In vivo comparison between two tip pressure transducer systems.

Experimental findings are presented of an in vivo comparison between a Sentron catheter and another tip transducer manometer: a Millar microtip catheter. Both catheters have been used simultaneously in the left ventricle of dogs. Pressure variations were elicited by drug infusion. Pressure values and derivatives obtained from both systems were compared. A cross correlation between episodes of the two pressures was computed. Results from this study showed good correlation between left ventricular systolic pressure measured with both manometers (R = 0.992, p < 0.0001), end-diastolic pressure (R = 0.809, p < 0.0001) and between first derivatives: positive derivative (R = 0.993, p < 0.0001) and negative (R = 0.634, p < 0.0001). The mean cross correlation between both pressure signals was 0.61 +/- 0.04. In the frequency domain no statistical difference was found between the location of the maxima of the peaks. It is concluded that a Sentron manometer can be a valid alternative, at a reasonable price, to a cheaper, though less accurate fluid filled catheter and a more expensive 'golden standard' microtip catheter.