Related Experiment Video
Updated: Jul 31, 2025
Transesophageal Atrial Burst Pacing for Atrial Fibrillation Induction in Rats
Published on: February 14, 2022
Optimal rate control in dogs with atrial fibrillation-ORCA study-Multicenter prospective observational study:
Brigite Pedro1,2,3,4,5, Antonia Mavropoulou6, Mark A Oyama7
1Willows Veterinary Centre and Referral Service, West Midlands, United Kingdom.
Background:
The optimal heart rate (HR) in dogs with atrial fibrillation (AF) is unknown. Impact of HR on survival needs elucidation.
Hypothesis/Objectives:
Dogs with a 24 hours Holter-derived meanHR ≤125 beats per minute (bpm; rate controlled) survive longer than dogs with higher meanHR. We further aimed to determine which variables predict ability to achieving rate control.
Animals:
Sixty dogs with AF.
Methods:
Holter-derived meanHR, clinical, echocardiographic, and biomarker variables were analyzed prospectively. Survival was recorded from time of rate control, with all-cause mortality as primary endpoint. Cox proportional hazards analysis identified variables independently associated with survival; Kaplan-Meier survival analysis estimated the median survival time of dogs with meanHR ≤125 bpm vs >125 bpm. Logistic regression explored baseline variables associated with inability to achieve rate control.
Results:
Structural heart disease was present in 56/60 dogs, 50/60 had congestive heart failure, and 45/60 died. Median time to all-cause death was 160 days (range, 88-303 days), dogs with meanHR >125 bpm (n = 27) lived 33 days (95% confidence interval [CI], 15-141 days), dogs with meanHR ≤125 bpm (n = 33) lived 608 days (95% CI, 155-880 days; P < .0001). Congenital heart disease and N-terminal pro-B-type natriuretic peptide were independently associated with higher risk of death (P < .01 and <.0001, respectively) whereas meanHR ≤125 bpm decreased the risk of death (P < .001). Increased left atrial size, increased C-reactive protein concentration and lower blood pressure at admission were associated with failure to achieve rate control.
Conclusions And Clinical Importance:
Rate control affects survival; an optimal target meanHR <125 bpm should be sought in dogs with AF. Baseline patient variables can help predict if rate control is achievable.
More Related Videos
08:05Optimization of Transesophageal Atrial Pacing to Assess Atrial Fibrillation Susceptibility in Mice
Published on: June 29, 2022
12:45Benefits of Cardiac Resynchronization Therapy in an Asynchronous Heart Failure Model Induced by Left Bundle Branch Ablation and Rapid Pacing
Published on: December 11, 2017
Related Concept Videos
01:25Dysrhythmias VI: Management of Dysrhythmias
01:31Regulation of Heart Rates
The SNS increases heart rate through the release of norepinephrine and epinephrine, which act on beta-1 adrenergic receptors in the heart. This action increases the rate of depolarization in the sinoatrial (SA) node, the heart's...
01:29Disturbances in Heart Rhythm
Arrhythmias are categorized by their speed, rhythm, and origin. A slow heart...
01:25Cardiopulmonary Resuscitation IV: Pharmacological Management
01:25Aortic Regurgitation III: Medical Management
01:19Cardiac Output I:Effect of Heart Rate on Cardiac Output
Cardiac output (CO) refers to the total amount of blood ejected by one of the ventricles in liters per minute (L/min). In a resting adult, CO ranges from 5 to 6 L/min, adjusting according to the body's metabolic requirements.
Effect of Heart Rate on Cardiac Output
Cardiac output adapts to metabolic demands during stress, physical activity, or illness. The autonomic nervous system regulates heart rate via the sinoatrial node. The parasympathetic nervous system decreases heart...