Pocket Medicine: The Massachusetts General Hospital Handbook of Internal Medicine (14 page)

•
Early diastolic decrescendo murmur at LUSB
(RUSB if dilated Ao root); ↑ w/ sitting forward, expir, handgrip; severity of AI ∝ duration of murmur (except in

acute and severe late);
Austin Flint murmur
: mid-to-late diastolic

rumble at apex (AI jet interfering w/ mitral inflow)

•
Wide pulse pressure
due to ↑ stroke volume, hyper-dynamic pulse → many of classic signs (see table); pulse pressure narrows in late AI with ↓ LV fxn; bisferiens (twice-beating) arterial pulse • PMI diffuse and laterally displaced; soft S
₁
(early closure of MV); ± S
₃
(≠ ↓ EF but rather just volume overload in AI)

Diagnostic studies

• ECG: can see LVH, LAD, abnl repol; CXR: cardiomegaly ± ascending Ao dilatation •
Echo
: severity of AI (severe = width of regurgitant jet >65% LVOT, vena contracta >0.6 cm, regurg fraction ≥50%, regurg orifice ≥0.3 cm
²
, flow reversal in descending Ao); LV size & fxn
Treatment (
Circ
2008;118:e523;
EHJ
2012;33:2451)

• Acute decompensation (consider ischemia and endocarditis as possible precipitants):

surgery
usually urgently needed for acute severe AI which is poorly tolerated by LV

IV afterload reduction (nitroprusside) and inotropic support (dobutamine)

± chronotropic support (↑ HR → ↓ diastole → ↓ time for regurgitation)

pure vasoconstrictors and IABP contraindicated

• In chronic AI, management decisions based on
LV size and fxn
(and before sx occur) •
Surgery (AVR
, replacement or repair if possible)

sx
(if equivocal, consider stress test)
severe AI
(if
not
severe, unlikely to be cause of sx)

asx severe AI
and
EF
≤ 
50%
or
LV dilation
(end syst. diam. >50–55 mm or end diast. diam. >70–75 mm, esp. if progression) or undergoing cardiac surgery

• Transcatheter AoV replacement (TAVR) being explored ( 
JACC
2013;61:1577) • Medical therapy:
vasodilators
(nifedipine, ACEI/ARB, hydralazine) if severe AI w/ sx or LV dysfxn & Pt not operative candidate or to improve hemodynamics before AVR; no clear benefit on clinical outcomes or LV fxn when used to try to prolong compensation in asx severe AI w/ mild LV dilation & nl LV fxn (
NEJM
2005;353:1342)

MITRAL REGURGITATION (MR)

Etiology (
Lancet
2009;373:1382;
NEJM
2010;363:156)

•
Leaflet abnormalities
:
myxomatous degeneration (MVP)
, endocarditis, calcific

RHD, valvulitis (collagen-vascular disease), congenital, anorectic drugs, XRT

•
Functional
: inferoapical
papillary muscle displacement due to ischemic LV remodeling
or other causes of DCMP; LV
annular dilation
due to LV dilation • Ruptured chordae tendinae: myxomatous, endocarditis, spontaneous, trauma • Acute papillary muscle
dysfxn
b/c of ischemia or
rupture
during MI [usu. posteromedial papillary m. (supplied by PDA only) vs. anterolateral (suppl. by diags & OMs)]

• HCMP: (see “Cardiomyopathy”)
Clinical manifestations

• Acute:
pulmonary edema
, hypotension, cardiogenic shock (
NEJM
2004;351:1627) • Chronic: typically asx for yrs, then as LV fails → progressive DOE, fatigue, AF, PHT

• Prognosis: 5-y survival w/ medical therapy is 80% if asx, but only 45% if sx
Physical exam

•
High-pitched
,
blowing
,
holosystolic murmur at apex
; radiates to axilla; ± thrill; ↑ w/ handgrip (Se 68%, Sp 92%),

