A vertical line on the ECG that indicates the pacemaker has discharged
Pacemaker spike
A pacemaker malfunction that occurs when the artificial pacemaker fails to recognize spontaneous myocardial depolarization
Undersensing
A pacemaker malfunction that occurs when the artificial pacemaker stimulus is unable to depolarize the myocardium
Failure to capture
The period between two consecutive paced events in the same cardiac chamber
Paced interval
This type of pacemaker stimulates the atrium and ventricle
Dual chamber
In dual-chamber pacing, the length of time between and atrial sensed or atrial paced event and the delivery of a ventricular pacing stimulus; an artificial or electronic PR interval
AV interval
This type of pacemaker discharges only when the patient's heart rate drops below the preset rate for the pacemaker
Demand
Ability of a pacemaker to increase the pacing rate in response to physical activity or metabolic demand
Rate modulation
This type of pacemaker continuously discharges at a preset rate regardless of the patient's intrinsic activity
Fixed-rate
A pacemaker malfunction that results from inappropriate sensing of extraneous electrical signals
Oversensing
Power source that houses the battery and circuitry for regulating a pacemaker
Pulse generator
The rate at which the pacemaker's pulse generator initiates impulses when no intrinsic activity is detected; expressed in pulses per minute
Base rate
The minimum amount of voltage (i.e., milliamperes) needed to obtain consistent capture
Threshold
Pacemaker response in which the output pulse is suppressed when an intrinsic event is sensed
Inhibition
A pacemaker malfunction that occurs when the pacemaker fails to deliver an electrical stimulus at its programmed time
Failure to pace
T/F
In a patient experiencing an acute coronary syndrome, ST segment elevation in the shape of a "smiley" face is usually associated with an acute injury pattern
False
T/F
Poor R-wave progression is a phrase used to describe R waves that decrease in size from V1 to V4
True
T/F
Placement of right chest leads is identical to the standard chest leads except on the right side of the chest
True
T/F
In most patients, the posterior wall of the left ventricle is supplied by the right coronary artery
False
T/F
When you read a 12-lead EKG from left to right, the EKG tracing is continuous
True
T/F
The six limb leads view the heart in the frontal plane as if the body were flat
True
Which of the following leads view the heart in the frontal plane?
I, II, III, aVR, aVL, aVF
T/F
In a patient presenting with an acute coronary syndrome, the presence of ST segment elevation on the ECG suggests that myocardial injury in progress.
True
Although a right ventricular infarction may occur by itself, it is more commonly associated with a(n) _____ wall myocardial infarction.
Inferior
Patients experiencing _________________ infarctions are most likely to develop a bundle branch block.
Septal and anteroseptal
Which of the following statements is true regarding ventricular hypertrophy?
Hypertrophy increases the QRS amplitude
When correctly positioned, lead V1 lies:
fourth intercostal space just right of sternum
If time does not permit obtaining an entire right-sided 12-lead ECG to view the right ventricle, the lead of choice is:
V4R
When leads I and aVF are used to determine electrical axis, left axis deviation is present if:
The QRS is positive in lead I and negative in lead aVF.
Which of the following leads are anatomically contiguous?
V2, V3, V4
In a patient experiencing an acute coronary syndrome, T-wave inversion suggests the presence of:
ischemia
Indicative ECG changes observed in leads I, aVL, V3, V4, V5, and V6 suggest that the __________________ is affected.
Anterolateral wall of the left ventricle
A branch of this vessel supplies most of the bundle branch tissue and a critical section of the left ventricle.
