Posts Tagged ‘physiological inter ventricualr desynchrony’

Right ventricle,being a venous chamber has distinct anatomical and physiological features to carry out this function.RV has a complex shape, its triangular in long axis and  crescent like in short axis , thin (<5mm)  more distendable  .Contraction of RV begins slightly early but ends later than LV  (30ms )

RV receives blood from RA and ejects in to PA in a sequential manner .The inflow, body and outflow contract somewhat like  intestinal peristalsis. This is facilitated  by the incremental  delay in the electrical depolarization of right ventricle.In physiological conditions, the later half of QRS  is  responsible for RV activity and RVOT is the last to contract. (This intrinsic electrical and mechanical  delay in RV contraction is a physiological inter ventricular  desynchrony . One  should be aware of this when planning cardiac resynchronisation therapy in cardiac failure.  )

Click over the image for an animation of RV contraction.


Image courtesey Oxford spcialist hand book in cardiology :Echocardiography Paul Leeson , Second edition ,.Oxford university press 2012 Multi media .

Note:LV is  a fairly   elliptical and strongly  muscular pump and contracts in a  single go with maximum force.(dp/dt).

Final message

Though both right and  left ventricle originate from same  straight heart tube , developmentally the right ventricle evolves for a different form and function . Now,we realise there are lots of sharing of parental muscle fibers that engulfs and bonds both chambers.(Mind you ,This is the fundamental mechanism of ventricular interdependence.Of course ,IVS is a common wall shared lifelong by both chambers  without any (sibling related?)  hemo-dynamic dispute !

3D echocardiography and MR imaging has helped us to understand the RV morphology better and exciting articles written by pioneers are available  free for those who are interested.


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