#teachingrounds

Pro-Tip: The slower the heartrate (<65 bpm), the taller the U wave will be.

A. In healthy adults, the T wave should be upright in all leads except aVR and V1. Inverted T waves are normal in children in the R precordial leads because of RV dominance; as a persistent juvenile T-wave pattern in V1-3, especially in young Afro-Caribbean women; and can be normal variant in lead III. However, NEW T-wave inversions are always abnormal and suggest acute MI, bundle branch block, ventricular strain from hypertrophy, pulmonary embolism, hypertrophic cardiomyopathy, or raised intracranial pressure. Pathological T wave inversions are usually symmetrical and deep (>3mm). Source: LITFL

A. No, the letter J on the EKG defines 2 totally different and unrelated events. The J point is a point in time marking the end of the QRS and the onset of the ST segment present on all EKGs. The J wave is a much less common, slow deflection of uncertain electrophysiological origin that was originally described in relation to hypothermia (T<30C) and is sometimes called an Osborn wave. Fairly specific for hypothermia (rules it IN), an Osborne or J wave can also been seen in hypERcalcemia, LVH due to HTN, myocarditis or Takotsubo cardiomyopathy, acute MI, or just early repolarization. Source: LITFL.

A. Early ventricular depolarization is reflected in the first upward deflection after the P wave (which represents atrial depolarization). Usually the size of the R wave increases from V1 to V3 If the R wave in lead V3 is shorter than expected (<3mm), then you should consider a prior anteroseptal MI, left ventricular hypertrophy, inaccurate lead placement (V1 and V3 swapped?), a normal variant, or dextrocardia.

Pathological Q waves usually indicate current or prior myocardial infarction. Source: LITFL

Source: LITFL

Image courtesy of Medical Humor (21 Dec. 2011).

https://pubmed.ncbi.nlm.nih.gov/40844370/ Ringel MD, Sosa JA, Baloch Z, Bischoff L, Bloom G, Brent GA, Brock PL, Chou R, Flavell RR, Goldner W, Grubbs EG, Haymart M, Larson SM, Leung AM, Osborne J, Ridge JA, Robinson B, Steward DL, Tufano RP, Wirth LJ. 2025 American Thyroid Association Management Guidelines for Adult Patients with Differentiated Thyroid Cancer. Thyroid. 2025 Aug;35(8):841-985. doi: 10.1177/10507256251363120. PMID: 40844370.