NURS 5354 EKG EXAM WITH QUESTIONS AND
ANSWERS
heart 4 chambers - ANSWER Right and Left atrium & Right and Left ventricle
Perfusion to the various chambers of the heart is via - ANSWER RCA & Left main
descends into LAD (left anterior descending artery)
RCA supplies blood to - ANSWER RA, RV, SA (sinoatrial node) & AV
(atrioventricular node)
LAD supplies blood to - ANSWER L front side of the heart
L circumflex artery supplies - ANSWER to left outer side as well as posterior side
of the heart
Both the LAD & RCA supply blood to - ANSWER the septum
Cardiac contraction happens when - ANSWER depolarization of the heart
3 heart components which spread electrical currents - ANSWER cardiac
pacemaker cells, specialized conduction tissue, & the heart muscle
Depolarization originates in - ANSWER SA node & spreads through the R&L
atrium which is followed by atrial contraction. The impulse travels to AV node
emerges and transmits through bundle of His, then L&R bundle branches, and
finally through the Purkinje fibers which facilitates activation of the ventricular
muscle
Purkinje Fibers - ANSWER activate ventricular muscle
Only electrical conduction between the atria and ventricles (healthy heart) -
ANSWER AV node
12-lead ECG - ANSWER electric potentials generated by the heart and captures
the electrical component (depolarization & repolarization)
12 lead ECG electrical activity measured from - ANSWER 12 perspectives (leads) of
the heart can be evaluated through 2 electrical planes (vertical and horizontal). 4
extremity or limb leads and 6 precordial or chest leads
Vertical plane provides info for leads - ANSWER I, II, III, aVR, aVL, & aVF
, Horizontal plane provides for leads - ANSWER V1, V2, V3, V4, V5, & V6
Lateral leads are - ANSWER Lead I, aVL, V5, and V6
Lateral leads represent - ANSWER Left circumflex artery
Inferior leads are - ANSWER Lead II, III, and aVF
Inferior leads represent - ANSWER RCA
Anteroseptal leads - ANSWER V1, V2, V3, and V4
Anteroseptal leads represent - ANSWER LAD
Septal leads - ANSWER V1 and V2. Represents LAD
Anterior leads - ANSWER V3 and V4. Represents LAD
PQRST complex represents - ANSWER depolarization and repolarization of the
heart
ECG box horizontal axis measures - ANSWER Speed
Vertical axis measures - ANSWER Amplitude of a given wave or deflection
One small square within a large box is - ANSWER 0.04 seconds and 0.1mV
A large square which contains five boxes across and five boxes down is - ANSWER
.2 sec and 0.5mV
Speed equates to - ANSWER the # of complexes on a ECG strip = HR
Isoelectric line - ANSWER designates the flat part of the diagram between the P
wave and T wave & significant variations in positive and negative deflections can
correlate with certain diseases or disorders
Appear above the isoelectric line - ANSWER Positive deflections
Appear below the isoelectric line - ANSWER Negative deflections
P wave - ANSWER first positive deflection. The P wave should be less than 0.12
secs
Abnormalities in the P wave best seen in - ANSWER inferior leads (Leads II, III,
and aVF) because the wave is more prominent in these leads
PR interval - ANSWER Reflects conduction through the AV node. 0.12 to 0.2 secs.
ANSWERS
heart 4 chambers - ANSWER Right and Left atrium & Right and Left ventricle
Perfusion to the various chambers of the heart is via - ANSWER RCA & Left main
descends into LAD (left anterior descending artery)
RCA supplies blood to - ANSWER RA, RV, SA (sinoatrial node) & AV
(atrioventricular node)
LAD supplies blood to - ANSWER L front side of the heart
L circumflex artery supplies - ANSWER to left outer side as well as posterior side
of the heart
Both the LAD & RCA supply blood to - ANSWER the septum
Cardiac contraction happens when - ANSWER depolarization of the heart
3 heart components which spread electrical currents - ANSWER cardiac
pacemaker cells, specialized conduction tissue, & the heart muscle
Depolarization originates in - ANSWER SA node & spreads through the R&L
atrium which is followed by atrial contraction. The impulse travels to AV node
emerges and transmits through bundle of His, then L&R bundle branches, and
finally through the Purkinje fibers which facilitates activation of the ventricular
muscle
Purkinje Fibers - ANSWER activate ventricular muscle
Only electrical conduction between the atria and ventricles (healthy heart) -
ANSWER AV node
12-lead ECG - ANSWER electric potentials generated by the heart and captures
the electrical component (depolarization & repolarization)
12 lead ECG electrical activity measured from - ANSWER 12 perspectives (leads) of
the heart can be evaluated through 2 electrical planes (vertical and horizontal). 4
extremity or limb leads and 6 precordial or chest leads
Vertical plane provides info for leads - ANSWER I, II, III, aVR, aVL, & aVF
, Horizontal plane provides for leads - ANSWER V1, V2, V3, V4, V5, & V6
Lateral leads are - ANSWER Lead I, aVL, V5, and V6
Lateral leads represent - ANSWER Left circumflex artery
Inferior leads are - ANSWER Lead II, III, and aVF
Inferior leads represent - ANSWER RCA
Anteroseptal leads - ANSWER V1, V2, V3, and V4
Anteroseptal leads represent - ANSWER LAD
Septal leads - ANSWER V1 and V2. Represents LAD
Anterior leads - ANSWER V3 and V4. Represents LAD
PQRST complex represents - ANSWER depolarization and repolarization of the
heart
ECG box horizontal axis measures - ANSWER Speed
Vertical axis measures - ANSWER Amplitude of a given wave or deflection
One small square within a large box is - ANSWER 0.04 seconds and 0.1mV
A large square which contains five boxes across and five boxes down is - ANSWER
.2 sec and 0.5mV
Speed equates to - ANSWER the # of complexes on a ECG strip = HR
Isoelectric line - ANSWER designates the flat part of the diagram between the P
wave and T wave & significant variations in positive and negative deflections can
correlate with certain diseases or disorders
Appear above the isoelectric line - ANSWER Positive deflections
Appear below the isoelectric line - ANSWER Negative deflections
P wave - ANSWER first positive deflection. The P wave should be less than 0.12
secs
Abnormalities in the P wave best seen in - ANSWER inferior leads (Leads II, III,
and aVF) because the wave is more prominent in these leads
PR interval - ANSWER Reflects conduction through the AV node. 0.12 to 0.2 secs.
