Are Q waves present in Nstemi?

Are Q waves present in Nstemi?

Non-ST Elevation Myocardial Infarction (NSTEMI) A certain number of patients with NSTEMI develop Q waves.

What does a pathologic Q wave indicate?

Pathologic Q waves are a sign of previous myocardial infarction. They are the result of absence of electrical activity. A myocardial infarction can be thought of as an elecrical ‘hole’ as scar tissue is electrically dead and therefore results in pathologic Q waves.

What can significant Q wave indicate?

Q waves represent the initial phase of ventricular depolarization. They are pathologic if they are abnormally wide (>0.2 second) or abnormally deep (>5 mm). Q waves that are pathologically deep but not wide are often indicators of ventricular hypertrophy.

How do you identify a pathological Q wave?

Q waves are considered pathological if:

1. > 40 ms (1 mm) wide.
2. > 2 mm deep.
3. > 25% of depth of QRS complex.
4. Seen in leads V1-3.

When do pathological Q waves develop?

Pathological Q waves Q waves may develop within one to two hours of the onset of symptoms of acute myocardial infarction, though often they take 12 hours and occasionally up to 24 hours to appear.

Why does Q wave deflect down?

The rule is: if the wave immediately after the P wave is an upward deflection, it is an R wave; if it is a downward deflection, it is a Q wave: small Q waves correspond to depolarization of the interventricular septum. Q waves can also relate to breathing and are generally small and thin.

Do Q waves always mean MI?

The presence of pathologic Q waves on ECG is not always associated with the presence of prior myocardial infarction on cardiac MRI. In addition, Q waves appear to modestly correlate with the location of the prior MI.

What leads are normal Q waves?

Q Waves. Q waves are normally seen in the inferior and left lateral precordial leads in pediatric patients.

Can a Q wave be a sign of NSTEMI?

Moreover, magnetic resonance imaging has suggested that pathological Q-waves may also arise due to extensive subendocardial infarction (NSTEMI). If pathological Q-waves occur as a result of myocardial infarction, the infarction may be classified as Q-wave infarction (this has negligible clinical implication).

When does a Pathological Q wave appear in an ECG?

The pathologically deep Q wave should appear in at least 2 contiguous leads (An isolated Q wave to lead III is a very common normal variant) Any Q wave in leads V1- V3 with a duration of >0.02seconds is likely to be pathological.

Can a Q wave be a permanent sign of infarction?

Standard textbooks have traditionally taught that the pathological Q-wave is a permanent ECG manifestation and that it represents transmural infarction (STEMI). However, recent studies challenge these notions. Pathological Q-waves may resolve in up to 30% of patients with inferior infarction.

What does Pathological Q wave without ST elevation mean?

Pathological Q waves without ST elevation, ST depression and/or T wave inversion indicate an OLD myocardial infarction – that means it has happened in the past at some point! Notice how in the acute picture, I have a Q wave that is about 8 little boxes down from the baseline?