Guidewire Method for Measuring Local Left Ventricular Electrical Activation Time During Cardiac Resynchronization Implantation

Abstract

ABSTRACT. The timing of local activation at left ventricular (LV) pacing leads is measured from the onset of the QRS complex to the peak of the LV electrogram (QLV). Pacing from the sites of late activation is associated with higher response rates to cardiac resynchronization therapy (CRTtechniques target the posterolateral wall of the left ventricle (LV) using a combination of radiographic appearance, pacing parameters, lead stability, and an absence of diaphragmatic stimulation to determine the final lead position. Unfortunately, CRT is associated with a nonresponder rate of 20% to 40%, depending on the definition used for response. One predictor of response to CRT is the timing of activation measured at the LV electrode relative to the onset of the QRS complex (QLV). Prolonged QLV (QLV > 95 ms) is associated with both an improved acute response to and marked long-term improvement with CRT. 3,4 Prospective measurement of QLV has been described

Time-related factors predicting a positive response to cardiac resynchronisation therapy in patients with heart failure

“…Identification of the segment with the highest LAT value and the left ventricular lead’s location in this area allows for corrections of delays and improved LV depolarization pattern. Intraoperative techniques using local activation time measured from a guidewire in potentially targeted cardiac vein with intracardiac electrocardiographic recording and the unipolar signal analysis from the guidewire presented by Rials et al 21 are also used to identify this area and select the target vessel. As a result, they have beneficial effects on resynchronization.…”

Reproducibility and repeatability of identifying the latest electrical activation during mapping of coronary sinus branches in CRT recipients

“…However, a recent study found a good correlation between two methods when measuring the activation delay. 25 Also, commercially available electroanatomical mapping systems known from radiofrequency ablation have been used to map CS branches and their activation. 24,26 This gives the advantage of automatically collecting and annotate a large number of data which might reduce observer variation, but on the other hand, it is more expensive and might be more time consuming.…”

“…A potential drawback could be that the recorded signal is different from the guidewire as compared to the LV lead since near and far activity reflects differently on the recorded EGMs. However, a recent study found a good correlation between two methods when measuring the activation delay 25 . Also, commercially available electroanatomical mapping systems known from radiofrequency ablation have been used to map CS branches and their activation 24,26 .…”