Mitral Valve Prolapse Causes, Symptoms And Treatments http://ping.fm/Tdi1V
An 82 year -old male presented with two days of progressive abdominal pain and worsening dyspnea. His systolic blood pressure was 85 mmHg. EKG Showed deep precordial ST depression with Q waves in inferior leads.
He underwent an emergent cardiac catheterization which showed two vessel coronary artery disease [distal right coronary artery (RCA)thrombotic total occlusion, mid left anterior descending (LAD) artery thrombotic subtotal occlusion]. Left circumflex artery did not present with any significant obstruction. Left ventricular function was severely depressed with an ejection fraction of 25 %.
The patient underwent successful percutaneous intervention of RCA and LAD with stent placement. An intraaortic balloon pump was inserted for hemodynamic support.
Five days following the coronary intervention, while recovering in the hospital, the patient became hemodynamically unstable and developed respiratory distress requiring emergent intubation. At auscultation, a loud systolic murmur of mitral regurgitation was audible at the apex.
Transesophageal echocardiography showed Type II mitral valve dysfunction due to papillary muscle rupture. The prolapse of the anterior leaflet was clearly visible as shown here. On Doppler echocardiography the jet was posteriorly directed. The ruptured segment of the muscle could be directly viewed as a mobile ventricular mass. There was severe mitral valve regurgitation. The overall left ventricular systolic function was preserved.
The patient was taken emergently to the operating room for mitral valve surgery. Following the exposure of the mitral valve, a detailed mitral valve analysis was performed and showed a prolapse of theA3 segment and the postero-medial commissure. The inspection of the left ventricle showed an extensive subendocardial hemorrhagic plaque involving the posterolateral wall. The examination of subvalvular apparatus showed a postero-medial papillary muscle with two heads. There was a complete rupture of the head which was supporting the anterior leaflet. The muscle was hemorrhagic, necrotic and very friable. The posterior head with chordae attachment to the posterior leaflet was intact. These anatomic findings were in accordance with echocardiographic findings of anterior leaflet prolapse.
The patient underwent a biologic mitral valve replacement with the preservation of the posterior leaflet. Postbypass transesophageal echocardiography showed a well-functioning bioprosthetic valve in the mitral position. Left ventricular function was mildly depressed.
Echocardiography is the key diagnostic tool used for determination of rheumatic valvular disease. Carpentier’s type IIIa is the most common dysfunction seen in patients with rheumatic mitral valve. The characteristic lesions are commissural fusion with or without calcification, leaflet thickening / retraction, and chordae fusion and shortening. The hemodynamic consequence of this valvular dysfunction is mitral regurgitation associated with varying degrees of mitral stenosis.
Type IIIa dysfunction of the posterior leaflet associated with limited prolapse of the anterior leaflet (mostly A2 segment) is very characteristic of rheumatic mitral valve disease.
The presence of associated valvular lesions involving the aortic and tricuspid valves is strongly in favor of rheumatic etiology of valvular heart disease.
Echocardiography is also critical in assessing the mobility of the anterior leaflet, the extent of subvalvular apparatus lesions, and the presence and the extent of valvular calcification as they all predict the feasibility of valve reconstruction.
Finally, echocardiography is used to obtain quantitative measures such as mitral valve orifice area applying the continuity equation. Transvalvular peak and mean gradients are calculated with continuous-wave and pulsed-Doppler echocardiography using the modified Bernoulli equation. In patients with mitral stenosis and minimal symptoms, it is important to calculate transvalvular gradient at rest and during exercise.
During the second half of the 20th century the improvement in the socio-economic situation and the widespread use of antibiotics led to the eradication of rheumatic fever in developed countries. In contrast, the incidence of this disease has remained extremely high in non-industrialized countries. Today, rheumatic fever still remains the principle cause of valvular heart disease and particularly mitral valve disease worldwide.As discussed extensively in the historic review section, a history of untreated group A Beta hemolytic streptococcal pharyngitis is the event that may lead to rheumatic fever. In this scenario, the rate of development of rheumatic fever is about 3%.The two major factors that should be considered regarding the risk of rheumatic fever are: 1) the intensity of the immune response during the episode of streptococcal pharyngitis and 2) the persistence of the organism during the recovery. The strain of Group A streptococcus also plays a role as M-types are associated with strong immune response. These so-called rheumatogenic strains have a cell wall which contains M proteins that are highly antigenic. The immunologic response to M proteins produces antibodies that may cross react with cardiac myosin. They also cross react with perivascular connective tissue leading to the formation of Aschoff bodies. It has also been suggested that cell-mediated immunity plays a definite role in the constitution of acute rheumatic valvular lesions. Jones Criteria, first described in 1944 and updated in 1992, remain relevant and are used for the diagnosis of initial attacks of rheumatic fever. They are divided into two categories of major and minor criteria. During the acute phase, carditis is noted in about 50% of patients. As mentioned first by Bouillaud, cardiac involvement is a pancarditis and acute valvulitis involving the left-sided valves is a characteristic feature of this disease. Mitral valve regurgitation due to type I dysfunction with annular dilatation is a hallmark of acute rheumatic carditis. With the resolution of the acute phase, the long-term prognosis is dominated by the extent and the progression of valvular heart disease.During the chronic phase, in patients with valvular manifestations but with no known history of rheumatic fever or untreated streptococcal pharyngitis, it may be difficult to establish the rheumatic origin of their valve disease. Echocardiography and intraoperative valve analysis may demonstrate characteristic lesions which would confirm this etiology.
Diagnostic tools such as sphygmography, X-ray, electrocardiogram, cardiac catheterization and more recently echocardiography. For each technology, we have provided the developmental background and then analyzed their applications in the diagnosis of the diseases of the mitral valve. This section covers primarily an era extending from the mid 19th century to the seventh decade of the 20th century.
Disease specific approach, focuses on the development of knowledge pertaining to the specific etiologies of valvular heart disease. We have described in a chronologic manner the progres which was made in our understanding of the most common causes of mitral valve disease namely rheumatic fever, infective endocarditis, degenerative disease and ischemic cardiomyopathy.
Chronologic approach the development of knowledge of the structure and function of the heart, circulatory system and subsequently the diseases of the heart with a particular emphasis on the mitral valve. In this section we analyze the work of major contributors from the European Renaissance until the end of the 19th century. Briefly, the 16th century can be viewed as the century of descriptional anatomy.
The development of the science of experimental physiology with the discovery of blood circulation took place in the 17th century. During that era, the science of histology was established and microscopic observation played a critical role in our understanding of the physiology of the circulation.The first pathological reports appeared toward the turn of this century with description of ossification of the cardiac valves . The 18th century witnessed the birth of anatomo-pathology and a great emphasis was placed on the correlation of clinical symptoms with autopsy findings. Finally, during the first half of the 19 century, great progress was made in physical diagnosis with the broader application of percussion and the invention of stethoscope.
Mitral Valve, Mitral Valve Repair, Mitral Valve Prolapse, Mitral Leakage, Mitral Disease, Mitral Valve Replacement, Farzan Filsoufi