As a medical professional with expertise in cardiology, I can explain the significance of Q waves on an ECG (electrocardiogram). Q waves on an ECG are typically indicative of myocardial infarction (heart attack) or myocardial necrosis (death of heart muscle tissue). They can also be seen in other conditions such as left ventricular hypertrophy (thickening of the heart muscle), bundle branch block (a delay or blockage in the electrical pathway of the heart), or Wolff-Parkinson-White (WPW) syndrome (a pre-excitation syndrome). It's important to note that the presence of Q waves alone is not diagnostic of a heart attack. The morphology (shape), duration, and location of the Q waves on the ECG are critical factors that must be considered in conjunction with the patient's clinical history and symptoms. For instance, Q waves that are too deep or too wide, or that appear in leads that wouldn't typically show Q waves, can be suggestive of a previous heart attack. In summary, while Q waves can be a sign of heart damage, the interpretation must be made within the context of the entire ECG reading and the patient's overall clinical presentation. read more >>

By definition, a Q wave on the electrocardiogram (ECG) is an initially negative deflection of the QRS complex. Technically, a Q wave indicates that the net direction of early ventricular depolarization (QRS) electrical forces projects toward the negative pole of the lead axis in question.read more >>