2. -The ventricles are unable to eject the blood during the period of
arrest, so the vent must be placed to protect the from distension.
-The left side of the heart receives blood from the bronchial
arteries and the thebesian veins.
-The right side of the heart receives blood from the coronary
sinus and leakage around the venous cannula.
3. Abnormal Sources :
On occasions, blood can return from abnormal sources include;
-Left sided SVC.
-Patent Ductus Arteriosus.
-ASD/VSD.
-Aortic regurgitation.
-Systemic to Pulmonary Shunt.
4. Sites Of Cardiac Venting :
-Pulmonary Artery.
-Right Superior Pulmonary Vein.
-Left Ventricle.
-Aortic Root.
5.
6. Purpose Of Venting The Heart:
-Aid visualization and provide bloodless field.
-Avoid chamber distension.
-Reduce Myocardial Rewarming.
-Prevent cardiac ejection of air.
The use of left atrial pressure monitoring line and pulmonary artery
catheter can help moderate left ventricle distension.
7. Venting Methods :
Venting can be achieved by;
-The aortic root cardioplegia cannula:This method does not allow venting during
cardioplegia administration.
-The right superior pulmonary vein:A vent is passed into the left atrium and
through the mitral valve into pulmonary vein.
-Left Ventricle :Through the left ventricular apex.
-The pulmonary artery :This may not be effective at venting the LV. When there is
aortic regurgitation with a competent mitral valve.
8. Monitoring Of LV distension :
-Inspection & Palpation of heart.
-PA catheter.
-Left atrial monitoring line.
9. Complications :
-Aneurysm of LV apex.
-Stenosis of pulmonary vein or pulmonary artery.
-Major complications of cardiac venting is air
embolism.
