Table 4.

Known risk factors for ventricular tachycardia / ventricular fibrillation during coronary angiography and percutaneous coronary intervention and approaches to mitigate the risk

Risk factors	Approaches to mitigate risk
Catheter wedging coronary ostium, damping pressure causes ischemia and stagnation of contrast medium[32].	1 Smaller caliber catheter to avoid damping
	2 Catheters with sideholes to avoid damping
	3 Dis-engage catheter, clear contrast before next injection to minimize ischemia
	4 Avoid prolonged injection or large amount CM injection
Contrast medium toxicity[33,64,97]	1 Use non-ionic, low osmolar contrast
Non-ionic CM has lower risk than ionic CM	2 Eliminating calcium-binding additive in CM
Low osmolarity CM has lower risk than high Osmolarity CM	3 Use electrolytes optimized CM
Calcium-binding additive in CM increase the risk of VT/VF
Catheter or wire tip irritation of LV[88]	1 Meticulously manipulating equipment
	2 More practice
High risk in RCA and bypass graft CAG[99]	Pay more attention to avoid or minimize ischemia during procedure
Direct injection into conus branch leading to VF[102,103]	Early recognition of conus branch engagement and avoid injection or abort injection
Increased risk of VF/VT in patients with severe CAD and cardiomyopathy	1 Pre-procedural workup to understand the risk
	2 Meticulous procedural technique
	3 Operators training and competency
	4 Close monitoring
	5 Early reperfusion therapy
Acute myocardial infarction and primary PCI patients have high risk of VF/VT	6 Consider mechanic circulatory support for AMI patients with cardiogenic shock or extensive CAD with severely reduced EF (high risk patients with high risk CAD)

CM: Contrast medium; VT: Ventricular tachycardia; VF: Ventricular fibrillation; LV: Left ventricular; CAG: Coronary angiography; CAD: Coronary artery disease; RCA: Right coronary artery; PCI: Percutaneous coronary intervention; EF: Ejection fraction.