ANAESTHETICS AND AIRWAY
INDUCTION IN SEVERE AS
PromptExplain cardiovascular collapse on induction of a patient with severe AS
ResponseAS leads to consentric LV hypertrophy and poorly compliant ventricle which is highly dependent on pre load for adequate diastolic filling
If you drop the pre-load (or the aortic end diastolic pressure) - eg. by vasodilation - LV filling is poor and stroke volume low
Also dependent on diastolic filling time - so causing tachycardia is also bad (AF is very bad as highly dependent on “Atrial kick” - normal heart give 20% of diastolic ventricular filling, in severe AS up to 40%)
If you drop the pre-load (or the aortic end diastolic pressure) - eg. by vasodilation - LV filling is poor and stroke volume low
Also dependent on diastolic filling time - so causing tachycardia is also bad (AF is very bad as highly dependent on “Atrial kick” - normal heart give 20% of diastolic ventricular filling, in severe AS up to 40%)