What does inferior Q waves on ECG mean?
Often, in the routinely performed 12-lead Electrocardiogram (ECG), the presence of Q waves in inferior leads (LII, LIII, aVF), results in computerized interpretation of Inferior Wall Myocardial Infarction (IMI) [1]. This leads to further imaging studies, additional costs and psychological stress for patients.
What does Q waves in inferior leads mean?
Q waves in the inferior leads present the picture of myocardial infarction of the lower, or frequently posterior, possibly laterally left ventricular wall.
How much Q wave is significant?
Q waves are considered pathological if: > 40 ms (1 mm) wide. > 2 mm deep. > 25% of depth of QRS complex.
What are abnormal inferior Q waves?
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.
What would be expected when evaluating an ECG for an inferior infarction?
Upon ECG analysis, inferior STEMI displays ST-elevation in leads II, III, and aVF. There are subtle differences in the ECG pattern depending on the artery occluded. Reciprocal changes (ST-segment depression) may be seen in lead aVL [6].
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 a significant Q waves indicate?
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. Although prominent Q waves are a characteristic finding in myocardial infarction, they can also be seen in a number of noninfarct settings.
What causes abnormal inferior 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.
Is inferior infarct serious?
Inferior myocardial infarctions have multiple potential complications and can be fatal. See the review on ST elevation myocardial infarction for more detail on complications of an inferior myocardial infarction and a detailed discussion on treatment.
Which criteria is indicative of a significant Q wave indicating possible MI?
Moderate risk of ischemc injury / possible Q wave MI: Q >= 30 ms and ST deviation > 0.20 mV (minor Q waves with STT abnormalities) Q >= 40 ms and ST deviation < 0.20mV (moderate Q waves without STT abnormalities)
What do abnormal Q waves mean?
Pathological (abnormal) Q waves are defined as greater than one third the height of the R wave, greater than 0.04 sec (40 msec) in duration, or present in the right precordial leads. Over the next few hours the ST segments return to normal and, shortly afterwards, the T waves become inverted but Q waves remain.
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 do Q waves mean?
medical Definition of Q wave. : the short initial downward stroke of the QRS complex in an electrocardiogram formed during the beginning of ventricular depolarization .
What does non Q wave mi mean?
Non-ST elevation MI (new term for non-Q wave MI, often referred to as non-STEMI), is an unstable coronary syndrome which is differentiated from unstable angina by a subsequent rise in cardiac enzymes. ECG findings often include ST depression but do not include new pathological Q waves.