In cases where DMVD becomes clinically significant, a '''cough''' is usually the first clinical sign noticed by the owner. The coughing is likely of multifactorial aetiology and may be related to pulmonary oedema, stimulation of the juxtapulmonary (J) receptors that are associated with pulmonary capillaries and detect increases in pulmonary venous pressure, compression of a mainstem bronchi by an enlarged left atrium and concurrent airway disease. Occasionally, '''syncope''' is the first sign of clinically significant DMVD. This may occur due to arrhythmias or on exertion where mitral regurgitation limits stroke volume and therefore cardiac output. | In cases where DMVD becomes clinically significant, a '''cough''' is usually the first clinical sign noticed by the owner. The coughing is likely of multifactorial aetiology and may be related to pulmonary oedema, stimulation of the juxtapulmonary (J) receptors that are associated with pulmonary capillaries and detect increases in pulmonary venous pressure, compression of a mainstem bronchi by an enlarged left atrium and concurrent airway disease. Occasionally, '''syncope''' is the first sign of clinically significant DMVD. This may occur due to arrhythmias or on exertion where mitral regurgitation limits stroke volume and therefore cardiac output. |