Mitral Valve Prolapse - Acquired Valvular Disorders

MITRAL VALVE PROLAPSE

Mitral valve prolapse, formerly known as mitral prolapse syndrome, is a deformity that usually produces no symptoms. Rarely, it progresses and can result in sudden death. Mitral valve prolapse occurs more frequently in women than in men. In recent years,this disorder has been diagnosed more frequently, probably as a result of improved diagnostic methods.

Pathophysiology

In mitral valve prolapse, a portion of a mitral valve leaflet balloons back  into  the  atrium  during  systole.  Rarely,  the  ballooning stretches the leaflet to the point that the valve does not remain closed during systole (ie, ventricular contraction). Blood then regurgitates  from  the  left  ventricle  back  into  the  left  atrium (Braunwald et al., 2001).

Clinical Manifestations

Many people have a ballooned leaflet but no symptoms. Others have symptoms of fatigue, shortness of breath, light-headedness,dizziness,  syncope,  palpitations,  chest  pain,  and  anxiety(Braunwald et al., 2001; Freed et al., 1999; Fuster et al., 2001).

Fatigue may occur regardless of the person’s activity level and amount of rest or sleep. Shortness of breath is not correlated with activity levels or pulmonary function. Atrial or ventricular dysrhythmias may produce the sensation of palpitations, but palpitations have been reported while the heart has been beating nor-mally. Another puzzling symptom is chest pain, which is often localized to the chest and may last for days.

Anxiety may be a response to the symptoms experienced by the patient; however, some patients report anxiety as the onlysymptom. Some clinicians speculate that the symptoms may be explained by dysautonomia, a dysfunction of the autonomic nervous system, although no consensus exists about the cause of the symptoms experienced by some patients with mitral valve prolapse.

Assessment and Diagnostic Findings

Often, the first and only sign of mitral valve prolapse is identified when a physical examination of the heart discloses an extra heart sound, referred to as a mitral click. The systolic click is an early sign that a valve leaflet is ballooning into the left atrium. In ad-dition to the mitral click, a murmur of mitral regurgitation may be heard if progressive valve leaflet stretching and regurgitation have occurred. A small number of patients experience signs and symptoms of heart failure if mitral regurgitation exists.

Medical Management

Medical management is directed at controlling symptoms. If dys-rhythmias are documented and cause symptoms, the patient is advised to eliminate caffeine and alcohol from the diet and to stop smoking; antiarrhythmic medications may be prescribed.

Chest pain that does not respond to nitrates may respond to calcium channel blockers or beta-blockers. Heart failure is treated the same as it would be for any other patient with heart failure . In advanced stages of disease, mitral valve repair or replacement may be necessary.

Nursing Management

The nurse educates patients about the diagnosis and the possibil-ity that the condition is hereditary. Because most patients with mitral valve prolapse are asymptomatic, the nurse explains the need to inform the health care provider about any symptoms that may develop. The nurse also instructs patients about the need for prophylactic antibiotic therapy before undergoing invasive proce-dures (eg, dental work, genitourinary or gastrointestinal proce-dures) that may introduce infectious agents systemically. This therapy is prescribed for symptomatic patients and for asympto-matic patients who have both a systolic click and murmur or mi-tral regurgitation. If in doubt about risk factors and the need for antibiotics, patients should consult their physicians.

To minimize symptoms, the nurse teaches patients to avoid caffeine and alcohol. The nurse encourages patients to read product labels, particularly in over-the-counter products such as cough medicine, because these products may contain alcohol, caffeine, ephedrine, and epinephrine, which may produce dys-rhythmias and other symptoms. The nurse also explores with patients possible diet, activity, sleep, and other lifestyle factors that may correlate with symptoms experienced.