Mitral valve prolapse and the mitral valve prolapse syndrome

Neurologic complications of nonrheumatic valvular heart disease

Valvular heart disease (VHD) is frequently associated with neurologic complications. Cerebral embolism is the most common, since thrombus formation results from the abnormalities in the valvular surfaces and the anatomic and physiologic changes associated with valve dysfunction, including atrial or ventricular enlargement, intracardiac thrombi, and cardiac dysrhythmias. Prosthetic heart valves, particularly mechanical valves, are very thrombogenic, which explains the high risk of thromboembolism and the need for long-term anticoagulation. Transcatheter aortic valve replacement (TAVR) has emerged as a nonoperative alternative to surgical aortic valve replacement for patients with intermediate or high surgical risk, and the procedure also has a risk of cerebral ischemia. In addition, anticoagulation, the mainstay of treatment to prevent cerebral embolism, has known potential for hemorrhagic complications. The emergence of new oral anticoagulants with similar effectiveness to warfarin and a better safety profile has facilitated the management of patients with atrial fibrillation. However, their application in patients with mechanical heart valves is still evolving. The prevention and management of these complications requires an understanding of their natural history to balance the risks posed by valvular heart disease, as well as the risks and benefits associated with the treatment.

Neurologic complications of valvular heart disease

Valvular heart disease (VHD) is frequently associated with neurologic complications; cerebral embolism is the most common of these since thrombus formation results from the abnormalities in the valvular surfaces or from the anatomic and physiologic changes associated with valve dysfunction, such as atrial or ventricular enlargement, intracardiac thrombi, and cardiac dysrhythmias. Prosthetic heart valves, particularly mechanical valves, are very thrombogenic, which explains the high risk of thromboembolism and the need for anticoagulation for the prevention of embolism. Infective endocarditis is a disease process with protean manifestations that include not only cerebral embolism but also intracranial hemorrhage, mycotic aneurysms, and systemic manifestations such as fever and encephalopathy. Other neurologic complications include nonbacterial thrombotic endocarditis, a process associated with systemic diseases such as cancer and systemic lupus erythematosus. For many of these conditions, anticoagulation is the mainstay of treatment to prevent cerebral embolism, therefore it is the potential complications of anticoagulation that can explain other neurologic complications in patients with VHD. The prevention and management of these complications requires an understanding of their natural history in order to balance the risks posed by valvular disease itself against the risks and benefits associated with treatment.

Prevalence of mitral valve prolapse in residents living at moderately high altitude

OBJECTIVE

Prolapse of mitral valve leaflets is a frequent disorder and the most common cause of severe mitral regurgitation in western countries. However, little is known about the effects of altitude on mitral valve prolapse. We studied the prevalence and echocardiographic characteristics of mitral valve prolapse at moderately high altitude and sea level.

METHODS

A total of 936 consecutive subjects who were admitted to 2 study institutions at Kars, Turkey (1750 m) and Istanbul, Turkey (7 m) were enrolled in this study to determine prevalence of mitral valve prolapse. Demographic and 2-dimensional echocardiographic characteristics of participants were recorded.

RESULTS

Prevalence of mitral valve prolapse was found to be significantly higher in people living at moderate altitude compared with those living at sea level (6.2% vs 2.0%; P = .007). Overall echocardiographic features regarding valve thickness (4.1 ± 0.80 mm vs 3.6 ± 0.66 mm; P = 0.169), maximal valve prolapse (4.6 ± 2.08 mm vs 3.9 ± 0.91 mm; P = .093), and frequency of mitral regurgitation (89% vs 73%; P = .65) were similar between groups, although anterior valve prolapse was seen more frequently at moderate altitude (50% vs 11%; P = .056) and posterior leaflet prolapse was significantly more frequent at sea level (66% vs 10%; P = .002).

CONCLUSIONS

Mitral valve prolapse is more frequently observed at moderately high altitudes. Further studies are needed to determine clinical importance of our findings.

Mitral valve prolapse in patients with pure rheumatic mitral stenosis: an angiographic study

Of 122 adult patients suspected of having rheumatic mitral stenosis, 112 fulfilled the hemodynamic and angiographic criteria for pure, isolated mitral stenosis. There were 88 females and 24 males with an age range of 16 to 60 years. The left ventriculograms (30 degrees right anterior oblique) were subjectively assessed for gross bulging of the mitral valve leaflets beyond the mitral fulcrum into the left atrium during a beat with maximal opacification. Seventeen percent of cases had typical evidence of mitral valve prolapse, which is much higher than the 3% to 5% rate reported for the general population. This phenomenon was independent of the patients' age, sex, hemodynamic findings, and/or their underlying cardiac rhythm, thus implying the direct role of rheumatic mitral stenosis in the genesis of secondary mitral valve prolapse.

Acute chest pain

Chest pain is the initial symptom of many life-threatening disease processes. Pain may arise from any structure located in the thoracic cavity. Cardiac causes of chest pain usually have anginal symptoms. Noncardiac causes have a variety of chest pain characteristics. Diseases that require immediate attention and intervention are myocardial infarction/unstable angina, dissecting aortic aneurysm, pericarditis, pulmonary embolism, pneumothorax, pneumonia, and acute chest syndrome. In order to evaluate a patient with the complaint of chest pain, the advanced practice nurse must be familiar with the differential diagnosis approach to acute chest pain.

Anatomic explanation of mobile systolic clicks: implications for the clinical and echocardiographic diagnosis of mitral valve prolapse

An echocardiogram (echo) is often ordered for suspected mitral valve prolapse (MVP). Using echo as the gold standard, we conducted a meticulous physical examination on 61 patients with this referral diagnosis. Ninety percent of patients with negative physical examination and echo results for MVP had physical examination findings likely to have been misinterpreted as MVP by the referring physician. Redundant portions of the mitral valve apparatus were found in 57% of patients with MVP on our physical examination but not on echo. A carefully performed physical examination (including dynamic auscultation) can exclude MVP. Not all mobile systolic clicks are associated with anatomic echo prolapse; they can be generated by redundant chordae tendineae and, in the absence of echo prolapse, probably by redundant leaflets. Patients with mobile systolic clicks should have an echo to determine the portion of the spectrum of echo prolapse present and to determine risk stratification and management.

Autonomic control of cardiovascular function: clinical evaluation in health and disease

The high- and low-pressure baroreceptor reflexes are integral to the control of blood pressure by the autonomic nervous system. Tests of the integrity of these baroreflexes make it possible to identify the site of autonomic dysfunction in patients with orthostatic hypotension. Clinical characteristics and typical results of autonomic testing in patients with autonomic failure, with carotid sinus hypersensitivity, and with hyperadrenergic autonomic dysfunction are described in this review.

John Barlow: mitral valve prolapse

Although the systolic click was first mentioned in the medical literature in 1887, it was not until the investigations of John Barlow and his colleagues in the 1960s that it became linked to the mitral valve and mitral valve prolapse identified as the cause. Mitral valve prolapse is currently the most commonly diagnosed cardiac valvular abnormality. Significant complications may occur with mitral valve prolapse, though most patients are asymptomatic. However, a number of issues persist regarding mitral valve prolapse, especially with respect to the mitral valve prolapse syndrome, a term which has been applied to patients who develop a variety of symptoms, including chest pain, shortness of breath, fatigue, lightheadedness, syncope, palpitations, anxiety, and panic attacks.