Table 2: Characteristics of the Principal Mechanical Haemodynamic Support Devices Used for Catheter Ablation of Ventricular Tachycardia.

Device	Type of Support	Insertion	Contraindications	Potential Complications
Intra-aortic balloon pump	Counter-pulsation based on ECG or pressure triggers Improves coronary artery perfusion and cardiac afterload with limited effect on CO	Percutaneous insertion in the thoracic descending aorta through arterial femoral access	Moderate-to-severe AR Aortic plaques Severe PAD	Arterial thromboembolism including stroke Vascular injury at the insertion site Bleeding
TandemHeart	Centrifugal continuous-flow pump improving CO up to 3.5–5.0 l/min	Percutaneous insertion through femoral venous access + transseptal puncture (inflow) and through femoral arterial access (outflow)	Severe PAD Ventricular sepal defects Moderate-to-severe RV dysfunction	Arterial thromboembolism including stroke Vascular injury at the insertion site Cardiac tamponade Residual atrial septal defect Bleeding
Impella (2.5/CP/5.0)	Axial continuous-flow pump delivering blood from LV to aorta up to 5 l/min	Percutaneous through femoral arterial access or surgical through femoral or axillary artery cutdown	Moderate-to-severe AR Severe PAD Mechanical aortic valve Severe aortic stenosis LV thrombus Ventricular sepal defect Moderate-to-severe RV dysfunction	Arterial thromboembolism including stroke Vascular injury at the insertion site Aortic valve injury during device placement
ECMO (veno-arterial)	Centrifugal continuous-flow pump with extracorporeal oxygenator providing CO >4.5 l/min	Percutaneous or surgical insertion through femoral arterial and venous access	Severe PAD Uncontrolled coagulopathy	Arterial thromboembolism including stroke Vascular injury at the insertion site Bleeding

AR = aortic regurgitation; CO = cardiac output; ECMO = extra-corporeal membrane oxygenation; LV = left ventricular; PAD = peripheral artery disease; RV = right ventricular.