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The effect of left atrial histology and dimension on P wave morphology
Insights
This study links left atrial appendage cell size to P wave amplitude and fibrosis to PR segment duration in patients with mitral valve disease, aiding electrocardiographic P wave understanding.
Area of Science:
- Cardiology
- Electrophysiology
- Histopathology
Background:
- Left atrial appendage (LAA) alterations are implicated in cardiovascular disease.
- P wave morphology on electrocardiography (ECG) reflects atrial electrical activity.
- Understanding the relationship between LAA structure and ECG findings is crucial.
Purpose of the Study:
- To correlate LAA cell size and fibrosis with P wave morphology in mitral valve disease patients.
- To investigate the relationship between echocardiographic left atrial size and P wave characteristics.
Main Methods:
- Stereological assessment of LAA fibrosis and cell diameter in 12 mitral valve disease patients.
- Echocardiographic measurement of left atrial size.
- Correlation analysis of LAA parameters with P wave amplitude, duration, PR segment, and PR interval.
Main Results:
- Significant correlation found between LAA cell diameter and P wave amplitude (r = .69, p = 0.01).
- Significant inverse correlation between LAA fibrosis and PR segment duration (r = -.72, p = 0.01).
- Significant direct correlation between LAA fibrosis and P wave length to PR segment ratio (r = .67, p = 0.01).
Conclusions:
- LAA cell size correlates with P wave amplitude.
- LAA fibrosis correlates with PR segment duration and P wave morphology.
- These findings enhance the understanding of P wave characteristics in relation to LAA structural changes.
Abstract:
This study correlates left atrial appendage cell size, atrial fibrosis and echocardiographic (echo) measurement of left atrial size with P wave morphology. Twelve patients with known mitral valve disease had echo measurements of left atrial size with P wave morphology. Twelve patients with known mitral valve disease had echo measurements of left atrial size prior to mitral valve surgery; patients had varying degrees of left atrial enlargement. The left atrial appendage, removed at the time of surgery, was stereologically assessed for percent fibrosis and the diameters of 50 cells were measured and averaged. These factors were correlated with P wave amplitude and duration in lead II, greatest length in any led, PR segment (end of P wave to onset of QRS), P to PR segment ratio (in lead II) and the PR interval. There was a good correlation of left atrial cell diameter with P wave amplitude (r = .69, p = 0.01). There was a good inverse correlation of percent fibrosis with the PR segment (r = -.72, p = 0.01) and a direct correlation of fibrosis with the ratio of P wave length to PR segment (r = .67 p = 0.01). There was a trend for percent fibrosis to correlate with PO wave duration but not height. No correlation was noted for any of the P wave characteristics and left atrial size. This study demonstrates that there is a correlation of P wave height with cell diameter and P wave length and PR segment with fibrosis. These data are helpful in understanding the electrocardiographic P wave.