Ch284 Mitral Valve Disease Flashcards
Leading cause of mitral stenosis
Rheumatic fever
Etiologies to obstruction of left ventricular inflow
- Congenital mitral valve stenosis
- Cor triatriatum
- Mitral annular calcification with extension into the leaflets
- Systemic lupus erythematosus
- Rheumatoid arthritis
- Left atrial myxoma
- Infective endocarditis with large vegetations
Chamber of the heart where thrombi arise more frequently in patients with atrial fibrillation
Dilated left atrium (within the LA appendage)
Normal area of mitral valve orifice
4-6cm2
Hemodynamic hallmark of MS
Abnormally elevated left atrioventricular pressure gradient drive the blood flow from LA to the LV
Area of mitral valve orifice in “severe” MS
<1.5cm2
T or F: Increase in heart rate shortens systole proportionately more than diastole
False
Shortens diastole proportionately more than systole and diminishes time available for flow across the mitral valve
Cardiac output in severe MS vs very severe MS
severe MS (CO): normal, rises subnormally during exertion
very severe MS (CO): subnormal at rest and fail to rise or may even decline during activity
Results from rupture of pulmonary-bronchial venous connections secondary to pulmonary venous hypertension
Hemoptysis
T or F: Hemoptysis is rarely fatal.
True
Auscultatory findings in MS
- Accentuated S1 in early stages of dse and slightly delayed
- P2 often accentuated with elevated PA pressures
- Opening snap (OS)
- low pitched, rumbling, Diastolic murmur / systolic murmur (grade I or II/VI in pure MS)
- Presystolic accentuation of murmur in patients with sinus rhythm
T or F: Opening snap is most readily audible in expiration.
True
Which is the correct order: A. S1-S2-OS-diastolic murmur B. S1-OS-S2-diastolic murmur C. S1-S2-diastolic murmur-OS D. OS-S1-S2-diastolic murmur
A. S1-S2-OS-diastolic murmur
OS generally follows the sound of aortic valve closure (A2) by 0.05-0.12s.
T or F: In MS with severe pulmonary hypertension, a pancystolic murmur can be audible along the left sternal border.
True
Sign wherein a murmur is usually louder during inspiration and diminishes during forced expiration
Carvallo’s sign
When does a diastolic rumbling murmur not detectable in MS? (Silent MS)
When cardiac output is markedly reduced
May reappear as compensation is restored
High-pitched, diastolic, decresendo blowing murmur along the left sternal border and occurs in patients with mitral valve disease and severe pulmonary hypertension
Graham Steell murmur of pulmonic regurgitation
Due to dilation of pulmonary valve ring
ECG findings in MS
- tall and peaked P wave in lead II and upright in lead V1 in severe pulmo HPN
- QRS complex usually normal
- Right axis deviation and RV hypertrophy with severe pulmo HPN
Role of transthoracic echocardiography (TTE) in MS
- Measurements of mitral inflow velocity during early (E wave) and late (A wave) diastolic filling
- Estimates the transvalvular peak and mean gradients and mitral orifice area
- Presence and severity of any associated MR
- Extent of leaflet calcification and restriction
- Degree of distortion of subvalvular apparatus
- Anatomic suitability for percutaneous mitral balloon valvotomy (PMBV)
- Assessment of LV and RV function, chamber sizes, PAP based on tricuspid regurgitant jet velocity
- Indication of presence and severity of any associated valvular lesions (AS and or AR)
Role of transesophageal echocardiography (TEE) in MS
- Indicated to exclude the presence of LA thrombus prior to PMBV
- Used when TTE is inadequate for guiding management decisions
CXR findings in MS
- Straightening of upper left border of cardiac silhouette as earliest changes
- Prominence of main pulmonary artery
- Dilation of upper lobe pulmonary veins
- Posterior displacement of esophagus by an enlarged LA
- Kerley B lines
Fine, dense, opaque, horizontal lines most prominent in lower and mid lung fields resulting from distention of interlobular septae and lymphatics with edema when resting mean LA pressure exceeds approx 20mmHg.
