Conference Goals
Registration
Abstract Submission
Preliminary Program
Plenary Lecture
Tutorial Program
Young Investigators
Venue
Past Conferences
THE VECTOR BASIS OF ELECTROCARDIOLOGY for Electrocardiographers and Engineers
ISCE 2009 Tutorial Thursday, April 23, 4-7 pm |
| Program | |
4:00-4:05 pm |
Overview Vladimir Shusterman, MD, PhD, University of Pittsburgh, Pittsburgh, PA |
|
Part I 4:05-4:40 pm |
Theory and development Vectors, Fields and the Heart: Some Clues to Understanding the ECG Robert L. Lux, PhD, University of Utah, Salt Lake City, UT |
|
4:40-4:45 pm
|
Discussion |
|
4:45-5:20 pm
|
Vectorcardiography and Electrocardiography: Two Sides of the Same Coin
Jan A. Kors, PhD, Erasmus University, Rotterdam, the Netherlands |
|
5:20-5:25 pm
|
Discussion |
|
5:25-5:40 pm
|
Break |
| Part II 5:40-6:15 pm |
Clinical Applications Vectorial Basis for ECG Ventricular Hypertrophy and Bundle Branch Block Paul Kligfield, MD, Cornell University Medical College, New York, NY |
|
6:15-6:20 pm
|
Discussion |
|
6:20-6:55 pm
|
ECG Patterns in Acute Myocardial Ischemia & Infarction Barbara J. Drew, PhD, USCF, San Francisco, CA |
|
6:55-7:00 pm
|
Discussion |
| Session Summary | |
| I |
Vectors, Fields and the Heart: Some Clues to Understanding the ECG |
|
Robert Lux, PhD |
During this brief tutorial session, we shall review the concepts of electric fields, vectors and how they relate to cardiac electricity at the macro level. The objective is to provide a simple (no equations! promise!) explanation of how currents generated in the myocardium produce the electric potentials on the body surface and why the definitive interpretation of ECGs often remains elusive. |
| II |
Vectorcardiography and Electrocardiography: Two Sides of the Same Coin |
|
Jan A. Kors, PhD
|
In this session, we will briefly review the concepts of heart vector, lead vectors, and how the heart vector relates to lead voltages. We will discuss lead transformations, and the additional value of recording leads beyond those of the standard 12-lead ECG. Finally, we will discuss the notion of the planar vectorcardiogram as a phase diagram of ECG signals, and the implications for ECG-based measurements, such as QT dispersion and Tp-Te. |
| III |
Vectorial Basis for ECG Ventricular Hypertrophy and Bundle Branch Block |
|
Paul Kligfield, MD
|
Although electrical activation of the heart involves many vectorial wavefronts, at any point in time cancellation of opposing vectors results in a net cardiac dipole that is recorded from the body surface by the ECG. This principle of vectorial cancellation (or summation) explains many of the surface ECG features associated with left and right ventricular hypertrophy and with abnormalities in the sequence of ventricular activation during bundle branch block. As acquired right ventricular hypertrophy increases, progressive outflow tract and free wall hypertrophy results in terminal rightward and anterior vectors while progressive cancellation of normally dominant left ventricular forces causes a decrease in precordial voltage. Summation of normally directed left ventricular vectors during left ventricular hypertrophy increases precordial and limb lead voltages. Abnormal septal depolarization during left bundle branch block eliminates the early QRS vector that is responsible for septal q waves and delayed left ventricular activation results in late terminal leftward and posterior vectors. Right bundle branch block results not only in late terminal rightward and anterior vectors, but also a reduction of precordial amplitudes due to increased vectorial cancellation of left ventricular forces. |
| IV |
ECG Patterns in Acute Myocardial Ischemia & Infarction |
|
Barbara J. Drew, PhD
|
This review will include changes in the cellular action potential with ischemia and how this translates to the ECG changes observed clinically. ECG differences with various locations of ischemia/infarction will be reviewed; i.e., epicardial versus endocardial; anterior versus posterior, right ventricular versus left ventricular. If time allows, mimics of ischemia/infarction (positional changes, bundle branch block, LVH) will be discussed with tips for making an accurate diagnosis in the presence of these ECG confounders. |