Negative T-waves

ECG: Sinus rhythm, normal PR-interval; negative, deep (> 5 mm in V2-V3), and symmetrical T-waves in V1, V2, V3 and biphasic in V4; left ventricular hypertrophy (positive Sokolow index); coronary angiography revealed a severe stenosis of the proximal LAD;

Comments: As explained previously, the normal T-wave in adults is positive in all leads except for aVR and V1. The appearance of negative T-waves is therefore abnormal and suspicious. One can thus typically differentiate physiological negative T-waves from small amplitude negative T-waves (< 5 mm), deep negative T-waves (between 5 and 10 mm) and giant negative T-waves (greater than 10 mm).

• Physiological negative T-waves: the T-wave is normally negative in aVR and in V1; a reversal may also be physiological from V1 to V3 in children or athletes; the T-wave can also be negative in lead III and more rarely in aVF;
• Pathological negative T-waves: any negative T-wave in an unexpected lead or any negative deflection of a previously positive T-wave can be considered as pathological although represents a very unspecific sign as it can be observed in many clinical situations: myocardial ischemia, pericarditis, conduction or rhythm disorder (bundle branch block, cardiac pacing), left or right ventricular hypertrophy, pulmonary embolism, metabolic disorder, severe stroke, pancreatitis, cocaine use, medical treatment (digitalis or lithium impregnation). Also after prolonged periods of ventricular activation (pacing or ventricular tachycardie), the T-wave may sustain an abnormal morphology, which is known as “memory sign”. The duration of observed pathological T-waves is related to the duration of ventricular activation.
• Ischemic T-wave: the electrocardiogram of a subepicardial ischemia is characterized by the presence of negative, symmetrical and peaked T-waves of “ischemic” appearance in several leads corresponding to a given myocardial territory; the symmetrical and peaked pattern is more frequently observed with deep T-waves; the pattern is furthermore suggestive of an ischemia in instances of pronounced inversion (> 5 mm), a biphasic T-wave, presence of a necrosis q wave, an evocative modification of the ST segment (elevation or depression, linear ST), a prolonged QT-interval or pathological U-wave and in the absence of electrical signs suggesting a heart disease of other origin (hypertrophic cardiomyopathy); inversion of the T-wave can be dynamic, appearing only during pain and regress spontaneously or after administration of nitroglycerine puffs;
•  Giant negative T-waves: very deep T-waves (> 5 to 10 mm depending on definitions) can be found in certain situations: apical hypertrophic cardiomyopathy (preferentially in lateral, inferior and mid precordial leads), myocardial ischemia (giant negative T-waves from V1 to V4 in Wellens syndrome), increased intracranial pressure, major right ventricular hypertrophy, subarachnoid hemorrhage with increased intracranial pressure (giant T-waves and prolonged QT-interval), post-tachycardia and post-pacing memory sign);

Take-home message: The presence of negative, symmetrical and peaked T-waves corresponding to a given myocardial territory should evoke an ischemic origin depending on clinical context.