Page 1 of 231
HESI Critical Care Comprehensive Exam 1 (Latest
2025)
P wave .....ANSWER.....Depolarization of the atria
PR interval .....ANSWER.....-Normal is 0.12 to 0.2 seconds
- onset of atrial depolarization until onset of ventricular
polarization
QRS complex .....ANSWER.....-Normal is 0.06 to 0.11 seconds
-Ventricular depolarization
-systole
T wave .....ANSWER.....-appears after QRS complex
- Ventricular repolarization
-Spiked T-wave occurs with hyperkalemia
U wave .....ANSWER.....- repolarization of the purkinje fibers
- seen in patients with hypokalemia
,Page 2 of 231
SA node .....ANSWER.....the pace-maker of the heart; where the
impulse conduction of the heart usually starts; located in the top
of the right atrium just below superior vena cava
*sends impulses 60-100 BPM
Normal Sinus Rhythm .....ANSWER.....Rate is 60-100/ minute
Rhythm is regular
P wave present
PR interval: normal 0.12-0.20
QRS complex:normal
Interpretation: normal sinus rhythm
normal QRS: 0.06- 0.10
Sinus Bradycardia .....ANSWER.....Rate is <60/minute
,Page 3 of 231
Rhythm is regular
P wave present
PR interval: normal 0.12-0.20
QRS complex:normal
Interpretation: treat sinus brady with *0.5mg atropine ( if
emergent)* , dopamine, epinephrine, pacer.
*normal in patients when sleeping or sleeping
-may occur with use of Beta blockers or calcium channel blockers,
digoxin, morphine, vagal stimulation, hypothermia, hypothroidism
Sinus Tachycardia .....ANSWER.....Rate is >100/min (usually
below 160)
Rhythm is regular
P wave present
, Page 4 of 231
PR interval: normal 0.12-0.20
QRS complex:normal 0.6-0.10
Interpretation: correct the underlying cause, adminster beta
blockers or calcium channel blockers.
*treat underlying cause.**
- may be a normal response from a fever, exercise, anxiety,
pain, dehydration. May accompany shock, LHF, hyperthyroidism,
anemia, hypovolemia, PE, MI
-can be caused by caffiene, nicotine, amphetemines, atropine,
cocaine.
Sinus Arrhythmia .....ANSWER.....Rate: increases on inspiration,
decreases on expiration
HESI Critical Care Comprehensive Exam 1 (Latest
2025)
P wave .....ANSWER.....Depolarization of the atria
PR interval .....ANSWER.....-Normal is 0.12 to 0.2 seconds
- onset of atrial depolarization until onset of ventricular
polarization
QRS complex .....ANSWER.....-Normal is 0.06 to 0.11 seconds
-Ventricular depolarization
-systole
T wave .....ANSWER.....-appears after QRS complex
- Ventricular repolarization
-Spiked T-wave occurs with hyperkalemia
U wave .....ANSWER.....- repolarization of the purkinje fibers
- seen in patients with hypokalemia
,Page 2 of 231
SA node .....ANSWER.....the pace-maker of the heart; where the
impulse conduction of the heart usually starts; located in the top
of the right atrium just below superior vena cava
*sends impulses 60-100 BPM
Normal Sinus Rhythm .....ANSWER.....Rate is 60-100/ minute
Rhythm is regular
P wave present
PR interval: normal 0.12-0.20
QRS complex:normal
Interpretation: normal sinus rhythm
normal QRS: 0.06- 0.10
Sinus Bradycardia .....ANSWER.....Rate is <60/minute
,Page 3 of 231
Rhythm is regular
P wave present
PR interval: normal 0.12-0.20
QRS complex:normal
Interpretation: treat sinus brady with *0.5mg atropine ( if
emergent)* , dopamine, epinephrine, pacer.
*normal in patients when sleeping or sleeping
-may occur with use of Beta blockers or calcium channel blockers,
digoxin, morphine, vagal stimulation, hypothermia, hypothroidism
Sinus Tachycardia .....ANSWER.....Rate is >100/min (usually
below 160)
Rhythm is regular
P wave present
, Page 4 of 231
PR interval: normal 0.12-0.20
QRS complex:normal 0.6-0.10
Interpretation: correct the underlying cause, adminster beta
blockers or calcium channel blockers.
*treat underlying cause.**
- may be a normal response from a fever, exercise, anxiety,
pain, dehydration. May accompany shock, LHF, hyperthyroidism,
anemia, hypovolemia, PE, MI
-can be caused by caffiene, nicotine, amphetemines, atropine,
cocaine.
Sinus Arrhythmia .....ANSWER.....Rate: increases on inspiration,
decreases on expiration
