[Solved] A hole in the interventricular septum in an infant may cause all of the following symptoms except A) mixing of oxygen-rich and oxygen-poor blood. B) a murmur to be heard. C) the heart to work harder. D) the individual to have low peripheral oxygen saturation. E) build-up of atherosclerotic plaque. P Wave: A deflection in the ECG representing the electrical activity of atrial depolarization, preceding the contraction of the atria. P-Q Segment: The portion of an electrocardiogram (ECG) trace between the end of the P wave and the start of the QRS complex, indicative of the time electrical impulse travels from the atria to the ventricles. Standard Leads: Predetermined positions on the body where electrodes are placed for the purpose of recording an electrocardiogram (ECG). Lab Exercise: A practical, hands-on activity or experiment carried out in a laboratory setting for educational purposes, often to explore scientific principles.