Course Review, NHA CET Domain Mapping, and Unit Assessment

Why This Review Lesson Matters

You have worked through cardiac anatomy, the conduction system, the cardiac cycle, autonomic control, and the pathophysiology concepts that underpin every EKG interpretation you will ever perform. This final lesson pulls all of that together in a structured way so you can walk into the NHA CET exam — and into clinical practice — with genuine confidence. The goal is not just to pass a test; it is to confirm that you have the knowledge needed to recognize abnormal findings and communicate them safely to the care team.

What the NHA CET Tests in the Cardiac Knowledge Domains

The NHA CET exam is organized into content domains. The cardiac anatomy and physiology content you have studied directly supports several of those domains. Understanding exactly where each topic lives in the exam blueprint helps you study smarter in the final hours before the exam.

• Anatomy and cardiac structures — chambers, valves, great vessels, coronary arteries. You must know structure names, locations, and functions.
• Electrical conduction system — SA node, AV node, bundle of His, bundle branches, Purkinje fibers, and the pathway impulses follow from initiation to ventricular contraction.
• The cardiac cycle — the sequence of systole and diastole, what happens to pressure and volume in each chamber, and how valve opening and closing relate to that sequence.
• Autonomic control of heart rate — sympathetic and parasympathetic divisions, how they speed up or slow down the heart, and which neurotransmitters are involved.
• Pathophysiology mechanisms — how ischemia, injury, and infarction differ; how electrolyte imbalances and drug effects alter the conduction system; why certain arrhythmias arise from specific anatomical or physiological disruptions.

When you complete the domain mapping worksheet today, you are making an explicit connection between each of those topic areas and the lessons where you studied them. That connection is what turns memorized facts into usable clinical knowledge.

Rapid Review: High-Yield Points for Each Domain Area

Anatomy and structures. The heart has four chambers. The right side receives deoxygenated blood and pumps it to the lungs; the left side receives oxygenated blood and pumps it to the body. The atrioventricular valves (tricuspid on the right, mitral on the left) prevent backflow from ventricles to atria. The semilunar valves (pulmonic and aortic) prevent backflow from arteries into ventricles. The coronary arteries arise from the aorta just above the aortic valve and supply the myocardium itself — an area of coronary artery disease will affect the region of myocardium that vessel supplies.

Conduction system. Normal impulse origin is the SA node, located in the right atrium near the superior vena cava. The impulse travels through internodal pathways to the AV node, which delays transmission to allow ventricular filling, then continues down the bundle of His, the right and left bundle branches, and finally the Purkinje fibers to depolarize the ventricular myocardium. On an EKG strip, the P wave reflects atrial depolarization, the PR interval reflects AV node delay, and the QRS reflects ventricular depolarization. Any interruption in this pathway produces a recognizable pattern on the strip.

Cardiac cycle. Systole is the contraction phase; diastole is the relaxation and filling phase. Stroke volume is the amount of blood ejected per beat. Cardiac output equals stroke volume multiplied by heart rate. The ejection fraction — the percentage of end-diastolic volume that is actually pumped out — is a key measure of left ventricular function, though EKG technicians do not calculate it; you should know what it represents when you see it in a chart.

Autonomic control. The sympathetic nervous system increases heart rate and contractility (fight-or-flight response). The parasympathetic nervous system, primarily through the vagus nerve, decreases heart rate (rest-and-digest). Beta-blockers reduce sympathetic effect; atropine blocks parasympathetic effect and increases heart rate. Understanding this helps you recognize why certain medications alter the EKG.

Pathophysiology mechanisms. Ischemia is reversible oxygen deprivation. Injury implies ongoing, more severe ischemia that may produce ST changes on the EKG. Infarction is cell death — irreversible. Hyperkalemia (elevated blood potassium) can cause peaked T waves and ultimately a sine-wave pattern. Hypokalemia can prolong the QT interval. These are mechanisms you need to recognize in scenario-based exam questions.

How the Unit Exam Is Structured

The 50-question exam uses the same mix of question types found on the NHA CET: direct-knowledge items ("Which node initiates the normal cardiac impulse?") and scenario-based items ("A patient's EKG shows a prolonged PR interval; which structure is most likely responsible for the delay?"). You will have a set time to complete the exam individually. Budget your time — read each question fully before selecting an answer and flag any you are unsure of to revisit if time allows.

The pass standard is 78%, meaning you must answer at least 39 of 50 questions correctly. This standard mirrors the overall course passing requirement and is consistent with the competency expectations for students preparing to sit the NHA CET.

Patient Safety Reminder

Everything in this course connects to patient safety. Accurate EKG acquisition and preliminary rhythm recognition depends on knowing anatomy so you place leads correctly, knowing conduction so you recognize what is normal versus abnormal, and knowing pathophysiology so you understand why you must escalate certain findings immediately. An EKG technician who mistakes lead placement because they do not recall cardiac anatomy may produce a misleading tracing. Always work within your scope of practice and report findings to the appropriate licensed clinician without delay.

After the Exam

If you score below 78%, do not view it as a failure — view it as diagnostic data. Meet with your instructor, identify which domain areas account for most of your missed questions, and build a targeted remediation plan before moving into Course 3. The NHA CET is achievable, and a focused review of your weak areas is the most efficient path forward.