Key Point Cannabis use is rising across recreational and medical contexts. Causation is not proven, but multiple contemporary studies associate cannabis with acute cardiovascular events, including MI, stroke, arrhythmias, and…
Key Points Definition and mechanics: Genetic hypertrophic cardiomyopathy with asymmetric LV hypertrophy, typically septal, causing dynamic LVOT obstruction from systolic anterior motion (SAM) of the mitral valve. Gradient worsens when…
Key Points Definition and mechanics: Hypertrophic cardiomyopathy variant with maximal hypertrophy at the LV apex (apical HCM, ApHCM). LVOT is often not obstructed at rest; some patients have mid-ventricular obstruction…
Key Points: ECG and monitor early: First-time seizure, near-syncope, unexplained LOC, or syncope all get a 12-lead now and continuous telemetry. Repeat ECG during symptoms or after another event. History…
Key Points: Definition: AIVR is a transient, usually benign ventricular rhythm often seen after reperfusion of an acute myocardial infarction (AMI), whether spontaneous or post-intervention (PCI or thrombolysis). Rate Differentiation:…
Key Points Context Matters: ECGs must be interpreted in the clinical setting. Chest pain, shock, or ACS risk factors increase pretest probability of STEMI/OMI, while atypical presentations lower it. Prevalence:…
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 BRASH is a synergistic spiral: bradycardia, renal failure, therapeutic AV-nodal blockade, shock, and hyperkalemia. The signature clue is disproportionate brady-shock despite only modest potassium elevation. Do not be…
Key Points Pattern vs syndrome: WPW pattern = pre-excitation on ECG without symptoms. WPW syndrome = pattern plus tachyarrhythmia symptoms (palpitations, syncope, “seizure,” aborted sudden cardiac arrest). Mechanism: Congenital accessory…
Key Points Tension pneumothorax is a clinical diagnosis—ECG changes are nonspecific but can provide supportive evidence in the right context. Electrical changes are primarily due to mechanical effects of air…
Key Points Aortic dissection or aneurysm can produce ischemic‑appearing ECGs due to coronary malperfusion, most often right coronary involvement causing inferior changes. Pseudo‑infarction patterns, ST‑deviation, and conduction blocks can occur…
Key Points Definition: The ST segment runs from the J point (end of QRS) to the start of the T wave, the interval between ventricular depolarization and repolarization. Normal: Usually…
Key Points Definition: Chronic pressure/volume overload → thickened RV (pulm HTN, congenital lesions, pulmonary disease). ECG signature: Rightward axis, dominant R in V1, deep S in V5–V6, with possible right-sided…
Key Points Definition and Measurement: A Q wave is the first negative deflection of the QRS. Measure width in ms from the onset below baseline to its return to baseline;…
Key Points Definition and measurement: The QRS complex is ventricular depolarization, measured from the earliest ventricular deflection (Q or R) to the latest S return to baseline in any lead….
Key Points Definition: QT = onset of QRS → end of T; reflects total ventricular depolarization + repolarization. Rate correction (QTc): Use corrected QT interval, because QT shortens with faster…
Key Points Definition: The R wave is the first positive deflection of the QRS complex, reflecting early ventricular depolarization, predominantly of the left ventricle. Normal progression: Precordial R amplitude increases…
Key Points ECG red flags: Bradycardia, PR/QRS/QT prolongation, flattened P, peaked T, → AV block/asystole at higher levels. Neuromuscular: Hyporeflexia → weakness → respiratory depression → coma. Immediate countermeasure (severe/symptomatic):…
Key Points Mechanism: Block in the left anterior fascicle → ventricular activation proceeds down the left posterior fascicle, then spreads inferior-to-superior and right-to-left across the LV. ECG signature: Left axis…
Key Points Definition: The PR interval runs from P-wave onset to the first ventricular deflection (Q or R). It reflects atrial depolarization plus AV node–His–Purkinje conduction delay. Normal range: 120–200…