**1.6 Indications for LV venting and unloading**

On ECMO, indicators of good LV decompression are AV opening with every beat, systemic arterial pulse pressure >10 mmHg, and low PCWP. As the initial therapy inotropes, vasopressors, diuretics, and CVVHD to aid with managing volume status should be tried. Additionally, ECMO flows should be titrated to the lowest acceptable level to reduce the LV afterload. If medical management fails, one should consider LV venting [21].

Percutaneous transvenous atrial septostomy can be created under fluoroscopic and echocardiographic guidance in the catheterization lab to vent the LV. However, LV decompression through atrial septostomy is limited and dependent upon associated MR.

### **1.7 Percutaneous devices for LV unloading**

LV can be unloaded by percutaneous devices like intra-aortic balloon pump (IABP) Impella, and TandemHeart. Impella is more robust device for LV unloading, and it also improves systemic perfusion. Impella is particularly important in patients with severely reduced LV contractility [22]. In our institute, we institute both arterial cannula and Impella 5.5 through AxA over Y chimney graft and venous cannula through IJV. Advantages of our technique are ambulation and weaning and ECMO decannulation with oversewing the Y limb of the graft can be done under local anesthesia and sedation.

### **1.8 Open surgical and minimally invasive LV unloading**

LV unloading can be done by a surgically placed vent into the LV *via* the right superior pulmonary vein or *via* LV apex. In nonpost-cardiotomy patients, a surgical vent can still be placed into the LV apex *via* a left anterolateral thoracotomy and sliced into the venous limb of the ECMO cannula. Compared to ECpella, this approach perfuses the oxygenated blood into the aortic root, brain, and upper body and it unloads both the RV and LV more efficiently [19, 23].

In a patient with VA-ECMO with LV venting, patient must have a right radial arterial line for oxygenation monitoring, and a Swan-Ganz catheter in place to check mixed venous saturation, PCWP, and PAP. Daily chest X-rays should be obtained to assess degree of pulmonary edema, Impella position, and ECMO venous cannula position. Echocardiography should be performed to ensure the Impella position and LV decompression [19].

### **1.9 Results**

Studies by Patel et al., Tepper et al., and Pappalardo et al. have shown improved survival in patients supported with ECpella with reduced all cause 30-day mortality compared to patients supported with VA-ECMO with inotropes or surgical LV venting. The studies attributed this improved survival to Impella as Impella was an effective means of LV unloading and prevented worsened pulmonary edema. Furthermore, the ECpella patients had a higher rate of successful bridging to either further recovery or further therapy [24–26].