Kerley B line
Differential diagnosis: MS vs ASD
ASD = Absence of LA enlargement and Kerley B lines + demonstration of fixed splitting of S2 with Grade II or III mid-systolic murmur over mid to upper left sternal border
Differential diagnosis: MS vs left atrial myxoma
Common: dyspnea, diastolic murmur, hemodynamic changes
LA myxoma = with features suggestive of systemic disease (wt loss, fever, anemia, systemic emboli, elevated serum IgG and IL-6)
Diagnosis: established by demonstration of echo-producing mass in LA with TTE
Role of Cardiac Catheterization in MS
- Useful when there is discrepancy between clinical and noninvasive findings
- Assess associated lesions (AS, AR)
- Not necessary decision-making about surgery in patients younger than 65 years
- Coronary angiography advised preop to identify those that should be bypassed at time of operation in these patients: Men>40y/o, women >45y/o, younger pt with coronary risk factors + positive noninvasive stress tests for myocardial ischemia
- Computed tomographic coronary angiography (CTCA) used to screen preop for presence of CAD in pt with VHD and low pretest likelihood of CAD
Treatment for secondary prevention of rheumatic fever in rheumatic MS
Penicillin prophylaxis of group A B-hemolytic strep infections
Drugs used in MS
- Restriction of sodium intake
- Oral diuretics in small doses
- Beta blockers, nondihydropyridine calcium ch blockers [verapamil, diltiazem], digitalis glycosides (slow ventricular rate in pt with AF)
- Warfarin therapy to those with AF or history of thromboembolism (INR 2-3)
Indication for electrical countershock OR reversion to sinus rhythm pharmacologically in MS
If AF is of relatively recent onset in pt whose MS is not severe enough to warrant PMBV or surgical commissurotomy
Indication for mitral valvotomy in MS
Symptomatic patients (NYHA FC II-IV) with isolated severe MS, valve area <1cm2/m2 bsa or <1.5cm2 in normal sized adults
2 techniques: PMBV and surgical valvotomy
Successful valvotomy definition
50% reduction in mean mitral valve gradient and doubling of mitral valve area
T or F: Valvotomy is NOT recommended for patients who are entirely asymptomatic and/or who have mild or moderate stenosis (mitral valve area >1.5cm2)
True
When should valvotomy be carried out in pregnant patients?
If pulmonary congestion occurs despite intensive medical treatment
PMBV is preferred strategy and performed with TEE and no or minimal xray exposure
When is mitral valve replacement (MVR) necessary in MS?
Necessary in patients with MS and significant associated MR, those in whom the valve has been severely distorted by previous transcatheter or operative manipulation, or those in whom surgeon does not find it possible to improve valve function significantly with valvotomy
Result from abnormality or disease process that affects any one or more ot the five functional components of the mitral valve apparatus (leaflets, annulus, chordae tendinae, papillary muscles, subjacent myocardium)
Mitral regurgitation (MR)
Causes of ACUTE MR
- Acute MI with papillary ms rupture (posteromedial > anteromedial)
- blunt chest wall trauma
- during course of infective endocarditis
Causes of CHRONIC MR
- Rheumatic disease
- MVP
- extensive mitral annular calcification
- congenital valve defects
- hypertrophic obstructive cardiomyopathy (H0CM)
- dilated cardiomyopathy
- Ischemic cardiomyopathy
- healed MI
Primary (degenerative, organic) MR VS Functional (secondary) MR
PRIMARY: leaflets and/or chordae tendinae are primarily responsible for abnormal valve function
FUNCTIONAL: leaflets and chordae tendinae are structurally normal but regurgitation is caused by annular enlargement, papillary muscle displacement, leaflet tethering, or combination
Prevalence of annular calcification is high among these patients
- Advanced renal disease
2. Women >65 years with HPN and DM
Severe nonischemic MR definition
- Regurgitant volume >/=60ml/beat
- Regurgitant fraction (RF) >/=50%
- effective regurgitant orifice area >/=0.40cm2
Most prominent complaints in patients with chronic severe MR
- fatigue
- exertional dyspnea
- orthopnea
T or F: Acute pulmonary edema is common in patients with acute severe MR
True
PE findings in MR
Chronic Severe MR
