Mitral regurgitation resident survival guide: Difference between revisions

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{{Mitral regurgitation}}
{{CMG}}; {{AE}} {{RT}}
{{CMG}}; {{AE}} {{RT}}


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* [[Myxomatous degeneration]]
* [[Myxomatous degeneration]]
* [[Rheumatic fever]]
* [[Rheumatic fever]]
==Diagnosis==
Shown below is an algorithm summarizing the approach to the initial evluation of mitral regurgitation according to 2014 AHA/ACC guidelines for management of valvular heart disease.<ref name="pmid24589852">{{cite journal| author=Nishimura RA, Otto CM, Bonow RO, Carabello BA, Erwin JP, Guyton RA et al.| title=2014 AHA/ACC Guideline for the Management of Patients With Valvular Heart Disease: Executive Summary: A Report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines. | journal=Circulation | year= 2014 | volume=  | issue=  | pages=  | pmid=24589852 | doi=10.1161/CIR.0000000000000029 | pmc= | url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=24589852  }} </ref>.<br>
<span style="font-size:85%">'''AF''': Atrial fibrillation; '''PMBC''': Percutaneous mitral ballon commissurotomy; '''TR''': Tricuspid regurgitation; '''S1''': First heart sound; '''P2''': Pulmonary component of second heart sound; '''EKG''': Electrocardiogram; '''TTE''': Transthoracic echocardiography; '''MS''': Mitral stenosis </span> <br>
{{familytree/start |summary=PE diagnosis Algorithm.}}
{{familytree | | A01 |A01=<div style="float: left; text-align: left; width: 26em; padding:1em;"> '''Characterize the symptoms:'''<br>
❑ [[Shortness of breath]]<br>
❑ [[Orthopnea]]<br>
❑ [[Paroxysmal nocturnal dyspnea]]<br>
❑ [[Exercise intolerance]]<br>
❑ [[Fatigue]]<br>
❑ [[Light-headedness]]<br>
❑ [[Cough]]<br>
❑ [[Palpitations]]<br>
</div>}}
{{familytree | | |!| | | | | | | | | | | | | | | | | | | | | | | | | }}
{{familytree | | B01 | | | | | | | | | | | | | | | | | | | | | | | |B01=<div style="float: left; text-align: left; width: 30em; padding:1em;">'''Examine the patient:'''<br>
'''[[Pulse]]'''<br>
: ❑ [[Tachycardia]]<br>
: ❑ Reduced [[pulse pressure]]<br>
: ❑ [[Irregularly irregular pulse|Irregularly irregular]] (with onset of [[AF]])<br>
: ❑ Reduced in volume<br>
'''Head''':<br>
❑ Mitral facies<br>
: ❑ Plethoric cheeks with bluish patches<br>
'''Neck''':<br>
❑ [[Jugular venous distension]]<br>
: ❑ Prominent [[a wave]] in [[right heart failure]]<br>
: ❑ Absent [[a wave]] in [[AF]]<br>
: ❑ Prominent [[v wave]] in [[TR]]<br>
'''Chest''':<br>
❑ Left parasternal [[heave]]<br>
❑ Loud [[S1]]<br>
❑ Loud [[P2]] (indicates [[pulmonary hypertension]])<br>
❑ Opening snap<br>
❑ [[Murmur]]<br>
: ❑ [[Mid diastolic murmur]] (low pitched, rumbling)<br>
: ❑ [[Holosystolic murmur]] indicates [[TR]]<br>
: ❑ [[Graham-Steell murmur]] indicates [[pulmonary regurgitation]]<br>
❑ [[Rales]]</div>}}
{{familytree | | |!| | | | | | | | | | | | | | | | | | | | | | | | | }}
{{familytree | | C01 | | | | | | | | | | | | | | | | | | | | | | | |C01=<div style="float: left; text-align: left; width: 30em; padding:1em;">❑ Perform [[EKG]]<br>❑ Perform [[chest X-ray]]<br>❑ Perform [[transthoracic echocardiography]]</div>}}
{{familytree | | |!| | | | | | | | | | | | | | | | | | | | | | | | | }}
{{familytree | | E01 | | | | | | | | | | | | | | | | | | | | | | | |E01=<div style="float: left; text-align: left; width: 30em; padding:1em;">'''Assess the following on [[TTE]]:'''<br>
❑ Valve area<br>
❑ Disease of other valves <br>
❑ Mean pressure gradient<br>
❑ Pulmonary artery pressure<br>
❑ Suitability of valve morphology for [[PMBV|PMBC]]<br> </div>}}
{{familytree | | |!| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | }}
{{familytree | | F01 | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |F01=<div style="float: left; text-align: left; width: 26em; padding:1em;"> '''Medical therapy'''<br>
❑ Consider [[Atrial fibrillation resident survival guide#Heart rate control|heart rate control]] in [[MS]] patients with:<br>
: ❑ Normal [[sinus rhythm]] and symptoms present on exercise<br>
: ❑ [[AF]] and fast ventricular response<br>
❑ Consider [[anticoagulation therapy]] in [[MS]] patients with:<br>
: ❑ [[AF]]<br>
: ❑ Prior embolic event<br>
: ❑ [[Left atrial thrombus]]  </div> }}
{{familytree | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | }}
{{familytree/end}}
==Diagnosis==
==Diagnosis==
===Symptoms===
===Symptoms===
* [[Acute miral regurgitation]] causes the following symptoms:
* [[Acute mitral regurgitation]] causes the following symptoms:
** [[Dyspnea]]
** [[Dyspnea]]
** [[Orthopnea]]
** [[Orthopnea]]

