Final answer:
Negative impulses on an ECG tracing are seen as downward deflections, which represent electrical activity moving away from the electrodes' positive pole.
Step-by-step explanation:
On an ECG tracing, negative impulses are seen as downward deflections. The ECG represents the electrical activity of the heart, with various waves corresponding to specific cardiac events. The P wave indicates atrial depolarization, the QRS complex indicates ventricular depolarization, and the T wave represents ventricular repolarization. Atrial repolarization is not distinctly represented on the ECG as it occurs during the QRS complex and is obscured by the larger electrical activity of the ventricles.
The negative impulses on an ECG indicate electrical activity moving away from the positive pole of the electrodes and result in downward deflections on the tracing. For instance, a negative Q wave will be shown as a downward deflection of the QRS complex. It's important to understand that the morphology and amplitude of ECG waves can indicate various cardiac conditions such as myocardial infarction (MI) or ventricular hypertrophy.