Final answer:
Regurgitation is the correct term for the backflow of blood in the heart, often accompanied by a heart murmur and resulting from valve malfunctions like prolapsed valves. It should not be mistaken for arrhythmia (irregular heartbeat) or stenosis (valve hardening or narrowing).
Step-by-step explanation:
Backflow of blood in the heart is called regurgitation. When the heart's valves do not close properly, the result is a backward flow of blood, typically creating a heart murmur that can be heard with a stethoscope. This disruption is due to issues such as prolapsed valves or damaged chordae tendineae, which are critical for the valve's closure mechanism.
Mitral regurgitation is the most common form of this condition. It's important not to confuse regurgitation with arrhythmia, which refers to an irregular heartbeat, or with stenosis, which is the hardening or narrowing of the heart's valves. Heart murmur is a key symptom of regurgitation. In severe cases of valve failure, the condition can escalate to 'insufficiency,' which refers to an inadequate blood flow due to a failing valve, named according to its location as aortic, mitral, tricuspid, or pulmonary insufficiency.