*The transmission of the electrical impulses in the heart begins here.
*Sets the rhythm of the heart's contraction
*Pacemaker of the heart
What is Sinoatrial (SA) Node
100
* Small upward curve
*Sinoatrial node impulse
*Wave of depolarization through atria
What is P wave
100
* Small upward curve sometimes found after T wave
* May be seen in:
- Normal individuals
- Patients experiencing slow recovery of Purkinje fibers
- Patients who have low potassium levels or other
other metabolic disturbances
What is U wave
100
* Condition of having two seperate poles, one of which is positive and the other negative
* A resting cardiac cell is ______, meaning
- negaive charge inside
- positive charge outside
What is Polarity
100
* Life-threatening
* Two lower pumping chambers of the heart begins to quiver
* No cardiac output
What is Ventricular Fibrillation (V-Fib)
200
* Located at the bottom of the right atrium
* Transmission of the impulse is slightly delayed
What is Atrioventricular (AV) Node
200
* Downward deflection
* Impulse going through both ventricles
What is S wave
200
* Includes Q, R, and S waves
* Contraction (following depolarization) of ventricles
* Larger than P wave because ventricles are larger than
atria
What is QRS complex
200
* When polarization is restored
What is Repolarization
200
* Charicterized by large erratic spikes
* Caused by muscle movement
What is Somatic Interference
300
*Cardiac muscle located in the septum between the ventricles.
*Acts as a relay station
What is Bundle of His
300
* Large upward spike
* Impulse going through left ventricle
What is R wave
300
* Connects end of QRS complex with beginning of T wave
* Time between contraction of ventricles and recovery
What is S-T segment
300
* Is the electrical inpulses that initiates a chain reaction resulting in contraction
* The wave of _______ flows from the SA Node to the ventricles and can be detected by electrodes that are placed on the body for an EKG
What is Depolarization
300
* Leads to fast heart beats (tachycardia)
* Causes can include:
- Hypertension
- Myocardial Infarction
- Overactive thyroid
- Heart Failure
What is Atrial Fibrillation
400
*Considered to be cardiac conducting muscle fibers
*Located in the ventricle walls
*When the impulse reaches this point, the ventricles contract
* Includes P wave and straight line connecting it to QRS
complex
* Time it takes for electrical impulse to travel from SA node to AV node
What is P-R interval
400
* Sensors that detect electrical activity
What are Electrodes
400
* Small electrical current given off by another piece of electrical equipment that is picked up on the EKG tracing
* Crossed wires may also cause ______
What is Alternating Current (AC) Interference
500
The sequence of contraction and relaxation that makes up a complete heartbeat
What is Cardiac Cycle
500
* Upward curve
* Recovery (repolarization) of ventricles
* Repolarization of atria is not obvious because it occurs while ventricles are contracting and producing QRS complex
What is T wave
500
* Includes QRS complex, S-T segment, and T wave
* Time it takes for ventricles to contract and recover, or repolarize
What is Q-T interval
500
* A substance that enhances transmission of electrical current
What is an Electrolyte
500
* A beat that occurs early in the clycle and is followed by a pause before the next cycle
* Can be caused by myocardial infarctions, electrolyte imbalances, lack of oxygen or certain medications