Which of the following is commonly referred to as an open heart surgery?

Open heart surgery is a term that specifically refers to surgical procedures where the chest cavity is opened, and the heart is directly accessed. One of the most common types of open heart surgery is coronary artery bypass grafting (CABG). This procedure involves creating a bypass around blocked coronary arteries to restore blood flow to the heart muscle, which often requires the surgeon to stop the heart and use a heart-lung machine to maintain circulation during the surgery.

In contrast, stenting and angioplasty are minimally invasive procedures performed to alleviate blockages in the coronary arteries without the need for opening the chest. Stenting involves placing a small mesh tube in the artery to keep it open, while angioplasty involves the use of a balloon to widen the narrowed artery. These techniques do not require the chest to be opened, thus they are not classified as open heart surgeries. A cardiac MRI is an imaging technique used to visualize the heart and its structures but is neither a surgical procedure nor involves any kind of access to the heart.