Mitral Regurgitation

Mitral Regurgitation • Chronic regurgitation caused by abnormal leaflet anatomy can be due to congenital or rheumatic disease, myxomatous degeneration(MVP), CTD, infective endocarditis and LV hypertrophy. • CTD associated with MR include SLE, rh arthritis, ank spondylitis, and scleroderma. • Valvular involvement in CTD is variable; about 50% of patients with SLE have detectable MR, and approximately 25% have significant regurgitation. • Acute severe MR is caused by infective endocarditis which result in chordae tendineae, acute MI with papillary muscle rupture or retraction usually from RCA, or prosthetic valve dysfunction. Almost always associated with MS. Pathogenesis • Long latent period 30-40 yrs. LA volume overload→ LV volume overload with ↓ foreword LV SV, Eccentric hypertrophy of the LV, Regurgitation fraction > 0.6 associated with severe MR, PAWP→ giant V wave, In acute MR there is sudden ↑ in LAP→ pul edema. History • Patients with chronic MR remain asymptomatic for an extended period. • Later, patients develop symptoms of fatigue and exertional dyspnea, followed by more overt symptoms of CHF, including orthopnea and paroxysmal dyspnea.

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When CHF develops→ rapid deterioration with 5 yrs mortality rate 50% Physical Findings • hyperactive precordium and displacement of the LV apical impulse due to LVenlargement. • The classic murmur of mitral regurgitation is a loud, blowing holosystolic murmur that may obliterate S1 and S2. The murmur is usually loudest at the apex with radiation to the axilla or to the back, Laboratory Findings • ECG: A fib, biphasic P wave, LVH, CXR: LA & LV enlargement. Anesthesia management Preload: maintain or little ↑ Contractility: maintain, avoid myocardial depressant drugs R&R: maintain NSR, avoid bradycardia maintain HR 80-90 Afterload: ↓ SVR, avoid sudden ↑ in SVR → CHF • In a choice of neuroaxial anesthesia the epidural is better than spinal, because it cause less ↓ in SVR by titrating the LA. • Consider antibiotics prophylactic coverage in a Pt with AS. • Monitors: consider TEE, PAC. • Continue antiarrhythmic drugs peri-op

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Post-op avoid any stress by optimizing pain control to avoid resp acidosis, hypercarbia, hypoxia, hypothermia which all may ↑ PVR A fib have less significant effect on MR compare to MS