↓ w/ Valsalva (Se 93%) (
NEJM
1988;318:1572)

ant. leaflet abnl → post. jet heard at spine

post. leaflet abnl → ant. jet heard at sternum

• ± diastolic rumble b/c ↑ flow across valve • Lat. displ. hyperdynamic PMI, obscured S
₁
, widely split S
₂
(A
₂
early b/c ↓ LV afterload, P
₂
late if PHT); ± S
₃

• Carotid upstroke brisk (vs. diminished and delayed in AS)

Diagnostic studies (
NEJM
2005;352:875)

• ECG: may see LAE, LVH, ± atrial fibrillation • CXR: dilated LA, dilated LV, ± pulmonary congestion •
Echo
: MV anatomy (ie, etiol); MR severity: jet area (can underestimate eccentric jets), jet width at origin (vena contracta) or effective regurgitant orifice (ERO; predicts survival); LV fxn (EF should be
supranormal
if compensated, ∴ EF <60% w/ sev. MR = LV dysfxn); TEE if TTE inconclusive or pre/intraop to guide repair vs. replace •
Cardiac cath
: prominent PCWP
c-v
waves (not spec. for MR), LVgram for MR severity & EF

Treatment (
Circ
2008;118:e523;
NEJM
2009;361:2261;
EHJ
2012;33:2451)

• Acute decompensation (consider ischemia and endocarditis as precipitants)

IV afterload reduction (nitroprusside), ± inotropes (dobuta), IABP, avoid vasoconstrictors

surgery
usually needed for acute severe MR as prognosis is poor w/o MVR

•
Surgery
(repair [preferred if feasible] vs. replacement w/ preservation of mitral apparatus)

sx severe MR
,
asx severe MR
and
EF 30–60%
or
LV sys. diam.
>
40 mm

consider MV
repair
for asx severe MR w/ preserved EF, esp. if new AF or PHT

if AF, maze procedure or pulm vein isolation may → NSR and prevent future stroke

• In Pts undergoing CABG w/ mod–sev fxnal MR, consider annuloplasty ring • Percutaneous MV repair: edge-to-edge clip less effective than surgery, but ? consider for elderly, fxnal MR or low EF (
NEJM
2011;364:1395); percutaneous valve under study • Medical:  clinical benefit in asx Pts; bB preserve LV fxn ( 
JACC
2012;60:833); if sx but not operative candidate ↓
preload
(↓ HF and MR by ↓ MV orifice): diuretics, nitrates (esp. if ischemic/fxnal MR); if LV dysfxn: ACEI, bB, ± BiV pacing; maintain SR

MITRAL STENOSIS (MS)

Etiology (
Lancet
2012;379:953)

•
Rheumatic heart disease
(RHD):
fusion of commissures
→ “fish mouth” valve

from autoimmune rxn to b strep infxn; seen largely in developing world today

•
Mitral annular calcification
(MAC): encroachment upon leaflets → functional MS

• Congenital, infectious endocarditis w/ large lesion, myxoma near MV, thrombus • Valvulitis (eg, SLE, amyloid, carcinoid) or infiltration (eg, mucopolysaccharidoses)
Clinical manifestations (
Lancet
2009;374:1271)

•
Dyspnea and pulmonary edema
(if due to RHD, sx usually begin in 30s)

precipitants: exercise, fever, anemia, volume overload (incl. pregnancy), tachycardia, AF

•
Atrial fibrillation
: onset often precipitates heart failure in Pts w/ MS

•
Embolic events
: commonly cerebral, esp. in AF or endocarditis • Pulmonary: hemoptysis, frequent bronchitis (due to congestion), PHT, RV failure • Ortner’s syndrome: hoarseness from LA compression of recurrent laryngeal nerve
Physical exam

•
Low-pitched mid-diastolic rumble at apex
w/ presystolic accentuation (if not in AF); best heard in L lat decubitus position during expi-ration, ↑ w/ exercise; severity proportional to
duration
(not intensity) of murmur •
Opening snap
(high-pitched early diastolic sound at apex) from fused leaflet tips;