What is the U wave in ischemia?

Inverted U waves Are a very specific sign of myocardial ischaemia . May be the earliest marker of unstable angina and evolving myocardial infarction.

What is a negative T wave in ischemia?

Negative T Wave, Usually Deep, as a Consequence of Reperfusion. In clinical setting of acute ischemia the appearance of deep negative symmetric T wave is usually related with reperfusion process . This means that the artery is totally o partially patent.

What does the U wave represent?

This is known as a U wave. In a normal heart beat, the T wave represents repolarisation of the ventricles, specifically the repolarisation of the AV node and bundle branches. The U wave occurs when the ECG machine picks up repolarisation of the Purkinje fibres .

What wave indicates ischemia?

Inverted T waves are associated with myocardial ischemia. The inversion of a T wave is not specific for ischemia, and the inversion itself does not correlate with a specific prognosis. However, if the clinical history is suggestive of ischemia in the setting of inverted T waves, this is correlative.

What does negative ischemia mean?

It means patient is suffering from ischemic heart disease . Negative result means even at moderate or high workload, patients heart is having enough blood supply and there is no signs of ischemic heart disease.

What does a negative wave in an ECG mean?

These ECG findings are typical of ischemic heart disease . A flat/negative T wave may be seen for years as a residual pattern in chronic ischemic heart disease with or without Q-wave myocardial infarction.

How to see ischemia on ECG?

Exercise ECG is widely used for the diagnosis of ischemic heart disease. The most common ECG sign of myocardial ischemia is flat or down-sloping ST-segment depression of 1.0 mm or greater . This report draws attention to other much less common, but possibly equally important, ECG manifestations of myocardial ischemia.

What are the ECG findings for ischemia?

Generally, ischemia will present with inverted T waves and flat or downsloping ST-segment depression , whereas myocardial infarction will show ST-segment elevation, T wave inversion, and Q waves. The best way to differentiate acute myocardial infarction (AMI) from ischemia is to look at the changes in multiple leads.

What is the Q wave on an ECG ischemia?

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.

What electrolyte causes U waves?

Hypokalemia, low blood potassium , results in: ST depression and flattening of the T wave. Negative T waves. A U-wave may be visible.

What is associated with large U waves on an EKG?

Prominent U waves may be present with hypokalemia and with use of certain cardiac medications (Table 1).

In reply: The negative U wave in the setting of demand ischemia (2024)

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In reply: The negative U wave in the setting of demand ischemia

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Sridhar Venkatachalam, MD

Curtis M. Rimmerman, MD, MBA

In Reply: We appreciate the comments from Drs. Suksaranjit, Cheungpasitp*rn, Bischof, and Marx on our recent article on the negative U wave in a patient with chronic aortic regurgitation.¹ The clinical data including electrocardiography, echocardiography, and coronary angiography were presented to emphasize the importance of identifying the negative U wave in the setting of valvular heart disease. We outlined the common differential diagnosis for a negative U wave (page 506). We believe that in the appropriate clinical setting the presence of a negative U wave provides diagnostic utility.

Several published reports to date have described the occurrence of the negative U wave in the setting of obstructive coronary artery disease^2–5 or coronary artery vasospasm.⁶ We were unable to find similar data in the setting of demand ischemia in the presence of normal coronary arteries (functional ischemia), but we fully recognize its likely occurrence, and we value the helpful insight.

References

Venkatachalam S, Rimmerman CM. Electrocardiography in aortic regurgitation: it’s in the details. Cleve Clin J Med 2011; 78:505–506.
Gerson MC, Phillips JF, Morris SN, McHenry PL. Exercise-induced U-wave inversion as a marker of stenosis of the left anterior descending coronary artery. Circulation 1979; 60:1014–1020.
Galli M, Temporelli P. Images in clinical medicine. Negative U waves as an indicator of stress-induced myocardial ischemia. N Engl J Med 1994; 330:1791.
Miwa K, Nakagawa K, Hirai T, Inoue H. Exercise-induced U-wave alterations as a marker of well-developed and well-functioning collateral vessels in patients with effort angina. J Am Coll Cardiol 2000; 35:757–763.
Rimmerman CM. A 62-year-old man with an abnormal electrocardiogram. Cleve Clin J Med 2001; 68:975–976.
Kodama-Takahashi K, Ohshima K, Yamamoto K, et al. Occurrence of transient U-wave inversion during vasospastic anginal attack is not related to the direction of concurrent ST-segment shift. Chest 2002; 122:535–541.

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Sridhar Venkatachalam, MD, MRCP
Cleveland Clinic

Curtis M. Rimmerman, MD, MBA
Cleveland Clinic

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Cleveland Clinic Journal of Medicine - 78(12)

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Cleveland Clinic Journal of Medicine

In reply: The negative U wave in the setting of demand ischemia (2024)

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