The ECG is abnormal in over 70% of patients with pulmonary embolism. Certain ECG abnormalities have been observed to return to normal after treatment. This case report describes an instructive ECG series in a patient with massive bilateral pulmonary embolism as shown by spiral computed tomography. The initial ECG showed sinus tachycardia with P pulmonale, although atrial tachycardia could not definitively be excluded. The patient had an increased troponin I concentration and echocardiographic evidence of right ventricular dysfunction and underwent thrombolysis with alteplase and anticoagulation with warfarin. P wave amplitude gradually decreased throughout admission and her tachycardia resolved. This may reflect a reduction in right atrial strain after treatment. This phenomenon has apparently not been described in this setting. The significance of ECG changes and the role of thrombolysis in pulmonary embolism are briefly discussed.
Keywords: ECG, P pulmonale, P wave, pulmonary embolism, right atrial strain