Effects of volume loading during experimental acute pulmonary embolism.

Volume loading is used to treat hemodynamically compromised patients with acute pulmonary embolism despite data to suggest that volume loading after embolism might cause a leftward shift of the ventricular septum with a subsequent decrease in left ventricular (LV) end-diastolic volume and stroke work. We studied 10 closed-chest, anesthetized, and ventilated dogs to assess the effects of volume loading after pulmonary embolism caused by autologous clot. LV, right ventricular, and right atrial pressures as well as LV anteroposterior, septum-to-right ventricular, and septum-to-LV free wall diameters (sonomicrometry) were measured. Pericardial pressure was measured with flat, liquid-containing balloons. The effects of volume loading were assessed before embolism, after one episode of embolization, and after repeated embolizations. The LV area index (as a reflection of LV volume) increased during volume loading before embolism (2,870 +/- 430 to 3,080 +/- 520 mm2; p less than 0.05), did not change significantly...