ECG Note Cards | ECG Note Card Answers |
Normal pacemaker of the heart | SA node |
· Located where the superior vena cava enters the right atrium | SA node |
SA node Fires at a rate of | 60-100 bpm |
Internodal tracts and Bachmann’s bundle | Existence of 3 internodal tracts is debatable |
Impulse travels to left atrium via Bachmann’s bundle | Internodal tracts and Bachmann’s bundle |
AV node is located | in the inferior right atrium |
AV node Delays impulse by _______seconds to give | by 0.04 seconds to give ventricles a chance to fill while atria contract |
AV node cannot generate an________ but ______ can | AV node cannot generate an impulse but junctional tissue can |
Beginning of the ventricular conduction system | Bundle of His |
_______Divides into right and left bundle branches | Bundle of His |
Bundle of His is where a Peacemaker fires at a rate of | 40-60 bpm when SA node doesn’t fire or impulse doesn’t reach AV note |
Extend down right and left side of interventricular septum | Bundle branches |
· Covers endocardial surfaces of both ventricles, spreads to myocardium and epicardium | Purkinje fibers |
Purkinje fibers is where a Peacemaker fires at a rate of | 20-40 bpm when impulse is blocked at/above bundle branches |
P wave represents | the electrical conduction through both atria. |
P wave Precedes_______, is ______ and ________. | QRS complex; is Rounded and smooth |
PR interval represents | _the impulse travel time through the AV node, through the bundle of His, and to the Purkinje fibers |
PR interval Measured | from the start of the P to the end of the Q/r where it starts to go down. |
Normal duration is - normal length for the PR interval is | 0.12 to 0.20 second. Should not be longer than 0.2 seconds and this is what you need to know. |
QRS complex Represents | QRS complex indicates that the electrical impulse has traveled through the ventricles |
QRS complex follows | the PR interval |
QRS complex consists of | 3 waves: Q (1st – deflection), R (1st + deflection), and S (2nd – deflection) |
QRS complex normal duration is | 0.06 to 0.10 second |
Represents the end of ventricular depolarization and the beginning of ventricular repolarization | ST segment |
ST segment follows | QRS, from end of S wave to beginning of T wave |
T wave Represents | Ventricular repolarization recovery |
T wave flows what? | Follows the ST segment |
What wave is slightly rounded and smooth? | T wave |
QT interval represents ___? | Represent ventricular depolarization - repolarization of ventricle cycle |
QT interval is measured from _________. | Start of Q to end of T |
QT interval duration is | normal QT interval is 0.12 to 0.42 seconds |
How do you figure the rate? | 1500/# ob boxes between two R points |
Sinus Bradycardia | is less than 60 |
Sinus Tachycardia | is over 100 |
Normal Sinus | 60-100 |