Value of the XXXX in electrocardiography.

@entity1 @entity162 @entity308 @entity5968 @entity583 @entity1563 @entity661 @entity453
Only bipolar lead recording are available during ambulatory monitoring. Their sensitivity in detecting ST segment changes in relation to standard electrocardiographic leads is not known. The magnitude and direction of ST segment changes in the @entity162 were compared with those in standard electrocardiographic leads in @entity1 during exercise testing and percutaneous transluminal coronary angioplasty. Thirty @entity1 with @entity453 were studied during exercise tests in which @entity308 (greater than 0.5 mm) occurred in one or more standard electrocardiographic leads and 13 @entity1 were studied during angioplasty that resulted in ST segment change in one or more leads (I, II, III, V2, V5, and CM5). Lead CM5 was the most sensitive lead (93%) during exercise testing and also showed the greatest magnitude of ST segment change below the isoelectric line in 93% of the @entity1 . Only two @entity1 , one with ST segment elevation in inferior leads and one with changes restricted to septal leads, had no @entity308 in lead CM5. When ST segment shift from the baseline electrocardiogram was measured the magnitude of @entity308 was greatest in lead CM5 in only 63% of the @entity1 . During angioplasty of the left anterior descending coronary artery, lead CM5 showed @entity308 in seven @entity1 , ST segment elevation in two, and a biphasic response in one. Two of the three @entity1 with @entity661 in right coronary artery developed ST segment elevation in lead CM5. Thus lead CM5 is a reliable lead for detecting subendocardial ischaemia experienced during everyday activities in anginal @entity1 . During total occlusion of coronary arteries (as in @entity5968 or @entity583 ) lead CM5 commonly shows @entity308 and changes due to @entity1563 may not be detected.
