AACN PCCN Exam Review Cardiac Latest Update.
Normal P wave - > <0.11 sec
Normal PR interval - > 0.12-0.20 sec
Normal QRS interval - > 0.04-0.10 sec
Inherent rate of sinus node - > 60-100 bpm
Inherent rate of AV node - > 40-60 bpm
Inherent rate of Purkinje fibers - > 20-40 bpm
Causes of U wave - > hypokalemia, abnormally prolonged repolarization, various drugs
Effects of atropine - > increase HR and eliminate irregularity
Treatment plan for A fib - > antithrombotic therapy such as warfarin to maintain INR 2-3,
or daily 325mg of aspirin if low stroke risk
Most common cause of VT - > CAD such as acute ischemia, acute MI, or prior MI
Preferred treatment of VT with pulse - > cardioversion if symptomatic, defibrillation if
there is no time to synchronize, and lidocaine if not severely symptomatic
Treatment of polymorphic VT - > electrical cardioversion with sedation if hemodynamic
compromise is present, IV beta blocker if ischemia is suspected, IV amiodarone for
recurrent, angiography with revascularization if PVT with myocardial ischemia
Treatment of Torsades de Pointes - > correct electrolyte abnormalities (Mag) and pacing
if due to heart block and symptomatic bradycardia
Standard of care for survivors of V fib - > implantable cardioverter defibrillator
Successful resuscitation of V fib/VT patients depends on - > early defibrillation
, Capture definition and measurement in pacing system - > when a pacing stimulus results
in depolarization of chamber being paced, measured by strength of the stimulus,
milliamperes mA
Sensing definition and measurement in pacing system - > Pacemaker ability to detect the
presence of intrinsic cardiac activity, measured in millivolts mV
What to do if indiscriminate pacing occurs - > must decrease the sensitivity to allow
pacemaker to "see" smaller signals from the heart
Difference between asynchronous and demand pacing - > asynchronous - paces at
programmed rate regardless of intrinsic cardiac activity, considered unsafe; demand -
pacemaker paces only when the heart fails to depolarize on its own
Define cardiac output and normal range - > amount of blood pumped by ventricles each
minute (CO = HR x SV), 4-8 L/min
Define stroke volume and normal range - > amount of blood ejected by ventricles with
each contraction, 50-100 mL/beat
Define ejection fraction and normal range - > how much blood is pumped with each
contraction in relation to the volume of available blood, >60%
Define preload - > volume of blood that exerts force or stretch on ventricles during
diastole, measured by CVP catheter or pulmonary artery catheter
Primary determinant of preload - > amount of venous return to the heart (venous
constriction, dilation, and changes in total blood volume)
What drugs increase preload - > epinephrine, dopamine doses greater than 10
mcg/kg/min, and norepinephrine
Causes of increased Right Atrial Pressure (RAP) - > intravascular volume overload,
cardiac tamponade, restrictive cardiomyopathies, RV failure
Normal P wave - > <0.11 sec
Normal PR interval - > 0.12-0.20 sec
Normal QRS interval - > 0.04-0.10 sec
Inherent rate of sinus node - > 60-100 bpm
Inherent rate of AV node - > 40-60 bpm
Inherent rate of Purkinje fibers - > 20-40 bpm
Causes of U wave - > hypokalemia, abnormally prolonged repolarization, various drugs
Effects of atropine - > increase HR and eliminate irregularity
Treatment plan for A fib - > antithrombotic therapy such as warfarin to maintain INR 2-3,
or daily 325mg of aspirin if low stroke risk
Most common cause of VT - > CAD such as acute ischemia, acute MI, or prior MI
Preferred treatment of VT with pulse - > cardioversion if symptomatic, defibrillation if
there is no time to synchronize, and lidocaine if not severely symptomatic
Treatment of polymorphic VT - > electrical cardioversion with sedation if hemodynamic
compromise is present, IV beta blocker if ischemia is suspected, IV amiodarone for
recurrent, angiography with revascularization if PVT with myocardial ischemia
Treatment of Torsades de Pointes - > correct electrolyte abnormalities (Mag) and pacing
if due to heart block and symptomatic bradycardia
Standard of care for survivors of V fib - > implantable cardioverter defibrillator
Successful resuscitation of V fib/VT patients depends on - > early defibrillation
, Capture definition and measurement in pacing system - > when a pacing stimulus results
in depolarization of chamber being paced, measured by strength of the stimulus,
milliamperes mA
Sensing definition and measurement in pacing system - > Pacemaker ability to detect the
presence of intrinsic cardiac activity, measured in millivolts mV
What to do if indiscriminate pacing occurs - > must decrease the sensitivity to allow
pacemaker to "see" smaller signals from the heart
Difference between asynchronous and demand pacing - > asynchronous - paces at
programmed rate regardless of intrinsic cardiac activity, considered unsafe; demand -
pacemaker paces only when the heart fails to depolarize on its own
Define cardiac output and normal range - > amount of blood pumped by ventricles each
minute (CO = HR x SV), 4-8 L/min
Define stroke volume and normal range - > amount of blood ejected by ventricles with
each contraction, 50-100 mL/beat
Define ejection fraction and normal range - > how much blood is pumped with each
contraction in relation to the volume of available blood, >60%
Define preload - > volume of blood that exerts force or stretch on ventricles during
diastole, measured by CVP catheter or pulmonary artery catheter
Primary determinant of preload - > amount of venous return to the heart (venous
constriction, dilation, and changes in total blood volume)
What drugs increase preload - > epinephrine, dopamine doses greater than 10
mcg/kg/min, and norepinephrine
Causes of increased Right Atrial Pressure (RAP) - > intravascular volume overload,
cardiac tamponade, restrictive cardiomyopathies, RV failure
