Activation Timing and Atrial Fibrillation
| Status: | Completed |
|---|---|
| Conditions: | Atrial Fibrillation, Cardiology, Cardiology |
| Therapuetic Areas: | Cardiology / Vascular Diseases |
| Healthy: | No |
| Age Range: | 18 - Any |
| Updated: | 11/8/2014 |
| Start Date: | January 2014 |
| End Date: | January 2015 |
| Contact: | Michal E Mollerus, MD |
| Email: | michael.mollerus@essentiahealth.org |
| Phone: | 218-786-3443 |
Proof-of-concept Study to Assess Ventricular Activation Timing During Atrial Fibrillation, or Bundle Branch Block and Sinus Rhythm
This is a single center, non-randomized, unblinded study of patients who are followed at
Essentia Health - St. Mary's Medical Center and who are referred for a clinically indicated
diagnostic electrophysiology (EP) study with or without ablation. During the procedure,
events of atrial fibrillation, sinus rhythm and bundle branch block that may occur during
the course of the case will be saved electronically and analyzed offline. The stored data
will be evaluated off-line for changes in activation timing of the near and far field
ventricular signals of the stored events.
This proof-of-concept study will attempt to assess whether atrial fibrillation, or bundle
branch block can change activation timing compared to baseline sinus rhythm. If no
significant activation change is seen, then this finding can be used as a basis to
distinguish ventricular tachycardia from atrial fibrillation in future rhythm discrimination
methods.
Essentia Health - St. Mary's Medical Center and who are referred for a clinically indicated
diagnostic electrophysiology (EP) study with or without ablation. During the procedure,
events of atrial fibrillation, sinus rhythm and bundle branch block that may occur during
the course of the case will be saved electronically and analyzed offline. The stored data
will be evaluated off-line for changes in activation timing of the near and far field
ventricular signals of the stored events.
This proof-of-concept study will attempt to assess whether atrial fibrillation, or bundle
branch block can change activation timing compared to baseline sinus rhythm. If no
significant activation change is seen, then this finding can be used as a basis to
distinguish ventricular tachycardia from atrial fibrillation in future rhythm discrimination
methods.
General Approach: Single center, non-randomized, unblinded study of patients who are
followed at Essentia Health - St. Mary's Medical Center and who are referred for a
clinically indicated diagnostic EP study with or without ablation. During the procedure,
events of atrial fibrillation, sinus rhythm or bundle branch block that may occur during the
course of the case will be saved electronically and analyzed offline. These events may occur
during the routine, clinically indicated portion of the procedure and will be saved should
they occur. The stored data will be evaluated for changes in activation timing of the near-
and far field ventricular signals of the stored events.
Methods and Materials: Up to 50 patients will be enrolled by the primary investigator and/or
associate investigators. As part of a usual EP study, catheters are placed in the coronary
sinus and right ventricle. For studies involving catheter ablation of atrial fibrillation or
other complex arrhythmias, a 3-dimensional mapping system is frequently used for catheter
location in 3-dimensional space and is left to the clinical discretion of the operator at
the time of the procedure. An EP-Med WorkMate workstation will be used to record and measure
events as part of the usual clinical procedure.
1. Data Acquisition: During the course of the case, a catheters placed in the right
ventricular apex and coronary sinus will be used to record both near- and far-field
signal during episodes of atrial fibrillation, sinus rhythm and bundle branch
conduction disturbances should they occur. Near field-signal will be recorded between
the distal and proximal pair of the catheter located in the right ventricular apex.
Far-field signal will be measured between the distal electrode of the catheter in the
right ventricular apex and distal electrode of the coronary sinus catheter. If
3-dimensional mapping is available, the spatial location of the right ventricular and
coronary sinus catheters will be recorded. If 3-dimensional mapping is not available,
fluoroscopic maps of catheter positions will be obtained. Recorded signal will be saved
on the EP-Med WorkMate workstation at a sampling rate of 2000 Hz and amplitude of 78 nV
per unit.
2. Analysis: Patient identifiers will be purged from the saved events and printouts, and a
study identification number will be assigned. Those saved events will be extracted for
input into Matlab or Octave for analysis. Custom algorithms written by the primary
investigator will be used. Both the ventricular far-field and ventricular nearfield
electrograms will be analyzed. Initially, 3 consecutive ventricular signals during
sinus rhythm will be evaluated for each patient and averaged to estimate the activation
timing changes. A baseline template or reference activation sequence will be created
for each patient and will be used as the reference for all further events from that
patient. The signal will be rectified but no additional filtering will be applied.
