What clinical condition could one suspect if the Q wave is abnormal?

Donald Bonagurio asked, updated on July 23rd, 2022; Topic: electrical conduction of the heart
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Abnormal Q waves on the electrocardiogram (ECG) usually represent remote or recent myocardial infarction. Q waves in coronary heart disease: newer understanding of their clinical implications.

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One may also ask, what does an elevated Q wave 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.

In any event, what do Q waves indicate? 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.

Despite everything, 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.

What does an abnormal Q wave on ECG mean?

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.

26 Related Questions Answered

What is Q wave myocardial infarction?

Q wave myocardial infarction refers to myocardial infarctions that in a Q wave forming on the 12-lead ECG once the infarction is completed.

What does sinus tachycardia look like on ECG?

Sinus tachycardia is recognized on an ECG with a normal upright P wave in lead II preceding every QRS complex. This indicates that the pacemaker is coming from the sinus node and not elsewhere in the atria, with an atrial rate of greater than 100 beats per minute.

What is anterior myocardial infarction?

An anterior wall myocardial infarction occurs when anterior myocardial tissue usually supplied by the left anterior descending coronary artery suffers injury due to lack of blood supply.

Are Q waves always pathological?

Q waves in the right precordium are always pathologic and are commonly associated with right ventricular hypertrophy. Deep Q waves in the left lateral precordial leads are often seen with left ventricular hypertrophy of many etiologies.

Which finding is a complication of myocardial infarction?

Complications of AMI include [1, 2]: Ischaemic (including failure of reperfusion): angina, re-infarction, infarct extension. Mechanical: heart failure, cardiogenic shock, mitral valve dysfunction, aneurysms, cardiac rupture. Arrhythmic: atrial or ventricular arrhythmias, sinus or atrioventricular (AV) node dysfunction.

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 causes Anteroseptal infarction?

Anteroseptal myocardial infarctions are commonly caused by the rupture of an unstable atherosclerotic plaque in the left anterior descending artery. Delayed or missed diagnosis of an anteroseptal myocardial infarction can lead to high morbidity and mortality.

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 causes myocardial ischemia?

Causes of myocardial ischemia Myocardial ischemia occurs when blood flow to the heart muscle (myocardium) is obstructed by a partial or complete blockage of a coronary artery by a buildup of plaques (atherosclerosis). If the plaques rupture, you can have a heart attack (myocardial infarction).

Which symptom is considered a typical symptom indicative of ACS?

Chest pain or discomfort is the most common symptom.

What can a significant Q wave indicate hypercalcemia?

The intervals Q-oTc (the interval from the beginning of the QRS complex to the beginning of the T-wave) of <0.18 s and Q-aTc of <0.30 s (measured from the beginning of the QRS complex to the apex of the T-wave) are reliable indicators of clinical hypercalcemia.

What is a Delta wave on an ECG?

“ A delta wave is slurring of the upstroke of the QRS complex. This occurs because the action potential from the sinoatrial node is able to conduct to the ventricles very quickly through the accessory pathway, and thus the QRS occurs immediately after the P wave, making the delta wave.

What does a pathologic Q wave indicate quizlet?

A pathologic Q wave: A. generally indicates that an acute myocardial infarction has occurred within the past hour.

How do you fix sinus tachycardia?

Treatments for sinus tachycardia focus on lowering the heart rate to normal by treating the underlying cause, such as infection or low blood pressure. Doctors may also recommend lifestyle changes, medications, and medical procedures, such as catheter ablation.

Can an echocardiogram detect sinus tachycardia?

Your doctor uses the angiogram to check for blocked or narrowed blood vessels in your heart. Cardiac imaging tests used to diagnose tachycardia include: Echocardiogram.

What is the difference between atrial tachycardia and sinus tachycardia?

The landmark physical finding in atrial tachycardias is the tachycardia itself, with a heart rate above 100 bpm and rarely dropping below but faster than the underlying sinus rhythm.

Is anterior infarct serious?

In the United States, between 1.2 and 1.5 million people suffer a myocardial infarction (MI) every year. And among MIs, anterior-wall MIs are the most serious and have the worst prognosis.

Should I worry about abnormal ECG?

An abnormal ECG can mean many things. Sometimes an ECG abnormality is a normal variation of a heart's rhythm, which does not affect your health. Other times, an abnormal ECG can signal a medical emergency, such as a myocardial infarction /heart attack or a dangerous arrhythmia.

What is the treatment for anterior infarct?

Thrombolytics are often used to dissolve clots. Antiplatelet drugs, such as clopidogrel, can be used to prevent new clots from forming and existing clots from growing. Nitroglycerin can be used to widen your blood vessels. Beta-blockers lower your blood pressure and relax your heart muscle.

How common are Q waves?

Small Q waves are present in the left precordial leads in more than 75 percent of normal subjects. They are seen most frequently in lead V6, less frequently in leads V5 and V4, and rarely in V3.

Are Q waves acute?

Acute myocardial infarction may be associated with the development of Q waves on the electrocardiogram (ECG), or with changes limited to the ST segment or T wave. The ECG changes do not accurately differentiate transmural from nontransmural infarction.

What are the precordial leads?

The precordial leads, or V leads, represent the heart's orientation on a transverse plane, providing a three- dimensional view (see Precordial Views). They are placed anatom ically over areas of the left ventricle. 1 Like the augmented leads, the precordial leads are unipolar with an electrically neutral center.

What is the most common cause of death in myocardial infarction?

After arrhythmias and cardiogenic shock, the commonest cause of death after acute MI is rupture.

What are the main causes of myocardial infarction?

A heart attack occurs when one of the heart's coronary arteries is blocked suddenly or has extremely slow blood flow. A heart attack also is called a myocardial infarction. The usual cause of sudden blockage in a coronary artery is the formation of a blood clot (thrombus).

Which of the following conditions is most commonly responsible for myocardial infarction?

The most common cause of a myocardial infarction is the rupture of an atherosclerotic plaque on an artery supplying heart muscle.

What happens to the ECG during myocardial infarction?

In a myocardial infarction transmural ischemia develops. In the first hours and days after the onset of a myocardial infarction, several changes can be observed on the ECG. First, large peaked T waves (or hyperacute T waves), then ST elevation, then negative T waves and finally pathologic Q waves develop.