Left coronary artery
Lead II is perpendicular to this lead
aVL
Significant ECG findings that are seen in leads that are opposite the affected area of the heart
Reciprocal changes
ST segment elevation in the leads suggest an anterior infarction
V3-V4
Tall T waves may be observed on the ECG during this phase of ST-elevation MI
Hyperacute phase
An increase in the diameter of a chamber of the heart caused by volume overload
Dilatation
Lead I + Lead III =
Lead II
The zone of _______________ is typically characterized by ST-segment depression
Ischemia
An increase in the thickness of a heart chamber because of chronic pressure overload
Hypertrophy
ST-elevation in these leads suggest and inferior infarction
II, III, aVF
This represents all of the frontal plane leads with the heart in the center
Hexaxial reference system
Pathologic Q waves may first appear on the ECG during this phase of ST-elevation MI
Fully evolved phase
Lead I is perpendicular to this lead
aVF
ST-segment elevation may be observed on the ECG during this phase of ST-elevation MI
Early acute phase
Occlusion of a branch of this vessel can result in an inferior or right ventricular infarction
Right coronary artery
ST-segment elevation is these leads suggest a lateral infarction
I, aVL, V5, V6
Leads used to view the right ventricle
V1R-V6R
The zone of _____________ is typically characterized by ST-segment elevation
Injury
ST segment elevation in these leads suggest a septal infarction
V1-V2
Significant ECG findings that are seen in leads that look directly at the affected area of the heart
Indicative changes
T/F
Evidence of sodium disturbances is typically viewed on the ECG as marked increases in the amplitude of P waves and T waves
False
T/F
An abnormal Q wave indicates the presence of dead myocardial tissue
True
Although and RVI may occur by itself, it is more commonly associated with a(n) ________________ wall MI
Inferior
Which of the following are commonly seen ECG changes in hyperkalemia?
Tall, peaked T waves
Normal electrical axis lies between __________ in the frontal plane
-30 and +90 degrees
In evaluating the ECG for indications of enlargement, a ECG machine's sensitivity must be calibrated so that a 1-mV electrical signal will produce a deflection measuring exactly _______ mm tall.
10
Which of the following ECG changes is one of the earliest to occur during a STEMI but may have resolved by the time the patient seeks medical assistance?
Hyperacute T waves
A 66 year old man presents with persistent chest pain that has been present for 1 hour. His 12 lead ECG reveals STE in leads V2, V3, and V4, and his cardiac biomarkers are elevated. You suspect
STEMI
Which of the following is probably the single best lead to use in differentiating between RBBB and LBBB?
Lead V1
A ___________________________ BBB produces an rSR' pattern in lead V1
RBBB
A ________________________ BBB produces a QS pattern in lead V1.
LBBB
This can produce ST segment elevation and wide Q waves that look remarkably similar to infarction
LBBB
Term that refers to either dilation of a heart chamber or hypertrophy of the heart muscle
Cardiac enlargement
Leads commonly used to determine axis deviation
I and aVF
NSTEMI and unstable angina
Non ST elevation acute coronary syndromes
Cardiac biomarkers are elevated when this is present
STEMI
Leads that view the septum
V1, V2
QRS pattern that is a characteristic of RBBB
rSR'
Most common form of cardiomyopathy
Dilated cardiomyopathy
Term used to describe a wide QRS that is not associated with a BBB pattern
Intraventricular conduction relay
The P wave is tall, peaked, and usually of normal duration
Right atrial abnormality
Vessel that is usually blocked with an inferior MI
Right coronary artery
Deflection of the terminal force of the QRS complex in V1 in RBBB
Positive
Vessel that is usually blocked with an anterior MI
Left anterior descending artery
Characteristic ECG changes associated with right ventricular hypertrophy
Tall R waves in leads V1 through V3 and deeper than normal S waves in leads I, aVL, V5, and V6
Leads that view the lateral wall of the left ventricle
I, aVL, V5, V6
The final portion of the QRS complex
Terminal force
Characteristic ECG changes associated with left ventricular hypertrophy
Increased QRS amplitude and changes in the ST segment and T wave
QRS pattern that is characteristic of LBBB
QS
Type of cardiomyopathy characterized by significant myocardial hypertrophy without ventricular dilation that results in a markedly reduced stroke volume because of impaired diastolic filling
Hypertrophic cardiomyopathy
Associated with prolongation of the middle and end of the P wave
Left atrial abnormality
Time measured between a sensed cardiac event and the next pacemaker output
Escape interval
The extent to which an artificial pacemaker recognizes intrinsic cardiac electrical activity
Sensitivity
The successful conduction of an artificial pacemaker's impulse through the myocardium, resulting in depolarization
Capture
Net direction, or angle in degrees, in which the main vector of depolarization is pointed
Electrical axis
Quantity having direction and magnitude, usually depicted by a straight arrow whose length represents magnitude and whose head represents direction
Vector
A disruption in impulse conduction from the bundle of His through the right or left bundle branch to the Purkinje fibers; a BBB may be intermittent or permanent
Bundle branch block; bbb