Key Points: Normal T Wave in V1: The normal ECG typically shows a flat or inverted T wave in lead V1 in sinus rhythm. An upright T wave in V1 can…
Key Points: Definition: Electrical storm is defined as three or more episodes of sustained ventricular tachycardia (VT), ventricular fibrillation (VF), or appropriate implantable cardioverter-defibrillator (ICD) shocks within 24 hours. Some…
Key Points: Definition: Organized electrical activity on ECG without a palpable pulse. PEA is a non-shockable arrest rhythm requiring CPR, epinephrine, and identification of reversible causes. Confirmation: Verify in two…
Key Points: Definition: Asystole is a non-shockable cardiac arrest rhythm characterized by absence of ventricular electrical activity. Treat with high-quality CPR, epinephrine every 3–5 minutes, and an urgent search for…
Key Points: Defibrillation First, Minimal Pauses: VF is rapidly fatal without immediate shocks and high‑quality CPR. Charge during compressions and resume compressions immediately after each shock. Chaotic Electrical Activity: VF…
Key Points: Definition: A malignant ventricular tachyarrhythmia with a regular, sine-wave–like waveform at ~250–350 bpm, no isoelectric baseline, and no discernible P/QRS/T distinction. Clinical importance: Rapidly degenerates into ventricular fibrillation…
Key Points: Early post-ROSC ECGs often mislead. Obtain the first ECG immediately after ROSC, but treat it as an early snapshot, not the entire story. Post-arrest physiology, defibrillation, acidosis, and…
Key Points: Unstable bradyarrhythmias cause poor perfusion which can rapidly progress to shock, irreversible organ injury, or cardiac arrest. Priority: Do not treat the heart rate alone — treat clinical…
Key Points: Intervene Immediately: Unstable tachyarrhythmias pose significant risk for rapid clinical deterioration that may lead to irreversible end-organ damage or cardiac arrest. Clinical Indicators of Instability: Altered Mental Status:…
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 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: 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: 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…