Which EKG finding is seen in pulmonary embolism?

Which EKG finding is seen in pulmonary embolism?

• A. Wide S in lead I; Wide Q in lead III; Inverted T in lead III
• B. Normal EKG
• C. ST elevations in II, III, aVF
• D. Peaked T waves in aVR

Answer: (A)

Pulmonary embolism often causes acute strain on the right ventricle, which shows up on the ECG as the classic S1Q3T3 pattern: a prominent or wide S wave in lead I, a Q wave in lead III, and an inverted T wave in lead III. The deep S in lead I reflects a shift of the heart’s electrical axis to the right from sudden right ventricular overload. The Q wave and the T-wave inversion in lead III arise from changes in depolarization and repolarization due to this acute right-sided strain. This pattern is a well-known clue in the right clinical context, even though it isn’t present in all cases. Other findings can include right axis deviation or new right bundle branch block, but the specific combination of S in I with Q and T inversions in III points toward PE rather than other conditions. The alternatives described (a normal ECG, ST elevations in inferior leads, or peaked T waves in aVR) align more with other diagnoses such as myocardial infarction or electrolyte disturbances.

Pulmonary embolism often causes acute strain on the right ventricle, which shows up on the ECG as the classic S1Q3T3 pattern: a prominent or wide S wave in lead I, a Q wave in lead III, and an inverted T wave in lead III. The deep S in lead I reflects a shift of the heart’s electrical axis to the right from sudden right ventricular overload. The Q wave and the T-wave inversion in lead III arise from changes in depolarization and repolarization due to this acute right-sided strain. This pattern is a well-known clue in the right clinical context, even though it isn’t present in all cases. Other findings can include right axis deviation or new right bundle branch block, but the specific combination of S in I with Q and T inversions in III points toward PE rather than other conditions. The alternatives described (a normal ECG, ST elevations in inferior leads, or peaked T waves in aVR) align more with other diagnoses such as myocardial infarction or electrolyte disturbances.