What does the Q wave represent on an ECG?
By definition, a Q wave on the electrocardiogram (ECG) is an initially negative deflection of the QRS complex. Technically, a Q wave indicates that the net direction of early ventricular depolarization (QRS) electrical forces projects toward the negative pole of the lead axis in question.
How do you identify a pathological Q wave?
Q waves are considered pathological if:
- > 40 ms (1 mm) wide.
- > 2 mm deep.
- > 25% of depth of QRS complex.
- Seen in leads V1-3.
Why does the Q wave go down?
As septal depolarization moves from left to right, the depolarization vector is directed towards the – electrode of lead II (RA), and therefore a negative-going deflection (Q-wave) is produced.
Are Q waves always pathological?
Q waves in the right precordium are always pathologic and are commonly associated with right ventricular hypertrophy.
What does a deep Q wave mean?
Myocardial infarction – particularly if extensive in size – typically manifests with pathological Q-waves. These Q-waves are wider and deeper than normally occurring Q-waves, and they are referred to as pathological Q-waves.
Is QRS systole or diastole?
The QRS complex refers to the combination of the Q, R, and S waves, and indicates ventricular depolarization and contraction (ventricular systole).
What do abnormal Q waves indicate?
Q-WAVE ABNORMALITIES Q waves that are pathologically deep but not wide are often indicators of ventricular hypertrophy. Q waves that are both abnormally deep and wide imply myocardial infarction.
What leads are Q waves normal?
Q Waves. Q waves are normally seen in the inferior and left lateral precordial leads in pediatric patients.
What is a normal Q wave size?
Small Q waves are normal in most leads. Deeper Q waves (>2 mm) may be seen in leads III and aVR as a normal variant. Under normal circumstances, Q waves are not seen in the right-sided leads (V1-3)
What is the difference between soft and hard real-time system?
The hard real-time system must assure to finish the real-time task within the specified deadline while this is not the case in the soft real-time system, it assigns the superior scheduling priority to the real-time tasks.
Are all hard systems embedded in soft systems?
A frequent problem I come across when discussing hard and soft systems views with engineers is that the terms ‘hard’ and ‘soft’ are rarely defined clearly. Based on conversations I’ve had over the years at the University of Bristol a common position can be characterised by the statement “ all hard systems are embedded in soft systems .”
What is the soft systems view of soft?
Instead of the rather vague association of soft with the social world, people, and human intentionality, the soft systems view moves away from this ontological commitment and treats the definition as a question of epistemology, i.e. what can we know or find out about the world?