We know the atrial pressure wave forms vary between right and left atrium .In the right atrium “a” waves are prominent and taller than “v” waves, while the reverse is true in left atrium .
Typical filling pattern of Right side chambers .Note The tall A waves . Source : http://www.ncbi.nlm.nih.gov/books/NBK2213/
Note the left atrial a waves are diminutive and v waves are tall .The dark black wave is pulmonary venous waves. Source :http://heart.bmj.com/content/89/2/231.full
The reasons for tall left atrial v waves are
- V waves are passive atrial filling waves and are timed during ventricular systole .Left atrium is relatively thick *,stiff , less compliant chamber .( Compliance : Rate of raise of pressure per unit change in volume .)
- Apart from relative thinness,* right atrial volume is more , hence it can accommodate more volume without raising its pressure .
- The left atrium is decompressed by relatively stiff pulmonary veins with a mean pressure of 8 mmhg , can not adequately dampen the refluxing tides of v waves , while the low pressure vena cava of RA dampen the right atrial v waves with ease .
- Further ,the adjoining systemic left ventricle , adds up to the stiffness of left atrial filling .
(*Thickness of RA -2mm, LA -3mm )
Related article .
What is left atrial pressure volume Loop ?
http://www.wellsphere.com/heart-health-article/left-atrial-pressure-volume-loop/1208152
Dr.S.Venkatesan MD 
Dr. Venkatesan – Image permission request here – I write from Pediatric Learning Solutions, a division of Children’s Hospital Association, a not-for-profit association that serves more than 200 hospitals, mostly in the United States.
Could we have permission to use the image from this page – the image labeled with “Typical filling pattern of Right side chambers .Note The tall A waves . Source : http://www.ncbi.nlm.nih.gov/books/NBK2213/“? Or should we contact ncbi.nlm.nih.gov for permission?
We would include the image in one or more of our online courses created for pediatric clinical staff. Please let me know. Thank you! Carla Jordan, carla.jordan@childrenshospitals.org.
Thank you for your query.
The Image is not mine. I don’t have a copyright As you have mentioned, please contact the publishers of the book which contain the Image.
Regards
Venkatesan
Hello,
Great blog you have here.
Perhaps you may be able to help me with a question about the atrial PV loop that has been bugging me for a while.
What is the physical explanation of the late conduit phase, where LA pressure increases but volume decreases ? This is before atrial contraction.
Thanks
Hi
thanks for your query.I have to tell you, my understanding about atrial PV loop is far from complete.
I guess, the conduit function and its componests as well as its exact duration are not fully elucidated.
It is importsnt to note right from pulmonary vien to LV cavity is a long conduit .To slice out LA conduit from this is problematic.
The point you have raised is , the late conduit phase , LA volume has low, but the LV has filled well to its capacity, and its resitance is reflected into LA hiking the pressure.
A stiff LV can raise the late LA pressure, and triggwring a more powerful atrial contraction , that forms the basis of E :A ratio reversal.
I just tried to pass on my thoughts.
Thanks for your probing query.
Venkatesan