Key Points: Short QT Interval: A QT interval is considered short when the corrected QT (QTc) interval is less than 350 ms. A short QT interval on the ECG can…
Key Points: The QT interval reflects the time it takes for total ventricular depolarization and repolarization (Q wave onset to T wave end). QT prolongation increases the risk of torsades…
Key Points: ST elevation describes an ECG finding, not a diagnosis. It reflects abnormal ventricular repolarization and can arise from ischemic, structural, metabolic, electrical, or extracardiac processes. Occlusion MI is…
Key Points: ST-segment elevation (STE) is an ECG finding, not a diagnosis. Multiple ischemic and non-ischemic processes can produce STE. Diffuse STE is often non-ischemic, in contrast to the regional…
Key Points: Early repolarization (ER) is a common, benign ECG pattern that most often appears in young, healthy patients. It can closely resemble acute anterior STEMI, creating a high-risk diagnostic…
Key Points: LV aneurysm pattern is a post MI scar pattern with persistent ST elevation in the prior infarct territory, usually with pathologic Q waves and a stable, non evolving…
Key Points: ST elevation (STE) in aVR with diffuse ST depression elsewhere most often reflects global subendocardial ischemia, not focal transmural infarction. High-risk coronary disease is one cause, not the…
Key Points: ST elevation is a pattern, not a diagnosis. STEMI represents one cause of ST elevation and requires correlation with ECG morphology, distribution, evolution, and clinical context. Most ED…
Key Points: Severe hyperkalemia is a true ECG chameleon. It can produce ST elevation, wide QRS complexes, axis shifts, and conduction blocks that closely mimic STEMI or ventricular tachycardia. New…
Key Points: Start by looking for STEMI, not pericarditis. The safest workflow is to actively search for occlusion MI features first, then use pericarditis features as supportive evidence. Reciprocal 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: 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: Clumped or grouped beats can cause irregular rhythms, often leading to misdiagnosis as atrial fibrillation. Misdiagnosing atrial fibrillation may lead to inappropriate rate/rhythm control or unnecessary anticoagulation in…
Key Points Large T waves are not a single diagnosis. Clinical context and associated ECG findings determine whether the cause is benign, metabolic, or a high-risk OMI pattern. The most…
Key Points PRWP is a pattern, not a diagnosis. Use clinical context and compare with prior ECGs before acting. Practical definition: R in V3 less than 3 mm or a…
Key Points: Syncope and the ECG: Syncope is a transient loss of consciousness and postural tone, characterized by rapid onset, brief duration, and spontaneous recovery without medical intervention. Cardiac syncope…
Key Points In patients presenting with acute chest pain, identifying life-threatening conditions is essential. Use a systematic ECG approach alongside clinical context to evaluate for high-risk diagnoses that require immediate…
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 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 Definition: Wide complex tachycardia (WCT) = QRS >120 ms with a steady R-R interval. This section focuses on regular WCT (RWCT). Wide & irregular rhythms are covered separately…