Papillary muscle rupture pathophysiology
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Papillary muscle rupture Microchapters |
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Diagnosis |
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Treatment |
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Papillary muscle rupture pathophysiology On the Web |
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American Roentgen Ray Society Images of Papillary muscle rupture pathophysiology |
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Risk calculators and risk factors for Papillary muscle rupture pathophysiology |
Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-In-Chief: Cafer Zorkun, M.D., Ph.D. [2]
Overview
The vascularization of the papillary muscles shows many individual variations and depends in part on coronary artery anatomy and dominance. However, the posterior papillary muscle is vascularized by posterior left ventricular branches that may have origin in the right, left or both coronary arteries. The anterior papillary muscle is vascularized by branches from diagonal, circumflex or even acute marginal branches of the left coronary artery. Papillary muscle ischemia occurs along with ischemia of the adjacent ventricular wall.
- Acute mitral regurgitation (as may occur due to the sudden rupture of a chordae tendineae or papillary muscle) causes a sudden volume overload of both the left atrium and the left ventricle.
- The left ventricle develops volume overload because with every contraction it now has to pump out not only the volume of blood that goes into the aorta (the forward cardiac output or forward stroke volume), but also the additional blood that regurgitated into the left atrium (the regurgitant volume).
- The combination of the forward stroke volume and the regurgitant volume is known as the total stroke volume of the left ventricle.
- In the acute setting, the total stroke volume (i.e. the forward plus the regurgitant volume) is increased, but the forward cardiac output into the aorta is decreased because a proportion of the blood is going backward into the left atrium. The mechanism by which the total stroke volume is increased as a result of increased left ventricular filling is known as the Frank-Starling mechanism.
The regurgitant volume causes acute volume overload and pressure overload of the left atrium as shown in the figure below. The sudden increase in pressure in the left atrium is transmitted backward into the pulmonary vein which in turn reduces drainage of blood from the lungs via the pulmonary veins and raises the pulmonary capillary sedge pressure. This causes pulmonary congestion.
Microscopic Pathology
Images shown below are courtesy of Professor Peter Anderson DVM PhD and published with permission. © PEIR, University of Alabama at Birmingham, Department of Pathology
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Papillary Muscle Infarct with Rupture: Gross, left ventricle opened partially to show infarct and ruptured muscle, an excellent example -
Papillary Muscle Infarct with Rupture: Gross, very good example
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Papillary Muscle Infarct: Gross, an excellent example -
Papillary Muscle Infarct: Gross, an excellent example
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Papillary Muscle Infarct with Rupture: Gross, horizontal section of left ventricle looking toward base of heart, a very good example with lateral wall transmural infarct and ruptured papillary muscle -
Papillary Muscle Infarct with Rupture: Gross, an excellent example of ruptured papillary muscle
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Papillary Muscle Infarct with Rupture -
Papillary Muscle Infarct with Rupture: Gross, natural color, close-up, well shown
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Papillary Muscle Infarct: Gross fixed tissue very well shown and typical papillary muscle infarct -
Papillary Muscle Infarct: Gross, natural color, close-up view of longitudinally section. Papillary muscle with obvious infarct, a very good example. There is a large old infarct with aneurysm in the anterior wall. The infarcted papillary muscle is the posterior one.
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Papillary Muscle Thinning: Gross, natural color, band-like anterior papillary muscles secondary to healed infarct which is present in picture (but not easily seen). An excellent example for papillary muscle change -
Mitral Valve Prosthesis and Large Apical Infarct: Gross, natural color, caged plastic ball with complete steel struts. A large recent infarct at apex of heart, at base of posterior papillary muscles. Etiology not completely clear but looks like an iatrogenic lesion (good illustration)
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Myocardial Hemorrhage Following Mitral Valve Replacement: Gross, natural color, horizontal section of left ventricle showing a large area of mural hemorrhage extending from anterior papillary muscle -
Papillary Muscle Infarct with Rupture: Gross, natural color, a close-up view (very good example)
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Papillary Muscle Infarct with Rupture: Gross, fixed tissue, a close-up view (quite good example) -
Papillary Muscle Infarct with Rupture: Gross, fixed tissue, but good color. Horizontal slice of LV with posterior infarct that appears old and a ruptured papillary muscle head.
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Papillary Muscle Infarct with Rupture: Gross, fixed tissue, but good color. An outstanding photo of ruptured head of posterior papillary muscle with entangled chordae -
Papillary Muscle Infarct with Rupture: Gross, fixed tissue, but good color. An outstanding photo of ruptured head of posterior papillary muscle with entwined chordae -
Papillary Muscle Infarct with Rupture: Gross, fixed tissue, but good color. An outstanding photo of ruptured head of posterior papillary muscle with entwined chordae
