PE ECG changes

Some non-specific changes but in combination PE should be considered

• Sinus tachycardia – the most common abnormality (seen in 44% of patients with PE)
• Right BBB(18%)
• Right ventrcular strain pattern –  T wave inversions in the right precordial leads (V1-4) ± the inferior leads (II, III, aVF). This pattern is associated with high pulmonary artery pressures (34%)
• Right axis deviation (16%). Extreme right axis deviation may occur, with axis between zero and -90 degrees, giving the appearance of left axis deviation (“pseudo left axis”)
• Dominant R wave in V1– a manifestation of acute right ventricular dilatation
• Right atrial enlargement – peaked P wave in lead II > 2.5 mm in height (9%)
• SI QIII TIII  pattern – deep S wave in lead I, Q wave in III, inverted T wave in III (20%). This “classic” finding is neither sensitive nor specific for PE
• New atrial tachyarrhythmias – AF, flutter and atrial tachycarida (8%)
• Non-specific ST segment and T wave changes, including ST elevation and depression (50%)