires invasive catheterization.
• Surface electrocardiography (ECG) offers a non-invasive alternative but faces challenges due to low signal intensity and background noise.
• Averaging techniques are essential for isolating faint cardiac signals from noise in surface ECG recordings.

Purpose:

• To investigate the feasibility of recording His potentials non-invasively using surface chest leads and signal averaging.
• To assess the reliability and correlation of non-invasively obtained His potentials with invasive measurements.
• To evaluate the potential clinical utility and limitations of this novel surface ECG technique.

Summary:

• His potentials were recorded from surface chest leads in 80 patients using signal averaging, identifying a signal in over a third of cases.
• The technique amplifies and processes signals preceding the R wave, synchronizing and summing successive cardiac cycles.
• Correlation with invasive methods in 14 patients showed good agreement, with a noted source of error being P wave after-potentials in short PR intervals.

Impact:

• This non-invasive approach provides a potential alternative for detecting His bundle activity, reducing the need for invasive procedures.
• The findings suggest that surface ECG with averaging may offer valuable diagnostic information, though clinical application requires further refinement.
• While unlikely to replace invasive techniques for specific tests, this method could complement existing diagnostic tools in cardiology.