This dilatation of the left ventricle can be due to any cause of dilated cardiomyopathy including aortic insufficiency, nonischemic dilated cardiomyopathy, and noncompaction cardiomyopathy. Because the papillary muscles, chordae, and valve leaflets are usually normal in such conditions, it is also called functional mitral regurgitation.Acute MR is most often caused by endocarditis, mainly S. aureus. Rupture or dysfunction of the papillary muscle are also common causes in acute cases, dysfunction, which can include mitral valve prolapse. Pathophysiology
The pathophysiology of MR can be broken into three phases of the disease process: the acute phase, the chronic compensated phase, and the chronic decompensated phase. Acute phase
Acute MR (as may occur due to the sudden rupture of the chordae tendinae 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 blood that regurgitates 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 stroke volume of the left ventricle is increased (increased ejection fraction); this happens because of more complete emptying of the heart. However, as it progresses the LV volume increases and the contractile function deteriorates, thus leading to dysfunctional LV and a decrease in ejection fraction.
Splenic lymphoma with villous lymphocytes is a rare type of lymphoma that involves mature B cells. Older names include  lymphoma simulating hairy cell leukemia and lymphoplasmacytic lymphoma with circulating villous lymphocytes. The characteristic villous lymphocytes will appear in a blood smear of the peripheral blood of patients with this type of lymphoma. These lymphocytes will have an oval nucleus with the “cobblestone” pattern of nuclear chromatin typical of more mature lymphoid cells. The cytoplasmic projections, or villi, are found in a polar distribution. Whether this condition is identical to splenic marginal zone lymphoma, or only highly similar, is a matter of debate. == References ==