Part I and II

Question 1

Arrhythmia

Answer 1

a disturbance in or loss of regular rhythm. (2) especially, any variation from the normal rhythm of the heartbeat, it may be an abnormality of either the rate, regularity, or site of impulse origin or the sequence of activation. The term encompasses abnormal regular and irregular rhythms as well as loss of rhythm.

Question 2

Automaticity

Answer 2

the state or quality of being automatic. (2) the capacity of a cell to initiate an impulse, such as depolarization, without an external stimulus.

Question 3

Biphasic

Answer 3

having two phases; in electrocardiography, having an impulse vector that is no moving exactly perpendicular, nor parallel, to the “observing” electrode, resulting in deflections that are both above and below the isoelectric baseline.

Question 4

Bradycardia

Answer 4

slowness of the heartbeat, as evidenced by slowing of the pulse rate to less than 60 beats per minute.

Question 5

Chronotropy

Answer 5

referring to the time or rate, as the rate of contraction of the heart. Something that causes positive chronotropy will result in an increase in heart rate (e.g., epinephrine, atropine), while a negative chronotrope causes a decrease in heart rate (e.g. beta-blockers, calcium channel blockers).

Question 6

Conductivity

Answer 6

the capacity of a body to transmit a flow of electricity or heat; it is the conductance per unit area of the body. When expressed in figures, electrical conductivity is the reciprocal of resistivity.

Question 7

Depolarization

Answer 7

1) the process or act of neutralizing polarity. (2) in electrophysiology, the reversal of the resting potential in excitable cell membranes when stimulated, i.e., the tendency of the cell membrane potential to become positive with respect to the potential outside the cell.

Question 8

Dromotropy

Answer 8

referring to the conductivity of a nerve fiber, such as the rate of depolarization, thus affecting the speed at which impulse transmission flow. Positive dromotropy refers to a state in which impulse transmission is made faster (e.g., epinephrine, atropine), whereas a negative dromotrope causes a reduction in the velocity of such transmission (e.g., digitalis, adenosine).

Question 9

Ectopic

Answer 9

arising in an abnormal site or tissue; in electrophysiology, the origin of an electrical impulse from a site outside of the sinoatrial node (SA node).

Question 10

Excitability

Answer 10

(1) irritability. (2) the capacity of a cell to depolarize and form an action potential when in the presence of a stimulus stronger than a threshold value.

Question 11

Inotropy

Answer 11

referring to the force or energy of muscular contraction. Something causing positive inotropy will result in an increase in the contractile force (e.g., dopamine, dobutamine), while a negative inotrope leads to a reduced or weaker degree of contractility (e.g., beta-blockers, calcium channel blockers).

Question 12

Interval

Answer 12

the space between two objects or parts, the lapse of time between two recurrences or paroxysms.

Question 13

Intrinsic/inherent

Answer 13

situated entirely within or pertaining exclusively to a part; implanted by nature; innate.

Question 14

Reentry

Answer 14

reexcitation of a region of cardiac tissue by a single impulse, continuing for one or more cycles and sometimes resulting in ectopic beats or tachyarrhythmias. It can exist over either an anatomical or a functional area of slowed impulse conduction and requires also refractoriness of tissue to stimulation and an area of unidirectional block to conduction.

Question 15

Refractory period

Answer 15

period of time following depolarization of a cell in which there is a state of resistance to subsequent stimulation.

Question 16

Repolarization

Answer 16

the reestablishment of polarity, especially the return of cell membrane potential to resting potential after depolarization.

Question 17

Segment

Answer 17

a portion of a larger body or structure, such as the ST segment incorporating the distance from the termination of the QRS complex to the beginning of the T wave.

Question 18

Tachycardia

Answer 18

excessive rapidity in the action of the heart; the term is usually applied to a heart rate above 100 beats per minute in an adult and is often qualified by the locus of origin as well as by whether it is paroxysmal or nonparoxysmal (sustained).

Question 19

Threshold

Answer 19

the minimum level of input required to cause some event to occur; the value at which a stimulus just produces a response by the cell.

Question 20

Aberrancy

Answer 20

related to deviation from the usual or natural way, such as aberrant ventricular conduction (the temporary abnormal intraventricular conduction of supraventricular impulses).

Question 21

Deviation

Answer 21

turning away from the regular standard or course, such as axis deviation (an axis shift in the frontal plane, as seen on an electrocardiogram).

Question 22

Escape rhythm

Answer 22

a heart rhythm initiated by lower centers when the sinoatrial node fails to initiate impulses, its rhythmicity is depressed, or its impulses are completely blocked.

Question 23

Hypertrophy

Answer 23

enlargement of myocardial cells and hyperplasia of nonmuscular cardiac components due to pressure and/or volume overload and sometimes to neurohumoral factors. Hypertrophy of the ventricular myocardium, due to chronic pressure overload manifests on an ECG as increased QRS complex voltage, frequently accompanied by repolarization changes.

Question 24

Infarction

Answer 24

the formation of a localized area of ischemic necrosis produced by anoxia following occlusion of the arterial supply or the venous drainage of the tissue, organ, or part.

Question 25

Ischemia

Answer 25

an insufficient supply of blood to an organ or tissues, usually due to either a blocked artery or a reduction in blood pressure.

Question 26

Monomorphic

Answer 26

existing in only one form or shape.

Question 27

Multifocal

Answer 27

arising from or pertaining to many sites or locations.

Question 28

Paroxysmal

Answer 28

pertaining to something that occurs briefly and transiently.

Question 29

Polymorphic

Answer 29

occurring in several or many different forms.

Question 30

Pre-excitation

Answer 30

premature excitation of a portion of the ventricle caused by stimuli passing along one of the auxiliary pathways of cardiac stimulation that are not subject to the same physiological delays at the AV node. Characterized electrocardiographically by a short PR interval and a wide QRS interval.

Question 31

Reciprocal

Answer 31

inversely related or opposing; being equivalent or complimentary; in ECGs, seen when the opposing leads show the opposite deflections and deviations to “mirror” leads (example: anterior leads will show the reciprocal or opposite changes as seen in posterior and inferior leads, and vice versa).