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The clinical usefulness of QRST isointegral maps (IQRST map) for detecting myocardial infarction that was complicated by intraventricular conduction disturbances was evaluated in patients with right bundle branch block (group RBBB, 64 patients) and left bundle branch block (group LBBB, 40 patients) by comparison with the normal mean IQRST map derived from 50 normal subjects. Myocardial infarction complicated the conduction disturbances in 24 of the 64 RBBB and in 18 of the 40 LBBB patients. A correlation coefficient was used for assessing the similarity of each map pattern with the normal mean IQRST map. The difference map was made by subtracting the average normal IQRST map from each abnormal IQRST map, and those differences that were less than 2 SD from the mean were retained as a significant area. The number of leads and their sum of differences were used to represent the size of the difference map. Correlation coefficients were significantly (p less than 0.001) smaller in patients with bundle branch block complicated by myocardial infarction than in patients with conduction disturbances not complicated by myocardial infarction. A significant area emerged in the difference map in all patients with myocardial infarction complicated by conduction disturbances. The emergence of a significant area revealed high diagnostic accuracy for detecting myocardial infarction in group RBBB (89.1%). The size of a significant area in a difference map was significantly larger in cases with complicated myocardial infarction than in cases with uncomplicated myocardial infarction in either group RBBB or group LBBB (p less than 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)

連続波ドップラー法で得られた三尖弁逆流速度を簡易Beronulli式に応用し,右室右房間の収縮期圧較差を算出した.さらに下大静脈横断像の前後径/横径より二分しそれぞれ右房圧を設定し,連続波ドップラー法で得られた圧較差に加え右室収縮期圧を求めた.連続波ドップラー法と心カテーテル検査で得られた圧較差はy=0.99x-3.6, r=0.98の相関を示した.連続波ドップラー法で求めた右室収縮期圧は心カテーテル検査で得られた右室収縮期圧とy=0.95x-1.6, r=0.97の相関を示し,三尖弁逆流の重症度,右心不全の有無および右室収縮期圧の程度によつては差を認めなかつた.連続波ドップラー法は簡易Bernoulli式を用い右室収縮期圧を算出可能と考えられた.

陳旧性心筋梗塞66例と狭心症18例の87誘導体表面電位図を記録し, T mapの分析を行なつた. T mapにおいて,胸部の正領域の中に,左肩から下方へ向けて舌状に負領域が陥入する所見を示した梗塞13例(20%, MI群)および狭心症6例(33%, AP群)の冠動脈および左室造影所見の検討を行なつた. MI, AP群共に全例に左冠動脈前下行枝(LAD)に有意狭窄を認め, MI群の全例およびAP群の3例(50%)に前壁の壁運動異常を認めた. T mapにおいて,負領域が左肩部から舌状に正領域に陥入する所見は, LAD病変あるいは,左室前壁,中隔部の壁運動異常を示唆すると考えられた.

標準12誘導心電図による心筋梗塞の診断が困難であるが,心血管造影にて,左室前壁に限局する収縮異常を示した冠動脈疾患患者48名(疾患群)を対象とし,体表面電位図を記録し,各誘導点のQ30(Q波≧30msec)の出現率を健常群57名のそれと比較した.疾患群ではV1・V2誘導点の上方領域および右胸部でQ30の出現率が有意に高かつた. Q30による感度は17～56%であつたが,陽性予測率は63～92%と高かつた.収縮異常高度群は軽度群に比べ,同様の領域でQ30の出現率が高かつた.これらの結果から,標準12誘導心電図誘導にV1・V2誘導点の上方領域および右胸部の誘導を加えることにより前壁収縮異常の心電図診断の精度が向上すると考えられた.