Comparison between acute hypoxia-induced and mechanically-induced pulmonary artery hypertension on the hemodynamics, myocardial contractility and regional blood flow in dogs

Autor: Arvieux Cc, Fargnoli Jm, P. Fourie, Claude Girard, B. Maitrasse
Rok vydání: 1995
Předmět:
Zdroj: Fundamental & Clinical Pharmacology. 9:554-561
ISSN: 1472-8206
0767-3981
DOI: 10.1111/j.1472-8206.1995.tb00533.x
Popis: Two groups of eight anesthetized dogs with pulmonary artery hypertension (PAH) were compared. PAH was induced by submitting one group (HP) to hypoxia (FiO2 range : 6-10%) and the other group (ME) to microemboli through glass microbead injection into the pulmonary circulation. Hypoxia-induced PAH was moderate (PAP : +65% ; PVR : +152%) contrasting with marked PAH after microbead injection (PAP : +190% ; PVR : +389%). For similar effects on left ventricular contractility (LV dP/dt max and segmental myocardial shortening), heart rate and systemic vascular resistance, left ventricular end-diastolic pressure showed significant differences between the two groups (HP group : +75%, ME group : -9%), and so did left ventricular end-diastolic length (HP : +9%, ME : -11%). Thus, contrary to the injection of microbeads, hypoxia did not give rise to any pulmonary barrier, and consequently the changes in cardiac output (HP : +19%, ME : -15%) and hepatic blood flow (HP : +383%, ME : -77%) were significantly different. Hypoxia, and not microbead injection, was responsible for systemic hypertension (MAP : +34% and 4%, respectively). The microbead model resulted in a significantly higher PVR/SVR ratio compared to the hypoxic model (HP : 0.14, ME : 0.41). Hypoxia increased left and right myocardial blood flows whereas microbead injection affected only right ventricular blood flow, leading to significantly different RV/LV endocardial perfusion ratios (HP : +10%, ME : +98%). We conclude that microbead-induced PAH is more appropriate than hypoxia-induced PAH for hemodynamic and pharmacological studies.
Databáze: OpenAIRE
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