NUR 5434 Module 2 Study Guide
Arrhythmia Review:
The word SYSTOLE usually refers to VENTRICULAR SYSTOLE or CONTRACTION Diastole:
relaxation= ventricles fill with blood
SA Node is the dominant pacemaker of the heart
2 Functions of AV Node
◦ Slows impulse conduction from atria to ventricles (gatekeeper)
◦ Back-up pacemaker of heart, if SA node fails
The AV Node and Bundle of His together are known as the A-V Junction
Electrical current moving toward a positive electrode will result in a positive deflection
P Wave – Activation of the atria – atrial depolarization
QRS Complex – Activation of the ventricles – ventricular depolarization
T wave – Recovery wave – ventricular repolarization
ST segment: early ventricular repolarization
5 steps to rhythm analysis 1.
Determine regularity?
◦ Measure R wave to R wave
2. Calculate the rate?
3. Examine P waves?
◦ P wave for each QRS?
◦ How is the morphology of the P wave?
4. Measure the PR interval
◦ .12-.20 seconds (3-5 small boxes)
5. Measure the QRS interval
◦ .06-.10 seconds (1.5-2.5 small boxes)
Methods to determine rate
First method: Rapid rate calculation: Count the number of R waves in a 6-second strip and multiply by 10
(Example 6 sec X10 =60 HR per Minute)
Electrical impulses moving toward a positive electrode will have a ________ deflection.
Positive
P waves: SHAPE = MORPHOLOGY
, Measure the PR interval -- Measure from beginning of P wave to the beginning of the QRS .12-
.20 seconds
3-5 small boxes
This time interval represents the onset of atrial depolarization to the onset of ventricular depolarization: P-R
interval
This time interval represents ventricular depolarization:
QRS interval
This time interval represents ventricular repolarization:
T wave
Sinus Bradycardia: rate <60/min
Sinus Tachycardia: rate 101-150/min
Sinus Arrhythmia (irregular rhythm at least 2 small boxes)
CAUSES:
Normal phenomenon, usually associated with phases of respiration
◦SA node speeds up with inspiration
◦SA node slows with expiration
Common in infants & children, but may occur at any age TREATMENT:
None required unless very slow rate causes symptoms
Originate from ectopic sites in the atria
◦WAP: Wandering Atrial Pacemaker
◦PAC: Premature Atrial Contraction
◦Conducted
◦Non-conducted
◦PAT or SVT: Paroxysmal Atrial Tachycardia or Supraventricular Tachycardia ◦A
Flutter: Atrial Flutter
◦A Fib: Atrial Fibrillation
The P wave in a PAC looks different from the sinus P wave – Why?
Impulse originates in a different part of the atria
Paraoxysmal Atrial Tachycardia (PAT/SVT): rate 150-250/min (P waves often hidden in previous T wave)
Atrial Flutter characteristics
Rhythm: regular or irreg, depending on conduction ratios
Rate: Atrial: 250-400/min
Ventricular: whatever the AV node allows through. May be constant or variable
P waves: none. Sawtooth “F” flutter waves are baseline. DOES NOT RETURN TO ISOELECTRIC LINE
Atrial Fibrillation characteristics
Rhythm: ALWAYS irregularly irregular
Rate: Atrial: usually >400/min. Atria are quivering
Ventricular: whatever the AV node allows through.
P waves: wavy baseline (fibrillatory waves)
Arrhythmia Review:
The word SYSTOLE usually refers to VENTRICULAR SYSTOLE or CONTRACTION Diastole:
relaxation= ventricles fill with blood
SA Node is the dominant pacemaker of the heart
2 Functions of AV Node
◦ Slows impulse conduction from atria to ventricles (gatekeeper)
◦ Back-up pacemaker of heart, if SA node fails
The AV Node and Bundle of His together are known as the A-V Junction
Electrical current moving toward a positive electrode will result in a positive deflection
P Wave – Activation of the atria – atrial depolarization
QRS Complex – Activation of the ventricles – ventricular depolarization
T wave – Recovery wave – ventricular repolarization
ST segment: early ventricular repolarization
5 steps to rhythm analysis 1.
Determine regularity?
◦ Measure R wave to R wave
2. Calculate the rate?
3. Examine P waves?
◦ P wave for each QRS?
◦ How is the morphology of the P wave?
4. Measure the PR interval
◦ .12-.20 seconds (3-5 small boxes)
5. Measure the QRS interval
◦ .06-.10 seconds (1.5-2.5 small boxes)
Methods to determine rate
First method: Rapid rate calculation: Count the number of R waves in a 6-second strip and multiply by 10
(Example 6 sec X10 =60 HR per Minute)
Electrical impulses moving toward a positive electrode will have a ________ deflection.
Positive
P waves: SHAPE = MORPHOLOGY
, Measure the PR interval -- Measure from beginning of P wave to the beginning of the QRS .12-
.20 seconds
3-5 small boxes
This time interval represents the onset of atrial depolarization to the onset of ventricular depolarization: P-R
interval
This time interval represents ventricular depolarization:
QRS interval
This time interval represents ventricular repolarization:
T wave
Sinus Bradycardia: rate <60/min
Sinus Tachycardia: rate 101-150/min
Sinus Arrhythmia (irregular rhythm at least 2 small boxes)
CAUSES:
Normal phenomenon, usually associated with phases of respiration
◦SA node speeds up with inspiration
◦SA node slows with expiration
Common in infants & children, but may occur at any age TREATMENT:
None required unless very slow rate causes symptoms
Originate from ectopic sites in the atria
◦WAP: Wandering Atrial Pacemaker
◦PAC: Premature Atrial Contraction
◦Conducted
◦Non-conducted
◦PAT or SVT: Paroxysmal Atrial Tachycardia or Supraventricular Tachycardia ◦A
Flutter: Atrial Flutter
◦A Fib: Atrial Fibrillation
The P wave in a PAC looks different from the sinus P wave – Why?
Impulse originates in a different part of the atria
Paraoxysmal Atrial Tachycardia (PAT/SVT): rate 150-250/min (P waves often hidden in previous T wave)
Atrial Flutter characteristics
Rhythm: regular or irreg, depending on conduction ratios
Rate: Atrial: 250-400/min
Ventricular: whatever the AV node allows through. May be constant or variable
P waves: none. Sawtooth “F” flutter waves are baseline. DOES NOT RETURN TO ISOELECTRIC LINE
Atrial Fibrillation characteristics
Rhythm: ALWAYS irregularly irregular
Rate: Atrial: usually >400/min. Atria are quivering
Ventricular: whatever the AV node allows through.
P waves: wavy baseline (fibrillatory waves)
