Heart rate variability and quality of life in dogs with mitral valve disease treated with metoprolol

Tamyris Beluque,Marlos Gonçalves Sousa,Roberto Navarrete Ampuero,Elizabeth Carvalho,Jaislane Bastos Braz,Aparecido Antonio Camacho,Raphaela Arantes Marques Canola,Murillo Daparé Kirnew

doi:10.29374/2527-2179.bjvm003020

Abstract

Mitral valve disease (MVD) is a progressive disease that can reduce cardiac output. Activation of the sympathetic autonomic nervous system is one of the body’s first responses in order to maintain cardiac output, but may have deleterious effects on the cardiovascular system. This study investigated the effect of metoprolol on heart rate variability and quality of life in dogs with severe MVD (stage C, according to the guidelines of the American College of Veterinary Internal Medicine). Eight dogs between nine and thirteen years of age were enrolled and screening tests such as complete blood count, serum biochemistry profile, systolic blood pressure, thoracic radiographs, electrocardiogram, echocardiogram and long-term electrocardiography (24 hours) were performed. The patients were treated with enalapril, furosemide, spironolactone, and pimobendan until considered clinically stable, and metoprolol was then added to the therapy. One month later, all animals were re-assessed. Owners responded to a questionnaire about their dog’s quality of life before and after beta-blocker therapy. The value for pNN50 (percentage difference between adjacent N-N intervals more than 50 ms) was significantly higher (P=0.039) after treatment with metoprolol, indicating higher heart rate variability as indicated by the increased parasympathetic component. Furthermore, quality of life was improved in 30% of patients after metoprolol was initiated. The results suggest that treatment with beta-blockers in dogs with stage C MVD may yield additional benefits in comparison to standard CHF treatment.

Highlights

Mitral valve disease (MVD) is the most prevalent cardiovascular disease in dogs, affecting up to 42.6% of animals over seven years of age (Santos et al, 2013)
All animals were attended at the Veterinary Hospital of the Faculdade de Ciências Agrárias e Veterinárias (FCAV) – Universidade Estadual Paulista (UNESP), the owners were informed about the study, and after agreeing to include the animals in the experiment signed terms of consent
Of the 18 dogs, eight (9-13 years old, 4-12 kg, four males and four females) with stage C MVD according to American College of Veterinary Internal Medicine (ACVIM) guidelines remained in the study (Keene et al, 2019)

Summary

Introduction

Mitral valve disease (MVD) is the most prevalent cardiovascular disease in dogs, affecting up to 42.6% of animals over seven years of age (Santos et al, 2013). This progressive condition often leads to congestive heart failure (CHF), resulting in low cardiac output and hypotension (Triposkiadis et al, 2009). Activating the SANS initially benefits the cardiovascular system, but as sympathetic activity becomes chronic several deleterious effects are observed, such as tissue hypoperfusion, left ventricular dysfunction, and greater reduction of cardiac output (Frigerio & Roubina, 2005; Mehta et al, 2003). Research on the benefits of beta-blockers to treat dogs with endocardiosis is relatively scarce and does not permit definitive conclusions about the effectiveness of this therapy

Methods

Results

Conclusion