Studies on the physiopathology of chronic obstructive pulmonary disease in the horse. VIII. Mean modal vectors of the P wave and the QRS complex.

This research study examines the changes in the P wave and QRS complex, components of a heart’s electrical activity, in horses and ponies afflicted with chronic obstructive pulmonary disease (COPD) compared to healthy ones.

Research Methodology

• The study was done on 34 individual subjects divided into two equal groups of 17. One group was of horses and ponies with COPD, and the second was a control group of clinically healthy horses and ponies.
• To minimize variations due to differing heart rates, subjects were paired such that heart rates between each pair exhibited no significant difference, not deviating by more than 2 cycles per minute.
• The mean modal vectors of P1, P2, and QRS were determined in three different planes of a semi-orthogonal EKG lead system.

Findings

• Through the experiment, variances were observed between the P1 vectors modal mean angles in those with COPD and those without in the transverse (T plane) and sagittal (S plane) planes.
• In the T plane, the mean angle for healthy subjects was 324 degrees +/- 24.6 degrees, while that for COPD was 342 degrees +/- 21.0 degrees with a t-value of 2.0 and a p-value less than 0.05, indicating statistical significance.
• Similar statistically significant differences were observed in the S plane; with mean angles of 331 degrees +/- 22.6 degrees for healthy subjects and 348 degrees +/- 16.2 degrees for COPD subjects with a t-value of 2.52 and a p-value less than 0.02.
• However, no significant differences were noted in the mean angles of planar modal QRS vectors between the control and COPD groups.

Conclusion

• This research indicates some changes in the P wave vectors of horses and ponies that have chronic obstructive pulmonary disease when compared to healthy counterparts.
• The observed variances in the P1 vectors in the T plane and S plane suggest possible physiological differences in the heart’s electrical activity due to COPD.
• However, regarding the QRS complex, no notable changes were observed, indicating that COPD might not significantly impact this aspect of a horse or pony’s heart activity.