Valvular heart diseases

Valvular heart diseases can take the form of stenosis, insufficiency (regurgitation), or a combination of the two. These defects are typically acquired as the result of infections, underlying heart disease, or degenerative processes. However, certain congenital conditions can also cause valvular heart diseases. Acquired defects are found primarily in the left heart as a result of higher pressure and mechanical strain on the left ventricle. The type of valvular disease determines the type of cardiac stress and subsequent symptoms. Valvular stenosis leads to a greater pressure load and concentric hypertrophy, while insufficiencies are characterized by volume overload and eccentric hypertrophy of the preceding heart cavities. Diagnostic procedures typically include ECGs, chest x-ray, and echocardiograms. Management consists of interventional or surgical procedures to reconstruct or replace valves, as well as medical treatment of possible heart failure.

• Aortic stenosis
  • Most common valve defect in industrialized countries
  • Mostly degenerative
  • Degenerative stenosis usually becomes symptomatic after the age of 75 and is most common in men.
  • Aortic stenosis in young people is usually secondary to congenital defects (e.g., bicuspid aortic valve).
• Aortic regurgitation
  • Age of onset: 40–60 years
  • Severity increases with age
• Mitral stenosis: symptom onset between 20 and 39 years ^[1]
• Mitral regurgitation
  • Overall prevalence of 0.6 to 2.4 %
  • Second most common valve defect
  • More common in women
• Tricuspid valve defects: occur in < 1% of the population
• Pulmonary valve defects: rare outside of congenital conditions

Epidemiological data refers to the US, unless otherwise specified.

Valvular heart defects may either be acquired or congenital. Acquired defects are more common and typically occur secondary to infections (postinflammatory), degenerative processes, or heart disease.

All valvular defects can eventually lead to symptoms of heart failure as a result of excessive strain on the ventricles.

• Aortic stenosis
• Aortic regurgitation
• Mitral stenosis
• Mitral regurgitation

Physical examination

• Complete heart examination: see cardiovascular examination and auscultation of the heart for details.

References:^[4][5][6][7]

Symptomatic

• Treatment of heart failure
• Endocarditis prophylaxis
• Prevention of thromboembolism (if necessary)

Causal

• Surgery: The choice of procedure is based on the patient's individual risk profile and an evaluation of benefits.
  • Valve reconstruction (annuloplasty)
    • Procedure: ring-shaped device attached to the outside of the valve opening to re-establish shape and function of valve
    • Reduced thromboembolic risk compared to mechanical prosthetic valve; but high risk of recurring stenosis
    • Lower mortality rate than valve replacements, though replacements are more durable
  • Prosthetic valve replacement
    • Immunosuppression not necessary

• Interventional valve replacement via catheter
  • Transcatheter aortic valve replacement (TAVR)
  • Transcatheter mitral valve replacement (TMVR)
• Percutaneous balloon valvuloplasty for stenoses

References:^[7][8]

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6. Gaasch WH. Tricuspid stenosis. In: Post TW, ed. UpToDate. Waltham, MA: UpToDate. http://www.uptodate.com/contents/tricuspid-stenosis.Last updated: June 8, 2015. Accessed: February 26, 2017.
7. Nishimura RA, Otto CM, Bonow RO, et al. 2017 AHA/ACC Focused Update of the 2014 AHA/ACC Guideline for the Management of Patients With Valvular Heart Disease. J Am Coll Cardiol. 2017; 70 (2): p.252-289. doi: 10.1016/j.jacc.2017.03.011 . | Open in Read by QxMD
8. Acker MA, Parides MK, Perrault LP, et al. Mitral-valve repair versus replacement for severe ischemic mitral regurgitation. N Engl J Med. 2014; 370 (1): p.23-32. doi: 10.1056/NEJMoa1312808 . | Open in Read by QxMD
9. Herold G. Internal Medicine. Herold G ; 2014