Pathologic Q waves: Difference between revisions
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== | ==Evaluation== | ||
[[File:SinusRhythmLabels.svg|thumb]] | [[File:SinusRhythmLabels.svg|thumb]] | ||
[[File:PathoQ.png|thumb|Pathologic Q wave]] | [[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 | ||
Line 11: | Line 12: | ||
*Q waves do not always indicate infarction | *Q waves do not always indicate infarction | ||
*Must distinguish normal septal q waves from pathologic Q waves: | *Must distinguish normal septal q waves from pathologic Q waves: | ||
**Normal septal q wave: | **Normal septal q wave: <0.04s, low amplitude | ||
**Abnormal septal q wave: | **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: | *Q-wave equivalents in the precordial leads: | ||
**R-wave diminution or poor R-wave progression | **R-wave diminution or poor R-wave progression |
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