Benign T Wave Inversion

Benign T wave inversion (BWTI) is an EKG finding that is not completely understood though is a repolarization variant. It seems to occur more in those of African descent and is commonly mistaken for ischemia. Besides the obvious T wave inversion, patients commonly have tall R waves and may have J point notching as well (J point notching is common in repolarization variants-ie benign early repolarization). The ST elevation should be concave (horizontal or convex ST elevation is always highly concerning for OMI). Most of the time, these findings are most prominent in V3-V6, though inferior lead involvement is fairly common. In addition, the QT is usually short (similar to early repolarization). One of the best ways to identify ischemia in the presence of a repolarization variant is the presence of terminal QRS distortion; lack of terminal distortion points away from ischemia. Although these T wave inversion may have minimal change, the changes should not be drastic over time (ie Wellen's syndrome). In contrast to other pathology (ie bundle branch block), the QRS should not be wide.

Because most of the patients with these findings are young, athletic African (males), one of the main differential diagnoses is HOCM. In HOCM, the QT is typically longer, the R wave is slightly wide, there are no J point notches, and there are no S waves in the lateral chest leads (ie V4). Additionally, most HOCM cases involve primarily the septum with a needle-like R wave in V1 that is not present in benign T wave inversion. However, these patients should undergo a screening Echo before vigorous activity to rule out HOCM. In patients with the potential for coronary ischemia with concerning symptoms, overlying ischemia can be difficult to assess due to the baseline changes. Although very similar to early repolarization with it being another repolarization variant, early repolarization does not classically have TWI.

Examples:

Source: Steve Smith's blog

This is BWTI. Note the tall R waves in V3-V6 with J point notching in V3-V6 with mild concave ST elevation in these leads and TWI (more terminal). There are no dagger S waves in V6, needle-like R waves in V1. Also note that the QT is quite short.

Source: Steve Smith's blog

This is also BWTI. Again, note the tall R waves with S waves present in V3-V6 with TWI and questionable ST elevation in V3-V4. Again, the QT is short. J point notching is not present, though also not required for the diagnosis.

Source: Steve Smith's blog

Again BWTI. There is, again, ST elevation in the anterolateral leads with tall R waves, J point notching, TWI, and short QT. There is no terminal QRS distortion in these leads.

Source: Steve Smith's blog

This is HOCM. Note the slightly wide R waves, terminal QRS distortion with T wave inversions. Although there are no needle-like R waves in V1 or dagger Q waves in V6, this is a typical variant of HOCM that is often confused with BTWI.