Severe emetic - zarah

[ArchivalUser]

well that conrad fisher rule is rite but in special conditions whr there is some superimposition eg AS+epi. u have 2 think in 2 dimension

[ArchivalUser]

MVP---4 understanding purpose -- itz the overlapping cusps that makes perfect alignment of the valve difficult...so more blood in vent --> dilated cavity --> perfect alignment of the valvular cusps and decrease in murmur

simple ? hmmm

[ArchivalUser]

how abt in valsalva
valsalva----dec preload----dec blood------inc murmur in IHSS
then y in phenylephrine/handgrip
phenylephrine/handgrip-----inc afterload----inc blood in heart---------Y dec murmur in aortic stenosis.there will certainly be a dec murmur in IHSS BUT Y IN AORTIC STENOSIS
(only according to the rule)
but logic wise wat u explained makes sense
its the rule i cant understand

[ArchivalUser]

well, dear itz the physiology that u r confused with
valsalva --> decrease cardiac output and decrease vent size ....itz the pulmonary circulation thatz affected by the valsalva not the cardiac function......so in AS decreased flow thru the valve makes the murmur softer and in IHSS, obliteration of the vent (bcoz less blood)makes the murmur louder

got it?

[ArchivalUser]

i think the conrad fischer rule says more bld flow across the valve lesion increases the murmur...the missing link in understanding is regarding the flow...as well explained by ben and.

[ArchivalUser]

hey the rule is right..... wht he meant by the rule ws

more blood goin through valves thn incr murmur
less blood goin through valves thn less murmur

exception of MVP nd IHSS
hope this clears it

[ArchivalUser]

The rule is correct no argument about that but you have to think of special circumstances depending on what is involved and how a drug or activity affects afterload or preload. Juts because w/ incr preload to the right side does not mean AS mumur will decrease.

And in valsava maneuvor ur are incr thoracic pressure. You are compression the heart by pushing against the Pt chest therby decr outflow on the left side as well as decr the amount of blood entering the heart (Valsava is the same as someone holding their breath in expiration)