Prediction of Location of Late Potentials for Ventricular Tachycardia Ablation with 99mTcMIBI Scintigram Scar

2019 Fiscal Year Final Research Report

• Project/Area Number: 18K15546
• Research Category: Grant-in-Aid for Early-Career Scientists
• Allocation Type: Multi-year Fund
• Review Section: Basic Section 52040:Radiological sciences-related
• Research Institution: Osaka University
• Principal Investigator: Kentaro Ozu 大阪大学, 医学部附属病院, 医員 (10650088)
• Project Period (FY): 2018-04-01 – 2020-03-31
• Keywords: 99mTcMIBI心筋シンチグラフィ / 心室頻拍 / カテーテル心筋焼灼術

Outline of Final Research Achievements

We evaluated that the uptake rate of 99mTcMIBI scintigram could predict the location of late potentials (LPs) which were the targets of the radiofrequency ablation for ventricular tachycardia (VT). In 7 patients with ischemic cardiomyopathy (ICM) and VT, electroanatomical map and scintigraphic image of left ventricular were obtained and were divided into twenty segments. The relation between LPs and scintigrafic characteristics were evaluated in total of 140 segments. LPs were recorded in 54 segments. According to the 99mTc uptake rate, cut off value 35% was set for the prediction of the distribution of LPs with ROC curve (area under the curve 0.89). LPs were observed in the lower scintigram perfusion segments with <35% uptake rate with statistical significance (sensitivity 81%, specificity 87%). Lower perfusion area of 99mTcMIBI scintigram could be utilized to predict VT substrate location in ICM cases. However, there was no significance for prediction of LPs location in nonICM cases.

Free Research Field

循環器内科学

Academic Significance and Societal Importance of the Research Achievements

低左心機能症例に合併することが多い心室頻拍に対し、心室頻拍のカテーテル心筋焼灼術は円滑に行われることが望ましく、ターゲットとする遅延電位の局在を術前に確認できる方法が存在することが重要である。傷害心筋内に存在する心室頻拍の不整脈基質の予測性を示唆されている造影MRIや造影CTを用いることが困難なICD等植込みデバイス装着例や腎機能低下例、重度心機能低下例において、99mTcMIBIシンチグラフィでのviability低下領域を評価することで、心室頻拍の不整脈基質の局在を予測し、円滑なカテーテル心筋焼灼術の施行が可能となりうるものと考える。