Percutaneous coronary intervention (PCI) is a medical procedure used to treat narrowed or blocked coronary arteries, which supply blood to the heart. During PCI, a thin tube called a catheter is inserted through a blood vessel, usually in the arm or leg, and guided to the heart. A small balloon at the tip of the catheter is then inflated to open the blocked artery, often followed by placing a stent to keep the artery open. This procedure is commonly performed to relieve symptoms of coronary artery disease, such as chest pain or shortness of breath. PCI is less invasive than traditional heart surgery and typically allows for quicker recovery times for patients.