SVEC III誘導法によるOrthogonalベクトル心電圖の臨床的研究(第2報) : 異常スカラー心電圖
スポンサーリンク
概要
- 論文の詳細を見る
The X, Y, Z leads of Schmitt's SVEC III lead system are considered quite an accurate representation of the horizontal, vertical and sagittal components of the electrical activity of the heart on the basis of model experiments. In this study, this lead system was applied to patients having various ECG abnormalities in conventional leads in order to assess its clinical applicability. About 230 tracings recorded on 173 patients are included. The scalar recordings were evaluated with reference to the normal range limits of the X, Y, Z leads which were obtained from the recordings on 303 healthy men and the deviations from the normal limits thus found were compared with the findings in the conventional leads.In normal patterns, the QRS and T of lead X are upright and similar to the left-sided precordial leads. The pattern of lead Y is similar to lead II, though the polarity is reversed. The QRS of lead Z is RS, the S usually being greater than the R, and the T of lead Z is almost always upright.In LVH, the composite voltage Rx+Sz, which has a correlation with the mean spatial QRS magnitude, increased and the presence of Rx+Sz>2.4 mV (normal limit) coincided with that of Sv_1+Rv_5>3.5mV in 28 of the 34 cases in which either one of these two items was present. The "strain-type" ST-T changes in the left precordial leads and in lead I were manifested in lead X.In the 14 cases examined having definite RVH which was confirmed from clinical findings and venous catheterization, in all the cases, the R/S ratio of lead was X below 1.2 which is outside its lower normal limit of 1.3; therefore, there can be no possibility of a false positive diagnosis. The S of lead X exceeded its normal limit of 0.4mV in 12 of these 14 cases. The positiveness of the above two items was much better than any of the individual criterion of the previously esta. blished criteria for RVH of conventional leads The "strain-type" ST-T changes in the right precordial leads were manifested in lead Z.The pattern of LBBB was characterized by a broad notched R in lead X and a small R followed by a wide deep S in lead Z. The pattern of RBBB was characterized by a wide and somewhat deep S after the R in lead X and an RsR' pattern of lead Z.The pattern of anterior wall infarct was characterized by a QS wave in lead Z and that of posterior wall infarct, by an initial R in lead Y. The serial ST-T changes typcial of recent infarcts were clearly recognized. Diagnotic accuracy for infarcts of this lead system was comparable to that of the conventional leads.The uniformity in the direction of the normal T vector in this lead system permitted clear distinction between normal and abnormal T waves. Abnormalities in the T waves of conventional leads were easily recognized with this lead system, excepting very few cases where only minor T abnormalities were present.The ST-T changes in the anterior wall are manifested in lead Z, those in the lateral wall, in lead X, and those in the posterior wall, in lead Y.Abnormal P waves including flutter and fibrillation waves and increased P amplitudes were also easily recognizable.The scalar display of the SVEC III leads was proven, by this study, to provide information superior or at least comparable to that from conventional leads. The minimal angular distortion and quantitative reliability of this lead system were most favorable and helpful in diagnosing ventricular hypertrophies; the tentative criteria for hypertrophies proposed in this lead system appear accurate and yet they are simple. The other abnormal patterns as well as the ST-T changes were all reflected very clearly in the SVEC III leads.
- 社団法人日本循環器学会の論文
- 1959-09-20
著者
関連論文
- SVEC III誘導法によるOrthogonalベクトル心電圖の臨床的研究(第2報) : 異常スカラー心電圖
- SVEC III誘導法によるorthogonalベクトル心電圖の臨床的研究(第1報) : 正常スカラー心電圖