TY - JOUR
T1 - Left ventricular size, output, and structure during guinea pig pregnancy.
AU - Morton, M.
AU - Tsang, H.
AU - Hohimer, R.
AU - Ross, D.
AU - Thornburg, K.
AU - Faber, J.
AU - Metcalfe, J.
PY - 1984/1
Y1 - 1984/1
N2 - We investigated left ventricular (LV) hemodynamics, pressure-volume relations, and morphometry to determine what cardiac changes characterize pregnancy in the guinea pig. Time-bred virgin guinea pigs were paired by weight with unbred controls. Hemodynamic studies and LV pressure-volume relations were obtained on days 59-68 of the 68-day gestation. Weight of control sows increased from 817 to 902 g (P less than 0.01) and pregnant sows from 810 to 1,251 g (P less than 0.01). LV weights were not different. When indexed for maternal weight minus uterus and contents, pregnancy produced increases in O2 consumption, +48% (P less than 0.01); cardiac output, +32% (P less than 0.05); and stroke volume, +46% (P less than 0.025). Passive LV pressure-volume curves (dP/dV) were shifted to the right (P less than 0.025), but dP/dV at constant pressure was unchanged. Using a thin-walled spherical model, elastic modulus at constant stress was not different. The percent LV inter- and intracellular volumes and myocyte myofibril and organelle volumes were unchanged during pregnancy. In the guinea pig, pregnancy increases LV output, stroke volume, and size without changes in LV mass, morphometry, or elastic modulus.
AB - We investigated left ventricular (LV) hemodynamics, pressure-volume relations, and morphometry to determine what cardiac changes characterize pregnancy in the guinea pig. Time-bred virgin guinea pigs were paired by weight with unbred controls. Hemodynamic studies and LV pressure-volume relations were obtained on days 59-68 of the 68-day gestation. Weight of control sows increased from 817 to 902 g (P less than 0.01) and pregnant sows from 810 to 1,251 g (P less than 0.01). LV weights were not different. When indexed for maternal weight minus uterus and contents, pregnancy produced increases in O2 consumption, +48% (P less than 0.01); cardiac output, +32% (P less than 0.05); and stroke volume, +46% (P less than 0.025). Passive LV pressure-volume curves (dP/dV) were shifted to the right (P less than 0.025), but dP/dV at constant pressure was unchanged. Using a thin-walled spherical model, elastic modulus at constant stress was not different. The percent LV inter- and intracellular volumes and myocyte myofibril and organelle volumes were unchanged during pregnancy. In the guinea pig, pregnancy increases LV output, stroke volume, and size without changes in LV mass, morphometry, or elastic modulus.
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M3 - Article
C2 - 6696101
AN - SCOPUS:0021296819
SN - 0002-9513
VL - 246
SP - R40-48
JO - The American journal of physiology
JF - The American journal of physiology
IS - 1 Pt 2
ER -