The nurse counts an adults heart beat at 110 beats per minute. The nurse describes this as

Modifiable risk factors for coronary artery disease (CAD) are those that can be changed or controlled to reduce the risk of developing CAD. These include high blood pressure, high cholesterol levels, smoking, physical inactivity, unhealthy diet, and obesity. High HDL (high-density lipoprotein) is actually a desirable factor, as it is known as the "good cholesterol" and helps to remove excess cholesterol from the body. Orthostatic hypotension, or a drop in blood pressure upon standing, is not considered a modifiable risk factor for CAD.

In the normal electrocardiogram, the PR interval represents

The PR interval represents the time from the onset of atrial activation to the onset of ventricular activity. During this time, the electrical impulse travels through the atria, the atrioventricular (AV) node, and the bundle of His before entering the ventricles and initiating ventricular depolarization. Option A is incorrect because the atrial depolarization is represented by the P wave. Option B is incorrect because the ventricular depolarization is represented by the QRS complex. Option D is incorrect because there is no such term as “electrical systole” of the ventricles in ECG interpretation.