Cardiac Rhythm Disorders - Level 4
Question and answers already passed
2026/2027
Dysrhythmias - correct answer -abnormal cardiac rhythms
-can start if triggered beats (early or late) come from an ectopic focus: area outside the normal
conduction pathway
-replaces the normal sinus rhythm
Autonomic nervous system effect on heart - correct answer -stimulation of the vagus nerve causes
decreased rate of firing of the SA node and slow impulse conduction through AV node
-stimulation of the sympathetic nervous system increases SA node firing, AV node impulse conduction,
and cardiac contractility
12 Lead ECG - correct answer -graphic tracing of the electrical impulses produced in the heart
-waves: ions move across the membranes of myocardial cells depolarizing and repolarizing the cell
-6 leads measure electrical forces in the frontal place
-they are either bipolar (positive or negative leads or unipolar (positive)
-the remaining 6 leads are unipolar and measure electrical forces in the horizontal plane
-1 or more leads can be used to con monitor a pt
-leads II and V1 are most common
-clip excess hair and rub skin w alcohol
Interpreting ECG - correct answer HORIZONTALLY
-1 small square = 0.04 sec
-1 large square = 0.2 sec
,VERTICALLY
-1 small square = 0.1 millivolt
-1 large square = 0.5 millivolts
-every 3 secs has a marker
-count the number of R-R intervals in 6 secs and multiple by 10 to estimate HR
-Artifact: a distortion of the baseline and waveforms, check connections if this occurs
Normal Sinus rhythm - correct answer -starts in the SA node at a rate of 60-100 BPM and follows the
normal conduction pathway
-SA node is the normal pacemaker of the heart
Secondary pacemaker - correct answer -if the SA node fails to regulate the HR, another site may fire to
regulate the HR
-will fire automatically
-may start from the AV node at 40-60 BMP
-or the HIS-Purkinje system at 20-40 BMP
Refractory phase/period - correct answer -recovery period
-absolute refractory period occur first: zero excitability and the heart cannot be stimulated
-relative refractory period slightly later, excitability more likely
Electrophysiologic study - correct answer -used to identify causes of dysrhythmias
Holter monitor - correct answer -con records the ECG while the pt is ambulatory and performing daily
activities
-pt keeps a diary and records activities and any symptoms
-events in the diary are correlated w any dysrhythmias seen on the ECG
, Event monitor - correct answer -recorders that the pt activates only when he or she experiences
symptoms
Exercise treadmill testing - correct answer -evaluates the pts heart rhythm during exercise
Signal averaged ECG - correct answer -identifies late potentials strongly suggesting that the pt may be at
risk for developing serious ventricular dysrhythmias
Sinus bradycardia - correct answer -same conduction pathway as sinus rhythm but SA node fires at a
rate of less than 60 BMP
-symptomatic bradycardia: pale, cool skin, hypotension, weakness, angina, dizziness, syncope,
confusion, disorientation, SOB
-may be normal in athletes and some people during sleep
-occurs in response to carotid sinus massage, valsalva maneuver, hypothermia, increased ICP, vagal
stimulation, drugs
-common disease states: hypothyroidism, increased ICP, hypoglycemia, inferior MI
Treatment of sinus bradycardia - correct answer -only if pt is symptomatic
-atropine
-transcutaneous pacing
-dopamine (Intropin)
-epinephrine (Adrenalin)
-permanent pacemaker
-if due to drugs, held or D/C
Sinus tachycardia - correct answer -same conduction pathway as sinus rhythm
Question and answers already passed
2026/2027
Dysrhythmias - correct answer -abnormal cardiac rhythms
-can start if triggered beats (early or late) come from an ectopic focus: area outside the normal
conduction pathway
-replaces the normal sinus rhythm
Autonomic nervous system effect on heart - correct answer -stimulation of the vagus nerve causes
decreased rate of firing of the SA node and slow impulse conduction through AV node
-stimulation of the sympathetic nervous system increases SA node firing, AV node impulse conduction,
and cardiac contractility
12 Lead ECG - correct answer -graphic tracing of the electrical impulses produced in the heart
-waves: ions move across the membranes of myocardial cells depolarizing and repolarizing the cell
-6 leads measure electrical forces in the frontal place
-they are either bipolar (positive or negative leads or unipolar (positive)
-the remaining 6 leads are unipolar and measure electrical forces in the horizontal plane
-1 or more leads can be used to con monitor a pt
-leads II and V1 are most common
-clip excess hair and rub skin w alcohol
Interpreting ECG - correct answer HORIZONTALLY
-1 small square = 0.04 sec
-1 large square = 0.2 sec
,VERTICALLY
-1 small square = 0.1 millivolt
-1 large square = 0.5 millivolts
-every 3 secs has a marker
-count the number of R-R intervals in 6 secs and multiple by 10 to estimate HR
-Artifact: a distortion of the baseline and waveforms, check connections if this occurs
Normal Sinus rhythm - correct answer -starts in the SA node at a rate of 60-100 BPM and follows the
normal conduction pathway
-SA node is the normal pacemaker of the heart
Secondary pacemaker - correct answer -if the SA node fails to regulate the HR, another site may fire to
regulate the HR
-will fire automatically
-may start from the AV node at 40-60 BMP
-or the HIS-Purkinje system at 20-40 BMP
Refractory phase/period - correct answer -recovery period
-absolute refractory period occur first: zero excitability and the heart cannot be stimulated
-relative refractory period slightly later, excitability more likely
Electrophysiologic study - correct answer -used to identify causes of dysrhythmias
Holter monitor - correct answer -con records the ECG while the pt is ambulatory and performing daily
activities
-pt keeps a diary and records activities and any symptoms
-events in the diary are correlated w any dysrhythmias seen on the ECG
, Event monitor - correct answer -recorders that the pt activates only when he or she experiences
symptoms
Exercise treadmill testing - correct answer -evaluates the pts heart rhythm during exercise
Signal averaged ECG - correct answer -identifies late potentials strongly suggesting that the pt may be at
risk for developing serious ventricular dysrhythmias
Sinus bradycardia - correct answer -same conduction pathway as sinus rhythm but SA node fires at a
rate of less than 60 BMP
-symptomatic bradycardia: pale, cool skin, hypotension, weakness, angina, dizziness, syncope,
confusion, disorientation, SOB
-may be normal in athletes and some people during sleep
-occurs in response to carotid sinus massage, valsalva maneuver, hypothermia, increased ICP, vagal
stimulation, drugs
-common disease states: hypothyroidism, increased ICP, hypoglycemia, inferior MI
Treatment of sinus bradycardia - correct answer -only if pt is symptomatic
-atropine
-transcutaneous pacing
-dopamine (Intropin)
-epinephrine (Adrenalin)
-permanent pacemaker
-if due to drugs, held or D/C
Sinus tachycardia - correct answer -same conduction pathway as sinus rhythm
