As a medical professional with expertise in cardiology, I can explain the significance of the Q wave on an electrocardiogram (ECG). The Q wave is an initially negative deflection of the QRS complex, which is the part of the ECG that represents ventricular depolarization. When a Q wave is present, it signifies that the net direction of the electrical forces during the early phase of ventricular depolarization is directed towards the negative pole of the lead axis being observed. This can be a normal finding, depending on the lead and the individual's heart structure, or it can indicate a previous myocardial infarction (heart attack), particularly if the Q wave is unusually deep or wide. It's important to interpret the Q wave in the context of the entire ECG and the patient's clinical history to determine its clinical significance. 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 >>