What is the significance of upward sloping T waves on an electrocardiogram (ECG) just prior to Left Anterior Descending (LAD) coronary artery occlusion?

From the Guidelines

Upward sloping T waves on an electrocardiogram (ECG) just prior to Left Anterior Descending (LAD) coronary artery occlusion are a critical warning sign of impending anterior wall myocardial infarction, requiring immediate cardiac catheterization and treatment as a cardiac emergency. The significance of these ECG findings cannot be overstated, as they are associated with severe proximal LAD stenosis and a high risk of cardiac morbidity and mortality if left untreated 1. The characteristic ECG changes, which may include biphasic or deeply inverted T waves in leads V2-V3, occur during pain-free periods in patients with unstable angina and indicate a critical need for prompt medical attention.

Key Considerations

• Upward sloping T waves are a specific type of ECG abnormality that requires immediate attention and treatment
• These ECG changes are associated with severe proximal LAD stenosis and a high risk of cardiac morbidity and mortality
• Patients with these ECG findings should be treated as a cardiac emergency, with immediate cardiology consultation, antiplatelet therapy, anticoagulation, and preparation for urgent coronary angiography
• Stress testing is contraindicated in these patients, as it may precipitate a massive anterior wall MI

Treatment Approach

• Immediate cardiology consultation and treatment as a cardiac emergency
• Antiplatelet therapy with aspirin 325mg and a P2Y12 inhibitor like ticagrelor 180mg loading dose
• Anticoagulation with heparin or enoxaparin
• Preparation for urgent coronary angiography and potential revascularization
• Avoidance of stress testing due to the risk of precipitating a massive anterior wall MI

Pathophysiology

• The pathophysiology involves reperfusion of severely ischemic but still viable myocardium, causing distinctive T wave abnormalities that precede Q wave formation and ST elevation if intervention is delayed 1
• The ECG changes are a result of the severe proximal LAD stenosis, which puts the patient at high risk of cardiac morbidity and mortality if left untreated.

From the Research

Significance of Upward Sloping T Waves on an ECG

• Upward sloping T waves on an electrocardiogram (ECG) can be a significant indicator of an impending Left Anterior Descending (LAD) coronary artery occlusion 2, 3.
• This ECG pattern is often characterized by ST-segment depression at the J-point with upsloping ST-segments and tall, symmetrical T-waves in the precordial leads 2.
• The presence of persistent hyperacute T waves should be regarded as an equivalent to ST-segment elevation, and immediate reperfusion therapy should be considered 3.
• Wellens syndrome is a precursor of LAD coronary stenosis, characterized by biphasic T waves in V2-V3 or negative deep T waves in V2-V4, and its recognition is crucial for urgent cardiac catheterization with percutaneous coronary intervention 4, 5.

Association with LAD Coronary Artery Occlusion

• The ECG pattern of upward sloping T waves is associated with proximal LAD artery occlusion, and its recognition is important for triaging patients for immediate reperfusion therapy 2.
• Cardiac magnetic resonance (CMR) findings have shown that this ECG pattern is associated with nearly transmural necrosis in the large myocardial area supplied by the LAD 3.
• The presence of upright T waves in lead aVR has been associated with cardiac death or hospitalization for heart failure in patients with a prior myocardial infarction 6.

Clinical Implications

• The recognition of upward sloping T waves on an ECG is crucial for the early diagnosis and treatment of LAD coronary artery occlusion 2, 3.
• Immediate reperfusion therapy should be considered in patients presenting with this ECG pattern 3.
• The association of this ECG pattern with Wellens syndrome highlights the importance of urgent cardiac catheterization with percutaneous coronary intervention in patients with critical LAD coronary stenosis 4, 5.