Restrictive Cardiomyopathy in Cats

Restrictive cardiomyopathy describes a pattern in which the muscular walls of the heart become stiff and less able to relax properly between beats. This stiffness limits how much blood the chambers can accept, which in turn affects how efficiently the heart fills and pumps. In cats, this is a less common form of heart muscle disease than hypertrophic cardiomyopathy, but it follows a similar trajectory once signs appear. Owners often arrive at this page after learning their cat has a heart murmur at a routine visit, or because their cat has become quieter, is breathing more rapidly, or has suddenly lost use of a hind leg. Some cats show no outward signs for months or years. The condition can also be identified during investigation of fluid accumulation in the chest or abdomen. This page explores the patterns that may prompt consideration of restrictive cardiomyopathy, what is understood about the changes in heart muscle that underlie it, how the condition is investigated using imaging and other tools, and the range of approaches used to support cats living with it.