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 (ARdur) 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
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 -
S1 = LA relaxation
S2 = RV Output
Mean LA Pressure
D = LV relaxation
A = LA Contractility
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
Comprehensive Textbook Of Perioperative Transesophageal Echocardiography - Robert M.Savage, Solomen Aronson, Stanton K.Shernan.