Cardiac resynchronisation therapy (CRT) is a promising treatment option in patients with chronic heart failure. In this article the roles of semi-invasive esophageal left-heart electrocardiography and functional cardiac nuclear imaging in the field of CRT are highlighted, as the combination of both could be a favourable diagnostic approach in special cardiac situations. Also original esophageal left heart electrogram data of exemplary CRT patients is presented

Heinke, Matthias

Ismer, Bruno

Melichercik, Juraj

Otte, Andreas

Heinke, Matthias (Prof. Dr.-Ing. med. habil.)

Hochschulschriftenserver der Hochschule Offenburg

33AbstractCardiac resynchronisation therapy (CRT)is a promising treatment option in pati-ents with chronic heart failure. In thisarticle the roles of semi-invasive esopha-geal left-heart electrocardiography andfunctional cardiac nuclear imaging inthe field of CRT are highlighted, as thecombination of both could be a favoura-ble diagnostic approach in special car-diac situations. Also original esophagealleft heart electrogram data of exemplaryCRT patients is presented.IntroductionDuring the last 15 years cardiac resyn-chronisation therapy (CRT) has made ahuge step forward from experimentalpacing to a routine and evidence-basedtreatment option in patients with chro-nic heart failure, who have ischemic ornon-ischemic cardiomyopathy at NYHAIII or IV, sinus rhythm, a left-bundlebranch block and a left ventricular ejec-tion fraction below 35% [1, 2].The relatively young field of biomedicalengineering has also found a rapid andpromising development in the two me-dical imaging disciplines radiology andnuclear medicine as well as semi-inva-Prof. Dr. med. Andreas OtteProf. Dr. rer. nat. habil. Bruno IsmerPD Dr. Ing. med. habil. Matthias HeinkeProf. Dr. med. Juraj MelichercikDr. Heinke is from the Department ofInternal Medicine I, Friedrich-Schiller-University of Jena, and Professor Meli-chercik is from the Mediclin Heartcen-ter Lahr1.4 Nuclear imaging and semi-inva-sive electrocardiography in CRTsive electrocardiographic methods andthus strengthened modern medicine.The role of nuclear imagingNuclear medicine diagnostic instru-ments provide various opportunities tohelp the patient in the battle against hisor her disease. In cardiovascular di-seases, electrocardiogram (ECG)-trigge-red myocardial perfusion single-photon-emission-computed-tomography(SPECT) or 18F-fluorodeoxy-D-glucose(FDG) positron emission tomography(PET) have become routine tools to de-tect viable myocardium, to study heartmotility and to define the ejection frac-tion, the left-ventricular or right-ventri-cular function.Although CRT is a promising treatmentoption, some patients do not respond toit [1]. van Campen et al., 2007, therefo-re, studied the relationship between via-ble myocardial tissue assessed by FDGPET and the improvement after CRT in39 patients with ischemic cardiomyopa-thy, ejection fraction 27±9% and a wideQRS complex [3]. They found a correla-tion between the extent of viable myo-cardiumand the hemodynamic responseto CRT (assessed by the cardiac indexmeasured by Doppler echocardiogra-phy) and concluded that FDG PET ima-ging may be a useful predicting tool todistinguish between responders andnon-responders. Siegrist et al., 2008,studied the role of left-ventricular phasehistograms of radionuclide ventriculo-graphy (RNV) for optimizing atrioventri-cular delay setting for CRT in 17 patientswith heart failure and could show thatRNV is a helpful instrument for the opti-mization of pacing parameters in CRT[4]. Looking at radiological tools, selec-tion of pacing sites can be improved e.g.by cardiac computer tomography of thecardiac veins. In addition to PET ima-ging, candidates with large myocardialscars can be excluded also by magneticresonance tomography [5].The role of semi-invasiveleft-heart electrocardiographyRecently, esophageal left heart electro-gram was demonstrated to be a simplebut useful semi-invasive method in thefield of CRT [6, 7]. It could be utilized toincrease responder rate (Figure 1.4-1).Performed preoperatively, this approachprovides more direct quantification ofthe left ventricular conduction delaythan QRS width in surface ECG. Dun-can et. al. found an underestimation ofduration of ventricular activation by the12-lead ECG compared with pacemakerdevice electrogram measurements [8].Previously measured esophageal leftventricular conduction delay can beused, intraoperatively, as valuable targetinterval to guide positioning of the leftventricular electrode. Missing this targetinterval should encourage the seekingfor another pacing position in order todecrease