Cardiology Flashcards
(107 cards)
1
Q
The circumflex artery is a branch of the:
A
Left coronary artery
2
Q
The tricuspid valve is:
A
located between the right atrium and right ventricle
3
Q
The thick, muscular middle layer of the heart wall necessary for contraction is the?
A
myocardium
4
Q
The cavity between the parietal and visceral pericardium contains pericardial fluid, approx?
A
30-50ml
5
Q
Myocytes are jointed together into a continuous mass of ned-to-end gap junctions called
A
intercalated discs
6
Q
T/F: the myocardial walls of each ventricle are much thicker than the atria
A
True
7
Q
T/F: the coronary arteries originate from the aorta and the suppliers of arterial blood to the heart
A
True
8
Q
Cardiac output
A
the amount of blood pumped by the left ventricle in 1 min
9
Q
Stroke volume is dependent on preload, after load, and _________
A
myocardial contractility
10
Q
A classic sign of decreased cardiac output is:
A
- change in mental status
- dyspnea
- hypotension
11
Q
Parasympathetic control of the heart is provided by the:
A
vagus nerve
12
Q
The ventricles are innervated mainly by the:
A
somatic nerve fibers
13
Q
The primary chief mediator of the sympathetic division of the autonomic nervous system is
A
norepinephrine
14
Q
Chronotropy refers to
A
heart rate
15
Q
Acetylcholine affects the heart by:
A
decreasing the heart rate
16
Q
T/F: contractile cells generate an initial spark that sends current through your pacemaker cells
A
False
17
Q
T/F: the nervous system can increase and decrease heart rate contractility and generate electrical impulses
A
False
18
Q
Resting membrane potential in contractile cells is always recorded from the inside of the cell as:
A
-70mV to -90mV
19
Q
In a normal heart, the primary pacemaker is the
A
SA node
20
Q
The inherent beats/min of the AV node is:
A
40-60
21
Q
T/F: The SA node is located in the left atrium, posterior to the tricuspid valve
A
False
22
Q
The AV node is also known as the
A
gatekeeper
23
Q
Depolarization takes place when
A
sodium ions rush into the cell
24
Q
The AV junction is formed by the AV node and the:
A
Bundle of His
25
Atrial kick is MOST accurately defined as
15-30% of ventricular filling caused by atrial contraction
26
The mechanism of ectopic impulses are:
enhanced automaticity AND re-entry
27
Re-entry occurs when an impulse is:
delayed or blocked
28
T/F: a specific polarity is designated to each electrode regardless of selection
False
29
T/F: precordial chest leads view electrical activity in the heart on a transverse/horizontal plane
True
30
T/F: lead aVF is a "distant recording electrode" and does NOT view any wall of the heart
True
31
Each small square represents __ mV
0.1
32
the vertical axis of the graph paper corresponds with
voltage
33
A biphasic waveform represents an electrical impulse that moves
perpendicular to the positive electrode
34
An ECG machine is properly calibrated when an electrical signs is produced measuring __ mV
1
35
ECG paper normally records at a constant speed of
25mm/sec
36
The most common cause of acute coronary syndromes is what
rupture of atherosclerotic plaque
37
T/F: s&s of angina may be atypical in diabetics, the elderly and women
True
38
S&S of stable angina may occur after
- exertion
- emotional distress
- eating
- environmental stressors (ex. heat)
39
T/F: pts will ALWAYS experience chest pain during myocardial infarctions
False
40
What are common signs of an MI?
- confusion
- denial
- ashen skin
41
T/F: distinguishing between unstable angina and AMI can be accomplished during initial presentation
False
42
With regards to 15 lead placement, V4R is placed:
5th intercostal space at right midclavicular line
43
The 1st change in the evolving pattern of STEMI is
development of the T wave
44
A Q wave is pathological when it is:
more than 1/3rd the height of the R wave in the lead
45
Reciprocal changes in inferior leads are
Leads I and AVL
46
15 lead ECG placement consists of which new leads:
V4R, V8 and V9
47
Acute coronary syndromes refer to all of the following
- ST segment elevation MI
- Non ST segment elevation
- unstable angina
48
The left coronary artery divides into which two branches:
- circumflex
- LAD artery
49
Mean vector lies between
0 and +90
50
Two lead method of axis deviation involves which leads:
I and aVF
51
Criteria for identification of a right or left BBB includes a QRS equal or greater than 0.12s and
A QRS produced by supraventricular activity
52
T/F: V2 is the single best lead to use when differentiating between right and left BBB
False
53
T/F: with regards to a RBBB, the last 0.04secs of the QRS is deflected upright
True
54
Increase in thickness of a chamber due to pressure overload:
hypertrophy
55
Right atrial enlargement produces
abnormally tall and peaked initial part of P wave
56
T/F: left ventricular hypertrophy is a STEMI imitator
True
57
T/F: with regards to pericarditis, symptoms are made better by lying flat and worse by sitting up
False
58
T/F: in pericarditis, concave ST elevation is noted in almost every lead (except aVR and V1)
True
59
Hyperkalemia is abnormally high level of what serum in the blood
Potassium
60
T/F: tall and tented T waves are present in mild cases of hyperkalemia
True
61
T/F: hyperkalemia is a STEMI imitator
True
62
VF and aystole occur in hyperkalemia patients with a blood serum of:
10-12 mEq/L
63
A 15 lead ECG should be performed on
- any inferior MI
- tall R waves and ST depression in V1-V3
64
Tunica intima is what layer of the coronary artery
innermost
65
Monomorphic ventricular tachycardia is best described as:
3 or more unifocal PVCs in a row at a rate >100
66
ST segment is best described as:
- early repolarization of the ventricles
67
PR interval is considered prolonged if it is more than how many seconds in duration
0.20s
68
Multifocal atrial tachycardia is best described as
irregularly irregular
