What causes an inverted T wave?

As a medical professional with expertise in cardiology, I can provide insight into the causes of inverted T waves on an electrocardiogram (ECG). T-wave inversion is a finding that can be indicative of various conditions, some of which are more serious than others. Inverted T waves can be caused by a number of factors, including but not limited to: 1. Acute Coronary Ischemia: This is a serious condition where the heart muscle does not receive enough blood flow, which can lead to T-wave inversion, particularly in the leads corresponding to the affected area of the heart. 2. Pulmonary Embolism: A blockage in the lung's main artery can cause changes in the ECG, including inverted T waves, due to the strain it places on the heart. 3. CNS Injury: Central nervous system injuries, such as a subarachnoid hemorrhage or other brain trauma, can affect the autonomic nervous system's control over the heart, leading to T-wave changes. 4. Normal Variant T-Wave Inversions: In some individuals, T-wave inversion may be a normal variant and not associated with any disease process. 5. Persistent Juvenile T-Wave Inversion: This is a benign condition where T-wave inversions persist from childhood into adulthood without any adverse health effects. 6. Electrolyte Imbalances: Abnormal levels of electrolytes like potassium, calcium, or magnesium can affect the ECG and cause T-wave inversion. 7. Myocardial Infarction (Heart Attack): T-wave inversion can be seen in the ECG after a heart attack, particularly in the leads related to the infarcted area. 8. Hyperkalemia: High levels of potassium in the blood can cause a characteristic T-wave inversion known as "tented T waves." 9. Certain Medications: Some drugs, such as tricyclic antidepressants and some antiarrhythmic medications, can cause T-wave inversion as a side effect. 10. Hypothermia: Low body temperature can also lead to changes in the ECG, including T-wave inversion. It's important to note that the presence of inverted T waves on an ECG should be interpreted in the context of the patient's clinical history, symptoms, and other ECG findings. A comprehensive evaluation by a healthcare provider is necessary to determine the underlying cause.

A variety of clinical syndromes can cause T-wave inversions, ranging from life-threatening events, such as acute coronary ischemia, pulmonary embolism, and CNS injury, to entirely benign conditions, such as normal variant T- wave inversions and the persistent juvenile T-wave inversion.