Q: What are some of the insights to Understanding Mitral Valve Prolapse?
A: Etiology and Pathophysiology
Mitral
Valve Prolapse (MVP) is a cardiovascular disorder negatively impacting
the mitral or bicuspid valve. Normally, the mitral valve allows blood
flow from the left atrium into the left ventricle. The prolapse of the
mitral valve is a pathologic abnormality affecting mitral leaflet
motion (Bouknight 2000). It is estimated from recent community studies,
that the prevalence of MVP is 2.4 % in the general population. (Freed
1999, 2002). However, other reports indicate MVP between 2% and 6% of
the population (Texas Heart institute 2006; Women's Heart Foundation
2006). From this data, this represents approximately 7.2 million
Americans and over 144 million individuals worldwide, and is the most
common valvular disorder in the United States (Hayek 2005). Although
common, the disorder is still a poorly understood clinical entity.
Interestingly, it was believed to be more prevalent in women, however
it is now known to affect both sexes and may be heredity (Nagle 1999,
Scordo 1998, Grau 2007).
As
previously mentioned, the mitral valve allows blood flow from the left
atrium to the left ventricle, and has 2 leaflets. Prolapse occurs when
1 or both leaflets of the leaflets billow back into the left atrium
during systole. Due to incomplete closing of the valve, mitral
regurgitation occurs (Figure 1) (Bougknight 2000, Mulumudi
2001).Leaflet dysfunction is the most common form of MVP. However, a
secondary form of MVP exists, although less common. With the secondary
form, leaflet dysfunction is not affected. Secondary causes include but
are not limited to rheumatic fever, myocardial infarction,
cardiomyopathy, and ruptured chordae tendiae (Nagle 1999).
Mitral
Valve Prolapse is typically benign, however, more serious complications
may arise that require critical care of the patient (table 1).
Summary of severe complications with MVP
-
Infectious Endocarditis
-
Cerebrovascular Incident
-
Heart Failure
-
Sudden Cardiac Death
-
Mitral Regurgitation
-
Ventricular Fibrillation
-
Atrial Fibrillation
-
Thromboembolic Event
(Bougknight 2000; Mulumudi 2001; Nagle 1999; Berbaric 2006; Hayes 1997)
Symptoms and Clinical Application
MVP
symptoms are multifactorial and range from none to mild to severe.
Palpitations, chest discomfort, and dyspnea represent the most common
symptoms. Other symptoms include paroxysmal supra ventricular
tachycardia, nocturnal dyspnea, and fatigue. (Bougknight 2000; Mulumudi
2001; Nagle 1999; Women's Heart Foundation 2006).
The
related chest discomfort can be traced to an increase adrenergic
activity, thus increasing heart rate and oxygen demand of the tissues
(Bouknight 2000). Associative symptoms include but are not limited too
migraine headache, nausea, panic disorder, syncope, tingling, and
anxiety (Bougknight 2000; Mulumudi 2001; Nagle 1999)
Clinical findings of MVP are presented in table 2.
Clinical summary of MVP (Sims, 2007)
The
associated murmur with MVP occurs mid to late systole, but is not
present in all patients. Due to blood leakage in the left atrium during
systole, this results in the murmur taking place. The murmur is best
heard with a stethoscope positioned at the apex of the heart at the
left sternal border and may radiate to the axilla (Nagle 99; Hayes
1997).
Interestingly,
a normal EKG may be present, but some patients experience abnormalities
such as ST depression and other irregularities, as such presented in
table 2.
Diagnosis
Diagnosis
Today,
the gold standard for diagnosis of MVP remains the echocardiogram. Two
dimensional and Doppler imaging are the most common tools used. The
echocardiogram shows posterior displacement of 1of both leaflets at
least 2mm during systole (Bougknight 2000; Mulumudi 2001; Nagle 1999).
Wu and colleagues (2004) explain the recent use of stress or exercise
echocardiogram to diagnosis MVP patients. It is likely the stress
echocardiogram could uncover exercise-induced mitral regurgitation for
patients not yet diagnosis or with minimal symptoms. The authors
explain that using stress echocardiogram may reveal hidden left
ventricular dysfunction, thus increasing the risk for future
cardiovascular episodes.
