British Medical Ultrasound Society Annual Congress, Edinburgh, December 2009
Anne French spoke about asymptomatic murmurs in cats, which is a common presentation in general practice. She stated that these murmurs do usually reflect disease, either primary cardiac disease or non-cardiac disease (especially hypertension of renal or hyperthyroid origin, but also acromegaly, hyperadrenocorticism, diabetes mellitus, amyloidosis and neoplastic infiltration). Echocardiography is recommended in these cats, following blood pressure analysis (which should be performed in all cats and dogs prior to cardiac investigation). Sedation will affect some components of the echocardiography examination and should be avoided where possible, although it was acknowledged that cats are time consuming and require one or more good assistants and a quiet environment. Hypertrophic obstructive cardiomyopathy is the most common cause of asymptomatic murmurs in cats, although thickening of the interventricular septum at the left ventricular outflow tract can be secondary to systolic anterior motion of the mitral valve. Other causes are right ventricular outflow obstruction and other acquired (hypertrophic, restrictive, unclassified, arhythmogenic right ventricular and dilated Cardiomyopathies) and congenital disorders.
Jo Dukes-Mcewan presented several interesting canine cardiac cases. One was a case of right atrial haemangiosarcoma in a dog with a pericardial effusion, with the key message being to look hard at the junction between the right atrium and the right ventricle on the right parasternal long axis view; if there is a slightly unusual appearance to this area, it may well reflect early haemangiosarcoma as the changes can be very subtle in the early stages. A case of tricuspid valve dysplasia was presented, and it was stressed that it is important to look for concurrent defects eg ASD, and that it can be very difficult to ascertain whether the tricuspid valve is definitely abnormal; tips were to look for abnormal chordae tendinae and papillary muscles, and for the presence of bands in the ventricle. Cases of PDA can look like mitral valve disease initially, as a mitral regurgitant murmur occurs due to dilation; if mitral regurgitation is detected always check the pulmonary artery. Important features are the diameter of the ostium and ampulla of the PDA, and also the degree of volume overload and systolic function.