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General Reference

Jama 2005;294:1944; Nejm 2003;348:2007

Pathophys and Cause

Cause:ASHD, dilated (systolic dysfunction), or hypertensive (diastolic dysfunction) cardiomyopathy; occasionally valve disease; and more rarely, high-output types, eg, AV malformations, Paget's disease, hyperthyroidism, beriberi, severe anemia as with pernicious anemia; tocolytic rx of premature labor (Ann IM 1989;110:714), NSAIDs in elderly

Pathophys: (Jama 2006;296:2209, 2217, 2259)

Most CHF is due to systolic dysfunction, but 30+% is due to diastolic dysfunction (Nejm 2440;350:1953) and >50% in elderly (Congestive Heart Failure in the Elderly), eg, chronic systemic hypertension, mitral stenosis, constrictive pericarditis, IHSS, conditions that prevent normal diastolic filling. Hypertrophy in response to load creates dysfunctional myocardial cells (Ann IM 1994;121:363). ACE inhibitors, -blockers, and calcium channel blockers may help relax hypertrophic myocardium as well as decrease afterload (Ann IM 1992;117:502; Nejm 1991;325:1557). Compensatory production of natriuretic peptide, atrial and ventricular B type, which promote diuresis (Nejm 2004;350:718; 1998;339:321).

Cardiac "asthma" is due to bronchial edema and hyperresponsiveness (Nejm 1989;320:1317)

Epidemiology

In US, incidence is 400 000/yr

Incr with hypertension, in 40% of men and 60% of women (Jama 1996;275:1557), systolic BP >160 just as significant as a diastolic >95; obesity (Nejm 2002;347:305); homocysteine levels (Jama 2003;289:1251)

Decr incidence by 1/2 in regular alcohol users, even heavy users ([Framingham] Ann IM 2002;136:181)

Signs and Symptoms

Sx:

Dyspnea on exertion, orthopnea, paroxysmal nocturnal dyspnea, ankle edema, bowel bloating and sense of fullness pc, nocturia

NY Heart Association Classification:

Si:

JVD, S3 gallop (techniques—Nejm 2001;345:612) in systolic dysfn; both correlate w worse prognosis (Nejm 2001;345:574); S4 in diastolic dysfn

Pulse >100 (pulse > dias BP = 53% sens, 80% specif—Bmj 2000;320:220); displaced point of maximal impulse, dullness in L 5th intercostal space gteq.gif10.5 cm from sternum (Am J Med 1991;91:328); pleural effusions R > L (Nejm 1983;308:696).

Central apnea in 45%, especially Cheyne-Stokes respirations from increased sens to pCO2 (Nejm 1999;341:949, 985), rx w theophylline 250 mg po bid (Nejm 1996;335:562)

Course

Diastolic and systolic dysfunction CHF types have same poor prognosis: 16% 6-mo, 25% 1-yr, and 65% 5-yr mortality (Nejm 2006;355:251, 260, 308; Jama 2006;296:2209, 2259). Prognosis worse w lower (<120 mm Hg) admission systolic BP (Jama 2006;296:2217)

Complications

Sleep apnea (Ann IM 1995;122:487)

Lab and Xray

Lab:

Chem:Hyponatremia due to inappropriate ADH (Nejm 1981;305:263)

Ventricular type B natiuretic peptide >100 pgm/cc 90% sens 75% specif by rapid fluorescent immunoassay, so run stat can r/o CHF in acute SOB or if >500 pgm/cc (vs >1500 for proBNP) can rule in to allow rapid aggressive rx (Nejm 2004;350:647; 2002;347:161; ACP J Club 2002;136:68). More false positives in elderly w pBNP (33%) than BNP alone (14%) (Jags 2005;53:643), and in pts w Afib (J am coll cardiol 2006;46:838)

Cystatin C levels >10 mg % linearly predict CHF, better than creatinine, muscle mass independent (Ann IM 2005;142:497)

Hem:ESR low when acute and severe, correlates with fibrinogen levels (Nejm 1991;324:353)

Inv monitoring:Swan-Ganz monitoring now discouraged because of incr morb and mort (Jama 2001;286:309), use only when cardiac output and/or wedge data will change rx; in and out as quickly as possible (Ann IM 1985;103:445) since cmplc are pulmonary infarction, pulmonary artery rupture, knotting, endocardial thrombosis (50%), subsequent endocarditis (8%) (Nejm 1984;311:1152)

Urine:Proteinuria, why? (Nejm 1982;306:1031)

Echocardiogram: EF <50% in systolic dysfunction, >50% in diastolic dysfunction often seen in elderly

Xray:Chest shows redistribution of blood to apices on upright, perihilar "haze," Kerley B lines, increased heart size, pleural effusions R > L (Nejm 1983;308:696) possibly because thoracic duct provides a "pop-off valve" to L pulmonary vasculature, ie, better lymphatic drainage (J. Sutherland 6/95)

Treatment

Rx:

(Nejm 1996;335:490, Ann IM 1994;121:363)

Acutely:

Chronically: (see medication section Anticoagulants for dosing) (Med Let 1999;41:12; Nejm 1998;339:1848). Generally use ACE inhibitors and other vasodilators, diuretics, + digitalis (Nejm 1993;329:1)

if IVCD (QRS >0.12-0.15 sec), atrio-biventricular pacing improves sx and function (Jama 2003;289:730; Nejm 2005;352:1539; 2004;350:2140) but many being done w/o prolongation of life

of fatal Vtach: ICD shock-only, in pts w EF <35% improves mortality (NNT-5 = 14) (Jama 2006;295:809; Nejm 2005;352:225, 285)

of Cheyne-Stokes breathing: O2 or CPAP improves survival (Nejm 1999;341:985), which also improves CHF in silent sleep apnea (Nejm 2003;348:1233)

Surgical: heart transplant, 3500/yr in US, 65% 5 yr survival (Jama 1998;280:1692)