©EMILLECT 2024/2025 ACADEMIC YEAR. ALL RIGHTS RESERVED
FIRST PUBLISH OCTOBER 2024
Critical Care Exam 1 Study Guide
Solutions
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 1/49
, ©EMILLECT 2024/2025 ACADEMIC YEAR. ALL RIGHTS RESERVED
FIRST PUBLISH OCTOBER 2024
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
Rhythm is regular
P wave present
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, ©EMILLECT 2024/2025 ACADEMIC YEAR. ALL RIGHTS RESERVED
FIRST PUBLISH OCTOBER 2024
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
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.**
Page 3/49
, ©EMILLECT 2024/2025 ACADEMIC YEAR. ALL RIGHTS RESERVED
FIRST PUBLISH OCTOBER 2024
- 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
Rhythm: *Always has irregular rhythm*
P waves?: yes
PR interval: normal
QRS: normal
Significance: usually a normal finding and usually is *not treated*
Premature Atrial Complexes - ANSWER✔✔-Rate: normal
Rhythm:abnormal
P waves?: Yes, has *EARLY* p waves
PR interval? WNL
Page 4/49
FIRST PUBLISH OCTOBER 2024
Critical Care Exam 1 Study Guide
Solutions
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 1/49
, ©EMILLECT 2024/2025 ACADEMIC YEAR. ALL RIGHTS RESERVED
FIRST PUBLISH OCTOBER 2024
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
Rhythm is regular
P wave present
Page 2/49
, ©EMILLECT 2024/2025 ACADEMIC YEAR. ALL RIGHTS RESERVED
FIRST PUBLISH OCTOBER 2024
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
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.**
Page 3/49
, ©EMILLECT 2024/2025 ACADEMIC YEAR. ALL RIGHTS RESERVED
FIRST PUBLISH OCTOBER 2024
- 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
Rhythm: *Always has irregular rhythm*
P waves?: yes
PR interval: normal
QRS: normal
Significance: usually a normal finding and usually is *not treated*
Premature Atrial Complexes - ANSWER✔✔-Rate: normal
Rhythm:abnormal
P waves?: Yes, has *EARLY* p waves
PR interval? WNL
Page 4/49
