Key Points: WPW alters ventricular depolarization, producing secondary repolarization abnormalities that can mimic or mask myocardial infarction. ST-segment deviation in WPW is often non-ischemic, driven by abnormal activation via the…
Key Points: Most missed occlusion MI. Isolated posterior occlusion MI is frequently missed because the standard 12-lead ECG often lacks ST elevation. Instead, posterior injury appears as reciprocal anterior ST…
Key Points: Takotsubo (stress) cardiomyopathy is a transient, non-ischemic LV dysfunction—classically apical ballooning with basal hyperkinesis—often after emotional or physical stress. Presentation mimics occlusion MI (chest pain, ECG changes, elevated…
Key Points ACS is dynamic. Coronary arteries can occlude, partially reperfuse, and re-occlude over minutes to hours, and the ECG can show these shifts before biomarkers do. The earliest actionable…
Key Points Reperfusion after fibrinolysis is a bedside diagnosis using a bundle of findings: symptoms, ECG trend, and hemodynamic/electrical stability. Best ECG marker of successful fibrinolysis: at least 50% ST-segment…
Key Points Reperfusion and re-occlusion can occur spontaneously or after therapy. The ECG often reflects these changes earlier than symptoms. Most useful bedside ECG marker of reperfusion is ST-segment resolution…
Key Points STEMI criteria alone miss some acute coronary occlusions, so look for subtle “occlusion clues,” not just traditional STEMI criteria cutoffs. Minor ST elevation under 1 mm paired with…
Key Points ACS is a clinical syndrome: classified by ischemic symptoms + ECG + troponin. ACS exists on a continuum of unstable angina, NSTEMI, STEMI, and patients can evolve between…
Key Points: Do not reflexively label ST depression in V1–V4 as “anterior ischemia/NSTEMI.” In ACS symptoms, posterior OMI is a major concern when the depression is most prominent in V1–V3…
Key Points STEMI Equivalent: The de Winter ECG pattern is an uncommon STEMI equivalent indicative of an unstable proximal occlusion of the LAD (left anterior descending coronary artery). Treat the…
Key Points Think proximal LAD / septal ischemia until proven otherwise when a patient with ischemic symptoms develops new RBBB + LAFB, especially with hemodynamic instability. Do not “normalize” ST…
Key Points: Pseudo-Wellens waves are anterior T-wave patterns that mimic the biphasic or deeply inverted T waves of true Wellens syndrome but are caused by non-LAD, non-ischemic physiology. These normal-variant…
Key Points: Clinical diagnosis, not an ECG pattern alone. Wellens syndrome requires the characteristic ECG findings plus the appropriate clinical scenario. Morphology alone is insufficient and high-risk if misapplied. Critical…
Key Points Wellens waves are anterior precordial T wave abnormalities (biphasic or deeply inverted) most often in V2–V3, occasionally extending to V1 and V4–V6. They signal a high likelihood of…
Key Points: High-risk STEMI morphology caused by fusion of the terminal QRS, J point, ST segment, and T wave into a single “triangular” deflection. Often massive apparent STE with loss…
Key Points SCAD Definition: A spontaneous, non-atherosclerotic tear in the coronary artery wall, often affecting young, otherwise low-risk women (including peripartum patients). SCAD presents similarly to ACS and is an…
Key Points Normal expectation: In V1, the S wave is typically larger than the R wave. A tall or dominant R wave (R/S > 1) is abnormal and should prompt…
Key Points Normal expectation: In aVR, the QRS is usually negative (deep S wave). A dominant or tall R wave (R > S) is abnormal and should prompt investigation. Mechanism:…
Key Points: Complexity of ACS: Arteries can spontaneously reperfuse or re-occlude. Understanding early ECG patterns of early acute ischemia can help detect dynamic changes and prompt rapid interventions. ECG Pattern…
Key Points The reference for ST-segment shift is the J point relative to an isoelectric baseline. The two candidates for that baseline are the TP segment and the PR segment….