Exam 25: Principles of Electrocardiography

The electrical activity of the heart is initiated in specialized tissue called the __________,which is located in the superior-posterior wall of the right atrium.

Which of the following leads records tracings between the left arm and left leg,which reflects the electrical activity of the inferior surface of the left ventricle?

An abrasive device must be applied to each electrode placement site before an ECG can be obtained.

The SA node is located in the lower wall of the right atrium near the ventricular septum.

A primary responsibility of the medical assistant when obtaining an ECG is to prevent artifacts or correct the problem that created an artifact and try again to print a clean strip.Explain the four artifacts that can occur,give an example of why the artifact might occur,and explain what the medical assistant can do to solve the problem.

The skin is an excellent conductor of electrical activity.

Which of the following is the most critical,life-threatening arrhythmia that can quickly result in death if not treated?

Which of the following represents the time from the beginning of atrial contraction to the beginning of ventricular contraction?

Six-channel ECG strips must be cut and mounted before they are placed in the patient's medical record.

Which of the following devices monitors the heart rhythm and delivers a shock to the heart if it detects a dangerous ventricular tachycardia or fibrillation?

The __________ leads use two limbs to record the heart's electrical activity.

Which of the following is not an immediate treatment for a heart attack?

Which statement is true about lead II?

The __________ is the electric recording of the heart at rest.

To check the standardization of the ECG machine,the medical assistant depresses the standardization button.The stylus should deflect how many millimeters?

Lead I records the electrical activity between the right arm and the left arm.

The P wave shows the beginning of cardiac depolarization.

The first three leads recorded are called the standard,or __________,limb leads,because they each use two limb electrodes to record the heart's electrical activity.

The QRS complex shows as a positive deflection in V₁ and V₂ views.

Tachycardia is defined as