Spasm of right coronary artery (RCA) noted as a discrete narrowing in the proximal RCA without any significant lesion elsewhere. This is a quite common observation in the RCA and can be related to irritation by the catheter tip. It may subside spontaneously on withdrawal of the catheter. Sometimes intra coronary nitroglycerine is given to relieve the spasm before taking a repeat shot to demonstrate relief of the spasm. Most often this can occur with deep throating of the catheter within the RCA. But sometimes deep throating is necessary to get guide support during an angioplasty procedure. The image below shows the relief of spasm after administering intra coronary nitroglycerine (NTG).