Heart Basics
This structure separates the right and left sides of the heart.
What is the septum?
The natural pacemaker of the heart.
What is the SA node?
How many electrodes are used in a standard 12-lead ECG?
What is 10?
Standard ECG paper speed.
What is 25 mm per second?
An artifact caused by muscle movement.
What is somatic tremor?
The thick muscular layer of the heart is responsible for pumping blood.
What is the myocardium?
This node delays the impulse so the atria can empty into the ventricles.
What is the AV node?
This limb electrode is the ground and not part of the recording.
What is RL (right leg)?
One small box horizontally equals this amount of time.
What is 0.04 seconds?
Small uniform spikes caused by nearby electrical equipment.
What is AC interference?
These top two chambers of the heart receive blood.
What are the atria?
This ECG wave represents ventricular depolarization.
What is the QRS complex?
Lead I measures the electrical activity between these two limbs.
What is the right arm to the left arm?
One small box vertically equals this amount of voltage.
What is 0.1 mV?
ECG complexes drifting up and down across the tracing.
What is wandering baseline?
Name the two phases of the cardiac cycle.
What are systole and diastole?
This wave represents ventricular repolarization.
What is the T wave?
V4 is placed at this location.
What is the 5th intercostal space, left midclavicular line?
During standardization, the stylus should move upward by this many millimeters for 1 mV.
What is 10 mm?
Breaks appear between waves on the tracing.
What is an interrupted baseline?
Trace the correct blood flow: vena cava → ______ → tricuspid valve → ______.
What is right atrium and right ventricle?
Put these in order: Purkinje fibers, SA node, AV node, Bundle of His.
What is the SA node → AV node → Bundle of His → Purkinje fibers?
Correct order for placing precordial electrodes.
What is V1 → V2 → V4 → V3 → V5 → V6?
When ECG complexes are too close together, this paper speed is used.
What is 50 mm per second?
Artifact appears in Leads I and II. Which electrode should you check?
What is the right arm electrode?