Aortic stenosis and ACE inhibitors

• in ACE inhibition when there is a decrease in systemic vascular resistance (e.g. in exercise) then there is a subsequent increase in cardiac output so that blood pressure is maintained
• however if there is a left ventricular outflow obstruction (if severe aortic stenosis is present) then cardiac output cannot be increased in response to a reduction in systemic vascular resistance - this leads to a fall in blood pressure (hypotension) and syncope
• if there is only mild aortic valve obstruction then ACE inhibition is likely to be well tolerated
• however if a patient has severe symptomatic aortic stenosis then this is a contraindication to ACE inhibition

Reference:

1. Pulse (2004), 64 (4), 68