A method for repeated high-fidelity micromanometer measurement of intracardiac pressures.

Dial-tipped, high-fidelity micromanometers were inserted through polyurethane catheters to acutely measure blood pressures within the chambers of the heart and the great vessels of baboons, rhesus monkeys, and goats. Repeated measurements of atrial, ventricular, aortic, and pulmonary artery pressure were possible with this method, with calibration of micromanometers accomplished immediately prior to and after pressure recordings to assure data accuracy. All attempts to pass micromanometers into the atria in all species were successful. Passage of micromanometers from the left ventricle across the aortic valve and into the aorta was successful in 97% of the attempts in baboons, 100% for rhesus monkeys, and 75% for goats; while insertions into the pulmonary artery from the right ventricle were successful in 64% of the baboons, 40% of the rhesus monkeys, and 75% of the goats. Advantages of this technique are that a permanent conduit for cardiac vascular access is available and that high-fidelity pressure signals may be acquired.