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The importance of Doppler-echocardiographic parameters of left ventricle for risk stratification and early prognosis in aortic stenosis

dc.contributor.advisorVujisić-Tešić, Bosiljka
dc.contributor.otherRistić, Miljko
dc.contributor.otherPetrović, Milan
dc.contributor.otherCvetković-Matić, Danica
dc.creatorBanović, Marko
dc.date.accessioned2016-01-05T12:05:39Z
dc.date.available2016-01-05T12:05:39Z
dc.date.available2020-07-03T08:53:15Z
dc.date.issued2012-12-27
dc.identifier.urihttp://nardus.mpn.gov.rs/handle/123456789/2364
dc.identifier.urihttp://eteze.bg.ac.rs/application/showtheses?thesesId=333
dc.identifier.urihttps://fedorabg.bg.ac.rs/fedora/get/o:5876/bdef:Content/download
dc.identifier.urihttp://vbs.rs/scripts/cobiss?command=DISPLAY&base=70036&RID=42630415
dc.description.abstractProcena rizika i donošenje odluka su posebno teški u grupi asimptomatskih pacijenata sa umerenom i tesnom aortnom stenozom (AS). Kada izvršiti hiruršku intervenciju kod ovih pacijenata jos uvek je nejasno, iako kasna hirurška intervencija i zamena aortnog zaliska može dovesti do suboptimalnog rezultata operacije. Opasnost od nagle srcane smrti kod asimptomatskih AS pacijenata postoji, kao i rizik od ireverzibilnog oštecenja miokarda zbog visokog naknadnog opterecenja leve komore (LK). Takode, pokazano je da visoko naknadno opterecenje LK uzrokuje i disfunkciju koronarne mikrocirkulacije, to jest smanjenje rezerve koronarnog protoka (CFR) kod asimptomatskih pacijenata sa AS i neopstruktivnim koronarnim angiogramom. Zbog toga, za ocekivati je da bi zamena aortnog zaliska pre pojave simptoma i disfunkcije LK bila od koristi, ali još uvek nema dovoljno uradenih prospektivnih studija koje bi ovu pretpostavku i potvrdile. Najcešce korišceni Doppler-ehokardiografski parametri, poput srednjeg gradijenta pritiska (Psrednje) i maksimalne brzine protoka (Vmax) su neophodni u odredivanju težine AS, ali su manje korisni u predikciji ishoda, pojave simptoma i odredivanju optimalnog vremena za zamenu zaliska kod asimptomatskih pacijenata. Novi ehokardiografski parametri, poput valvulo-arterijalne impedance (Zva), i indeksa gubitka energije (ELI) su predloženi kao alternativa, ali još uvek nema dovoljno longitudinalnih-prospektivnih studija koje bi potvrdile njihovu korisnost. Primena dobutaminskog testa (DSE) u asimptomatskoj AS je obecavajuca, s obzirom na cinjenicu da je vecina Doppler-ehokardiografskih parametara koji se koriste u proceni AS zavisna od kolicine protoka preko aortne valvule. Farmakološki indukovano povecanje protoka moglo bi biti od pomoci u utvrdivanju težine AS, otkrivanju latentnih simptoma, proceni funkcije sistolne funkcije LK kod pacijenata sa ocuvanom ejekcionom frakcijom u miru (EF) i, najvažnije, donošenju optimalnih klinickih odluka. Ciljevi ove doktorske disertacije bili su da se definišu ehokardiografski parametri koji mogu da indentifikuju pacijente sa povecanim rizikom da dobiju neželjeni kardiovaskularni dogadaj u jednogodišnjem vremenskom intervalu, kao i da se utvrdi prediktivni znacaj promene sistolnih i dijastolnih parametara LK tokom DSE testa kod asimptomatskih pacijenata sa umerenom i tesnom AS i ocuvanom vrednosti EF LK u miru...sr
dc.description.abstractRisk stratification and decision making are particularly complex in asymptomatic patients with moderate or severe aortic stenosis (AS). When to intervene in these patients is still matter of controversy, and misinterpreting the findings might lead to an unnecessary delay of aortic valve replacement. The risk of sudden death without preceding symptoms remains a concern, as well as the risk of irreversible myocardial damage due to the high global afterload. These factors may also be responsible for an impairment of coronary flow reserve (CFR) and microvascular coronary dysfunction, which has been observed in patients with AS and without obstructive epicardial coronary artery disease. Therefore, valve replacement prior to the onset of symptoms and LV dysfunction may be recommended; however, data in patients with purely asymptomatic AS are lacking. The most frequently used parameters such as mean pressure gradient (Pmean) and maximal jet velocity (Vmax) are necessary in determining the AS severity, but less useful in predicting the outcome and when to intervene in asymptomatic patients. The dobutamine testing (DT) in asymptomatic AS is promising having in mind that most of the Doppler-echocardiographic indices used for evaluation of AS is flow-dependent. The pharmacologic increase of flow could help to correctly assess disease severity, discover the existence of latent symptoms, assess the LV systolic function and, therefore, to guide clinical decisions. The new hemodynamic measurements of severity such as valve resistance (Zva) and the energy-loss index (ELI) have been proposed, however, a common limitation of most of these new indices, as well of the usefulness of DT, is that longitudinal follow-up data from prospective studies are lacking. The aim of this study was to assess which echocardiographic parameter(s) can identify subset of asymptomatic AS patients who are at high risk of short to mid-term cardiac events and to analyze the value of LV systolic and diastolic parameters change during low-dose DT in asymptomatic patients with moderate or severe AS and preserved EF at rest...en
dc.formatapplication/pdf
dc.languagesr
dc.publisherУниверзитет у Београду, Медицински факултетsr
dc.rightsopenAccessen
dc.sourceУниверзитет у Београдуsr
dc.subjectehokardiografijasr
dc.subjectechocardiographyen
dc.subjectaortna stenozasr
dc.subjectdobutaminski testsr
dc.subjectrezerva koronarnog protokasr
dc.subjectprediktivna vrednostsr
dc.subjectaortic stenosisen
dc.subjectdobutamine infusionen
dc.subjectcoronary flow reserveen
dc.subjectpredictive valueen
dc.titleZnačaj Doppler-ehokardiografskih parametara leve komore za procenu stepena aortne stenoze i ranu prognozu toka bolestisr
dc.titleThe importance of Doppler-echocardiographic parameters of left ventricle for risk stratification and early prognosis in aortic stenosisen
dc.typedoctoralThesisen
dc.rights.licenseBY-NC-ND
dcterms.abstractВујисић-Тешић, Босиљка; Ристић, Миљко; Петровић, Милан; Цветковић-Матић, Даница; Бановић, Марко; Значај Допплер-ехокардиографских параметара леве коморе за процену степена аортне стенозе и рану прогнозу тока болести; Значај Допплер-ехокардиографских параметара леве коморе за процену степена аортне стенозе и рану прогнозу тока болести;
dc.identifier.fulltexthttp://nardus.mpn.gov.rs/bitstream/id/10843/Disertacija.pdf


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