Assessment of Non-linear RR Interval Metrics in Canine Atrial Fibrillation
Overview
This study evaluates non-linear RR interval metrics in dogs with atrial fibrillation (AF) and their correlation with 24-hour average heart rate. It identifies rate-coupled and rate-independent metrics.
Background
Atrial fibrillation is a prevalent cardiac arrhythmia in both dogs and humans, with effective rate control being crucial for management. Current monitoring practices primarily rely on the 24-hour Holter mean heart rate, which may not fully capture the complexity of heart rate variability.
Data Highlights
Metric
Correlation (|ρ|)
R²
CVRR
0.91
0.75
SD1
0.64
0.42
SD1/SD2 ratio
<0.14
<0.01
Jensen gap (D)
mean -13.4 bpm
range -29.9 to -5.8
Key Findings
Ten non-linear RR metrics were evaluated in 50 dogs with confirmed AF.
Metrics were classified into rate-coupled (CVRR, SD1, SD2, |ΔRR|, DFA-α) and rate-independent (SD1/SD2 ratio, turning-point ratio, MScEn) classes.
All dogs exhibited a negative Jensen gap, indicating RR irregularity.
Rate-independent metrics differed significantly between pre- and post-drug treatment dogs.
The 125-bpm threshold for rate control may not accurately reflect the underlying RR distribution.
Clinical Implications
The findings indicate the evaluation of non-linear RR interval metrics in dogs with atrial fibrillation.
Conclusion
This study highlights the importance of non-linear RR interval metrics in understanding atrial fibrillation in dogs.
