Advanced Dysrhythmias
exam questions with
complete verified solutions
P wave:
PR interval:
QRS complex:
(ST segment)
T wave:
QT interval: - answer • 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
Systematic Approach to analyzing EKG (7 steps) - answer 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.
Determining HR from EKG strip - answer 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
To improve lead conduction... (4) - answer - 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
Normal Sinus Rhythm - answer • 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
Sinus Bradycardia - answer • 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
Etiology of Sinus Brady (causes) - answer • Lower metabolic needs - Sleep,
Athletes, Hypothyroidism
exam questions with
complete verified solutions
P wave:
PR interval:
QRS complex:
(ST segment)
T wave:
QT interval: - answer • 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
Systematic Approach to analyzing EKG (7 steps) - answer 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.
Determining HR from EKG strip - answer 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
To improve lead conduction... (4) - answer - 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
Normal Sinus Rhythm - answer • 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
Sinus Bradycardia - answer • 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
Etiology of Sinus Brady (causes) - answer • Lower metabolic needs - Sleep,
Athletes, Hypothyroidism
