T- and U- Wave Changes

T-waves

Condition	EKG Changes
Normal	Upright in all leads other than aVR and V1 with the amplitude normally being less than 5 mm in limb leads and 10 mm in precordial leads
Hyperkalemia MI	Tall T-waves
Kids and young adults	T-wave inversions in V1-3 are normal in kids(Juvenile T-wave pattern). May persist into adulthood (Persistent Juvenile T-wave pattern)
LBBB/ LVH/ Paced rhythm/RBBB/ RVH	Discordant T-waves
PE	S1Q3T3 pattern. T-wave inversions in inferior leads and V1-V3.
Hypertrophic cardiomyopathy	Deep inverted T-waves in all precordial leads
Raised Intracranial pressure	Deep inverted T-waves
Wellens Syndrome	Biphasic (positive and then negative deflection- Type A) or inverted (deep symmetric inversion of T-waves- Type B) in V2 and V3. Suggests a LAD lesion.
Hypokalemia	T-waves may be biphasic (negative and then positive) and will progressively disappear while U waves become more pronounced. With U waves, the QU interval becomes prolonged.
Double peaking T-waves	Either because of U-waves or because of P-waves getting superimposed on T-waves.
Ischemia/ Infarction	Ischemia: T-wave flattening/ inversion. In Infarction, “hyper acute T waves” (very tall T-waves) may be seen with reciprocal changes.

Condition	EKG Changes
Normal	usually a small deflection after the T-waves, in the same direction as the T-wave. Usually seen at lower heart rates.
Bradycardia Hypokalemia/ Hypomagnesemia/ Hypocalcemia Hypothermia Raised Intracranial Pressure LVH Drugs like Class Ia, III anti-arrhythmics, Digoxin	Prominent U-waves (>1 mm or 25% of the height of the T wave.)
Severe Heart Disease (ischemia/ valvular/ congenital/ cardiomyopathy,etc.)	Inverted U-waves.