Complete atrioventricular block associated with lymphocytic myocarditis of the atrioventricular node in two young adult dogs.

A histological investigation of the atrioventricular (AV) conduction system was performed in two young adult dogs with complete AV block. In both cases, infiltration of lymphocytes and plasma cells into the AV node and loss and disappearance of the conduction fibres were observed. Such inflammatory lesions of the AV conduction system were associated with complete AV block.

Examination of quantitative analysis and measurement of the regurgitation rate in mitral valve regurgitation by the "proximal isovelocity surface area" method.

In 33 dogs with mitral valve insufficiency (MR), assessed as severe by semi-quantitative color flow Doppler echocardiography, regurgitation volumes were measured by the "Proximal Isovelocity Surface Area" (PISA) method. Good correlation (p<0.01, r=0.