00:00 / 00:00
Bundle branch block
Pulseless electrical activity
Atrioventricular nodal reentrant tachycardia (AVNRT)
Premature atrial contraction
Long QT syndrome and Torsade de pointes
Premature ventricular contraction
Coronary steal syndrome
Coarctation of the aorta
Polycystic kidney disease
Renal artery stenosis
Peripheral artery disease
Subclavian steal syndrome
Superior mesenteric artery syndrome
Human herpesvirus 8 (Kaposi sarcoma)
Chronic venous insufficiency
Deep vein thrombosis
Acyanotic congenital heart defects: Pathology review
Aortic dissections and aneurysms: Pathology review
Atherosclerosis and arteriosclerosis: Pathology review
Cardiac and vascular tumors: Pathology review
Cardiomyopathies: Pathology review
Coronary artery disease: Pathology review
Cyanotic congenital heart defects: Pathology review
Dyslipidemias: Pathology review
Endocarditis: Pathology review
Heart blocks: Pathology review
Heart failure: Pathology review
Hypertension: Pathology review
Pericardial disease: Pathology review
Peripheral artery disease: Pathology review
Shock: Pathology review
Supraventricular arrhythmias: Pathology review
Valvular heart disease: Pathology review
Vasculitis: Pathology review
Ventricular arrhythmias: Pathology review
Mitral valve disease
0 / 26 complete
0 / 7 complete
fragile X syndrome p. 60
renal cyst disorders and p. 628
The mitral valve has two leaflets: the anterior leaflet and the posterior leaflet. Together, they separate the left atrium from the left ventricle. During systole the valve closes, which means blood cannot do anything but be ejected out of the aortic valve and into circulation.
If the mitral valve doesn’t completely shut, blood can leak back into the left atrium; this is called mitral valve regurgitation. During diastole, the mitral valve opens and lets blood fill into the ventricle. If the mitral valve doesn’t open enough, it gets harder to fill the left ventricle; this is called mitral valve stenosis.
Let’s start with mitral valve regurgitation. The leading cause of mitral valve regurgitation, and the most common of all valvular conditions, is mitral valve prolapse. When the left ventricle contracts during systole, a ton of pressure is generated so that the blood can be pumped out of the aortic valve; therefore, a lot of pressure pushes on that closed mitral valve. Normally, the papillary muscles and connective tissue, called chordae tendineae or heart strings, keep the valve from prolapsing, or falling back into the atrium.
With mitral valve prolapse, the connective tissue of the leaflets and surrounding tissue are weakened; this is called myxomatous degeneration. Why this happens isn’t well understood, but it is sometimes associated with connective tissue disorders, such as Marfan syndrome and Ehlers-Danlos syndrome. Myxomatous degeneration results in a larger valve leaflet area and elongation of the chordae tendineae, which can sometimes rupture; this rupture typically happens to the chordae tendineae on the posterior leaflet, and can cause the posterior leaflet to fold up into the left atrium.
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