Before 1950 rheumatic fever was one of the most common epidemics in the world, with considerable socioeconomic consequences. As an example, acute rheumatic fever was the most common cause of draft rejection in the United States Armed Forces during World War II. Dramatic changes took place when in the mid-1940s sulfanilamides were found to be efficient in the treatment of streptococcal pharyngitis, the cause of rheumatic fever. Since then, with the widespread use of antibiotics, this disease has been practically eradicated in developed countries although a resurgence may appear from time to time because of the emergence of new strains of Streptococcus . By contrast, the prevalence remains high in developing countries, where progress has been more limited because of unfavorable socioeconomic conditions and the financial burden of prophylaxis. In populations at risk, systematic echocardiography screening showed that the prevalence is much greater than previously thought and 10 times higher than the number of cases determined by clinical screening.
Today the incidence of rheumatic fever varies considerably from one country to another, and from one social community to another. It remains the main cause of valvular disease worldwide.
CLINICAL PRESENTATION
“Rheumatic disease enters the throat, licks the joints and bites the heart.” *
* “Le rhumatisme articulaire aigu entre par la gorge, lèche les articulations et mord le coeur.”
This aphorism from Jean-Baptiste Bouillaud, the French physician who first demonstrated the relationship between this disease and its valvular manifestations, summarizes the clinical characteristics. Although its pathophysiology is still not fully understood, it has been proven that the rheumatic process is caused by a streptococcus group A pharyngitis. Of note, more than one third of the infections that trigger rheumatic fever are asymptomatic. Therefore in the presence of valvular disease, a rheumatic origin cannot be ruled out in patients who have no history of sore throat. Other associated manifestations of rheumatic disease should be systematically investigated. In the acute phase of rheumatic fever, transient episodes of polyarthritis or polyarthralgia are a common feature. As pointed out by Bouillaud, they only “lick the joints” and do not leave any residual disability. Other possible transient clinical manifestations—such as subcutaneous nodules, erythema marginatum, or chorea (all part of Jones criteria) —are suggestive of rheumatic fever.The absence of previous typical manifestations of rheumatic fever or throat infection does not rule out the possible rheumatic origin of a valvulitis.
In contrast to these systemic manifestations, rheumatic fever “bites the heart,” and the cardiac involvement is responsible for the mortality associated with this disease. Cardiac manifestations can develop either during the acute phase or later during the chronic phase of the disease. In the acute phase, pancarditis symptoms are always present and type I mitral regurgitation is generally observed. In the chronic phase, establishing the diagnosis of rheumatic fever is more difficult. In patients with valvular manifestations, the rheumatic origin is suggested by echocardiography and intraoperative examination ( Fig. 25-1 ). For example, in the presence of mitral valve regurgitation (a) , three findings are strongly in favor of the diagnosis of rheumatic valvular disease: (1) type IIIa mitral valve dysfunction predominant on the posterior leaflet, contrasting with discrete prolapse of the anterior leaflet (b) ; (2) specific valvular lesions, that is, commissural fusion with doming of the leaflet in diastole, leaflet thickening, and chordae fusion (c) ; and (3) associated aortic or tricuspid valve lesions. A congenital malformation of the mitral valve may occasionally make it more difficult to establish a differential diagnosis. The young age of the patient is particularly suggestive of a malformation if a cardiac murmur has been diagnosed before the age of 2 years. Also suggestive is the presence of associated cardiac malformations. Identification of rheumatic valvular disease has important consequences since secondary prevention can be effective.
The association of a type IIIa dysfunction of the posterior leaflet and a limited type II of the anterior leaflet is characteristic of a rheumatic mitral valve.
PATHOLOGY
In the acute phase of rheumatic disease, exudative inflammatory reactions involve the connective tissues of the heart, brain, joints, and skin. The interstitial connective tissue is edematous and eosinophilic with fragmentation and separation of the collagen fibers. Mononuclear cells and in particular multinucleated histiocytes form Aschoff bodies in the myocardium but not in other organs. Cardiac involvement is a pancarditis but most characteristic is the involvement of cardiac valves, in order of frequency the mitral, aortic, tricuspid, and pulmonary valves. Acute valvulitis with edema and cellular infiltration is followed by hyaline degeneration of the leaflets with the formation of verrucae at the leaflet edge. All the components of the valve, including the annulus, can be involved in this acute process, which eventually leads to leaflet and chordae thickening and commissural fusion during the chronic phase. In the chronic phase ( Fig. 25-2 ), the annulus of the mitral valve is severely dilated and deformed; the dilatation is often asymmetrical, predominant at the P3 segment and the posterior commissure (a) . The valvular tissue displays marked changes; the posterior leaflet is thickened and the indentations are no longer visible (b) . The anterior leaflet is generally less altered, with the exception of the coaptation area, which is slightly prolapsed, thickened, and sometimes calcified (c) . The chordae of the anterior leaflet may be elongated or displaced, particularly the paramedial chordae. In contrast, the chordae of the posterior leaflet are shortened and often thickened and fused, characteristic of rheumatic mitral valve regurgitation. The height of the leaflets is reduced. The commissural areas are thickened and fused (d) . The aortic valve ( Fig. 25-3 ) and tricuspid valve display similar fibrotic lesions with annular dilatation, commissure fusion, and leaflet thickening.
