What does U wave on ECG mean?

What does U wave on ECG mean?

The ‘U’ wave is a wave on an electrocardiogram (ECG). It comes after the T wave of ventricular repolarization and may not always be observed as a result of its small size. ‘U’ waves are thought to represent repolarization of the Purkinje fibers. However, the exact source of the U wave remains unclear.

Is the U wave normal?

The normal U wave is best seen at rest in the precordial leads and is more commonly seen during sinus bradycardia. Studies evaluating the response of the QT interval to tachycardia (produced by exercise or atrial pacing) in healthy individuals have often ignored the U waves.

What causes pathological U waves on ECG?

The origin of the U wave is still in question, although most authorities correlate the U wave with electrophysiologic events called “afterdepolarizations” in the ventricles. These afterdepolarizations can be the source of arrhythmias caused by “triggered automaticity” including torsade de pointes.

Is U wave part of QT interval?

The QT interval implies that the U-wave should not be included in the measurement, as one would then need to determine the QU interval. However, it is clear that cardiac repolarization is only finished after the end of the U-wave (Fig.

What does an inverted U wave mean?

Inverted U wave, a specific electrocardiographic sign of cardiac ischemia.

Are U waves associated with electrolyte imbalance?

Similar to elevated potassium levels, low potassium levels can cause myocardial arrhythmias and significant ectopy. EKG changes can include increased amplitude and width of P wave, T wave flattening and inversion, prominent U waves and apparent long QT intervals due to merging of the T and U wave.

When does the U wave occur?

In a normal heart beat, the T wave represents repolarisation of the ventricles, specifically the repolarisation of the AV node and bundle branches. The U wave occurs when the ECG machine picks up repolarisation of the Purkinje fibres.

Is the U wave present on every strip?

The U Wave is thought to represent late repolarization of the Purkinje fibers in the Ventricles and is more often not shown on a rhythm strip.

Does QT interval include U wave?

The QT interval implies that the U-wave should not be included in the measurement, as one would then need to determine the QU interval. However, it is clear that cardiac repolarization is only finished after the end of the U-wave (Fig. ​2).

What electrolyte causes U wave?

How do you read the QT interval on an ECG?

Measure the QT interval from the beginning of the QRS complex to the end of the T wave. This is the uncorrected QT. Measure at least three successive beats, with the maximum interval taken, in case these three beats differ.

What does QT interval indicate?

The Q-T interval is the section on the electrocardiogram (ECG) – that represents the time it takes for the electrical system to fire an impulse through the ventricles and then recharge. It is translated to the time it takes for the heart muscle to contract and then recover.