Posts Tagged ‘why is aortic second sound loud in tof ?’

Second heart sound in TOF is often single and loud . It is often  best heard in left 2nd intercostal space as well as on right 2nd  space.

This is primarily due

  1. Presence of  pulmonary stenosis  and  resultant reduced pulmonary blood flow makes P2 soft or absent .Hence  A2 becomes loud by default.
  2. In tune with any  cono -truncal anomaly  , aortic root  is  anteriorly  malposed  in TOF. This brings the aorta  closer to chest wall  (Nullifying the  aquastic insulation  of main  pulmonary trunk  ) and results in a  booming aortic  second heart sound.
  3. Increased flow across  aortic valve . In cyanotic heart disease with reduced pulmonary blood flow aortic flow is augmented and may even result in dilatation of aorta . A large aorta with increased flow is perfect setting  for  generating a loud A2  . It  is common to hear a  aortic ejection click as well in these situations .

When you hear a single  second heart sound at  the base  of heart  , how do you recognise it to be   A2  or P2 ?

Will be answered shortly.

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