Currently,
there is no cure for MVP. Therefore many patients require minimal
treatment. The main function of the treatment is to alleviate the
symptoms associated with MVP. Many individuals experience symptoms that
affect their activities of daily living (ADL). For this reason, proper
daily management and medication may be needed to ensure safety. Proper
management techniques such as regular exercise, hydration, and limiting
caffeine intake can be utilized (Sims 2007). Specific education is
extremely important and critical for patients with MVP (table 3).
Although some symptoms are more alarming than others, positive support
and comfort should be used for MVP patients to guarantee reassurance
and adherence.
Patient Education Tips
1. Patients with a click or a murmur should receive antibiotic
prophylaxis before any invasive medical or dental procedure.
2. Serial echocardiograms may be done every 3 to 5 years. For patients at high risk for complications, the echocardiograms may be done annually.
3. Teach the patient about any medications given to relieve or control
symptoms such as beta-blockers, antiplatelet therapy, calcium
channel blockers, or digoxin.
4. Avoid caffeine.
5. Aerobic exercise is recommended.
6. Follow a heart healthy diet.
7. Increase fluid intake if orthostatic symptoms are present. Fluid
intake should be at least 64 oz of liquids not containing caffeine,
sugar, or alcohol.
8. Avoid extreme heat and humidity.
9. Join a support group.
10. Avoid over-the-counter medications that contain ephedrine
or ephedra.
11. Maintain good dental hygiene.
12. Do not limit salt intake unless required for another condition.
13. Avoid extreme diets.
(Nagle 1999; Hayes 1997; Scordo 1998)
MVP
is a common clinical entity. Its entire etiology has yet to be
completely elucidated. Although serious complications are rare, upon
occurrence, they lead to severe and progressive morbidity and
mortality. Management requires a combination of follow-up, medication,
and regular adherence to activities of daily living.
References
1:
Berbarie RF, Roberts WC.Frequency of atrial fibrillation in patients
having mitral valve repair or replacement for pure mitral regurgitation
secondary to mitral valve prolapse. Am J Cardiol. 2006 Apr
1;97(7):1039-44.
2: Bouknight DP, O'Rourke RA.Current management of mitral valve prolapse.
Am Fam Physician. 2000 Jun 1;61(11):3343-50, 3353-4. Review.
3:
Freed LA, Levy D, Levine RA, Larson MG, Evans JC, Fuller DL, Lehman B,
Benjamin EJ. Prevalence and clinical outcome of mitral-valve prolapse.
N Engl J Med. 1999 Jul 1;341(1):1-7.
4:
Freed LA, Benjamin EJ, Levy D, Larson MG, Evans JC, Fuller DL, Lehman
B, Levine RA. Mitral valve prolapse in the general population: the
benign nature of echocardiographic features in the Framingham Heart
Study. J Am Coll Cardiol. 2002 Oct 2;40(7):1298-304
5: Hayek E, Gring CN, Griffin BP. Mitral valve prolapse. Lancet. 2005 Feb 5-11;365(9458):507-18. Review.
6: Hayes DD. Mitral valve prolapse revisited. Nursing. 1997 Oct;27(10):34-9; quiz 40. Review.
7:
Grau JB, Pirelli L, Yu PJ, Galloway AC, Ostrer H. The genetics of
mitral valve prolapse. Clin Genet. 2007 Oct;72(4):288-95. Review.
8:
Mulumudi MS, Vivekananthan K. Mysteries of mitral valve prolapse.
Proper treatment requires consideration of all clues. Postgrad Med.
2001 Aug;110(2):43-4, 47-8, 53-4.
9: Nagle BM, O'Keefe LM. Closing in on mitral valve disease Nursing. 1999 Apr;29(4):32cc1-7.
10: Sims JM, Miracle VA. An overview of mitral valve prolapse. Dimens Crit Care Nurs. 2007 Jul-Aug;26(4):145-9. Review.
11: Scordo KA. Mitral valve prolapse syndrome: interventions for symptom control.
Dimens Crit Care Nurs. 1998 Jul-Aug;17(4):177-86. Review.
12: Texas Heart Institute. Heart Conditions - Mitral Valve Prolapse. July 2006. texasheartinstitute.org
13: Women's Heart Foundation. Mitral Valve Prolapse. December 2006. womensheartfoundation.org
14:
Wu WC, Aziz GF, Sadaniantz A. The use of stress echocardiography in the
assessment of mitral valvular disease. Echocardiography. 2004
Jul;21(5):451-8. Review.
Jonathan Mike, MS, CSCS, USAW, NSCA-CPT, Doctoral Student, Assistant Editor
