Mitral Valve Stenosis, Animation

The mitral valve serves to ensure one-way blood  flow from the left atrium to left ventricle of   the heart. It opens when left atrial pressure is  higher than left ventricular pressure, allowing   blood to fill the left ventricle; and closes when  the ventricles contract, to prevent blood from   flowing back to the atrium. The mitral valve has  2 flaps, or leaflets, supported by a fibrous ring.  Mitral stenosis occurs when these  leaflets thicken and become stiff,   causing the valve opening to narrow, reducing  blood flow. As a result, blood volume and   pressure in the left atrium increases, and,  over time, this may have several consequences.  First, the left atrium enlarges and becomes a  risk factor for developing atrial fibrillation,   a condition in which the atria beat rapidly  and irregularly. The atrium quivers rather than   contracts, and does not empty completely into  the ventricle. Ineffective pumping causes the   blood to stagnate, facilitating the formation of  blood clots. These clots may then pass into the   bloodstream, get stuck in small arteries and block  them, resulting in stroke and other problems.  Second, because the left atrium  receives blood from the lungs,   pulmonary pressure may increase, causing secondary  pulmonary hypertension, which in turn, may lead to   right ventricular heart failure, as well as  tricuspid or pulmonary valve regurgitation.  Mitral stenosis is most commonly caused by  rheumatic fever, a complication of untreated strep   throat or scarlet fever during childhood. For  this reason, it is most prevalent in developing   countries where rheumatic fever is more common.  Rarely, mitral stenosis may develop with age,   as a result of accumulated calcium deposits on  the valve. Mitral stenosis can also be congenital.  Symptoms progress slowly, over years or even  decades, so patients may not be aware until atrial   fibrillation or heart failure develops. Symptoms  may appear or worsen with increased heart rates,   such as during exercise or stress.  Women may suddenly discover they   have the condition as they become pregnant. Mitral stenosis produces a characteristic heart   murmur that can be heard with a stethoscope.  Diagnosis is confirmed with echocardiography,   which uses ultrasound to visualize  cardiac structures and blood flow.   Echocardiography also helps determine the severity  of the disease by measuring the mitral valve area.   ECG recordings and chest X-ray may  show signs of left atrial enlargement.  Because most cases of mitral stenosis  are caused by rheumatic fever,   prompt treatment of strep throat  with antibiotics effectively   prevents both rheumatic fever and mitral stenosis. Treatment is not needed for asymptomatic patients.   Patients with mild symptoms may be treated with  diuretics to reduce blood pressure; beta-blockers   or calcium channel blockers to control heart  rates; and anticoagulants to prevent blood clots.  Valve repair or replacement surgery may  be indicated for moderate to severe cases.  In percutaneous valvuloplasty, a catheter with  a balloon is threaded through a vein and into   the heart. The balloon is inflated to widen the  opening of the valve, then deflated and removed.  Patients with heavy calcification may require  open heart surgery to repair the valve.   Valve replacement is considered  when repair is not possible.   Artificial valves can be mechanical or  bio-prosthetic. Mechanical valves last longer   but usually require life-long anticoagulation  to prevent formation of blood clots. you

Channel: Alila Medical Media

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Keywords: mitral valve, left atrium, heart, valvular heart diseases, left atrial pressure, flaps, mitral stenosis, stenotic valve, secondary pulmonary hypertension, risk factor, afib, AF, rheumatic fever, strep throat, MS, surgery, ECG, EKG, left atrial enlargement, P wave morphology, tachycardia, medications, medicines, surgical, percutaneous mitral balloon valvotomy, valvuloplasty, anatomy, cardiac, cardiology, cardiovascular, disorders, medical, medicine, pathology, pathophysiology, physiology, procedure

Id: dip_4io2_4A

Length: 4min 8sec (248 seconds)

Published: Tue Mar 30 2021