Inferior-lead lambda (λ) wave on ECG indicated critical 95% right coronary artery stenosis, resolving after PCI with sustained stent patency and no syncope recurrence.
Lambda waves in inferior leads can be an uncommon ECG marker of transient ischemia due to critical coronary artery stenosis, which resolves with successful revascularization.
Lambda (λ) waves are uncommon ECG markers of malignant arrhythmias, usually associated with channelopathies or transient ischemia. We report a 34-year-old man with recurrent syncope preceded by subxiphoid chest pain and diaphoresis. Admission ECG showed λ-like morphology in the inferior leads with dynamic ST changes. Laboratory tests and echocardiography were normal, while Holter monitoring demonstrated persistent ST-segment depression. Coronary angiography revealed diffuse right coronary artery disease with a critical 95% stenosis, treated with drug-eluting stent placement. ECG abnormalities resolved after PCI, and syncope did not return. Serial angiography over 3.5 years confirmed sustained stent patency.
Xiong et al. (2026) studied this question. Inferior-lead lambda (λ) wave on ECG indicated critical 95% right coronary artery stenosis, resolving after PCI with sustained stent patency and no syncope recurrence.