The ECG changes in the figure below:
are diagnostic of:
On this electrocardiogram, there is a sinus tachycardia. The voltage is low and in the V1 and II rhythm strips, electrical alternans can be seen. This is an ECG from a patient with cardiac tamponade (pericardial effusion).
are seen in:
This electrocardiogram shows a sinus tachycardia. There is a generalized T-wave inversion. The T waves are symmetric, deep, and have a long QT interval. This is an electrocardiogram from a patient with a major CNS event such as a subarachnoid or intraventricular hemorrhage.
This electrocardiogram shows a sinus rhythm. There is prolongation of the QT interval. The T wave has a fairly normal duration and contour, however. This is an example of hypocalcemia. (Type III congenital long QT syndrome also has this appearance.)
are suggestive of:
On this electrocardiogram, there is a sinus rhythm. It is sinus bradycardia. There is a prolongation of the QT interval. In this case, there is ST-segment depression, T-wave flattening, and TU fusion with prominent U waves in the lateral precordial leads. This should suggest hypokalemia. Another possibility is digitalis plus an antiarrhythmic drug’s effects (such as quinidine or procainamide).
The Ecg changes in the figure below:
This patient has a sinus tachycardia. There is symmetry of the T waves and there is a degree of QT prolongation. This is an example of a mixed electrolyte abnormality, hyperkalemia, and hypocalcemia. Values at the time were potassium of 7.2 and calcium of 80.
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