Tap a card to reveal the definition. Cards close after 8 seconds — you can reopen any card as many times as you need.
Tap a term, then tap its definition. Each correct match earns 1 point.
Read carefully — the next page builds directly on this passage.
Every heartbeat begins with a tiny electrical pulse. That pulse fires from the sinoatrial (SA) node, a cluster of specialized cells in the upper right atrium. The SA node acts as the heart's natural pacemaker, setting a resting rhythm of about 60 to 100 beats per minute in healthy adults.
The signal spreads across the atria, causing them to contract. This produces the small bump on an ECG known as the P wave. The pulse then pauses briefly at the atrioventricular (AV) node before racing down the bundle of His and the Purkinje fibers into the ventricles. The sharp, tall QRS complex on an ECG marks ventricular contraction — the powerful squeeze that pumps blood to the lungs and body. The rounded T wave that follows shows the ventricles resetting electrically, ready for the next beat.
When this conduction system breaks down, the rhythm becomes abnormal — an arrhythmia. Some arrhythmias are harmless, but others can be deadly. Atrial fibrillation replaces clean P waves with chaotic atrial activity and an irregularly irregular pulse, sharply raising the risk of stroke because blood pools and clots in the quivering atria. Ventricular fibrillation is a true emergency — the ventricles twitch instead of pump, no blood reaches the brain, and death follows within minutes unless an electrical shock from a defibrillator resets the rhythm. By contrast, asystole — a flat line — cannot be shocked; only CPR and medications can give the heart a chance to restart.
Reading an ECG is pattern recognition under pressure. A trained technician can identify a life-threatening rhythm in seconds, page the cardiology team, and give a patient their best chance at survival.
Five short tasks based on the reading. Each item is worth 1 point.
The sets the heart's resting pace, while the complex marks the contraction of the .
"Atrial fibrillation increases stroke risk."
"Doctors record ECG signals."
You are the cardiac tech on shift. Identify each rhythm, then complete the patient log below.
Below is a Normal Sinus Rhythm at about 70 BPM. Every healthy beat has three waves in this exact order: a small P wave, a tall sharp QRS complex, and a rounded T wave. Use this as your reference — anything that looks different is abnormal.
Each strip is 6 seconds long. Count the number of QRS complexes (the tall sharp peaks) and multiply by 10 to get beats per minute.
Example: If you count 7 QRS complexes in a 6-second strip → 7 × 10 = 70 BPM (normal).
Ask these four questions in order. Stop at the first match.
Suppose you see this strip on your screen:
Complete every cell — your BPM estimates, your diagnosis, and the treatment priority you would assign. Filling in the table earns up to 4 points toward your final grade.
| Patient | Heart Rate (BPM) | Rhythm Diagnosis | Treatment Priority |
|---|
This patient wore a portable monitor for one full day. Use the graph to answer the questions.
5 questions drawn at random from a 20-question bank. You need 60% to demonstrate mastery. Each question is worth 1 point.
Your full lab record, ready to print or save as PDF.
| Patient | Heart Rate (BPM) | Rhythm Diagnosis | Treatment Priority |
|---|