Exam 1 Cardiac Flashcards
1
Q
What is the resting coronary blood flow? Answer in ml/min, ml/gm and % of CO.
A
Approx. 250ml/min (1ml/100gm), 4-5% of CO.
2
Q
When is angina pectoris considered “stable”?
A
Angina pectoris is considered “stable” when there has been no change in the patient’s angina symptoms for at least 60 days. Factors related to the angina that should be evaluated include the precipitating factors, frequency, and duration. (Miller, pg 416).
3
Q
When is angina pectoris considered “unstable”?
A
When there has been a recent change in the patient’s angina symptoms. Changes that should be evaluated include the degree of activity a patient can do before the onset of angina and the duration of each anginal episode. