NHA EKG Exam Notes

What is the primary function of the heart?

To pump blood throughout the body, providing oxygen and nutrients while removing wastes.

What is the normal heart rate at rest?

60–100 beats per minute.

What does an ECG record?

The electrical activity of the heart, not the actual contraction.

What are the three layers of the heart?

Epicardium (outer), Myocardium (middle), Endocardium (inner).

What is the function of the SA Node?

It acts as the natural pacemaker of the heart, initiating each heartbeat.

What does the PR interval measure?

The time it takes for the electrical impulse to travel from the SA Node through the AV Node to the ventricles.

What is the normal duration for the QRS complex?

Less than 0.12 seconds.

What does ST elevation indicate in an ECG?

Possible acute myocardial injury.

What are the ECG characteristics of Atrial Fibrillation?

Irregularly irregular rhythm with absent P waves.

What is a PVC?

A premature ventricular contraction, which is an early heartbeat that begins in the ventricles.

What is the main danger of Ventricular Tachycardia?

The ventricles may not pump blood effectively, risking cardiac output and oxygen delivery.

What are standard precautions in infection control?

Treating all patients as if they may carry infectious organisms, including proper hand hygiene and PPE.

What key feature differentiates Mobitz I from Mobitz II?

Mobitz I has progressively lengthening PR intervals before a dropped beat, while Mobitz II has constant PR intervals with sudden drops.

What do tall T waves indicate?

Possible hyperkalemia (high potassium levels).

What does the term 'myocardial infarction' mean?

Death of heart muscle tissue due to lack of blood supply.

What does the QT interval represent?

The total time required for ventricular depolarization and repolarization.

What does ischemia mean?

Reduced blood flow to heart tissue that can lead to muscle stress, indicated by ST depression.

What are the four heart valves?

Tricuspid, Pulmonary, Mitral (Bicuspid), and Aortic valves.

Why is the left ventricle the thickest chamber of the heart?

Because it pumps blood to the entire body and must withstand higher pressure.

Define heart block.

A condition where the electrical impulses from the atria do not properly travel to the ventricles.

What is the primary risk of Atrial Fibrillation?

Increased risk of blood clots which can lead to strokes.

What is a Holter monitor?

A portable ECG device that records heart activity continuously for an extended period, usually 24-48 hours.

What is the main job of coronary arteries?

To supply blood and oxygen to the heart muscle.

What is an important aspect of professional conduct as an EKG technician?

Maintaining patient confidentiality and privacy.