What does an abnormal Q wave on ECG mean?
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 causes abnormal Q waves?
Background: Abnormal Q waves (AQW) in the electrocardiogram are commonly ascribed to underlying myocardial infarction (MI). As an imperfectly specific sign of MI, the usefulness of AQW in identifying MI depends on its incidence in the population studied.
Can Q waves go away?
The development of Q waves on the surface electrocardiogram generally is considered indicative of myocardial infarction. Such Q waves are usually permanent, though may regress and disappear over months to years. Transient Q waves have been described during myocardial ischemia without evidence of infarction.
What does permanent Q wave mean?
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.
Where is the Q wave?
The Q wave is the first downward deflection after the P wave and the first element in the QRS complex. When the first deflection of the QRS complex is upright, then no Q wave is present. The normal individual will have a small Q wave in many, but not all, ECG leads.
How long do Q waves take to develop?
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. The presence of pathological Q waves, however, does not necessarily indicate a completed infarct.
What does abnormal inferior Q waves mean?
Conclusion: Abnormal Q waves on the admission electrocardiogram (ECG) are associated with higher peak creatine kinase, higher prevalence of heart failure, and increased mortality in patients with anterior MI. Abnormal Q waves on the admission ECG of patients with inferior MI are not associated with adverse prognosis.
Are Q waves bad?
Q-WAVE ABNORMALITIES 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. Q waves that are both abnormally deep and wide imply myocardial infarction.
What does septal Q waves mean?
Abstract. Background: Small Q waves in the left lateral leads are termed septal q waves, and their response to exercise has been reported to be a marker of septal ischemia in coronary artery disease.
How do you find the Q wave?
Q Wave
- The Q wave represents the normal left-to-right depolarisation of the interventricular septum.
- Small ‘septal’ Q waves are typically seen in the left-sided leads (I, aVL, V5 and V6)
What happens during the Q wave?
This is known as a Q wave and represents depolarisation in the septum. Whilst the electrical stimulus passes through the bundle of His, and before it separates down the two bundle branches, it starts to depolarise the septum from left to right.
Are Q waves ever normal?
QRS. The Q wave is a small negative deflection that precedes the R wave. Small Q waves (<0.03 seconds in duration) are a normal finding in all leads except V1 through V3, where they are always pathologic. Q waves of any size may be normal in leads III and aVR.
What do Q waves mean on an EKG?
The ekg has waves with amplitude and direction. A q wave reflects a lack of electrical force in a certain direction. This lack of force has some correlation when a change in pattern with a loss of muscle as is seen in heart damage like a heart attack. Old infarct.
What is a Q wave?
The Q Wave. A Q wave is any negative deflection that precedes an R wave. The Q wave represents the normal left-to-right depolarisation of the interventricular septum .
What is Q wave mi?
A pathological Q wave is a result of absence of electrical activity, following myocardial damage. They generally take several hours to develop after an MI, and usually persist indefinitely. The exception to this is if seen during an acute MI, but the myocardial tissue is reperfused early by Primary PCI (Percutaneous Coronary Intervention).
