The effects of chronic respiratory failure (hypoxia and hypercapnia) on the contractile properties of cardiac muscle are not established. A study was performed of the isometric contractile properties of isolated papillary muscle removed from rats exposed in a normobaric environmental chamber to 28 days of hypoxia (fractional inspired oxygen (FIO2) 10%, fractional inspired carbon dioxide (FICO2) less than 1%), hypercapnia (FIO2 21%, FICO2 5%), and hypoxia with hypercapnia (FIO2 10%, FICO2 5%). Rats exposed to both hypoxia and hypoxia with hypercapnia developed selective right ventricular hypertrophy. Exposure to hypercapnia alone did not alter right ventricular weight. No change in right ventricular papillary muscle contractility per unit muscle mass was observed as measured by maximum active tension, maximum rate of rise or fall of tension, or time to peak tension. Rat cardiac muscle adapts successfully to the altered acid-base environment and increased work load associated with prolonged exposure to hypoxia and mild hypercapnia.
Statistics from Altmetric.com
If you wish to reuse any or all of this article please use the link below which will take you to the Copyright Clearance Center’s RightsLink service. You will be able to get a quick price and instant permission to reuse the content in many different ways.