The value of catheter mapping during sinus rhythm to localize site of origin of ventricular tachycardia.

Abstract

We assessed the value of endocardial catheter mapping in 52 patients in sinus rhythm and with 102 morphologically distinct ventricular tachycardias. The local bipolar electrograms from various regions of the left ventricle were assessed and quantitatively classified with respect to the characteristics of amplitude and duration. With the use of this assessment we found that electrograms from the site of origin were of significantly lower amplitude and longer duration; however, because such an overlap occurred with electrograms that were not from sites of origin, this does not serve as a useful clinical marker. Various types of electrograms, including normal, abnormal, fractionated, abnormal late, fractionated late, and longest, were evaluated with respect to sensitivity, specificity, and positive predictive value. None of these types possessed the ability to reliably localize the site of origin of ventricular tachycardia. We therefore conclude that endocardial catheter mapping during sinus rhythm is not useful as a guide in localized surgical therapy of ventricular tachycardia. Surgery guided only by the results of mapping during sinus rhythm would result in a more extensive excision than that directed by maps obtained during ventricular tachycardia and in some cases would result in the exclusion of the area considered to be the site of origin of the tachycardia.

Endocardial catheter mapping in patients in sinus rhythm: relationship to underlying heart disease and ventricular arrhythmias.

“…The technical limitations of interpreting data obtained by catheter mapping during sinus rhythm have been previously reported.7' 11. 1 18 Catheter mapping during sinus rhythm is a relatively specialized invasive technique that is not widely available. The information obtained in this study, however, may provide additional insight into risk factors for malignant ventricular arrhythmias.…”

Clinical Application of an Integrated 3-Phase Mapping Technique for Localization of the Site of Origin of Idiopathic Ventricular Tachycardia

“…16 Endocardial segment of origin of a certain QRS integral map pattern is indicated by encircled number of that map in a schematic of appropriate ventricle. 18,19 Additional numbers 1 through 18 represent 18 endocardial catheter mapping sites previously identified by Josephson et al 18 Reproduced with permission of the American Heart Association. the 8 VTs (62%) were localized to or in the vicinity of segment LV15, to the apical posterior septum or apical posterior wall of the LV.…”

Characteristics and identification of sites of chagasic ventricular tachycardia by endocardial mapping

“…Electrophysiological definitions -Fractionated electrogram -electrical activity with multiple components, low amplitude, increased duration, and high frequency 13 ; amplitude -measurement (in mV) of the greatest deflection of the intracavitary electrogram (peak-to-peak) 13 ; durationmeasurement of electrogram extent (in ms), from the first to the last electrical activity varying from the stable baseline 13 ; presystolic activity -electrical activity detected during SVT, before any intracavitary ventricular electrogram or QRS complex onset 14 ; entrainment -technique consisting of stimulus trains during SVT, using a cycle at least 20 ms less than the tachycardia cycle length, accelerating the tachycardia to the stimulated frequency. Stopping the stimulation, no change is seen in the tachycardia cycle or morphology 14 .…”