Key result
RBBB with QR pattern in V1 flags high-risk PE in sudden cardiac arrest.
Why the study?
High-risk pulmonary embolism can lead to sudden cardiac arrest, making it crucial to identify clues that might precede high-risk PE in resuscitated SCA.
Does right bundle branch block with a QR pattern in V1 on ECG predict high-risk pulmonary embolism in a patient with sudden cardiac arrest?
Case Report (n=1)
Does right bundle branch block with a QR pattern in V1 on ECG predict high-risk pulmonary embolism in a patient with sudden cardiac arrest?
An initial ECG demonstrating RBBB with a QR pattern in V1 should raise a high clinical suspicion for high-risk pulmonary embolism in cases of sudden cardiac arrest or hemodynamic collapse.
Answers are grounded in this paper and cite their sources.
May prompt PE consideration in arrest with this ECG pattern; hypothesis-generating and requires prospective validation before practice change.
BACKGROUND High-risk pulmonary embolism (PE) refers to a subset of massive PE that can lead to sudden cardiac arrest (SCA) or hemodynamic collapse. It is crucial to identify the clues that might precede high-risk PE in resuscitated SCA. The presence of right bundle branch block (RBBB) with a QR pattern in V1 on the electrocardiogram (ECG) has a high positive predictive value for diagnosing cardiac arrest caused by high-risk PE. Therefore, we present a case study of SCA caused by high-risk PE. CASE REPORT A 44-year-old woman with no medical history presented to the emergency room due to SCA. The first ECG showed sinus tachycardia and RBBB with a QR pattern in V1. The clinical manifestations, particularly the abnormal ECG findings, led to the consideration of high-risk PE. Urgent thrombolytic therapy was administered before confirmation with computed tomographic pulmonary angiogram (CTPA). The patient was eventually diagnosed with antiphospholipid antibody syndrome and treated with warfarin. CONCLUSIONS RBBB with a QR pattern in V1 on ECG has a high positive predictive value for the diagnosis of cardiac arrest caused by high-risk PE. Furthermore, the presence of a QR pattern in V1 performs as an independent predictor for high-risk PE patients who may require advanced treatments, including systemic thrombolysis or invasive embolectomy. It is worth further exploring the prioritization of thrombolysis for high-risk PE patients before confirmation with CTPA, when ECG findings strongly suggest the diagnosis.
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Wang et al. (2025) conducted a case report in High-risk pulmonary embolism with sudden cardiac arrest (n=1). Right bundle branch block (RBBB) with a QR pattern in V1 was evaluated on Diagnosis of cardiac arrest caused by high-risk pulmonary embolism. The presence of right bundle branch block with a QR pattern in V1 on ECG served as an important early predictor of high-risk pulmonary embolism in a patient presenting with sudden cardiac arrest.
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