ECG Quiz #1

A Holter monitor is a small box used to monitor and record the heart rhythm for 24 to 48 hours. Unlike a 12-lead ECG, which is a one-time test, a Holter monitor is worn by the patient for an extended period of time, allowing for continuous monitoring of the heart's electrical activity. This device is commonly used to detect and diagnose irregular heart rhythms, such as arrhythmias, that may not be captured during a short ECG test. A pacemaker, on the other hand, is an implanted device that helps regulate the heart's rhythm and is not used for monitoring purposes.

The Tricuspid valve is located on the right side of the heart

Repolarization is the correct answer because it refers to the process in which the electrical potential across the cell membrane returns to its resting state after depolarization. During repolarization, the myocardial cells relax and prepare for the next contraction. This phase is crucial for the heart's proper functioning and allows for efficient pumping of blood.

The Q wave can be described as the conduction of the impulse down the intraventricular septum, the wave that immediately precedes the R wave, and the wave that immediately follows the P wave. In other words, it encompasses all of the above options.

The first deflection being positive and known as the R wave is not true. The R wave is actually the first upward deflection in a normal electrocardiogram (ECG) waveform. It represents the depolarization of the ventricles of the heart. Therefore, the correct answer is False.

An ambulatory ECG is a type of electrocardiography that is performed while the patient is exercising or undergoing physical activity, typically on a treadmill. It is also referred to as exercise electrocardiography or a treadmill stress test. This test helps to evaluate the heart's response to exercise and can provide important information about the presence of any underlying heart conditions or abnormalities. Therefore, the statement that an ambulatory ECG is also known as exercise electrocardiography or treadmill stress test is true.

Depolarization is the process by which the electrical charge of the myocardial cells changes, leading to the contraction of the heart muscle. During depolarization, the electrical stimulus causes the myocardial cells to become less negative, which triggers the release of calcium ions. These calcium ions then initiate a series of events that ultimately result in the contraction of the heart muscle, allowing it to pump blood throughout the body. Therefore, depolarization is the correct answer as it directly leads to myocardial contraction.