ECG Case 018

Rate:

• 150

Rhythm:

• Regular without p waves

Axis:

• LAD (-39 deg)

Intervals:

• PR – No visible p waves
• QRS – Normal (100-120ms)
• QT – 280ms (QTc Bazett 440ms)

Segments:

• Possible ST depression V3-6

Additional:

• Flutter waves visible in V1
• T Wave Inversion V1-2, aVL
• LVH (aVL>11mm)

Atrial Flutter 2:1 Block

• Narrow Complex Tachycardia
• Ventricular rate 150bpm

Other differentials include AVNRT / AVRT however the rate is usually higher in these.

‘Mapping’ of flutter waves may be helpful, this may be easier if paper speed is altered e.g. 50mm/sec

Trial of vagal maneuvers of adenosine may help differentiate Atrial Flutter

This patient received adenosine, rhythm strip below, revealing obvious flutter waves. In comparison to ECG Quiz 017, this patient does not cardiovert to sinus rhythm following an adenosine bolus. Instead, the degree of AV block is transiently increased, revealed underlying flutter waves and confirming the diagnosis of atrial flutter with a 2:1 block.

Would the Lewis Lead have helped?

The Lewis lead configuration can help to detect atrial activity and its relationship to ventricular activity. Useful in:

• Observing flutter waves in atrial flutter
• Detecting P waves in wide complex tachyarrhythmia to identify atrioventricular dissociation

Lewis lead placement

• Right Arm (RA)electrode on manubrium
• Left Arm (LA) electrode over 5th ICS, right sternal border.
• Left Leg (LL) electrode over right lower costal margin.
• Monitor Lead I

• ECG Library – Atrial flutter
• ECG Library – Left Ventricular Hypertrophy
• Dr Smith – What’s the rhythm?
• Emcrit – The Lewis Lead
• Bakker ALM. The Lewis Lead: Making Recognition of P Waves Easy During Wide QRS Complex Tachycardia. Circulation 2009

• Wiesbauer F, Kühn P. ECG Mastery: Yellow Belt online course. Understand ECG basics. Medmastery
• Wiesbauer F, Kühn P. ECG Mastery: Blue Belt online course: Become an ECG expert. Medmastery
• Kühn P, Houghton A. ECG Mastery: Black Belt Workshop. Advanced ECG interpretation. Medmastery
• Rawshani A. Clinical ECG Interpretation ECG Waves
• Smith SW. Dr Smith’s ECG blog.
• Wiesbauer F. Little Black Book of ECG Secrets. Medmastery PDF