Abnormalities of Ventricular Repolarization
The specificity—sensitivity spectrum of the ventricular complex can be compared to a pennant on a pole (Fig. 2-9, p. 44); even the smallest breeze can move the tip, a stronger wind will straighten it out all the way, and a real hurricane will bend the pole. When the wind subsides, the pennant will return to its undisturbed position, alongside the pole if the pole is still vertical, but apart from it if the pole has been bent. QRS-ST-T abnormalities are similar in many respects. Change may be induced in T by almost any stimulus, even a drink of cold water, a more severe or sustained one is needed to affect the ST segment, and QRS abnormality, especially of duration or contour, almost always means structural abnormality in the ventricular wall. T and ST may return to normal when the stimulus is removed, but QRS abnormality is likely to persist. Change in the route of depolarization influences that of repolarization; abnormality in ST-T may be secondary to that in QRS.
KeywordsCatheter Depression Ischemia Sedimentation Anemia
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