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Electrocardiographic Differential Diagnosis of T Wave Abnormalities: The Prominent T Wave and T Wave Inversions

Amita Sudhir¹ and William J. Brady²

¹ Department of Emergency Medicine, University of Virginia School of Medicine, Charlottesville, VA, USA

² Departments of Emergency Medicine and Medicine, University of Virginia School of Medicine, VA, Charlottesville, USA

Prominent T Waves

Hyperacute T waves of early ST segment elevation myocardial infarction: In the setting of an early ST segment elevation myocardial infarction (STEMI), one of the first ECG findings is the prominent, or hyperacute T wave. The hyperacute T wave is seen as early as 5 minutes after the onset of coronary occlusion; it will likely evolve into some form of ST segment elevation by 30 minutes of acute infarction. The T wave is asymmetric in morphology, broad based, and very tall (Figure 27.1). By asymmetric, it is meant that the T wave’s upsloping limb is “less steep” compared to the downsloping portion. These T waves are most obvious in the anterior leads V1–V4. As the infarction progresses, the J point (juncture between the QRS complex and ST segment) will elevate along with the ST segment. In essence, the ST segment continues to elevate, producing a prominent form of ST segment elevation, in many cases termed the giant R wave or tombstone ST segment elevation.

Hyperkalemia: This potentially fatal electrolyte abnormality commonly presents with a number of ECG findings. Abnormalities of T wave are an early finding in this setting with the “peaked” T wave. The T wave of hyperkalemia is quite tall with a symmetric and narrow morphology (Figure 27.2).

Benign early repolarization: Benign early repolarization (BER) is a normal variant pattern that is not associated with any significant underlying cardiac pathology. BER is best known for ST segment elevation, yet also can present with large, prominent T waves. These T waves have a large amplitude and are slightly asymmetric in morphology (Figure 27.3). The T waves may appear “peaked,” suggestive of the hyperacute T wave encountered in patients with STEMI. The T waves are concordant with the QRS complex (i.e. on the same side of the major portion of the QRS complex); they are best observed in the precordial leads V1–V4.

Acute pericarditis: In addition to diffuse ST segment elevation and PR segment depression, the ECG in pericarditis may demonstrate prominent T waves (Figure 27.4). These T waves are large in amplitude and broad based with asymmetric structure.

Left bundle branch block: In leads with a predominantly negative QRS, the T waves are likely to be large and upright (Figure 27.5). These T waves, especially in leads V1–V4, have a convex upward shape or a tall, vaulting appearance similar to the hyperacute T wave of early STEMI. The T waves are usually discordant with respect to the primary portion of the QRS complex – that is, the T wave is located on the opposite side of the baseline from the major portion of the QRS complex. Similar findings are noted with ventricular paced rhythms (Figure 27.6).

See Table 27.1.

T Wave Inversion

Normal T wave inversion: Inverted T waves are seen normally in leads III, aVL, aVR, and V1. Inverted T waves are also normal in children and adolescents in the precordial leads; at times, these T wave inversions can persist into early adulthood, demonstrating the persistent juvenile T wave pattern.