dynamic auscultation

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Dynamic auscultation refers to using maneuvers to alter hemodynamic parameters during cardiac auscultation in order to diagnose the etiology of a heart sound or murmur.

Valsalva maneuver: The Valsalva maneuver is performed by having a patient “bear down” like they are going to have a bowel movement and exhaling forcefully with the airway closed. The hemodynamic changes that occur are complex, however the ultimate result is a decrease in left ventricular preload.

The most important use of the Valsalva maneuver is to distinguish the murmur of aortic stenosis from hypertrophic obstructive cardiomyopathy (HOCM) or simply to bring for the murmur of HOCM. Aortic stenosis will soften or not change while the murmur of HOCM becomes quite loud with Valsalva.




The Valsalva maneuver is also performed during routine echocardiographic examinations to see if patients with grade II or worse diastolic function can decrease their left ventricular filling pressures adequately. If the Valsalva maneuver fails to reduce the left ventricular pressure in the setting of diastolic heart failure, then grade IV diastolic dysfunction is said to be present which indicates a poor prognosis.

Squatting from a standing position: Squatting forces the blood volume that was stored in the legs to return to the heart increasing preload and thus increasing left ventricular filling.



This maneuver will decrease the murmur of hypertrophic obstructive cardiomyopathy has the increased left ventricular volume helps displace the hypertrophied interventricular septum causing less outflow tract obstruction.

This maneuver causes the click of mitral valve prolapse to move later in systole.


Standing from a squatting position: Standing quickly from a squatting position causes blood to move from the central body to the legs resulting in less blood returning to the heart decreasing left ventricular preload similar to that seen with the Valsalva maneuver.

This maneuver will increase the murmur of hypertrophic obstructive cardiomyopathy and decrease that of aortic stenosis.

This maneuver causes the click of mitral valve prolapse to move earlier in systole.

Leg raising: Passive leg raising is permed simply by raising the legs high in a patient lying supine. This results in blood that was pooled in the legs returning to the heart increase left ventricular filling and preload similar to squatting from a standing position.
This maneuver will decrease the murmur of hypertrophic obstructive cardiomyopathy has the increased left ventricular volume helps displace the hypertrophied interventricular septum causing less outflow tract obstruction.

This maneuver causes the click of mitral valve prolapse to move later in systole.

Handgrip exercise: Isometric handgrip exercises are performed by having a patient squeeze hart repetitively. This results in increased blood pressure (similar to exercise) and thus increased afterload. Elderly individuals may have a hard time with this maneuver and thus transient arterial occlusion can be used instead.

This maneuver will increase the intensity of left-sided regurgitant murmurs including mitral regurgitation and aortic regurgitation. Handgrip exercises will have no effect on the murmur of aortic stenosis which helps distinguish the presence of coexistent mitral regurgitation from that of the Galiveridin phenomenon.

Transient arterial occlusion: This maneuver is performed by placing a blood pressure cuff on both arms and inflating it to 20 to 40 mmHg above the systolic blood pressure for 20 seconds. This results effectively in increased afterload.

This maneuver will increase the intensity of left-sided regurgitant murmurs including mitral regurgitation and aortic regurgitation and is especially useful in elderly individuals who are not able to perform adequate handgrip exercises.



Amyl nitrate inhalation:
Amyl nitrate decreases left ventricular afterload by dilating the peripheral arteries. and would decrease the murmur of mitral regurgitation.

When the afterload is decreased, there is less resistance to blood flow from the left ventricle through the aortic valve and thus less blood regurgitates through the mitral valve, decreasing the intensity of the murmur.

Amyl nitrate can be given via inhalation to reduce afterload for diagnostic purposes in the cardiac catheterization laboratory (to invoke a LV outflow tract gradient in hypertrophic obstructive cardiomyopathy patients) or as a diagnostic tool during cardiac physical examination. Due to the advancement of echocardiography, it is not commonly used any longer.


easy tips

1. There are four systolic murmurs of concern-MR, VSD, AS, and HOCM.
2. There are five manuevers: Remember this mnemonic--VALSH (Valsalva, AmylNitrate, Leg Raising, Squatting, Handgrip-also called Phenylephrine)
3. The next step is to remember the response to maneuvers for HOCM. Remember that out of VALSH, VA-cause increase in the murmur of HOCM. LSH-causes decrease in the murmur of HOCM.
4. Except for V and L all the responses of AS (aortic Stenosis) are the same as HOCM. [That is AS murmur too increases with A and decreases with SH] For V and L the response is opposite. That is The AS murmur decreases with V and increases with L.
5. The response for MR and VSD is totally the opposite that of HOCM except for squatting which does not affect the murmur of MR and VSD.


Overview of heart murmur
systolic murmur
diastolic murmur
dynamic auscultation


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