the amount of nonresponders(Figure 1.4-2).Furthermore, postoperatively, esophage-al left atrial electrogram recording ena-bles measurement of implant-relatedinteratrial conduction intervals. The lat-ter mainly determine individual durati-on of the hemodynamically optimal AVdelay programming.Actually, the semi-invasive esophagealleft heart electrogram is a feature of theBiotronik ICS3000 (Biotronik GmbH,Berlin, Germany) standard programmer,solely. Applying, perorally, a TOslimesophageal electrode (Osypka AG,Nuclear imaging and semi-invasiveelectrocardiography in CRTProf. Dr. med. Andreas Otte,Facharzt für NuklearmedizinFakultät Elektrotechnikund Informationstechnik (E+I)Badstraße 2477652 OffenburgTel. 0781 205-338E-Mail: andreas.otte@hs-offenburg.de1987-1994: Studium der Physik (1987-88), Universität Konstanz;Studium der Humanmedizin (1988-1994), Albert-Ludwigs-Universität Freiburg; Promotion zum Dr. med.1994-1999:Weiterbildung zum Facharzt für Nuklearmedizin,Universitätskliniken Basel und Freiburg1999-2010: Leitende Positionen in der klinischen Forschung(u.a. Bereichsleiter ZNS bei Gödecke/Pfizer, Freiburg; Stv. Leiterdes Zentrums Klinische Studien, Universitätsklinikum Freiburg)Lehre: 2002-2009: Visiting Professor Universität Gent/Belgien; seit2007 Honorarprofessor Hochschule Lahr; seit 2010 Professor für biomedizinische Systemtechnik,Hochschule OffenburgForschungsgebiet: Neurosysteme; biomedizinische bildgebendeVerfahren34Rheinfelden-Herten, Germany) con-nected to the PK199 programmer cable,depending on esophageal electrode po-sition, filtered esophageal left ventricu-lar or left atrial electrograms can be re-corded simultaneously with three-channel surface ECG in patients withoutor with pacing systems irrespective oftheir make and model.ConclusionNuclear imaging as well as semi-inva-sive left-heart electrogram studies in CRTare still rare, and the number of patientsstudied is low. Both methods, however,can help CRT in special situations. The-refore, further clinical studies combiningthe two disciplines may be a favourableapproach.References[1] Abraham WT, Fisher WG, Smith ALet al.: MIRACLE Study Group: Multi-center InSync Randomized ClinicalEvaluation. Cardiac resynchroniza-tion in chronic heart failure. 346:1845 – 53, N Engl J Med 2002Fig. 1.4-1: Example of CRT patient presenting distinct eso-phageal left ventricular conduction delay Q-ELV of 112 ms.In contrast to that, the left ventricular electrode is placedin unfavourable region with left ventricular electrode delayQ-LV of 60 ms, only. Intraoperatively, this suboptimal situa-tion should encourage the seeking for another left ventri-cular electrode position in order to avoid nonrespondersFig. 1.4-2: Example of CRT patient demonstrating the eso-phageal left ventricular conduction delay Q-ELV of 54 msas minimal target interval for left ventricular electrodepositioning. In this constellation with Q-LV of 74 ms,response to CRT could be expected[2] Götze S, Butter C, Fleck E.: KardialeResynchronisation bei Herzinsuffi-zienz [Cardiac resynchronisationtherapy for heart failure]. 95 (suppl.4): 1 – 18, Clin Res Cardiol 2006[3] van Campen CM, Visser FC, van derWeerdt AP et al.: FDG PET as a pre-dictor of response to resynchronisa-tion therapy in patients with ischae-mic cardiomyopathy. 34: 309 – 15Eur J Nucl Med Mol Imaging 2007[4] Siegrist PT, Comte N, Holzmeister Jet al.: Effects of AV delay program-ming on ventricular resynchronisati-on: role of radionuclide ventriculo-graphy. 35: 1516 – 22, Eur J NuclMed Mol Imaging 2008[5] Flachskampf FA.The non-respondersin cardiac resynchronisation thera-py: do we have solution? EuropeanSociety of Cardiology, Congress Re-port 2011: link: http://www.escardio.org/congresses/esc-2011/congress-reports/Pages/101-Flachskampf.aspx[retrieved: Nov 22, 2011][6] Ismer B, Kleimenhagen F, Heinke Met al.: Significance of new electro-cardio-graphic parameters to impro-ve cardiac resynchronization thera-py. 56(Suppl. 1). Walter de Gruyter,Berlin, Boston: DOI 10.1515/BMT.2011.512, Biomed Tech 2011[7] Heinke M, Ismer B, Kuehnert H etal.: Transesophageal left ventricularelectrogram-recording and tempora-ry pacing to improve patient selec-tion for cardiac resynchronization.Med Biol Eng Comput 2011;49: 851 – 8. DOI 10.1007/s11517-011-0767-6[8] Duncan AM, Lim E, MebrateY et al.:Underestimation of duration ofventricular activation by 12-leadECG compared with direct measure-ments of activation duration derivedfrom implanted pacemaker leads.152: 35 – 42, Intern J Cardiol 2011

Nuclear imaging and semi-invasive electrocardiography in CRT

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