TEE FOR PULMONARY VEINS AND ITS IMPORTANCE

Echocardiography of  Pulmonary  Veins

Pulse wave doppler interrogation is done  in left upper pulmonary vein or  n  right upper pulmonary  vein

Sample volume should be placed 1 to 2 cms  from the opening of PV in the left atrium

Waveform  shows -

S  wave – systolic  forward  flow  during  LV   systolic contraction as at this time LA is relaxing and hence pulmonary veins empty in LA giving rise to forward flow.

It  may be biphasic with  S1 and S2 Waves

S1 =Fall in the LA  pressure  during atrial  relaxation

S2 = Increase  in  PV  forward  flow due to  continued descent  of  LV  base   and   decrease in  LA pressure

D  =  diastolic  forward  flow  during  early  diastole.

AR = retrograde  flow from  LA  to  pulmonary  veins during   atrial  contraction  

Normal values -

S wave velocity is 30 – 80 cm/sec.

D wave velocity is 20 – 70 cm/sec.

AR velocity is 10 – 25 cm/sec.

Duration of AR (AR_dur) is 30-160 msec.

TEE to locate Left Pulmonary Veins -

The left upper pulmonary vein (LUPV) lies above or posterior to the left atrial appendage (LAA).

Laminar Color Doppler flow above coumadin ridge identifies LUPV .

Left Upper Pulmonary Vein -

Obtain  Midesophageal  2 Chamber  view and identify the LA appendage then withdraw the probe slightly and turn it slightly left

LUPV is seen above LA appendage

Left Lower pulmonary Vein -

Center the LUPV and  increase the angle to 90-100°

Right pulmonary veins -

Obtain Midesophageal  4 chamber view

Center the RA and withdraw the probe slightly and turn to the right

Right lower pulmonary vein (RLPV) is seen entering the LA,  increase the angle to 30-40° to see the Right upper pulmonary vein (RUPV)

RUPV can be also be identified in ME modified bicaval view. Color Doppler shows  RUPV above the RA appendage. Put color doppler in the area of the SVC and increase angle to 120° with slight rotation of probe to the right

Importance   -

 1) S  wave  >>  D wave      indicate  isolated  relaxation   abnormality        

 2) S<<  D  -   indicate  restrictive  Physiology 

 3) The descent  of S  wave  corresponds   to  V   wave   of  LA  pressure  waveform

 4)   D  wave corresponds   to ‘ Y’  descent  of  LA pressure waveform  

 5)  D  wave  particularly  reflects   abnormalities  of LV   compliance   as   during  this  phase  the  MV   is    open  and  LA  -  LV   are  an   open conduit 

Determinants of  PV   flow  Velocities   -

Velocity              Determinants

S1                =       LA    relaxation

S2                =      RV    Output

                            LA  Compliance

                            Mean   LA  Pressure

D                 =   LV      relaxation 

A                 =   LA    Contractility 

                         LV    Compliance

Factors   affecting  PV  Flow  Pattern  -

1     Sinus  tachycardia - S  and   D   may  fuse  as  the  diastolic  filling   time  is   decreased.  

2     Atrial fibrillation  - systolic   forward  flow  is  decreased or absent, the diastolic flow is main  contributor  to  LV  filling

3     Mechanical  ventilation - may  decrease  systolic flow   during   inspiration (because of  increased airway pressure)  and increase diastolic flow at  the end of expiration

 Applications  of  PV  waveforms 

1)  LAP  > 15  mmHg - S  wave  is  blunted  reflecting  most forward  flow occurs  in diastole 

2)  To  differentiate constrictive pericarditis from restrictive cardiomyopathy

3)  Estimation of  LV filling pressures  

4)  Evaluation of  LV diastolic dysfunction  

5)   Grading  mitral regurgitation

     Ratio of  peak  systolic to   diastolic  PV  velocities  is-

    Normal  if  ratio   of  S/D    = >1  

    Blunted   if  ratio  of   S/D   -   0  to 1

    Reversed  if   ratio  of   S/D   <   0

 PV  flow  pattern   is   influenced   by-

1) Change  in  LV  compliance 

2) Change   in  LA   Compliance

3) Change   in   myocardial  relaxation

4) Change   in   loading  conditions

5) Systolic   and  diastolic  dysfunction

6) Arrythmias  -  AF

Reference –

Comprehensive Textbook Of Perioperative Transesophageal Echocardiography - Robert M.Savage, Solomen Aronson, Stanton K.Shernan.

- by Dr Amarja