STOPPED-FLOW EPICARDIAL LYMPH PRESSURE IS AFFECTED BY LEFT-VENTRICULAR PRESSURE IN ANESTHETIZED GOATS

We measured epicardial lymph pressure (P(lymph)) in the anesthetized g oat (n = 5 goats). To study the transmission of systolic left ventricu lar pressure (P(LV)) to P(lymph), the effect of an increase in P(LV) c aused by clamping of the descending aorta on P(lymph) was evaluated. P eak systolic P(LV) was 131 +/- 4 (+/- SE) mmHg during control (43 beat s) and 188 +/- 4 mmHg when elevated due to aortic clamping (157 beats) . Peak systolic P(lymph) was 24.8 +/- 1.0 and 34.8 +/- 1.1 mmHg during control and elevated P(LV), respectively. In the first beat of elevat ed P(LV), peak P(lymph) did not change, although the pressure waveform did. In the subsequent beats, P(lymph) increased proportionally with increased P(LV). When P(LV) was decreased back to control, P(lymph) al so decreased but did not reach control level until after three beats. The relationship between normalized P(lymph) and normalized P(LV) is g iven by P(lymph) = 0.70 . P(LV) + 0.09. The results show that P(LV) do es affect P(lymph) in a normal beating heart.