Role of Purkinje Fibers in Post-Infarction Ventricular Tachycardia
Frank Bogun, MD*,
Eric Good, DO,
Stephen Reich, MD,
Darryl Elmouchi, MD,
Petar Igic, MD,
David Tschopp, MD,
Sujoya Dey, MD,
Alan Wimmer, MD,
Krit Jongnarangsin, MD,
Hakan Oral, MD1,
Aman Chugh, MD,
Frank Pelosi, MD and
Fred Morady, MD1
University of Michigan Medical Center, Ann Arbor, Michigan.
View larger version (22K):
[in this window]
[in a new window]
[Download PPT slide]
|
Figure 2 Recordings from the distal poles of the mapping catheter (Map) positioned at a posteroseptal left ventricular site where a Purkinje potential preceded the QRS complex by 20 ms during sinus rhythm (A) and by 35 ms during ventricular tachycardia (VT) (B). Pacing during VT at this site demonstrates concealed entrainment with a stimulus-QRS interval of 35 ms (C). The stimulus-QRS interval during pacing matches the Purkinje potential-QRS interval during VT.
|
|
View larger version (15K):
[in this window]
[in a new window]
[Download PPT slide]
|
Figure 3 An example of spontaneous variation in the ventricular tachycardia (VT) cycle length, with changes in the interval between Purkinje potentials preceding the changes in RR interval. Displayed are 2 panels recorded at different times during the same VT. Leads V1 and V6 and intracardiac recordings from the mapping catheter (Map) and the right ventricular apex (RVA) are shown. The Purkinje potential intervals and RR intervals are indicated.
|
|
View larger version (22K):
[in this window]
[in a new window]
[Download PPT slide]
|
Figure 4 Recordings from the distal poles of the mapping catheter (Map dist) located at a site in the posteroseptal left ventricle where a Purkinje potential precedes the QRS complex by 20 ms during sinus rhythm (A) and by 35 ms during ventricular tachycardia (VT) (B). Pace mapping performed at this site during sinus rhythm (C), shows a match with the VT morphology (D).
|
|
View larger version (7K):
[in this window]
[in a new window]
[Download PPT slide]
|
Figure 5 Continuous recording showing termination of ventricular tachycardia (VT) (left) and resumption of sinus rhythm (right) with a catheter at the His position (arrows). A His bundle depolarization is present during sinus rhythm but not VT, ruling out bundle branch re-entry.
|
|
View larger version (20K):
[in this window]
[in a new window]
[Download PPT slide]
|
Figure 6 Demonstration of concealed entrainment at a site remote from the Purkinje system. (A) Electrogram during sinus rhythm without Purkinje potentials. (B) Mid-diastolic isolated potential at this site during ventricular tachycardia (VT). The electrogram-QRS interval measured from the isolated potential is 160 ms. (C) Entrainment mapping performed at this site shows a matching stimulus-QRS interval of 160 ms during concealed entrainment. The catheter moved and ablation was not attempted at this site. This VT was ablated at a site displaying Purkinje potentials during both VT and sinus rhythm.
|
|
View larger version (68K):
[in this window]
[in a new window]
[Download PPT slide]
|
Figure 7 A voltage map displayed in an apicoseptal view of the left ventricle. It illustrates a scar (voltage <1.0 mV) involving the posteroseptal wall and parts of the lateral left ventricle. Sites with Purkinje potentials are marked with blue dots. The position of the His bundle electrogram is marked with an orange dot. Contiguous sites of the Purkinje system within normal myocardium are displayed in the right-sided inserts. Contiguous sites of Purkinje fiber recordings within scar tissue are displayed in the left-sided inserts. The inserts display lead V6 and the recordings from the distal electrode pair of the mapping catheter. The point marked by a rose tag indicates the exit site of the ventricular tachycardia, and the green tag marks the effective ablation site where concealed entrainment was documented.
|
|
View larger version (22K):
[in this window]
[in a new window]
[Download PPT slide]
|
Figure 8 Schematic illustration of a re-entry circuit around an inferoseptal scar. Surviving muscle bundles within the myocardium and in the Purkinje system are components of the re-entry circuit.
|
|
|
