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The classic EKG pattern associated with pulmonary embolism is identified as S1Q3T3. This pattern refers to specific changes observed in the electrocardiogram (ECG) of a patient suspected of having a pulmonary embolism.

In this pattern, the first lead (S1) shows a dominant S wave, which reflects right ventricular strain or overload. The S wave in lead I suggests that the right heart is carrying a heavier load than normal. The third lead (Q3) displays a Q wave, indicating some degree of right ventricular strain, and the T wave inversion (T3) in lead III further suggests right-sided cardiac stress or ischemia. This combination of findings can be indicative of acute cor pulmonale caused by a significant pulmonary embolism impacting the right side of the heart.

Understanding this classic pattern is pivotal in clinical practice, as it can guide healthcare professionals in the early recognition of pulmonary embolism, allowing for timely intervention and management in critically ill patients.