Lewis lead

Lewis lead is a specific type of electrocardiographic (ECG) lead configuration used primarily in the monitoring of atrial activity and the detection of atrial arrhythmias. This lead configuration is particularly useful in identifying atrial flutter and atrial fibrillation.

Configuration

The Lewis lead configuration involves repositioning the standard electrodes to enhance the visibility of atrial activity. Typically, the right arm (RA) electrode is placed in the second intercostal space to the right of the sternum, and the left arm (LA) electrode is placed in the fourth intercostal space at the right sternal border. The left leg (LL) electrode remains in its standard position.

Clinical Use

The primary use of the Lewis lead is in the detection and monitoring of atrial arrhythmias. It is particularly effective in identifying P waves, which are often difficult to discern in standard ECG leads. This enhanced visibility can aid in the diagnosis of conditions such as atrial flutter, atrial fibrillation, and other supraventricular tachycardias.

Advantages

The Lewis lead configuration offers several advantages:

• Improved visualization of atrial activity
• Enhanced detection of P waves
• Better differentiation between atrial arrhythmias and ventricular arrhythmias

Limitations

While the Lewis lead is beneficial for specific diagnostic purposes, it is not a replacement for the standard 12-lead ECG. It is primarily used as an adjunctive tool in the clinical setting.

History

The Lewis lead is named after Sir Thomas Lewis, a pioneering British cardiologist who made significant contributions to the field of electrocardiography and the study of cardiac arrhythmias.

See Also

• Electrocardiography
• Atrial flutter
• Atrial fibrillation
• P wave
• Cardiac arrhythmia