Oh Seil
Department of Internal Medicine, Seoul National University Hospital, Seoul National University College of Medicine, Seoul, Korea.
Korean Circ J. 2020 May;50(5):420-429. doi: 10.4070/kcj.2019.0240. Epub 2020 Jan 15.
It is difficult to estimate the depth of the focal source by activation mapping. The present study was performed to demonstrate the usefulness of a simple maneuver in estimating the depth of the focal activation source (S).
A total of 44 sites (15 shallow, depth<3.5 mm; 29 deep, depth>5.5 mm) were analyzed in 3 canine left ventricles under general anesthesia. A custom-made bipolar needle electrode was used to simulate a focal activation source. A mapping catheter with an electrode tip size of 2 mm, band electrode size of 1 mm, and inter-electrode spacing of 2-10-2 mm was placed at the mapping area. The position of the center of the distal 2 electrodes was kept at the insertion site of the needle electrode. The time interval between distal and proximal electrodes of the mapping catheter (T) was measured during needle electrode pacing. The time interval between distal and proximal electrodes (T) was measured during pacing with distal electrodes of a mapping catheter. Depth index (δ) was defined as T/T. Using in vivo data, simulation was performed to evaluate the depth and δ.
T was 24±7.7 ms and 15±5.6 ms for shallow source and deep source simulation, respectively (p<0.001). δ values were 0.86±0.21 and 0.55±0.21 for shallow source and deep source simulation, respectively (p<0.001). According to simulation data, if δ<0.52, the depth of the focal source will be >5.5 mm.
T was shorter and δ was smaller for a deep S than for a shallow S.
通过激活标测来估计局灶性激动源的深度具有一定难度。本研究旨在证明一种简单操作方法在估计局灶性激动源（S）深度方面的实用性。
在全身麻醉下，对3只犬的左心室共44个部位（15个浅部，深度<3.5mm；29个深部，深度>5.5mm）进行分析。使用定制的双极针电极模拟局灶性激动源。将电极尖端尺寸为2mm、带状电极尺寸为1mm且电极间距为2 - 10 - 2mm的标测导管置于标测区域。标测导管远端2个电极中心的位置保持在针电极的插入部位。在针电极起搏期间，测量标测导管远端和近端电极之间的时间间隔（T）。在用标测导管的远端电极起搏期间，测量远端和近端电极之间的时间间隔（T）。深度指数（δ）定义为T/T。利用体内数据进行模拟，以评估深度和δ。
浅部激动源模拟和深部激动源模拟时，T分别为24±7.7ms和15±5.6ms（p<0.001）。浅部激动源模拟和深部激动源模拟时，δ值分别为0.86±0.21和0.55±0.21（p<0.001）。根据模拟数据，如果δ<0.52，局灶性激动源的深度将>5.5mm。
深部S的T比浅部S短，δ比浅部S小。
