Table of Contents
Diagnosis Categories
The ECG Quiz organizes all ECG diagnostic statements into defined Diagnosis Categories. These categories help determine how your selections are graded, how differential and multiple valid interpretations are handled, and how results are displayed.
Each category contains multiple individual diagnostic statements used during ECG annotation. Below is an overview of each category, including representative examples.
Conduction Abnormalities
Conduction abnormalities occur when electrical impulses are delayed or blocked as they pass through the AV node, His–Purkinje system, or bundle branches.
Examples:
- First-Degree AV Block — Prolonged PR interval (≥200 ms) from delayed AV nodal conduction.
- Bundle Branch Block (BBB) — Delayed ventricular depolarization (e.g., LBBB, RBBB) altering QRS morphology.
Electrolytes and Drugs
These diagnoses reflect ECG changes caused by electrolyte imbalance or medications affecting cardiac conduction and repolarization.
Examples:
- Prominent U Waves, Consider Hypokalemia — Low potassium levels causing large U waves.
- Short QT Interval, Consider Hypercalcemia — Elevated calcium shortening the QT interval.
Hypertrophies
Hypertrophic patterns represent enlargement or thickening of cardiac chambers, usually related to chronic pressure or volume overload.
Examples:
- Left Ventricular Hypertrophy (LVH) — Voltage criteria with associated strain pattern.
- Right Atrial Enlargement (RAE) — Tall, peaked P waves suggesting right atrial dilation.
Myocardial Infarctions
These findings signify myocardial necrosis due to coronary occlusion. Changes are typically localized based on which ECG leads show ST elevation, Q waves, or reciprocal depression.
Examples:
- Myocardial Infarction, Acute, Anterior — Involves V1–V4; usually LAD territory.
- Myocardial Infarction, Acute, Inferior — Involves II, III, aVF; usually RCA or LCx.
Myocardial Ischemias
Ischemia represents reduced coronary perfusion without tissue death. It manifests primarily as ST-segment depression and T-wave abnormalities.
Examples:
- ST & T Wave Changes, Consider Lateral Ischemia — Changes in I, aVL, V5–V6 suggesting lateral wall ischemia.
- ST & T Wave Changes, Consider Anterior Ischemia — Changes in V1–V4 suggesting anterior wall ischemia.
Other ST and T Wave Abnormalities
These are repolarization abnormalities not clearly attributable to classic ischemia or infarction.
Examples:
- Early Repolarization — Benign pattern with J-point elevation and ST elevation in inferior and lateral leads.
- Left Ventricular Strain — Downsloping ST depression and T-wave inversion associated with LVH.
Pacemakers
Pacemaker diagnoses describe paced rhythms or device malfunction affecting sensing, capture, or output.
Examples:
- Pacemaker Failure to Capture (Ventricles) — Pacemaker spikes present but no myocardial depolarization.
- Pacemaker Failure to Sense (Ventricles) — Pacemaker does not detect intrinsic ventricular activity.
Rhythms
This category classifies primary rhythms and arrhythmia patterns observed on the ECG.
Examples:
- Sinus Tachycardia — Sinus rhythm ≥100 bpm.
- Atrial Fibrillation — Irregularly irregular rhythm with no discrete P waves.
Summary Features
Summary Features provide a high-level impression of the ECG or highlight issues with signal acquisition.
Examples:
- Artifact — Includes baseline wander, motion artifact, and muscle noise that distort the tracing.
- Lead Malposition — Incorrect electrode placement producing misleading ECG patterns.
Summary Table of All Diagnosis Categories
The table below provides a consolidated overview of all categories and representative diagnoses used in The ECG Quiz.
| Diagnosis Category | Description | Example Diagnoses |
|---|---|---|
| Conduction Abnormalities | Delay or block in conduction pathways | First-Degree AV Block; RBBB; LBBB |
| Electrolytes & Drugs | ECG effects of electrolyte imbalance or medications | Prominent U Waves (Hypokalemia); Short QT (Hypercalcemia) |
| Hypertrophies | Chamber enlargement or thickening | LVH; RAE |
| Myocardial Infarctions | Evidence of myocardial necrosis | Acute Anterior MI; Acute Inferior MI |
| Myocardial Ischemias | Evidence of inadequate perfusion | ST/T Changes Suggesting Lateral or Anterior Ischemia |
| Other ST & T Wave Abnormalities | Non-ischemic repolarization variants | Early Repolarization; LV Strain Pattern |
| Pacemakers | Paced rhythms and pacemaker malfunctions | Ventricular Failure to Capture; Failure to Sense |
| Rhythms | Rhythm origin and organization | Sinus Tachycardia; Atrial Fibrillation |
| Summary Features | General findings or acquisition issues | Artifact; Lead Malposition |
Important
Be sure to read how Differential Diagnoses and Multiple Interpretations are handled in The ECG Quiz.