TY - JOUR
T1 - Atrial septostomy benefits severe pulmonary hypertension patients by increase of left ventricular preload reserve
AU - Koeken, Yvette
AU - Kuijpers, Nico H. L.
AU - Lumens, Joost
AU - Arts, Theo
AU - Delhaas, Tammo
PY - 2012/6
Y1 - 2012/6
N2 - Koeken Y, Kuijpers NH, Lumens J, Arts T, Delhaas T. Atrial septostomy benefits severe pulmonary hypertension patients by increase of left ventricular preload reserve. Am J Physiol Heart Circ Physiol 302: H2654-H2662, 2012. First published April 27, 2012; doi:10.1152/ajpheart.00072.2012.-At present, it is unknown why patients suffering from severe pulmonary hypertension (PH) benefit from atrial septostomy (AS). Suggested mechanisms include enhanced filling of the left ventricle, reduction of right ventricular preload, increased oxygen availability in the peripheral tissue, or a combination. A multiscale computational model of the cardiovascular system was used to assess the effects of AS in PH. Our model simulates beat-to-beat dynamics of the four cardiac chambers with valves and the systemic and pulmonary circulations, including an atrial septal defect (ASD). Oxygen saturation was computed for each model compartment. The acute effect of AS on systemic flow and oxygen delivery in PH was assessed by a series of simulations with combinations of different ASD diameters, pulmonary flows, and degrees of PH. In addition, blood pressures at rest and during exercise were compared between circulations with PH before and after AS. If PH did not result in a right atrial pressure exceeding the left one, AS caused a left-to-right shunt flow that resulted in decreased oxygenation and a further increase of right ventricular pump load. Only in the case of severe PH a right-to-left shunt flow occurred during exercise, which improved left ventricular preload reserve and maintained blood pressure but did not improve oxygenation. AS only improves symptoms of right heart failure in patients with severe PH if net right-to-left shunt flow occurs during exercise. This flow enhances left ventricular filling, allows blood pressure maintenance, but does not increase oxygen availability in the peripheral tissue.
AB - Koeken Y, Kuijpers NH, Lumens J, Arts T, Delhaas T. Atrial septostomy benefits severe pulmonary hypertension patients by increase of left ventricular preload reserve. Am J Physiol Heart Circ Physiol 302: H2654-H2662, 2012. First published April 27, 2012; doi:10.1152/ajpheart.00072.2012.-At present, it is unknown why patients suffering from severe pulmonary hypertension (PH) benefit from atrial septostomy (AS). Suggested mechanisms include enhanced filling of the left ventricle, reduction of right ventricular preload, increased oxygen availability in the peripheral tissue, or a combination. A multiscale computational model of the cardiovascular system was used to assess the effects of AS in PH. Our model simulates beat-to-beat dynamics of the four cardiac chambers with valves and the systemic and pulmonary circulations, including an atrial septal defect (ASD). Oxygen saturation was computed for each model compartment. The acute effect of AS on systemic flow and oxygen delivery in PH was assessed by a series of simulations with combinations of different ASD diameters, pulmonary flows, and degrees of PH. In addition, blood pressures at rest and during exercise were compared between circulations with PH before and after AS. If PH did not result in a right atrial pressure exceeding the left one, AS caused a left-to-right shunt flow that resulted in decreased oxygenation and a further increase of right ventricular pump load. Only in the case of severe PH a right-to-left shunt flow occurred during exercise, which improved left ventricular preload reserve and maintained blood pressure but did not improve oxygenation. AS only improves symptoms of right heart failure in patients with severe PH if net right-to-left shunt flow occurs during exercise. This flow enhances left ventricular filling, allows blood pressure maintenance, but does not increase oxygen availability in the peripheral tissue.
KW - computer modeling
KW - exercise
KW - blood pressure
KW - circulation
KW - oxygen delivery
U2 - 10.1152/ajpheart.00072.2012
DO - 10.1152/ajpheart.00072.2012
M3 - Article
C2 - 22523252
SN - 0363-6135
VL - 302
SP - H2654-H2662
JO - American Journal of Physiology-heart and Circulatory Physiology
JF - American Journal of Physiology-heart and Circulatory Physiology
IS - 12
ER -