Miscellaneous ECG 5
- Atrial flutter with an uncontrolled ventricular response and variable conduction
Not all atrial flutters demonstrate the typical "sawtooth" pattern. During the times of lesser conduction on this ECG, the flutter waves are more apparent. The atrial rate is organized at a rate of about 300 beats per minute. The P waves are negatively deflected in the inferior leads which would normally mean the atrial flutter is counterclockwise, however this situation is different due to the presence of dextrocardia (the heart located in the right side of the chest instead of the left side) and thus these rules do not apply (see atrial flutter review by clicking below).
The ECG findings of dextrocardia include a predominantly negative P wave (when sinus rhythm is present), negative QRS complex, and negative T wave in lead I. This results in a rightward QRS axis. There will also be low voltage in leads V3-V6 since these leads are placed on the left side of the chest and no heart is present at that location. The dextrocardia ECG findings can appear similar to limb lead reversal in lead I, however if the limb leads are simply misplaced, leads V3-V6 will appear normal and not low in voltage as seen in dextrocardia.