II. Normal findings: Duration
- Limb leads (I, II, III): 0.05 to 0.10
- Precordial leads (V1 to V6): 0.06 to 0.12
III. Causes: Wide QRS or Prolonged QRS Complex (over 0.12)
- Abnormal interventricular conduction (e.g. Left Bundle Branch Block)
- See Bundle Branch Block
- Hypothermia
- Hyperkalemia
- Wolff-Parkinson-White Syndrome (WPW)
- Ventrciular ectopy
- Ventricular Tachycardia
- Medications (e.g. Toxin Ingestion or Overdose)
- Results from Sodium channel blockade
- Emergency management
- See Toxin Ingestion
- See Tricyclic Overdose
- Sodium Bicarbonate 1-2 amps IV push with repeat bolus until QRS narrows (adults)
- Causes
- Tricyclic Antidepressants
- Dry and sedated
- Cocaine
- Diaphoretic and agitated
- Diphenhydramine (Benadryl)
- Local anesthetics (esp. Bupivacaine)
- Antiarrhythmics (e.g. Quinidine, Flecainide)
- Propoxyphene (not available in U.S.)
- Digoxin Toxicity
- Associated with frequent PVCs and sagging ST depression
- Tricyclic Antidepressants
IV. Causes: Low QRS amplitude (<5 mm in limb leads)
- Diffuse Coronary Artery Disease
- Congestive Heart Failure
- Pericardial Effusion
- Myxedema
- Amyloidosis
- Obesity
- Emphysema (?OPD)
- Anasarca
V. Causes: High QRS amplitude
- Evaluate for Left Ventricular Hypertrophy
VI. References
- Mattu (2016) Crit Dec Emerg Med 30(8):16
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| Concepts | Organism Attribute (T032) |
| SnomedCT | 251208001 |
| LNC | LP31031-5, MTHU019811 |
| English | QRS complex duration (observable entity), QRS duration, QRS complex duration |
| Spanish | duración del complejo QRS (entidad observable), duración del complejo QRS |
Ontology: QRS complex feature (C0429097)
| Definition (NCI) | An electrocardiographic finding that represents depolarization of the ventricular myocardium. Normally the ventricles are activated simultaneously. |
| Concepts | Finding (T033) |
| SnomedCT | 142119004, 164949005 |
| LNC | LP31569-4, MTHU024513 |
| Dutch | QRS-complex |
| French | Complexe QRS |
| German | QRS-Komplex |
| Italian | Complesso QRS |
| Portuguese | Complexo QRS |
| Spanish | Complejo QRS, característica del complejo QRS (entidad observable), característica del complejo QRS, complejo QRS (entidad observable), complejo QRS |
| Japanese | ＱＲＳ群, QRSｸﾞﾝ |
| Czech | QRS komplex |
| English | qrs complex, QRS Complex, QRS complex (observable entity), QRS complex, QRS complex feature (observable entity), QRS complex feature |
| Hungarian | QRS komplex |