SURGICAL INDICATIONS
Acute Phase of Rheumatic Fever
Until the early 1970s cardiac surgery was considered to be contraindicated during the acute phase of rheumatic fever. The normally effective medical treatment used in adults (i.e., high doses of antibiotics and corticosteroids) often had little impact on the inflammatory process in children with valvular disease. In 1970 at our institution, we performed valvular surgery on two children with severe inflammatory syndrome resistant to medical therapy and with persistent hemodynamic disturbances resulting from severe mitral regurgitation. Surprisingly, following mitral valve reconstruction, the inflammatory syndrome receded as a result of the hemodynamic improvement. Since then, other authors have reported similar observations, suggesting a definite link between improvement of hemodynamic conditions and reduction of the inflammatory process. These studies have also shown that good results could be obtained with low operative mortality when surgery is performed in the acute phase.
Our current treatment and prophylactic protocol is described in Table 25-1 . After rheumatic valve surgery, 1 month of corticosteroid therapy and strict penicillin prophylaxis for many years are strongly recommended. Medical therapy does not always prevent the progression of the valvular disease. Recurrent mitral valve dysfunction can develop, which may necessitate valve replacement at a later stage. Since the progression of this disease is unpredictable, we still recommend valve reconstruction rather than replacement in the first surgery during the acute phase of rheumatic valvular disease.
Acute Phase
|
|
Valvular surgery is not contraindicated in patients with an active rheumatic inflammatory process not responding to medical therapy.
Chronic Phase of Rheumatic Fever
Mitral valve stenosis with signs of pulmonary venous hypertension—such as orthopnea, paroxysmal nocturnal dyspnea, and episodes of pulmonary edema—requires surgical intervention. Other indications are complications such as systemic embolization, hemoptysis, atrial fibrillation, or infective endocarditis.
Intervention should also be considered if asymptomatic mitral valve stenosis exists in the presence of a mitral orifice smaller than 1 cm 2 , a mean gradient >10 mm Hg at rest, an atrial thrombus, or a systolic pulmonary artery pressure greater than 50 mm Hg. A significant increase in the mitral gradient with exercise is another potential indication.
The type of intervention that is recommended for mitral valve stenosis has been widely discussed. There is general agreement that patients with pliable noncalcified valves, a normal size annulus, discrete subvalvular lesions, and minimal regurgitation are best treated by percutaneous balloon mitral dilatation, *
* note : The term “balloon dilatation” is preferred to “balloon commissurotomy,” which is sometimes used because in Greek the suffix “tomy” means “section” or “cutting.” “Valvuloplasty” is also inappropriate since it implies a complex surgical procedure.
unless a left atrial thrombus exists. Another alternative, still widely used in developing countries for economic reasons, is closed commissurotomy with reusable mechanical dilators introduced through the left atrium (Dubost’s dilator), the left ventricle (Tubbs dilator), or the femoral artery (Cribier’s dilator). When a closed procedure is contraindicated, patients are candidates for valve reconstruction or replacement. The timing of surgery in asymptomatic patients is strongly influenced by the likelihood of a successful valve reconstruction. The classic signs that indicate feasible valve reconstruction are a loud opening snap at auscultation and good leaflet mobility with minimal subvalvular lesions or calcification on echocardiography ( Table 25-2 ).| Minimal Subvalvular Lesions | Severe Subvalvular Lesions and/or Calcifications | |
|---|---|---|
| Pliable Leaflets | Reconstruction feasible | Probably not feasible |
| Rigid Leaflets | Probably feasible | Not feasible |
Atrial fibrillation is a turning point in the evolution of mitral valve disease, reducing the functional capacity and increasing the risk of complications.
Stay updated, free articles. Join our Telegram channel
Full access? Get Clinical Tree
