Negative T waves are frequently observed during coronary ischemia. However, ischemia is not the only cause of negative T waves.

  When ischemia is over, T waves are usually expected to become positive again.

  Ischemia may also result in
biphasic T waves.

  Ischemic T wave changes are usually accompanied by ST segment shift.




Causes of negative T waves

  Ischemia (symmetrically negative T waves)

  Misplacement of chest electrodes (frequent). Incorrect placement of leads V2 and/or V3 may result in negative T waves
confined to either lead V2 or lead V3.

  Juvenile T pattern

  Right ventricular overload (acute pulmonary embolism, chronic pulmonary disease)

  Early repolarization (sometimes negative T waves may accompany the ST elevation)

  Hyperventilation

  As juvenile T pattern in leads V1-V3 in well-trained athletes

  Cardiomyopathies (including hypertrophic cardiomyopathy and arrhythmogenic right ventricular dysplasia)

  After an attack of paroxysmal tachycardia

  Cerebrovascular accidents

  Intermittent left bundle branch block (LBBB)

  After artifically pacing the heart with a pacemaker

  WPW syndrome

  After truncal vagotomy (%9)





ECG 1a. ST depression in leads C4, C5, C6 and symmetrical negative T waves are seen in chest leads of a patient with unstable
angina. This patient underwent coronary artery bypass surgery for significant stenosis of the LAD and Cx vessels.

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ECG 1b. T wave negativity and ST segment depression in chest leads disappeared after successful coronary artery bypass
surgery.

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ECG 2.
Flattening of the ST segment and peaking of the T wave are the first signs of coronary ischemia. This patient
complained of severe effort angina. Coronary angiography showed 3 vessel disease (extensive coronary artery disease).

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ECG 3a. Above is an ECG from an apparently healthy middle-aged man.
He does not have any cardiac symptom.
Only lead V3 shows negative T waves.
Bu durumda, ilk önce V2 ile V3 elektrodlarının göğüs üzerine yanlış yerleştirilmiş olabileceği düşünülmelidir.

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ECG 3b. The ECG above belongs to the same patient.
It was recorded after correct placement of lead V2 and lead V3 electrodes.
Negative T waves are not seen in lead V3 any more.

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