Overview of Dynamic Auscultation

00:02 My students always ask me "Dr. Raj, an attending who asked me what it meant to clench one's fist, in the intensity of its murmur whether it is increased or decreased and I always got that question wrong and then I always went to the back of the class and I felt so that I could come up and answer me questions properly." So what we will do here as we go through dynamic auscultation as continued building up your confidence so that whatever environment that you are in that you are able to fill confident about your answer because you are walking through every aspect of the pathophys. So, up until now we have talked about inspiration, expiration, clenching of the fist and squatting and we've put that into different categories and diagnoses and it is kind of been plastered all over sporadically. So let us take all of these maneuvers and put them all together and organize it so that for one final time we have all of it in one place. Wouldn't that be nice? So, if it is respiration, and you are doing inspiration, the diaphragm is going to move downwards. It contracts. It causes then your thoracic portion to decrease and it becomes or behaves more like a vacuum.

01:18 And so therefore, the sucking up blood into the right side and so, therefore, the murmurs on the right side will be increased in intensity, as simple as that. When you exercise, you are causing what? You are causing your aterials to vasodilate so that you increase amount of blood flow to the skeletal muscles that are also starving for oxygen. And then in the meantime causing venoconstriction resulting in increased venous return to the right side.

01:44 And so, therefore, murmurs caused by blood flow across normal or obstructed valves such as aortic stenosis in the setting of exercise, and mitral stenosis and pulmonic stenosis will only increase in intensity with exercise. Now, one of our discussions earlier with mitral valve prolapse exercise is actually recommended because it then causes delaying of the click, making it closer to S2, squishing the murmur and, therefore, the intensity was decreasing in that patient with MVP. There was one big exception. Not to worry. We will bring that up once again. Respiration, inspiration, exercise, and what kind of effect on stenotic valves.