The electrocardiogram, vectorcardiogram and spatiocardiogram in the rabbit.

Area of Science:

• Cardiovascular physiology
• Electrocardiography
• Comparative anatomy

Background:

• Electrocardiography (ECG) is crucial for understanding cardiac electrical activity.
• Standard ECG leads provide a limited view of the heart's electrical vectors.
• Orthogonal lead systems offer a more comprehensive spatial analysis.

Purpose of the Study:

• To spatially characterize ventricular activation in rabbits using orthogonal electrocardiographic leads.
• To compare findings from standard and orthogonal lead systems in a preclinical model.

Main Methods:

• Recorded simultaneous ECGs from 25 rabbits using standard limb leads and three orthogonal leads (I, aVF, V10).
• Analyzed ECG parameters including rate, rhythm, intervals, and amplitudes.
• Calculated P, QRS, and T wave vectors in frontal, sagittal, and transverse planes.

Main Results:

• Ventricular activation patterns were spatially determined using orthogonal leads.
• Findings indicated spatial orientation of ventricular activation towards sinistrad/dextrad, ventrad, and caudad directions.
• QRS complex waveforms were analyzed across all recorded leads.

Conclusions:

• Orthogonal lead ECG provides detailed spatial orientation of ventricular activation in rabbits.
• This spatial orientation is predominantly sinistrad/dextrad, ventrad, and caudad.
• The study contributes to understanding cardiac electrophysiology in preclinical models.