Transvenous echo Doppler in baboons: a new window to the cardiovascular system

Ultrasound examinations of the heart and major peripheral arteries have bee n performed as separate procedures; both potentially limited by suboptimal views in certain subjects and the inability to obtain ideal pictures of par ticular intracardiac structures. Transvenous ultrasound may offer new advan tages in certain areas, we therefore studied six adult baboons using a sing le-plane 5.5-10 MHz transducer mounted on a 10 French (10F) catheter, intro duced via the right femoral vein and positioned under fluoroscopic control. Imaging and Doppler studies were performed to delineate cardiovascular ana tomy as well as ventricular function response to positive (dobutamine) and negative inotropic (esmolol) agents. The procedure was safe and feasible in all cases. Clear and novel two-dimensional and flow information were obtai ned from the iliac arteries, descending aorta, both renal artery origins. a scending aorta, including the aortic arch, main pulmonary artery and its bi furcation, as well as head and neck vessels. Novel intracardiac views were obtained, including right ventricular long axis, left ventricular apex and 'flask' views of the left ventricle. Excellent dynamic information for left ventricular function was also available [e.g. myocardial V-max of the ante rior left ventricular wall was 6.8+/-2.5 cm/s at rest, 14.6+/-5.5 cm/s afte r dobutamine (P = 0.009) and 4.5+/-1 cm/s after esmolol (P = 0.03 compared with control)]. We conclude that, in adult primates, transvenous ultrasound safely and reliably provides novel information of cardiovascular structure and function.