U. Klima et al., CONTRIBUTION OF THE INTERVENTRICULAR SEPTUM TO MAXIMAL RIGHT-VENTRICULAR FUNCTION, European journal of cardio-thoracic surgery, 14(3), 1998, pp. 250-255
Objective: Maximal right ventricular (RV) function is influenced by le
ft heart hemodynamics, possibly mediated by the interventricular septu
m (IVS). We examined the potential contribution of the IVS function to
right heart function. Methods: In 12 canine isovolumic right heart pr
eparations, incremental volumes were introduced into a high compliance
RV balloon until RV failure occurred. Maximal RV developed pressure (
RVDP) and maximal positive RV dP/dt were determined with a working IVS
at a constant left ventricular (LV) output of 2 l/min and at a consta
nt mean arterial pressure of 80 mmHg. Thereafter the IVS was thermally
inactivated, and measurements were repeated using the same protocol.
Results: At constant arterial pressure and constant LV output, thermal
inactivation of the IVS led to a significant decrease in maximal RVDP
(inactivated vs. working IVS: 36.1 +/- 9.8 vs. 56.8 +/- 16.2 mmHg, re
spectively, P < 0.001), and RV dP/dt (inactivated vs. working NS: 720
+/- 220 vs. 1350 +/- 190 mmHg/s, respectively, P < 0.001). Conclusions
: These results suggest that the functional status of the IVS is a maj
or determinant of maximal RV function. At constant LV conditions and a
rterial pressure, an inactivated IVS leads to a significant decrease i
n maximal RVDP and RV dP/dt under the conditions of this study. (C) 19
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