1. Heart distention in low EF patient (post OP course)

2. Harmful effect of post ischemic reperfusion in dilated heart
40 isolated feline heart were subjected
hypothermic circulatory arrest(group 1-2-3)
Hypothermic ventricular fibrillation(group4&5)
LV pressure was maintained 0 in 1 & 4 group
LV pressure was maintained 30 mmhg in group 2 & 45 mmhg in group 3 & 5

3. parameter Myocardial gas tention LV function Coronary blood flow
Endo/epi flow
Myocardial water content

4. No difference in parameters in heart undervent arrest
In VF normal parameter in group 4 but in group 5 we have increase CO2 tension, impaired endo/epi flow rate & decrease ventricular performance

5. comment
Ventricular distention is not harmful during period of ischemia but during of VF produces impaired sub endocardial flow , resulting decrease ventricular performance

6. The harmful effects of ventricular distention during post ischemic reperfution
16 canine hearts were objected to 45 minutes of hypothermic cardiopelegic arrest
Isovolumic LV pressure & n
Rate of rise LV pressure (dp/dt) were measured with intraventricular baloon
Endocardial/epicardial flow rate microsphers
Myocardial gas tension were measured with mass spectrometry

8. During early reperfusion
Group 1(no=8) end diastolic pressure 0 mmhg
Group 2(no=8) end diastolic pressure 20 mmhg for initial 15 minutes of reperfusion

9. Group 2 hearts demonstrated impaired subendocardial blood flow after 5 minutes of reflow & persistent elevation of intramyocardial CO2 tension
In addition post ischemic ventricular function was significantly worse in group 2 dp/dt

14. These data demonstrate that even mild tension during early reperfusion can result in reduced subendocardial perfusion & delay washout of CO2
Although myocardial blood flow & CO2 tension subsequently returned to normal in distended hearts but LV performance remained significantly depressed

15. a positive correlation has been demonstrated between early postischemic subendocardia perfusion and the return of left ventricular function

16. This injury can occur clinically in non vented hearts prior to resumption of effective ventricular contraction

17. Buckberg & associate
Myocardial O2 consumption is influenced by three factor
The contractile state of the heart
Heart rate
Wall stress

18. Use of inotrope agents which allows premature discontinuation of CPB will result in significantly worse recovery of ventricular function duo to elevation of LVEDP ,increasing contractile state & rise in heart rate & O2 consumption

19. Volume loaded ventricle during this critical period increase work of contraction associated with greater wall stress

20. Effective LV venting with avoidance of both volume overload & inapropriate inotrope using lead to increase coronary sinus lactate ,hydrogen ion , potassium & reduce ventricular function recovery

21. SHARIATI HOSPITAL

22. MATERIAL & METHOD

23. prospective
36 Patient
Sever MS & MR with mild to mod AR
Mean EF 35%
Mean age 60 years
FC 3 to4
Mean weight <59 kg
MVR 90% &MVR –CABG10%
Cardiomegaly

24. After MVR for this group of patient we passed one folly catheter trans prosthetic valve & closed LA but did not tie it & it was open around folly catheter

25. After unclamping flow that regurgitated from AR ,passed to LA from insufficient mitral valve & emerge to pericardium . This blood returned to circulation with pump suction.

26. Venting was continuated until normal sinus rhythm
Venting was continuated until normal sinus rhythm . This time was about 5 minute. During this time of reperfusion we hadnot any subendocardial pressure .

27. After resumption of NSR folly catheter extracted & LA was tied
After resumption of NSR folly catheter extracted & LA was tied. During this time not only LV vented & solve post reperfusion wall stress injury but also this manner aimed to complete deairing in left side of the heart.

28. If we did not use vent after unclamping due to some degree of AR & no contraction LVEDP reach to pump pressure (50 to 60mmhg)in reperfusion phase while article show subendocardial injury in 20mmhg LVEDP

29. This manner of venting not use cardiotomy like apex venting or pulmonary artery opening vent

30. Farther more this form venting aim to complete deairing of left heart side.

31. We use this way & all patient easily came off from CPB
We use this way & all patient easily came off from CPB. We did not saw any major CVA. All patient discharge from hospital at mean 6.2 days.

32. One patient died from GI bleeding after one month
One patient died from GI bleeding after one month. In 2 month follow up all patient were in class 1&2

33. Conclusion This way of venting is safe & use easily in patient undergo MVR along with some degree of AR.