Lorenz Plot Analysis in Dogs with Sinus Rhythm and Tachyarrhythmias

Area of Science:

• Veterinary Cardiology
• Cardiovascular Physiology
• Data Visualization

Background:

• Heart rate variability (HRV) analysis is crucial for assessing cardiac health.
• The Lorenz plot (LP), a graphical HRV representation, remains understudied in canine cardiology.
• Understanding LP patterns can aid in diagnosing canine arrhythmias.

Purpose of the Study:

• To describe graphic features of Lorenz plots in dogs with sinus rhythm (SR) and tachyarrhythmias.
• To analyze the diagnostic utility of Lorenz plot pattern recognition in dogs.
• To establish repeatability and reproducibility of Lorenz plot pattern classification.

Main Methods:

• Retrospective analysis of 119 canine Holter recordings.
• Classification of cardiac rhythms: SR, SR with frequent premature ectopies (atrial, ventricular, or both), atrial fibrillation (AF), and AF with frequent VPCs.
• Qualitative and quantitative evaluation of Lorenz plots, classifying them into distinct patterns (LPPs).

Main Results:

• Ten distinct Lorenz plot patterns (LPPs) were identified.
• Excellent repeatability and reproducibility of LPP classification were achieved.
• The double side-lobe (DSL) pattern demonstrated high sensitivity (91.3%) and specificity (94.5%) for SR with frequent premature ectopies.

Conclusions:

• Distinct cardiac rhythms in dogs produce unique and reproducible Lorenz plot patterns.
• The double side-lobe pattern is a reliable indicator of sinus rhythm with frequent premature ectopies.
• While most canine LPPs are specific, they generally exhibit low sensitivity for diagnosing SR and tachyarrhythmias.