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: 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 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: 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: Hypermagnesemia is usually seen in the setting of renal impairment or excessive magnesium exposure, including laxatives, antacids, bowel preps, or therapeutic magnesium infusion. The key ECG concern is…
Key Points: LAFB occurs when conduction through the left anterior fascicle is delayed or blocked. Ventricular activation travels preferentially down the left posterior fascicle, then spreads inferior-to-superior and rightward-to-leftward across…
Key Points Definition: The PR segment is the flat line from the end of the P wave to the beginning of the QRS. It reflects conduction through the AV node,…
Key Points Definition: The TP segment is the isoelectric interval from the end of the T wave to the start of the P wave. It reflects electrical diastole when the…
Key Points Definition and origin: The U wave is a small deflection following the T wave, best seen in V2–V3. It likely reflects late ventricular repolarization or Purkinje repolarization. Normal…
Key Points Definition: The T wave reflects ventricular repolarization. Measure amplitude from baseline to peak and identify the end of T to help define the QT interval. Normal appearance: Upright…
Key Points Definition and measurement: The S wave is the first negative deflection after the R wave within the QRS. Measure depth in mm from baseline to nadir; width contributes…
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: Rare, inherited ventricular arrhythmia triggered by adrenergic stress during exertion or emotion. Classically presents in children or adolescents with syncope or cardiac arrest despite a normal resting ECG…
Key Points: Always get a 12-lead ECG in altered or confused patients. The ECG is a great triage and risk stratification tool and can reveal reversible, life-threatening causes when history…