Check out our original post of this ECG and the excellent comments here.
|Click to enlarge|
- Ventricular rate 42 bpm
- Atrial rate ~230 bpm
- Irregular ventricular activity
- Regular atrial activity
- Flutter waves
- Normal (~75 deg)
- PR - Nil P waves visible
- QRS - Prolonged (120ms)
- QT - 400ms
- Minor ST depression V4-6
- rSR' Pattern V1-2
- Variable notching of QRS complexes secondary to superimposed flutter waves
- Flutter waves
- Alternating positive / negative morphology in inferior leads
- Flutter waves are narrow and small
- Relatively long isoelectric segment
- Atrial flutter
- Variable block
Dr Arieh Keren and Dr Shakeeb Razak, electrophysiology specialists and ECG of the Week blog team members, have reviewed this ECG and shared there thoughts below:
Atypical vs typical flutter
- Typical atrial flutter involves the cavotricuspid isthmus (CTI)
- Atypical flutter involves a different location than the CTI.
Micro vs macro re-entrant circuit
- Given the small flutter waves and isoelectric segment length this is more likely to be micro re-entry flutter.
- Macro re-entry flutter results in the classic saw tooth pattern with atrial activation occuring throughout the flutter cycle length.
Underlying cause in this case
- The alternating positive / negative atrial morphology suggests an uncommon circuit type.
- A possibility is two seperate micro re-entry ciruit close to each other.
- This suggests a more likely cause in this case of:
- Previous cardiac surgery
- Congential cardiac disease
- Major metabolic derrangement
Dr Razak has suggested some interesting articles which further explore some of the features and questions raised by this ECG.
- Medi C, Kalman JM. Prediction of the atrial ﬂutter circuit location from the surface electrocardiogram. Europace (2008) 10, 786–796. FULL TEXT
- Pedrinazzi C, Durin O, Mascioli G, Curnis A, Raddino R, Inama G, Dei Cas L. Atrial flutter: from ECG to electroanatomical 3D mapping. Heart Int. 2006;2(3-4):161. FULL TEXT
Both papers provide in-depth reviews of atrial flutter classifications, both new & old, and how the ECG and advanced EP techniques can help differentiate them
Causes of Atrial Flutter
There are a wide range of general potential causes for atrial flutter with variable block including:
- Sinus node dysfunction
- Calcium-channel blockers
- Other anti-arrhythmic drugs
- Electrolyte abnormality
- Acid / base disturbance
- Hyper- / hypo-thyroid
A 83 year old patient presents to your Emergency Department complaining of lethargy, nausea, and vomiting. There are on multiple medications but are unable to remember their names.
BP 105/64 RR 17 Temp 37.4 C
Describe and interpret their ECG (100%)
Life in the Fast Lane
- Atrial flutter here
- Chan TC, Brady WJ, Harrigan RA, Ornato JP, Rosen P. ECG in Emergency Medicine and Acute Care. Elsevier Mosby 2005.