左室変形挙動の定量的解析の試みとその有用性

A quantitative analysis of left ventricular behavior in cineangiogram

　左心室Cine angiogramによる局所壁運動解析は，冠動脈病変に基づく虚血部位及びその心筋機能を知る上に重要であり，多くの解析方法が試みられ，或いは臨床応用されている。しかし回転楕円体としての局所的左室異常運動収縮運動の正確な評価は未だ不充分であり，特に強度のasynersisを有する場合の長・短軸或いは角度の変位に準じた定量的識別に若干の問題が残されているのが現状であろう。そこで著者らは，asynersisの定量解析を局所壁運動と左心室全体の収縮状態との相互関係，即ち，左心室全体の調和運動度（Left ventricular behav—ior）として捉えるため一回拍出時の収縮長の平均を基準化し，左室全体の不均一度として相対標準偏差Coeffi—cient of variation（以下CVと略す）を提案し，自動解析システムを考案^1），その臨床的有用性，妥当性，及びその限界等について検討し，考察を加える。

This investigation was designed to analyze quantitatively the left venticular behavior in patients with coronary artery disease.

The dynamic phase of the left ventricle was measured for its distance between to each segmental length from center gravity based on the center gravity radiation method which was the principle of left ventricular regional wall motion. The stroke length (SL) of one pulse was thus measured. Then the coefficient variation (CV) of each SL was measured and proposed as an index to evaluate the irregular behavior of left ventricular wall. In other words, SL of 90 points was calculated from the formula, SL-1_edv-1_esv and the CV was calculated from the formula, LCV=δSL√SL*100. The center of ESV gravity as the shortening point the changes of SL values were traced on the graph of coordinates and the tracing showed a plateau as in normal LV behavior and the CV value was 45±10%.

While the CV value of akinetic group and dyskinetic group were 71±33 with EF : 54%±10% and 89±21 with EF : 38%±14%, respectively. The condition of patient with major anteroapical aneurysm before and after the aneurysmectomy was compared. CV value was down significantly from pre-operational value of 133% to 52%. Moveover, the relationship among changes of CV values, regional wall motion analysis and various indices of LV performance was investigated.

As conclusions, this CV value have possibilities of developing into useful index of myocardial viability as well as LV abnormal behavior.