Windkessel Effect In Aorta With Experimental Evidence!

Transcript of the video: Windkessel effect is applicable to large elastic arteries like aorta, which are situated close to the heart. They have more of elastic tissue than muscular tissue. The term Windkessel comes from German language and means air chamber.

Here is an illustration of the Windkessel, used in 18th century, by fire fighters. The additional pressure built up in the air chamber will ensure continuous delivery of water for fire fighting. A similar thing occurs in elastic arteries like aorta. During systole, more blood enters the aorta, than what leaves the aorta, because aorta expands. This additional blood received during systole, is released during diastole, so that aorta acts as a second pump in diastole. This is very important for coronary perfusion, as coronaries get perfused mainly in diastole. In systole, contraction of the myocardium, compresses the intramyocardial vessels, so that subendocardial region gets more of blood supply in diastole. So, maintaining a good pressure in diastole, is important for the coronaries. So the second pump in diastole by the elastic aorta, give a boost to coronary circulation. When elastic arteries become less elastic as by aging with arteriosclerosis of the aorta, the second pump function or the Windkessel effect of aorta decreases. That is the clinical importance of Windkessel effect.

Now, I will show a simple experiment, to demonstrate what happens in Windkessel effect. In this video clip, you can see, the tap being opened and water flowing out well and you can also see that as the tap is closed, the water flow completely stops. In this second video clip, you can see that the outflow is occluded before the tap is being closed, so that there is a pressure build-up in the elastic hose pipe. And you can see that, when the pressure is released, there is a sudden gush of water, after closing the tap. You can see that the tap is closed, still, there is a gush of water. This illustrates the Windkessel effect occurring in the garden hose, which is quite elastic. This will not occur in a solid pipe made of PVC or GI.