Practice exam

Which term describes a cardiac cell's ability to receive an electrical stimulus and transfer the impulse to an adjacent cell?
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Terms in this set (26)
Which term describes a cardiac cell's ability to receive an electrical stimulus and transfer the impulse to an adjacent cell?
Conductivity
In the normal sequence of electrical conduction, what structure acts as the dominant pacemaker of the heart?
Sinoatrial (SA) node
What phase of the cardiac action potential occurs when ions move across a cell membrane to restore a negative charge inside the cell?
Repolarization
On an electrocardiogram tracing, what does the downslope of the P wave represent?
Left atrial depolarization
Which finding on an electrocardiogram suggests injury to the myocardium?
ST segment elevation greater than 1 mm
What is considered an abnormal characteristic of the QRS complex?
Predominately negative QRS complex in lead II
During which event in the cardiac cycle is blood propelled through the systemic and pulmonary circulation and toward the atria?
Ventricular systole
Which vessels stem from the left main coronary artery and supply blood to the anterior surface of both ventricles, as well as most of the right and left bundle branches?
Left anterior descending artery
What is afterload?
The pressure or resistance against which the ventricles must pump to eject blood
Which electrocardiogram leads view the heart in the horizontal plane, allowing a view of the front and left sides of the heart?
Precordial leads
While reviewing a patient's electrocardiogram (ECG) rhythm tracing, you note 30 large boxes along the horizontal axis. How many seconds does this represent?6 secondsWhich of these leads views the inferior surface of the heart?IIWhich layer of the heart contains nerve fibers and fat?EpicardiumWhat causes the tricuspid and mitral valves to close completely?Ventricular pressure exceeds atrial pressureWhich statement accurately describes the S4 heart sound?Occurs during atrial contraction as a result of ventricular hypertrophy or tissue damageHow do you determine atrial regularity on a rhythm tracing?Measure the distance between two consecutive P-P intervals and compare that distance with the other P-P intervalsHow do you determine ventricular rate using the small-box method?Divide the number of small boxes between two consecutive QRS complexes into 1,500A male patient, age 55, reports chest pain and pressure. What is the earliest indicator that he is experiencing an inferior wall myocardial infarction (MI)?Hyperacute T waves in leads II, III, and aVFWhat is the mean QRS vector?The average amplitude and direction of impulses in the right and left ventricles during depolarizationAfter performing an electrocardiogram (ECG) on a patient, you note that the QRS complex is negative in lead I and positive in aVF. Using the two-lead method of axis determination, what can you determine about this ECG?Right axis deviation is present.From which direction does lead aVF view the heart's electrical activity?From the left foot, looking at the inferior surface of the left ventricleST segment elevation is noted in leads I and aVL on a patient's electrocardiogram. Which vessel do you suspect may be occluded?Left coronary artery, circumflex branchWhich type of chamber enlargement would show deeper than normal S waves and small R waves in leads V5 and V6 on an electrocardiogram?Right ventricular hypertrophyA patient is diagnosed with a left bundle branch block. What would you expect to see on her electrocardiogram?QRS complex greater than 0.12 seconds in duration and a negative terminal portion of the QRS complex in V1Which electrocardiogram (ECG) changes are associated with hypercalcemia?Prolonged PR and shortened QT intervalsWhat characteristic of a rhythm tracing indicates multifocal atrial tachycardia (MAT)?There are at least three different P-wave configurations.