Right-sidedheartfailurecanalsoleadtoelevatedpressureintheportalveinanditstributaries(portal hypertension), withvascularcongestionproducingatense,enlargedspleen(congestive splenomegaly). Ifsevere,chronicpassivecongestionandattendantedemaofthebowelwallmayinterferewithabsorptionofnutrientsandmedications.
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Pleural, Pericardial, and Peritoneal Spaces. Systemicvenouscongestionduetoright-sidedheartfailurecanleadtotransudates (effusions) inthepleuralandpericardialspaces,butusuallydoesnotcausepulmonaryparenchymaledema.Pleuraleffusionsaremostpronouncedwhenthereiscombinedright-sidedandleft-sidedheartfailureleadingtoelevatedpulmonaryandsystemicvenouspressures.Acombinationofhepaticcongestion(withorwithoutdiminishedalbuminsynthesis)andportalhypertensioncanleadtoperitonealtransudates(ascites). Ifuncomplicated,effusionsassociatedwithright-sidedCHFaretrasudateswithalowproteincontentandlackofinflammatorycells.
Subcutaneous Tissues. Edemaofdependentportionsofthebody,especiallythefeetandlowerlegs,isahallmarkofright-sidedCHF.Inchronicallybedriddenpatients,theedemamaybeprimarilypresacral.
Unlike left-sided heart failure, pure right-sided heart failure typically is not associated with respiratory symptoms. Instead, the clinical manifestations are related to systemic and portal venous congestion and include hepatic and splenic enlargement, peripheral edema, pleural effusion, and ascites. Venous congestion and hypoxia of the kidneys and brain due to right-sided heart failure can produce deficits comparable to those caused by the hypo-perfusion of left-sided heart failure.
Of note, cardiac decompensation is often marked by the appearance of biventricular CHF, encompassing features of both right-sided and left-sided heart failure. As CHF progresses, patients may become frankly cyanotic and acidotic, as a consequence of decreased tissue perfusion resulting from both diminished cardiac output and increasing congestion.
CHFoccurswhentheheartisunabletoprovideadequateperfusiontomeetthemetabolicdemandsofperipheraltissues;inadequatecardiacoutputusuallyisaccompaniedbycongestionofthevenouscirculation.
Left-sidedheartfailureismostcommonlysecondarytoischemicheartdisease,systemichypertension,mitraloraorticvalvedisease,orprimarydiseasesofthemyocardium;symptomsaremainlyaconsequenceofpulmonarycongestionandedema,althoughsystemichypoperfusioncancauserenalandcerebraldysfunction.
Right-sidedheartfailureisduemostoftentoleft-sidedheartfailureand,lesscommonly,toprimarypulmonarydisorders;signsandsymptomsarerelatedchieflytoperipheraledemaandvisceralcongestion.
Congenital heart diseases are abnormalities of the heart or great vessels that are present at birth. They account for 20% to 30% of all birth defects and include a broad
Table 11.1
Frequency of Congenital Cardiac Malformations* *Summaryof44publishedstudies.Percentagesdonotaddto100%becauseofrounding.DatafromHoffmanJI,KaplanS:Theincidenceofcongenitalheartdisease,J Am Coll Cardiol 39:1890,2002.