- usually normal arterial pressure
- carotid arterial pulse may show a sharp, low-volume upstroke
- systolic thrill palpable at cardiac apex
- hyperdynamic LV with a brisk systolic impulse
- palpable rapid-filling wave (S3)
- apex beat often displaced laterally
Acute Severe MR
- reduced arterial pressure
- narrow pulse pressure
- jugular venous pressure and wave forms are normal or increased and exaggerated
- apical impulse not displaced
- signs of pulmonary congestion are prominent
Auscultatory findings in MR
- holosystolic murmur (chronic severe MR)
- S1 generally absent, soft, or buried in murmur
- wide, physiologic splitting of S2
- low-pitched S3 occurring 0.12-0.17s after aortic valve closure sound
- short, rumbling, mid-diastolic murmur
- fourth heart sound audible in acute severe MR in sinus rhythm
- systolic murmur (grade III/VI) is most characteristic auscultatory finding in chronic severe MR
- systolic murmur prominent at apex and radiates to axilla
- systolic murmur of MR not due to MVP is intensified by isometric exercise (handgrip) but reduced during strain phase of valsalva
When is TTE indicated in MR
- Assess mechanism of MR and its hemodynamic severity
2. Follow the course of patients with chronic MR and provide rapid assessment for any clinical change
T or F: TTE provides greater anatomic detail than TEE
False
TEE>TTE
T or F: Patients with chronic severe MR may have asymmetric pulmonary edema
False
Actue severe MR if regurgitant jet is directed predominantly to orifice of an upper lobe pulmonary vein
Medical treatment for MR
- Warfarin once AF intervenes (INR: 2-3)
- Novel oral anticoagulants not approved for this indication
- Cardioversion should be considered depending on clinical context and LA size
- Treatment for heart failure (Beta blockers, ACE inhibitors, digitalis, biventricular pacing)
Indications for surgery for chronic nonischemic severe MR
- Once symptoms occur and valve repair is feasible
- recent-onset AF and pulmo hypertension
- asymptomatic pt when LV dysfunction is progressive and LVEF falling below 60% and/or end systolic dimension increasing beyond 40mm
Prognosis of surgery for chronic nonischemic severe MR
- low perioperative mortality risk in pt <75 y/o with normal LV systolic function and no CAD
- 1% risk of stroke
- Incidence of reoperative surgery for failed primary repair is 1% per year for first 10 years after surgery
Surgery for functional, ischemic MR and prognosis
More complicated and Includes simultaneous coronary artery revascularization
Prognosis:
- low perioperative mortality rate
- Higher rate of recurrent MR over time
- with EF <30%: risk of surgery higher, recovery of LV performance incomplete, long term survival reduced
Also termed systolic click-murmur syndrome, Barlow’s syndrome, floppy-valve syndrome, billowing mitral leaflet syndrome
Mitral valve prolapse (MVP)
MVP is a frequent finding in patients with heritable disorders of connective tissue. These conditions are:
- Marfan’s syndrome
- Osteogenesis imperfecta
- Ehlers-Danlos syndrome
T or F: MVP is more common among men ages 15-30 years
False
More common in women ages 15-30.
Auscultatory findings in MVP
- mid or late systolic click 0.14s or more after S1
- Multiple systolic clicks
- high-pitched, mid-late systolic crescendo-decrescendo murmur, “whooping” or “honking” heard best at apex
- Manuevers: standing, strain phase of valsalva maneuver to exaggerate propensity of mitral leaflet prolapse
- Avoid: squatting and isometric exercises
ECG findings in MVP
- normal
- biphasic or inverted T waves in leads II, III, AVF
- occ supraventricular or ventricular premature beats
Use of TTE in MVP
Identify abnormal position and prolapse of mitral valve leaflets
MVP on 2d echo
Systolic displacement (parasternal long axis view) of mitral valve leaflets by atleast 2mm in the LA superior to the plane of mitral annulus
Indication of TEE
- More accurate info is required and is performed routinely for intraoperative guidance for valve repair
Is infective endocarditis prophylaxis indicated for all MVP?
No, only for patients with prior history of endocarditis
Drugs used in MVP
- Beta blockers
- ASA to pt with TIA, and if not effective, use warfarin
- Warfarin indicated ONCE AF intervenes
