Advanced Dysrhythmias
1. P wave:
PR interval:
QRS complex:
(ST segment)
T wave:
QT interval:: • P wave - atrial depolarization and contraction
• PR interval - time of travel from the SA node to AV node (.12-.2)
• QRS - ventricular depolarization and contraction (.08-.12)
- Note: Atrial repolarization occurs during this time, but cannot be seen on EKG
• T wave - ventricular repolarization
• QT interval - start of ventricular contraction to end of relaxation
2. Systematic Approach to analyzing EKG (7 steps): 1. Determine atrial &
ventricular rate and rhythm.
2. Identify P waves and shape, and if there are P waves for every QRS.
3. Determine PR interval (0.12-.2), and if consistent, irregular but with pattern to
irregularity, or just irregular.
4. Determine QRS duration, consistency, and shape. (<0.12)
5. Identify T wave and shape.
6. Identify ST segment, and any elevation/depression.
7. Identify any ectopic beats occurring outside underlying rhythm.
3. Determining HR from EKG strip: Typical heart rhythm strips will contain 6
seconds (30 big boxes)
• Rates in a 6 second strip can be obtained by
- Ventricular rate = QRS (QRS to QRS-the gaps) x 10
- Atrial rate = P waves x 10
OR Ventricular rate = 1500 / # of small boxes between 2 QRS; Atrial rate = 1500 /
# of small boxes between 2 P waves
• 1 small box = .04sec, 5 boxes/large box = 0.2sec; 5 large boxes = 1 second, 15
large = 3sec
, Advanced Dysrhythmias
•
4. To improve lead conduction... (4): - Clean and dry skin with soap and water
- Remove excess hair
- Gentle abrasion of skin with clean gauze to expose epidermis (dry gauze, not
alcohol which acts as barrier, skin is a natural conductor)
- Have patient remain still and supine
5. Normal Sinus Rhythm: • Ventricular and atrial rate: 60 to 100 bpm
• Ventricular and atrial rhythm: Regular
• QRS shape and duration: Usually normal, but may be regularly
abnormal
• P wave: Normal and consistent shape; always in front of the
QRS
PR interval: Consistent interval between 0.12 and 0.20 seconds
• P:QRS ratio: 1:1
6. Sinus Bradycardia: • Atrial/ventricular rate and rhythm: < 60 and regular
• P wave: Normal and consistent shape; always in front of QRS
• PR interval: Consistently between 0.12 and 0.2 seconds
• QRS shape and duration: Usually normal, but may be regularly abnormal
• Concern - decreased cardiac output and tissue perfusion
7. Etiology of Sinus Brady (causes): • Lower metabolic needs - Sleep, Athletes,
Hypothyroidism
• Vagal stimulation (triggers parasympathetic) - Vomiting, Suctioning, Pain
• Medications - CCB, BB, Amiodarone
• Idiopathic sinus node dysfunction
• Increased intracranial pressure
• Coronary artery disease
*Management will depend on cause and symptoms
8. H's and T's for abnormal heart rhythms (6/5): • Hypovolemia - weight loss,
low
•
1. P wave:
PR interval:
QRS complex:
(ST segment)
T wave:
QT interval:: • P wave - atrial depolarization and contraction
• PR interval - time of travel from the SA node to AV node (.12-.2)
• QRS - ventricular depolarization and contraction (.08-.12)
- Note: Atrial repolarization occurs during this time, but cannot be seen on EKG
• T wave - ventricular repolarization
• QT interval - start of ventricular contraction to end of relaxation
2. Systematic Approach to analyzing EKG (7 steps): 1. Determine atrial &
ventricular rate and rhythm.
2. Identify P waves and shape, and if there are P waves for every QRS.
3. Determine PR interval (0.12-.2), and if consistent, irregular but with pattern to
irregularity, or just irregular.
4. Determine QRS duration, consistency, and shape. (<0.12)
5. Identify T wave and shape.
6. Identify ST segment, and any elevation/depression.
7. Identify any ectopic beats occurring outside underlying rhythm.
3. Determining HR from EKG strip: Typical heart rhythm strips will contain 6
seconds (30 big boxes)
• Rates in a 6 second strip can be obtained by
- Ventricular rate = QRS (QRS to QRS-the gaps) x 10
- Atrial rate = P waves x 10
OR Ventricular rate = 1500 / # of small boxes between 2 QRS; Atrial rate = 1500 /
# of small boxes between 2 P waves
• 1 small box = .04sec, 5 boxes/large box = 0.2sec; 5 large boxes = 1 second, 15
large = 3sec
, Advanced Dysrhythmias
•
4. To improve lead conduction... (4): - Clean and dry skin with soap and water
- Remove excess hair
- Gentle abrasion of skin with clean gauze to expose epidermis (dry gauze, not
alcohol which acts as barrier, skin is a natural conductor)
- Have patient remain still and supine
5. Normal Sinus Rhythm: • Ventricular and atrial rate: 60 to 100 bpm
• Ventricular and atrial rhythm: Regular
• QRS shape and duration: Usually normal, but may be regularly
abnormal
• P wave: Normal and consistent shape; always in front of the
QRS
PR interval: Consistent interval between 0.12 and 0.20 seconds
• P:QRS ratio: 1:1
6. Sinus Bradycardia: • Atrial/ventricular rate and rhythm: < 60 and regular
• P wave: Normal and consistent shape; always in front of QRS
• PR interval: Consistently between 0.12 and 0.2 seconds
• QRS shape and duration: Usually normal, but may be regularly abnormal
• Concern - decreased cardiac output and tissue perfusion
7. Etiology of Sinus Brady (causes): • Lower metabolic needs - Sleep, Athletes,
Hypothyroidism
• Vagal stimulation (triggers parasympathetic) - Vomiting, Suctioning, Pain
• Medications - CCB, BB, Amiodarone
• Idiopathic sinus node dysfunction
• Increased intracranial pressure
• Coronary artery disease
*Management will depend on cause and symptoms
8. H's and T's for abnormal heart rhythms (6/5): • Hypovolemia - weight loss,
low
•
