This structure's normal function is affected by Brugada syndrome, and its performance is measured by the stroke volume. It's not a digestive organ, but regurgitation can occur when this organ is defective. Bundle branches and Purkinje fibers relay signals that the (*) SA and AV nodes produce to regulate the activity of this organ, which contains two semilunar valves and is surrounded by the pericardium. Coronary arteries 
This structure's normal function is affected by Brugada syndrome, and its performance is measured by the stroke volume. It's not a digestive organ, but regurgitation can occur when this organ is defective. Bundle branches and Purkinje fibers relay signals that the (*) SA and AV nodes produce to regulate the activity of this organ, which contains two semilunar valves and is surrounded by the pericardium. Coronary arteries supply oxygen to this organ, which is connected to the vena cava and the aorta and contains sections like the left atrium and right ventricle. For ten points, name this four-chambered organ that circulates blood through the body.
This structure's normal function is affected by Brugada syndrome, and its performance is measured by the stroke volume.
human heart