DK2985_C000 1..28 - AlSharqia Echo Club

298 Transesophageal Echocardiography(A)(B)LARARVLV(C)(D)RALALVRV(E)(F)LARARVLV(G)(H)RALARVLVFigure 13.16 Signs of right ventricular dysfunction in a 69-year-old man following cardiopulmonary bypass. With positive-pressureventilation (PPV), right ventricular dilatation (A, B) with moderate tricuspid valve regurgitation (C, D) was present. The use of jet ventilationhas a favorable effect on right ventricular function, with a reduction of right-sided cardiac chamber size (E, F) and tricuspid regurgitation(G, H) with associated increase in cardiac index (CI) and oxygen partial pressure (PaO 2 ) at an inspired oxygen of 100%. Thereduction in pulmonary vascular resistance could be secondary to both the reduced tidal volume with jet ventilation and improved oxygenation(LA, left atrium; LV, left ventricle; MAP, mean arterial pressure; MPAP, mean pulmonary artery pressure; Paop, pulmonaryartery occlusion pressure; Pra, right atrial pressure; RA, right atrium; RV, right ventricle).detrimental. The mechanisms of cardioprotection arelargely unknown, although potential mechanisms includefavorable alteration of the determinants of myocardialoxygen supply and demand, preservation of high energyphosphates, modification of intracellular calcium handlingand activation of adenosine triphosphate-regulated potassiumchannels. (Effects of inhalational anesthetics onsystemic hemodynamics and the coronary circulation.In: Kaplan JA, ed. Cardiac Anesthesia. 4th ed. Chapter16. WB Saunders Company, 1999.)