Mechanical thrombectomy rapidly reversed right heart strain and resolved the S1Q3T3 ECG pattern in a 63-year-old male presenting with a saddle pulmonary embolus.
Case Report (n=1)
Early recognition of the S1Q3T3 EKG pattern can accelerate the diagnosis of acute pulmonary embolism, and mechanical thrombectomy can rapidly reverse right heart strain.
Abstract Introduction The S1Q3T3 electrocardiogram pattern—characterized by a prominent S wave in lead I, Q wave in lead III, and T wave inversion in lead III—is a classic but nonspecific sign of acute right ventricular strain, often seen in saddle pulmonary embolism. Its presence suggests significant clot burden and right heart overload, though its sensitivity and specificity are limited1-3. Case Presentation A 63-year-old male with hypertension, hyperlipidemia, and diabetes presented after a syncopal episode. He reported one week of exertional dyspnea. At an outside hospital, he was diagnosed with pulmonary embolism (PE) and started on apixaban. He described feeling lightheaded after standing and then lost consciousness. A second syncopal episode prompted evaluation. EKG showed sinus tachycardia (rate 108) and an S1Q3T3 pattern. CT angiogram revealed bilateral pulmonary emboli with saddle embolus, right heart strain, and pulmonary hypertension. The patient was admitted to the ICU and started on a heparin infusion. Interventional Radiology performed thrombectomy, removing a significant clot burden (Figure 1). He remained in the ICU for two days for monitoring. Follow-up EKG showed resolution of S1Q3T3, and echocardiogram confirmed normalization of right ventricular strain. The patient was transitioned to apixaban and discharged two days later. Discussion The S1Q3T3 pattern is a recognized but nonspecific marker of acute PE, seen in only 15% of confirmed cases1. Although right ventricular strain findings such as right bundle branch block or T-wave inversions may accompany large clot burdens, their diagnostic accuracy is limited and should not be used in isolation 4,5. The S1Q3T3 pattern, however, can accelerate evaluation for right ventricular injury when interpreted within the full clinical context6. The current gold standard for diagnosis remains spiral computed tomography7. Conclusion Early recognition of the S1Q3T3 pattern should prompt evaluation for acute pulmonary embolism. Mechanical thrombectomy can rapidly reverse right heart strain and improve outcomes in massive PE. This abstract is funded by: None
Litsky et al. (Fri,) conducted a case report in Saddle pulmonary embolism (n=1). Mechanical thrombectomy was evaluated. Mechanical thrombectomy rapidly reversed right heart strain and resolved the S1Q3T3 ECG pattern in a 63-year-old male presenting with a saddle pulmonary embolus.