69
Common characteristics of SVT include
- p waves are non-discernable
- regular
- >100 bpm
70
Atrial flutter is most commonly caused by
a rapid re-entry circuit
71
Location of MI - V1 and V2 elevated
- affected myocardial area: septal
- occluded artery: proximal LAD
72
Location of MI - V3 and V4 elevated
- affected myocardial area: anterior
- occluded artery: LAD
73
Location of MI - V5 and V6 elevated
affected myocardial area: lateral (apical)
occluded artery: distal LAD, circumflex or right coronary artery
74
Location of MI - I and aVL elevated
affected myocardial area: lateral
occluded artery: circumflex artery
75
Location of MI - II, aVF, and III elevated
affected myocardial area: inferior
occluded artery: 90% RCA, 10% LCx
76
Location of MI - V7, V8 and V9 elevated
affected myocardial area: posterolateral (posterior)
occluded artery - RCA or LCx
77
When does the left coronary artery become occluded:
lateral, septal and anterior MI
78
STEMI ECG Changes - 1st change
Development of T wave (hyperacute phase)
- increases in height, more symmetrical and pointed
- may occur within first few mins of infarction
79
STEMI ECG Changes - 2nd change
ST elevation (early acute phase)
- primary indication of myocardial injury in progress
- may occur within the first few hours of infarction
80
STEMI ECG Changes - 3rd change
T wave inversion (later acute phase)
- T wave inversion suggests presence of ischemia
81
STEMI ECG Changes - 4th change
Development of Q wave (fully evolved phase)
- 1st evidence that tissue death has occurred
82
STEMI ECG Changes - final change
The Q wave remains (healed phase)
- in time, the T wave regains its normal contour and ST segment returns to isoelectric line BUT Q waves remain as evidence an infarct occurred
83
What is automaticity?
ability of cardiac pacemaker cells to generate or initiate their own electrical impulse
84
What is excitability?
irritability: the ability of cardiac cells to respond to an electrical stimulus
85
What is conductivity?
ability of cardiac cells to transmit an electrical stimulus to other cardiac cells
86
What is contractility?
ability of cardiac cells to shorten, causing cardiac muscle contraction in response to electrical stimulus
87
What is polarization?
phase of readiness
-the muscle is relaxed and the cardiac cells are ready to receive and impulse
88
What is depolarization?
phase of contraction
- the cells have transmitted an electrical impulse, usually causing the cardiac muscle to contract
89
What is repolarization
recovery phase
- the muscle has contracted and the cells are returning to a ready state
90
Cardiac Action Potential - Phase 0
Rapid depolarization phase
- cell membrane has reached "threshold potential"
- sodium channels permit rapid entry of Na into cells making inside more positive than outside of the cell
91
Cardiac Action Potential - Phase 1
Early repolarization phase
- flow of sodium into cell stops
- potassium channels open which results in a decrease in the number of positively charged ions in the cell and drop in membrane potential
92
Cardiac Action Potential - Phase 2
Plateau phase - prolonged repolarization phase
- calcium channels open
- at the same time, potassium continues to leave the cell
93
Cardiac Action Potential - Phase 3
Rapid repolarization phase
- calcium channels close
- while potassium continues to exit the cell
94
Cardiac Action Potential - Phase 4
Resting membrane potential
- there is still excess of Na inside and K outside, which causes the sodium-potassium pump to activate
- the Na travels back out and K travels back in
- membrane returns to its resting membrane potential
- phase 0 begins all over again
95
Beginning with the right atrium, describe the normal flow of blood through the heart, lungs and to the systemic circulation
- through the inferior and superior vena cava into the right atrium, through the tricuspid valve into the right ventricle, through the pulmonary valve, through to the right and left pulmonary arteries, to the lungs to become oxygenated
- down through the right and left pulmonary veins into the left atrium through the bicuspid valve into the left ventricles, where it is pumped through the aortic valve into the aortic arch and to the rest of the body
96
What are the phases of Systole
4 phases
- phase 1 - isovolumetric contraction (ventricles squeezing but not pumping)
- phase 2 - ventricular ejection (pumping vigorously)
- phase 3 - protodiastole (pumping less)
- phase 4 - isovolumetric relaxation (relaxing, valves closing to end systole)
97
Discuss the phases of diastole
3 phases
- phase 1 - rapid refilling (atria dumping blood into ventricles)
- phase 2 - diastasis (slowing blood flow)
- phase 3 - atrial kick (atria contracting to squeeze remainder of blood into ventricles)
98
"All-or- nothing" principle
- the action potential along the cell membrane acts as a stimulus to the adjacent regions of the cell membrane
- this causes excitability and once started, it spreads and continues on to the next cell and so forth
99
Define absolute refractory period
the cardiac muscle cannot respond to any stimulation
100
Define relative refractory period
the cardiac muscle is more difficult than normal to excite, yet it can still be stimulated
101
Intrinsic rate of the SA node:
60-100
102
Intrinsic rate of the purkinje fibres:
20-40
103
Right coronary arteries:
Right coronary artery
- posterior descending artery
- right marginal artery
104
Left coronary arteries:
Left coronary artery
- circumflex artery
- left anterior descending artery
105
What is the single best lead to use for differentiating between a right and left BBB?
Lead V1
106
1st degree AV block
PR interval is prolonged (>0.20secs), prolonged and constant
107
2nd degree Type I AV block
PR interval lengthens with each cycle
- gradually longer PR interval until a QRS complex is dropped
