Valve Closure
Valve Closure - Related Videos
07:37
Neural Tube Closure in Mouse Whole Embryo Culture
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Cited by 22 •
2011
A method allowing for direct pharmacological manipulation of mouse embryos during neurulation that bypasses maternal metabolism is described. The technique can be adapted to study different aspects of neurulation by varying the time point and pharmacological agent.
04:19
Pressure Fixation of Isolated Murine Pulmonary Valve: A Procedure to Isolate and Chemically Fix the Mouse Pulmonary Valve in Closed Conformation
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2025
In this video, we describe the procedure to isolate and chemically fix the mouse pulmonary value in closed conformation via perfusion pressurization.
23:33
The WATCHMAN Left Atrial Appendage Closure Device for Atrial Fibrillation
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Cited by 49 •
2012
The accompanying video describes a procedure for percutaneous placement of the WATCHMAN Left Atrial Appendage (LAA) Device. The WATCHMAN is a nitinol device designed to be permanently implanted at, or slightly distal to, the opening of the left atrial appendage (LAA) to trap blood clots before they exit the LAA, preventing thromboembolic stroke.
28:13
Catheter Ablation in Combination With Left Atrial Appendage Closure for Atrial Fibrillation
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Cited by 11 •
2013
Catheter ablation is combined with placement of the WATCHMAN Left Atrial Appendage Closure Device to prevent ischemic stroke in a patient with non-valvular atrial fibrillation.
08:55
Isolation and Characterization of Primary Rat Valve Interstitial Cells: A New Model to Study Aortic Valve Calcification
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Cited by 16 •
2017
This protocol describes the isolation, culture, and calcification of rat-derived valve interstitial cells, a highly physiological in vitro model of calcific aortic valve disease (CAVD). Exploitation of this rat model facilitates CAVD research in exploring the cell and molecular mechanisms that underlie this complex pathological process.
FAQs
The decisive signal is a reversal of the pressure gradient across the valve. During ventricular contraction, rising ventricular pressure closes the atrioventricular valves. As the ventricles relax, the semilunar valves close when the pressure relationship changes. This sequence separates ventricular filling from ejection and limits backward blood movement during each cardiac cycle.
Leaflets and cusps are the valve structures that respond to changing pressure and seal the opening. Their closure maintains separation between the cardiac spaces connected by each valve, so blood does not move backward when the pressure relationship changes. This structural response helps clinicians assess whether cardiac flow remains properly directed.
Valve closure assessment is relevant to both stenosis and insufficiency, but the clinical concern differs. Stenosis is included among conditions affecting valve function, whereas insufficiency directly involves inadequate sealing and regurgitation. Examining valve motion and its effects on flow helps place these conditions within the broader evaluation of abnormal cardiac valve performance.
An abnormal closure pattern can disrupt the expected one-way movement of blood through the heart. The resulting disturbance may be detected clinically as a murmur, while ineffective flow control can contribute to volume overload or reduced cardiac output. These consequences explain why valve motion receives attention during cardiovascular assessment.
Physical examination provides an initial clinical assessment of valve function and its consequences. Findings such as murmurs can suggest that closure or flow is abnormal, prompting more focused evaluation. In this way, examination connects observable cardiovascular findings with possible valve problems, including impaired sealing, regurgitation, or other abnormal valve motion.
Echocardiography is used alongside physical examination to evaluate cardiac valve motion. It can help investigate whether the valves close appropriately and whether abnormal motion is associated with conditions such as stenosis or insufficiency. This assessment supports clinical interpretation of suspected regurgitation, volume overload, or reduced cardiac output.
Effective closure supports efficient, one-way blood flow through the heart, linking valve performance to overall cardiovascular function. When closure is abnormal, the resulting regurgitation or altered flow may place an excessive volume burden on the circulation or reduce cardiac output. Consequently, valve motion is relevant when evaluating both symptoms and cardiac performance.