Acute pulmonary embolism
An anterior ischemic pattern of symmetric T-wave inversion in the precordial leads V1 through V4 may also be a sign of acute or chronic right ventricular strain, particularly acute pulmonary embolism. Sinus tachycardia is usually present, but other signs of pulmonary embolism, such as right ventricular hypertrophy and right bundle branch block, may be absent. In fact, T-wave inversion in leads V1 through V4 is noted in 19% of patients with nonmassive pulmonary embolism and in 85% of patients with massive pulmonary embolism, and is the most sensitive and specific electrocardiographic finding in massive pulmonary embolism.23
In addition, acute pulmonary embolism may be associated with T-wave inversion in leads III and aVF,24 and changes of concomitant anterior and inferior ischemia should always raise the question of this diagnosis.
In one retrospective study of patients with acute pulmonary embolism, nonspecific ST-segment or T-wave changes were the most common finding on electrocardiography, noted in 49%.25 Rapid regression of these changes on serial tracings favors pulmonary embolism rather than myocardial infarction.
ST-segment depression reciprocal to a subtle ST-segment elevation
When ST-segment elevation occurs in two contiguous standard leads while ST-segment depression occurs in other leads, and when the ST-segment and T-wave abnormalities are ischemic rather than secondary to depolarization abnormalities, ST-segment elevation is considered the primary ischemic abnormality whereas ST-segment depression is often considered a reciprocal “mirror image” change. This “reciprocal” change may also represent remote ischemia in a distant territory in patients with multivessel coronary disease.26,27
Reciprocal ST-segment depression is present in all patients with inferior myocardial infarction and in 70% of patients with anterior myocardial infarction.28
Hypokalemia and digitalis effect
DIFFUSE (GLOBAL) T-WAVE INVERSION
Walder and Spodick36 have found this pattern to be caused most often by myocardial ischemia or neurologic events, particularly intracranial hemorrhage, and it seems more prevalent in women. Other causes include hypertrophic cardiomyopathy, stress-induced cardiomyopathy (takotsubo cardiomyopathy), cocaine abuse, pericarditis, pulmonary embolism, and advanced or complete atrioventricular block.36,37
The prognosis in patients with global T-wave inversion is determined by the underlying disease, and the striking T-wave changes per se do not imply a poor prognosis.38
OTHER CAUSES OF T-WAVE INVERSION OR ST-SEGMENT DEPRESSION
Various other entities may cause T-wave inversion, notably acute pericarditis or myocarditis, 41,42 memory T-wave phenomenon,43,44 and normal variants of repolarization (Table 1, Figure 9).45 Additionally, a nonpathologic junctional ST-segment depression may be seen in tachycardia (Figure 10).