RT-198
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Transesophageal atrial pacing with different electrodes for initiation of late potential in patients after acute myocardial infarction
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Matthias Heinke, Helmut Kühnert, Frank-Michael Malur, Ralf Surber, Gundrun Dannberg, Hans-Reiner Figulla.
University Hospital of Internal Medicine III, Division of Cardiology, Jena, Germany
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Abstract
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To evaluate the influence of transesophageal atrial pacing with different
electrodes for initiation of ventricular late potential during accelerated heart rate in 32 patients (7 female, 25 male,
mean age 63±12 years) after acute myocardial infarction, we recorded the signal averaged ECG during
spontaneous rhythm and accelerated heart rate with transesophageal atrial pacing. We recorded the QRS
triggered signal averaged ECG during transesophageal atrial pacing with cylindrical electrodes (4 mm diameter)
without electrical insulation in 18 patients and with hemispherical electrodes (6 mm diameter) with electrical
insulation in 14 patients.
18 patients with cylindrical electrodes transesophageal atrial pacing and 11±3.3 ms stimulus duration had 16.7±3.2
mA capture threshold for transesophageal atrial pacing and 15 patients 12.6±5.2 mA feeling threshold for
transesophageal atrial pacing. The minimum of the capture threshold for cylindrical electrodes transesophageal
atrial pacing was 11 mA at 9.9 ms. The minimum of the feeling threshold for cylindrical electrodes
transesophageal atrial pacing was 6 mA at 9.9 ms. Fourteen patients with hemispherical electrodes
transesophageal atrial pacing and 9.9 ms stimulus duration had 9.8±3.1 mA capture threshold for
transesophageal atrial pacing and 10.9±5 mA feeling threshold for transesophageal atrial pacing. The minimum
of the capture threshold for hemispherical electrodes transesophageal atrial pacing was 5 mA at 9.9 ms. The
minimum of the feeling threshold for hemispherical electrodes transesophageal atrial pacing was 4 mA at 9.9 ms.
Seven patients after acute myocardial infarction had positive late potential at spontaneous rhythm and 25
patients after acute myocardial infarction had negative late potential at 71±16/min spontaneous rhythm with
initiation of late potential during accelerated heart rate with transesophageal atrial pacing in 6 patients after
acute myocardial infarction with 51±8 ms late potential duration, 13±4 µV late potential amplitude, 108±21 ms
QRS-duration and 118±18/min heart rate. The mean noise amplitude of the signal averaged ECG was 0.42±0.08
µV during spontaneous rhythm, 0.89±0.43 µV during transesophageal atrial pacing with hemispherical electrodes
and 0.92±0.5 µV during transesophageal atrial pacing with cylindrical electrodes.
In conclusion, the application of hemispherical electrodes allowed transesophageal atrial pacing with low
capture threshold. The capture threshold for transesophageal atrial pacing was lower than the feeling threshold
for transesophageal atrial pacing with hemispherical electrodes and the capture threshold for transesophageal
atrial pacing was higher than the feeling threshold for transesophageal atrial pacing with cylindrical electrodes.
Accelerated heart rate with transesophageal atrial pacing with different electrodes allowed the initiation of late
potential in the signal averaged ECG to better differentiation between acute myocardial infarction patients with
and without late potential.
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Key Words
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