Left ventricular outflow tract pressure gradient changes after carvedilol-disopyramide cotherapy in a cat with hypertrophic obstructive cardiomyopathy.

Abstract

Disopyramide reduces the left ventricular outflow tract (LVOT) pressure gradient and improves symptoms in humans with hypertrophic obstructive cardiomyopathy (HOCM). However, the efficacy of disopyramide in cats has not been reported. We treated a cat with HOCM with carvedilol and disopyramide cotherapy and monitored the changes in LVOT flow velocity and N-terminal pro B-type natriuretic peptide (NT-proBNP) concentration. A 10-month-old neutered male Norwegian Forest cat was referred with a moderate systolic cardiac murmur. Echocardiography revealed thickening of the left ventricular wall, systolic anterior motion of the mitral valve leaflets, and turbulent aortic flow in the LVOT at systole. The LVOT flow velocity was 5.6 m/s. The plasma NT-proBNP concentration exceeded 1,500 pmol/L. The cat was diagnosed with HOCM and the β-blocker carvedilol was started and gradually increased to 0.30 mg/kg, bid. After 57 days, the LVOT flow velocity (4.8 m/s) and plasma NT-proBNP concentration (870 pmol/L) had decreased but remained elevated. Therefore, disopyramide was added at 5.4 mg/kg po bid and increased to 10.9 mg/kg po bid after 22 days. After 141 days of carvedilol and disopyramide treatment, the systolic anterior motion of the mitral valve leaflets had disappeared and the LVOT flow velocity and plasma NT-proBNP concentration had decreased to 0.7 m/s and 499 pmol/L, respectively. No adverse effect has been observed during the follow-up. Disopyramide might relieve feline LVOT obstruction after only partial response to a beta-blocker. Further large-scale studies are required to investigate the efficacy and safety of disopyramide use in cats with moderate to severe HOCM.

• Authors: Y Hori, E Fujimoto, Y Nishikawa, T Nakamura
• Journal: Journal of veterinary cardiology : the official journal of the European Society of Veterinary Cardiology (J Vet Cardiol) Vol. 29 Pg. 40-46 (Jun 2020) ISSN: 1875-0834 [Electronic] Netherlands
• PMID: 32464577 (Publication Type: Case Reports)
• Copyright: Copyright © 2020 Elsevier B.V. All rights reserved.

Chemical References

• Adrenergic beta-Antagonists
• Peptide Fragments
• Voltage-Gated Sodium Channel Blockers
• pro-brain natriuretic peptide (1-76)
• Carvedilol
• Natriuretic Peptide, Brain
• Disopyramide

Topics

• Adrenergic beta-Antagonists (therapeutic use)
• Animals
• Cardiomyopathy, Hypertrophic (veterinary)
• Carvedilol (therapeutic use)
• Cat Diseases (drug therapy)
• Cats
• Disopyramide (therapeutic use)
• Echocardiography (veterinary)
• Male
• Natriuretic Peptide, Brain (blood)
• Peptide Fragments (blood)
• Ventricular Outflow Obstruction (drug therapy, veterinary)
• Voltage-Gated Sodium Channel Blockers (therapeutic use)