Subacute bacterial endocarditis in a patient with isolated, nonejection systolic click but without a murmur

A controlled evaluation of the risk of bacterial endocarditis in persons with mitral-valve prolapse

The absence of controlled evidence and the high prevalence of mitral-valve prolapse have created substantial uncertainty about whether this condition is an important risk factor for bacterial endocarditis. We evaluated this risk in a case-control study of hospital inpatients who had undergone echocardiography and who lacked any known cardiovascular risk factors for endocarditis, apart from mitral-valve prolapse and isolated mitral-regurgitant murmurs. Thirteen (25 per cent) of 51 patients with endocarditis had mitral-valve prolapse, as compared with 10 (seven per cent) of the 153 matched controls without endocarditis. For the 51 matched case-control sets, the odds ratio (8.2; 95 per cent confidence interval, 2.4 to 28.4) indicated a substantially higher risk of endocarditis for people with mitral-valve prolapse than for those without it. This association remained statistically significant when parenteral drug abuse and routine antibiotic prophylaxis preceding dental work and other forms of instrumentation were taken into account. Furthermore, the risk may be higher than is indicated by this study, since 46 per cent of the controls underwent echocardiography for clinically suspected mitral-valve prolapse, suggesting an overrepresentation of mitral prolapse in the control group. The results support the contention that mitral-valve prolapse is a significant risk factor for bacterial endocarditis.

Pulsed doppler echocardiographic detection of mitral regurgitation in mitral valve prolapse: correlation with cardiac arrhythmias

The incidence of mitral regurgitation in mitral valve prolapse was studied retrospectively in 88 consecutive hospital based patients with mitral valve prolapse using pulsed Doppler echocardiography. Pulsed Doppler findings of turbulence in the left atrium were predictive of angiographic findings of mitral regurgitation in 31 patients. On 24-hr Holter monitoring, patients with mitral valve prolapse and mitral insufficiency had a higher prevalence of ventricular arrhythmias than patients without mitral insufficiency (61 vs 22%; P less than 0.02). Detection of mitral insufficiency identified individuals with mitral valve prolapse who are at higher risk of ventricular arrhythmias.

Mitral valve prolapse: etiology, diagnosis, and management

Mitral valve prolapse is a common cardiac anomaly in which diagnosis is generally made by auscultation. In a typical case, a midsystolic click followed by a late systolic murmur is heard, although this pattern can vary. Selected pharmacologic agents (vasopressors and vasodilators) may be useful in diagnosis, and echocardiography can be helpful in cases without auscultatory signs. In the majority of cases, mitral valve prolapse is benign and no specific treatment is needed except reassurance and perhaps endocarditis prophylaxis. Patients with chest pain and symptomatic arrhythmias may benefit from propranolol, those with ventricular tachycardia should receive antiarrhythmic therapy, and those with abnormal resting ECGs or frequent ventricular premature beats should be further tested because of increased risk of sudden death or possibility of associated ischemic heart disease.

The systolic click-murmur syndrome: clinical recognition and management

The midsystolic click-late systolic murmur syndrome is a complex entity with variable manifestations that involves a primary process causing myxomatous degeneration of the mitral valve leaflet(s) and subsequent systolic mitral valve leaflet prolapse. Other cardiac diseases may cause mitral valve prolapse and regurgitation associated with a midsystolic click that mimics this primary syndrome. The prolapsing mitral valve leaflet(s) syndrome occasionally may be familial. Most patients are asymptomatic but some complain of chest pain, palpitation, dyspnea or fatigue. Prolapsing mitral valve leaflet(s) can be distinguished from other causes of systolic clicks and mitral regurgitation murmurs by the characteristic movement of the clikmurmur complex in systole with various hemodynamic interventions. The clinical diagnosis usually can be confirmed by echocardiography, which demonstrates the abnormally prolapsdrome usually is minimal but can be progressive and lead to the need for prosthetic valve replacement. Most symptomatic patients can be managed medically but some require cardiac catheterization to evaluate the possibility of coexistent coronary artery disease, to assess the degree of mitral regurgitation and to evaluate other associated cardiac lesions. All patients with this syndrome should receive antibiotic prophylaxis prior to any surgical or dental procedures. Those patients suspected of having arrhythmias should be evaluated by continuous ambulatory ECG monitoring and dangerous arrhythmias probably should be treated. The prognosis usually is excellent, but sudden death and rapidly progressive mitral regurgitation due to ruptured chordae tendineae have been reported. Although more than a decade has elapsed since the midsystolic click-late systolic murmur syndrome was first recognized, much remains to be learned about this common but complex clinical entity.