Describe and interpret this ECG.
[expand title=”Interpretation”]
Rate:
Atrial = 240 min-1
Ventricular = 80 min-1
Rhythm:
Atrial flutter with variable 3:1 and 4:1 blockade
P waves:
Duration = 80 ms
PR interval:
Duration = 160 ms
Morphology = normal
QRS complex:
Duration = 112 ms
Axis = 77°
Q Waves:
Nil
R wave progression:
Normal
LV Hypertrophy [Sokolow; SV1 + (RV5 or RV6) > 35mm) or RI + SIII > 25mm]?
No
RV Hypertrophy [R/S ratio V5 or V6 < 1 or R/S ratio V1 > 1 or S1S2S3 pattern]?
No
ST segments:
N/A
T waves:
N/A
QT interval:
N/A
Additional comments:
Nil
Interpretation: There is atrial flutter with variable 3:1 and 4:1 blockade. The atrial rate is slower than anticipated (240 min-1 rather than 300 min-1). This implies that the patient is likely to be on rate control medications (β-blockers, CCBs, Class III anti-arrhythmics).
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