Introduction
Angiocardiography and cineangiocardiography have become standard procedures in canine cardiology for the study of heart disease, and in the diagnosis and prognosis of clinical cases (6,7,20,32). When preceded by complete cardiac catheterization and pressure measurement, information is obtained on the physiological status of the heart, including an assessment of the severity of stenoses and shunts in congenital heart disease. More information can be obtained using the Fick principle to measure cardiac output (40). End diastolic volume (EDV) and end systolic volume (ESV) can be measured by the indicator-dilution method (15, 29,40). The stroke volume (SV) is the difference between EDV and ESV, and from it, the minute volume or cardiac output is obtained. The measurement of maximal rate of rise of the left ventricular pressure by integration of the left ventricular pressure tracing (15) is one of many methods used to assess myocardial contractility. These methods require equipment additional to that used for pressure measurements and angiocardiography