Revision as of 16:11, 12 March 2014

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: Raviteja Guddeti, M.B.B.S. [2]

Overview

Mitral regurgitation refers to the disruption of mitral valve apparatus causing inability of the valve to close properly during systole. This leads to leakage of blood flow from left ventricle to left atrium during systole and reduction in cardiac output.

Causes

Life Threatening Causes

Life-threatening causes include conditions which may result in death or permanent disability within 24 hours if left untreated.

Common Causes

Diagnosis

Shown below is an algorithm summarizing the approach to the initial evluation of mitral regurgitation according to 2014 AHA/ACC guidelines for management of valvular heart disease.[2].
AF: Atrial fibrillation; PMBC: Percutaneous mitral ballon commissurotomy; TR: Tricuspid regurgitation; S1: First heart sound; P2: Pulmonary component of second heart sound; EKG: Electrocardiogram; TTE: Transthoracic echocardiography; MS: Mitral stenosis

 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Examine the patient:

Pulse

Tachycardia
❑ Reduced pulse pressure
Irregularly irregular (with onset of AF)
❑ Reduced in volume

Head:
❑ Mitral facies

❑ Plethoric cheeks with bluish patches

Neck:
Jugular venous distension

❑ Prominent a wave in right heart failure
❑ Absent a wave in AF
❑ Prominent v wave in TR

Chest:
❑ Left parasternal heave
❑ Loud S1
❑ Loud P2 (indicates pulmonary hypertension)
❑ Opening snap
Murmur

Mid diastolic murmur (low pitched, rumbling)
Holosystolic murmur indicates TR
Graham-Steell murmur indicates pulmonary regurgitation
Rales
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
❑ Perform EKG
❑ Perform chest X-ray
❑ Perform transthoracic echocardiography
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Assess the following on TTE:

❑ Valve area
❑ Disease of other valves
❑ Mean pressure gradient
❑ Pulmonary artery pressure

❑ Suitability of valve morphology for PMBC
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Medical therapy

❑ Consider heart rate control in MS patients with:

❑ Normal sinus rhythm and symptoms present on exercise
AF and fast ventricular response

❑ Consider anticoagulation therapy in MS patients with:

AF
❑ Prior embolic event
Left atrial thrombus
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 

Diagnosis

Symptoms

  • Chronic mitral regurgitation may have a prolonged asymptomatic interval phase until the heart decompensates and the symptoms of low cardiac output and pulmonary congestion start. By the time the symptoms develop, left ventricular dysfunction may have already occurred.

