Pathologic Q waves: Difference between revisions
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== [[Q | ==Evaluation== | ||
[[File:SinusRhythmLabels.svg|thumb]] | |||
[[File:PathoQ.png|thumb|Pathologic Q wave]] | |||
*Significant if >1 box wide or if is 1/3 of entire QRS amplitude | *Significant if >1 box wide or if is 1/3 of entire QRS amplitude | ||
*Early Repolarization: | *Early Repolarization: | ||
**[[ST Elevation]] most prominent in | **[[ST Elevation]] most prominent in lateral precordial leads (V4-6) | ||
***Lack of reciprocal changes helps to differentiate from STEMI | |||
**T waves usually broad, tall (>5mm) & upright | **T waves usually broad, tall (>5mm) & upright | ||
**Limb leads may also have ST elevation, rarely >2 mm | **Limb leads may also have ST elevation, rarely >2 mm | ||
===Details=== | |||
*Q waves do not always indicate infarction | |||
*Must distinguish normal septal q waves from pathologic Q waves: | |||
**Normal septal q wave: <0.04s, low amplitude | |||
**Abnormal septal q wave: >0.04s in I OR in II, III, '''AND''' aVF OR V3, V4, V5, '''AND''' V6 | |||
*Q-wave equivalents in the precordial leads: | |||
**R-wave diminution or poor R-wave progression | |||
**Reverse R-wave progression (R waves increase then decrease in amplitude) | |||
***Must distinguish from lead misplacement | |||
**Tall R waves in V1, V2 (representing "Q waves" from posterior infarction) | |||
==Differential Diagnosis== | |||
===Q Wave (Pathologic)=== | |||
*[[Pathologic Q waves]] (Ischemic) | |||
*[[LBBB]] | |||
*[[LVH]] | |||
*Chronic lung disease | |||
*[[Hypertrophic cardiomyopathy]] | |||
*[[Dilated cardiomyopathy]] | |||
==See Also== | ==See Also== | ||
*[[ECG Basics]] | *[[ECG Basics]] | ||
[[Category: | [[Category:Cardiology]] | ||
Latest revision as of 03:52, 9 March 2019
Evaluation
- Significant if >1 box wide or if is 1/3 of entire QRS amplitude
- Early Repolarization:
- ST Elevation most prominent in lateral precordial leads (V4-6)
- Lack of reciprocal changes helps to differentiate from STEMI
- T waves usually broad, tall (>5mm) & upright
- Limb leads may also have ST elevation, rarely >2 mm
- ST Elevation most prominent in lateral precordial leads (V4-6)
Details
- Q waves do not always indicate infarction
- Must distinguish normal septal q waves from pathologic Q waves:
- Normal septal q wave: <0.04s, low amplitude
- Abnormal septal q wave: >0.04s in I OR in II, III, AND aVF OR V3, V4, V5, AND V6
- Q-wave equivalents in the precordial leads:
- R-wave diminution or poor R-wave progression
- Reverse R-wave progression (R waves increase then decrease in amplitude)
- Must distinguish from lead misplacement
- Tall R waves in V1, V2 (representing "Q waves" from posterior infarction)
Differential Diagnosis
Q Wave (Pathologic)
- Pathologic Q waves (Ischemic)
- LBBB
- LVH
- Chronic lung disease
- Hypertrophic cardiomyopathy
- Dilated cardiomyopathy