Takeshi Shimaji

T wave alternans in patients with cardiac sarcoidosis

Abstract There has been no report on T wave alternans (TWA) in patients with cardiac sarcoidosis. In this study, we investigated TWA in patients with cardiac sarcoidosis. Electrocardiographic recording for TWA was performed in 6 patients, using the CH2000 (Cambridge Heart). TWA was defined as positive in cases where alternans voltage of >1.9 μV and alternans ratio of >3.0 persisted more than 1 minute during exercise with ergometer with heart rate above 105 beats/min. TWA was positive in 3 patients, negative in 2 patients, and not determined in 1 patient. Arrhythmia was noted on Holter electrocardiogram in all 3 patients with positive TWA: sustained ventricular tachycardia in 1 patient and nonsustained ventricular tachycardia in 2 patients. Mean left ventricular ejection fraction in the 3 patients with positive TWA was 39.0%, whereas in the 2 patients with negative TWA it was 58.5%. A close relationship was suggested between TWA and severity of cardiac sarcoidosis.

Body surface distribution of ventricular late potentila evaluated by the signal-averaged ECG mapping. (I). Studies in patients with previous myocardial infarction.

心筋梗塞症 (MI) における加算平均心電図 (SAEOG) の体表面分布を知るため, 発症後1ヵ月以上経過したMI93例 (前壁群50例: A群, 下壁群43例: I群) を対象とし, 胸背部28点よりSAECGマッピングを行い, 濾波後QRS時間 (fQRSd) の分布を検討した.各々の誘導点が有するアーチファクトや誘導部位の影響を除くため, 患者のfQRSdより健常対照11例のfQRSdの平均値を減じ, その値のばらつきの程度を標準偏差 (SD) に対する比で表し, departure ratio map (DR map) と命名した.DR mapの極大はA群, I群ともに前胸部から背部にかけて広く分布したが, A群で左胸部, I群で右胸部下部に2SD以上の極大と, 正領域に取り囲まれたように位置する負領域を有した例の心室頻拍 (VT) 合併率は有意に高かった.DR mapのかかる特定のパターンはVTの発生基盤に関係している可能性が示唆され, fQRSdの体表面分布を評価する場合, 延長領域ばかりでなくそれに囲まれた相対的短縮領域にも着目すべきことが示唆された.