Myxomatous Mitral Valve Disease (MMVD)

Practice flashcards covering the pathophysiology, diagnosis, staging, and treatment of Myxomatous Mitral Valve Disease (MMVD) based on lecture notes.

Myxomatous mitral valve disease (MMVD)

The most common canine heart disease, accounting for $75\%$ of cardiac cases, primarily affecting older, small to medium breed dogs.

Left apical systolic murmur

The characteristic auscultatory finding for MMVD; its grade typically increases as the disease progresses.

Eccentric hypertrophy

The enlargement of the left atrium and left ventricle resulting from chronic volume overload caused by mitral valve regurgitation.

Vertebral heart score (VHS)

A radiographic measurement used to assess heart size; a score $\ge 11.5$ (or a breed-adjusted increase) indicates enlargement.

LA:AO ratio

The ratio of the left atrial diameter to the aortic root diameter measured via echocardiogram to evaluate remodeling.

NT-proBNP

A biomarker used to differentiate the cause of respiratory distress; normal levels make cardiac disease very unlikely.

Stage A

Classification for dogs at high risk for developing MMVD but currently without structural changes.

Stage B1

A stage of MMVD where structural disease (murmur) is present, but there is minimal to no heart remodeling on radiographs or echocardiography.

Stage B2

Advanced mitral valve regurgitation with atrial and ventricular enlargement (murmur $\ge III/VI$) where treatment is initiated to delay congestive heart failure.

Stage C

Classification for dogs with current or past clinical signs of congestive heart failure (CHF).

Stage D

End-stage MMVD where congestive heart failure is refractory to standard treatment.

Pimobendan

An inodilator used in Stage B2 to prolong the preclinical period and in Stages C and D to manage congestive heart failure.

EPIC study

The clinical trial that demonstrated pimobendan prolongs the preclinical period in dogs with Stage B2 MMVD.

Furosemide

A loop diuretic used in acute CHF treatment (up to $8\,\text{mg/kg}$ over four hours) and chronic management.

Spironolactone

An aldosterone antagonist used in advanced MMVD cases to reduce the risk of death.

Atrial fibrillation (a-fib)

An arrhythmia often associated with significant atrial enlargement, more commonly seen in large breed dogs with MMVD.

B-lines

Ultrasound findings on T-FAST indicate pulmonary edema secondary to congestive heart failure.

Cardiac cachexia

The loss of muscle mass in heart disease patients; it is a negative prognostic indicator.

Butorphanol

An opioid used to manage anxiety during the acute treatment of congestive heart failure.

Mean survival time

The average period of survival after the onset of CHF in MMVD cases, typically eight to 10 months.