Physical Examination

  • S3 and S4 may be heard on auscultation.
  • A holosystolic murmur is heard in the apical region of the heart. MR murmur radiates to the axillary region. It may be soft, short and even absent. 70% of the cases of papillary muscle rupture have no murmur.
Holosystolic murmur of acute mitral regurgitation.
Holosystolic murmur of chronic mitral regurgitation.

Imaging

Transthoracic echocardiography

Echocardiographic findings indicating the presence of severe mitral regurgitation include:

  • Regurgitant volume >60 ml
  • Regurgitant fraction >55%
  • Effective regurgitant orifice (ERO) (ratio of regurgitant flow volume to the velocity of the mitral insufficiency jet: ERO = Flow / Velocity) >0.4 cm2
  • If the left ventricular and left atrial sizes are normal on echocardiography, mitral regurgitation is not severe.
  • Central jets indicate the presence of a fairly normal mitral valve and therefore the mitral regurgitation is not severe.
  • Wide eccentric jets indicate that the regurgitation is severe.
  • Echocardiographic findings must match the symptoms, if they do not, perform transesophageal echocardiography (TEE) or cardiac catheterization. TTE can underestimate the magnitude of mitral regurgitation in patients with clinical signs of severe MR.

Treatment

Acute Severe Mitral Regurgitation

  • If the patient is clinically unstable , the treatment options are:
    • IV nitroprusside is used to maintain blood pressure. Ionotropes are added when needed.
    • If medical therapy is not effective, an intra aortic balloon pump can be inserted to maintain hemodynamic stability.
    • Surgical treatment is usually indicated.
    • Knowledge of the etiology of the mitral regurgitation is important to know if the valve can be repaired or replaced.

Chronic Mitral Regurgitation

Why the Mitral valve is replaced Before Symptoms in Patients with Chronic Mitral Regurgitation

  • Mitral regurgitation is a syndrome of pure volume overload whereas aortic regurgitation is a combination of both volume and pressure overload.
  • Both syndromes are associated with an increase in preload.
  • in mitral regurgitation, the afterload is reduced whereas in aortic regurgitation the afterload is increased. This is very important because when the mitral valve is repaired, there is no longer a reduction afterload and the left ventricle may fail due to an abrupt rise in the afterload. In aortic regurgitation, because the afterload is already increased chronically, replacement of the valve is not as likely to precipitate acute left ventricular failure due to an abrupt rise in afterload.
  • By the time symptoms develop, there is already left ventricular dysfunction.
  • Because of the low pressure system into which the blood is ejected into through the mitral valve, the ejection fraction is always high in mitral regurgitation. If the ejection fraction appears to be "normal", there is already decline in left ventricular function.
  • There is no indication for vasodilator therapy in the absence of systemic hypertension in asymptomatic patients with preserved left ventricular function.

Indications for Surgery in Chronic Mitral Regurgitation

The indications for surgery in chronic mitral regurgitation are:

  • Any symptoms - this is unlike mitral stenosis where surgeons operate on the heart when patients have class III or IV symptoms.
  • Severe organic MR.
  • Left ventricular dysfunction - ejection fraction <60% and end systolic diameter >40 mm2.
  • Surgery can be considered in asymptomatic patients in the following cases:
    • Truly severe MR
    • Low operative mortality
    • High chance of successful repair (e.g: posterior leaflet - MVP)
  • Pre-operative ejection fraction has a prognostic impact in patients who undergo mitral valve repair or replacement. The lower the ejection fraction is, the higher the mortality is.

References

  1. Otto CM (2001). "Clinical practice. Evaluation and management of chronic mitral regurgitation". N Engl J Med. 345 (10): 740–6. doi:10.1056/NEJMcp003331. PMID 11547744.
  2. Nishimura RA, Otto CM, Bonow RO, Carabello BA, Erwin JP, Guyton RA; et al. (2014). "2014 AHA/ACC Guideline for the Management of Patients With Valvular Heart Disease: Executive Summary: A Report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines". Circulation. doi:10.1161/CIR.0000000000000029. PMID 24589852.


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