Using the peak farfield signal as time 0, the difference between near- and far-field
peak signals will be measured and averaged for the three ventricular events. In turn
any available atrial fibrillation or bundle branch block conduction disturbance evens
will be analyzed using the same techniques. Differences between the reference
activation sequence and other events will be measured and compared. In Figure 1, the
upper pane shows an episode of baseline rhythm (sinus rhythm). During baseline rhythm
for this event, the near-field peak signal consistently comes after the far-field peak
signal. During ventricular tachycardia, the two peaks are nearly simultaneous,
representing a change in activation timing because of a change in the activation
circuit in the ventricles.
followed at Essentia Health - St. Mary's Medical Center and who are referred for a
clinically indicated diagnostic EP study with or without ablation. During the procedure,
events of atrial fibrillation, sinus rhythm or bundle branch block that may occur during the
course of the case will be saved electronically and analyzed offline. These events may occur
during the routine, clinically indicated portion of the procedure and will be saved should
they occur. The stored data will be evaluated for changes in activation timing of the near-
and far field ventricular signals of the stored events.
Methods and Materials: Up to 50 patients will be enrolled by the primary investigator and/or
associate investigators. As part of a usual EP study, catheters are placed in the coronary
sinus and right ventricle. For studies involving catheter ablation of atrial fibrillation or
other complex arrhythmias, a 3-dimensional mapping system is frequently used for catheter
location in 3-dimensional space and is left to the clinical discretion of the operator at
the time of the procedure. An EP-Med WorkMate workstation will be used to record and measure
events as part of the usual clinical procedure.
1. Data Acquisition: During the course of the case, a catheters placed in the right
ventricular apex and coronary sinus will be used to record both near- and far-field
signal during episodes of atrial fibrillation, sinus rhythm and bundle branch
conduction disturbances should they occur. Near field-signal will be recorded between
the distal and proximal pair of the catheter located in the right ventricular apex.
Far-field signal will be measured between the distal electrode of the catheter in the
right ventricular apex and distal electrode of the coronary sinus catheter. If
3-dimensional mapping is available, the spatial location of the right ventricular and
coronary sinus catheters will be recorded. If 3-dimensional mapping is not available,
fluoroscopic maps of catheter positions will be obtained. Recorded signal will be saved
on the EP-Med WorkMate workstation at a sampling rate of 2000 Hz and amplitude of 78 nV
per unit.
2. Analysis: Patient identifiers will be purged from the saved events and printouts, and a
study identification number will be assigned. Those saved events will be extracted for
input into Matlab or Octave for analysis. Custom algorithms written by the primary
investigator will be used. Both the ventricular far-field and ventricular nearfield
electrograms will be analyzed. Initially, 3 consecutive ventricular signals during
sinus rhythm will be evaluated for each patient and averaged to estimate the activation
timing changes. A baseline template or reference activation sequence will be created
for each patient and will be used as the reference for all further events from that
patient. The signal will be rectified but no additional filtering will be applied.
Using the peak farfield signal as time 0, the difference between near- and far-field
peak signals will be measured and averaged for the three ventricular events. In turn
any available atrial fibrillation or bundle branch block conduction disturbance evens
will be analyzed using the same techniques. Differences between the reference
activation sequence and other events will be measured and compared. In Figure 1, the
upper pane shows an episode of baseline rhythm (sinus rhythm). During baseline rhythm
for this event, the near-field peak signal consistently comes after the far-field peak
signal. During ventricular tachycardia, the two peaks are nearly simultaneous,
representing a change in activation timing because of a change in the activation
circuit in the ventricles.
Inclusion Criteria:
- any patient followed at Essentia Health - St. Mary's Medical Center, Duluth, MN and
who is referred for a diagnostic EP study with or without ablation.
Exclusion Criteria:
- any patient who will undergo an EP study without usual placement of a coronary sinus
catheter;
- any patient with permanent (chronic) atrial fibrillation or tachycardia who will not
undergo restoration of sinus rhythm during the course of the procedure as a usual
part of the procedure;
- any patient who is not willing or unable to provide informed consent.
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