1. Imaging Electrical Activity of the Heart Özlem Özmen Okur BM573 CARDIOVASCULAR IMAGING Student Presentation

2. 28.11.2005Imaging Electrical Activity of the Heart2/21 Contraction of a Cardiac Muscle Cell In the heart: Iionic current triggers the rhythmic muscle contractions that pump blood in and out. http://butler.cc.tut.fi/~malmivuo/bem/bembook/06/06.htm

3. 28.11.2005Imaging Electrical Activity of the Heart3/21 The Different Waveforms for Each of the Specialized Cells http://butler.cc.tut.fi/~malmivuo/bem/bembook/06/06x/conducti/0607i.htm

4. 28.11.2005Imaging Electrical Activity of the Heart4/21 Need for Mapping of Electrical Activity To understand the mechanisms responsible for the normal cardiac rhythm and for the initation and maintenance of arrhythmias. http://www.comsol.com/stories/heart/ http://butler.cc.tut.fi/~malmivuo/bem/bembook/06/06x/isochron/65.htm

5. 28.11.2005Imaging Electrical Activity of the Heart5/21 Problems (1)  Normal Sinus Rhythm (: All complexes normal, evenly spaced Rate 60 - 100/min  Sinus Bradycardia: All complexes normal, evenly spaced Rate < 60 - 100/min  Sinus Tachycardia: All complexes normal, evenly spaced Rate > 100/min  Sinus Arrythmia: All complexes normal, rhythm is irregular

6. 28.11.2005Imaging Electrical Activity of the Heart6/21 Problems (2)  WANDERING PACEMAKER (Impulses originate from varying points in atria): Variation in P-wave contour, P-R and P-P interval and therefore in R-R intervals  ATRIAL FLUTTER (Impulses travel in circular course in atria): Rapid flutter waves, ventricular response irregular  ATRIAL FIBRILLATION (Impulses have chaotic, random pathways in atria): Baseline irregular, ventricular response irregular  VENTRICULAR FIBRILLATION Chaotic ventricular depolarization

7. 28.11.2005Imaging Electrical Activity of the Heart7/21 Wave pattern (a single spiral) on the ventricular surface, during monomorphic tachycardia http://www.math.utah.edu/~keener/lectures/maw/slide8.html

8. 28.11.2005Imaging Electrical Activity of the Heart8/21 Surface View of Fibrillation http://www.math.utah.edu/~keener/lectures/maw/slide13.html

9. 28.11.2005Imaging Electrical Activity of the Heart9/21 Imaging Electrical Activity of the Heart  Reconstruction from internally located electrodes  Electrocardiographic Imaging  Optical Imaging  Magnetocardiographic Imaging

10. 28.11.2005Imaging Electrical Activity of the Heart10/21 Ventricular Jacket Array Vahlhaus, Christian, et al; “Direct epicardial mapping predicts the recovery of left ventricular dysfunction in chronic ischaemic myocardium”; European Heart Journal; v. 25; n. 2; pp. 151-157; 2003.

11. 28.11.2005Imaging Electrical Activity of the Heart11/21 Internally Located Defibrillation Electrodes  Left: anterior, right: posterior view of the heart and the major vessels of the heart.  Red: regions of large current densities  Blue: regions of relatively lower current densities. http://www.lib.utah.edu/gould/2000/lecture00.html

12. 28.11.2005Imaging Electrical Activity of the Heart12/21 Electrocardiographic Imaging  Noninvasive  Using body surface measurements  Reconstruction on the heart's surface using geometrical information from computed tomography (CT) and a mathematical algorithm. Burnes, John, et al; "A Noninvasive Imaging Modality for Cardiac Arrhythmias"; Nature Medicine; n. 10; pp. 422-428; 2004. Burnes, John, et al; "A Noninvasive Imaging Modality for Cardiac Arrhythmias"; Nature Medicine; n. 10; pp. 422-428; 2004.

13. 28.11.2005Imaging Electrical Activity of the Heart13/21 Optical Imaging of Electrical Activity in the Heart Cardiac action potentials are recorded using voltage-sensitive dyes to monitor Cardiac action potentials are recorded using voltage-sensitive dyes to monitor cellular potential, cellular potential, cell to cell interactions, and cell to cell interactions, and propagation and repolarization "patterns" propagation and repolarization "patterns" underlying cardiac arrhythmias. http://www.metrohealthresearch.org/hvrcresearchelectrophys.html

14. 28.11.2005Imaging Electrical Activity of the Heart14/21 Optical Properties of Membrane-Bound Dyes That Have Been Used to Measure Membrane Potential Changes   Fluorescence,   Absorption,   Dichroism,   Birefringence,   Fluorescence resonance energy transfer,   Nonlinear second harmonic generation, and   Resonance Raman absorption. considerably less sensitive to movement artifacts generated by muscle contractions Efimov, Igor, et al; "Optical Imaging of the Heart"; Circ. Res.; n.95; pp. 21-33; 2004.

15. 28.11.2005Imaging Electrical Activity of the Heart15/21 Schematics of a Typical Optical Mapping System

16. 28.11.2005Imaging Electrical Activity of the Heart16/21 Mapping of Activation and Repolarization

17. 28.11.2005Imaging Electrical Activity of the Heart17/21 Magnetocardiographic Imaging http://www.hitachi.com/ICSFiles/afieldfile/2004/06/08/r2001_01_103.pdf Magnetocardiographs taken from the front and back of the heart. Using a special magnetic sensor called SQUID (8100 fT to severeal tens of pT is emitted from the heart) While clothed.

18. 28.11.2005Imaging Electrical Activity of the Heart18/21 Ischemic Heart Disease Example http://www.hitachi.com/ICSFiles/afieldfile/2004/06/08/r2001_01_103.pdf

19. 28.11.2005Imaging Electrical Activity of the Heart19/21 Magnetocardiographic 3-D Visualization of Heart Current Distribution

20. 28.11.2005Imaging Electrical Activity of the Heart20/21 References  Burnes, John, et al; "A Noninvasive Imaging Modality for Cardiac Arrhythmias"; Nature Medicine; n. 10; pp. 422-428; 2004.  Vahlhaus, Christian, et al; “Direct epicardial mapping predicts the recovery of left ventricular dysfunction in chronic ischaemic myocardium”; European Heart Journal; v. 25; n. 2; pp. 151-157; 2003.  Efimov, Igor, et al; "Optical Imaging of the Heart"; Circ. Res.; n.95; pp. 21-33; 2004.  http://butler.cc.tut.fi/~malmivuo/bem/bembook/06/  http://www.comsol.com/stories/heart/  http://www.math.utah.edu/~keener/lectures/maw/  http://www.lib.utah.edu/gould/2000/lecture00.html  http://www.nature.com/nm/journal/v10/n4/abs/nm1011.html  http://www.metrohealthresearch.org/hvrcresearchelectrophys.html  http://www.hitachi.com/ICSFiles/afieldfile/2004/06/08/r2001_01_103.pdf

21. 28.11.2005Imaging Electrical Activity of the Heart21/21 Thank You...