Chordae tendineae, often called “heart strings,” are cord-like structures within the human heart. These fibrous connective tissues play a fundamental role in blood circulation. Their primary purpose is supporting the heart’s valves, ensuring blood flows efficiently and in the correct direction through its chambers.
Anatomy and Role in the Heart
The chordae tendineae are thin, strong, and inelastic cords primarily composed of collagen fibers, which provide robust tensile strength. These structures originate from the papillary muscles, which are muscular projections extending from the inner walls of the heart’s ventricles. From these muscles, the chordae tendineae stretch upwards, attaching firmly to the edges of the cusps, or leaflets, of the atrioventricular (AV) valves.
Specifically, on the right side of the heart, the chordae tendineae connect to the tricuspid valve, which has three cusps. On the left side, they attach to the mitral valve, also known as the bicuspid valve, which consists of two cusps. When the ventricles relax, allowing blood to fill from the atria, the chordae tendineae are relaxed, and the AV valves open.
As the ventricles contract to pump blood out of the heart, pressure within these chambers rapidly increases. This rising pressure pushes against the AV valve cusps, attempting to force them backward into the atria. The chordae tendineae become taut and pull on the valve leaflets, preventing them from inverting or bulging into the atria. This action ensures that the valves remain securely closed, directing blood flow forward into the main arteries and preventing any backflow into the atria. The coordinated contraction of the papillary muscles and the tension in the chordae tendineae are essential for maintaining this unidirectional blood flow.
Maintaining Heart Health
The proper integrity and function of the chordae tendineae are fundamental for efficient blood circulation. These structures ensure that the heart’s atrioventricular valves close completely, preventing blood from leaking backward. Without their precise action, the heart would struggle to pump blood effectively, impacting overall cardiovascular performance.
If chordae tendineae become damaged, stretched, or rupture, they can no longer adequately hold the valve leaflets in place. This can lead to a condition known as valve regurgitation, where blood flows backward into the atria during ventricular contraction. For example, if the chordae tendineae of the tricuspid valve are compromised, blood can flow back into the right atrium, reducing the amount of blood pumped to the lungs and subsequently to the rest of the body. Such inefficiency can compromise heart health and may lead to symptoms related to reduced blood flow or increased pressure in the heart chambers.