Discussion
IE is a commonly encountered clinical problem, especially in the patients with predisposing heart disease (1). Most often, the mitral valve regurgitation in IE is due to the destruction of the valvular leaflets themselves. The isolated rupture of the antero-lateral papillary muscle is much rarer and has only been described to the best of our knowledge in four previous cases (3 - 6). There are many possible causes of ruptures of papillary muscle in IE that include ischemic necrosis due to coronary embolism (7), deposition of bacteria due to aortic regurgitation (8), or direct invasion along the sub-valvular apparatus by virulent germ like staphylococcus (9). In our case, the cause of mitral regurgitation was due to direct germ invasion of the papillary muscle. The transesophageal echocardiography (TEE), with the trans-gastric view is essential to determine the mechanism of mitral regurgitation in such cases (10). The ruptured anterolateral papillary muscle is well-defined as a separate mass attached to the chordae (10). Although we were unable to show any bacteria on histological examination and culture of the papillary muscle, active inflammation was a strong criterion for the IE diagnosis. The absence of isolated germ may be explained by the use of empiric antibiotics in our patient at admission.
In conclusion, if a huge mass is observed attached to the mitral apparatus on echocardiography in the case of sepsis, the diagnosis of IE should be made even in the absence of valvular disease and the rupture of the papillary muscle in the setting mitral regurgitation should be considered.
Acknowledgments: None
Conflict of interest: None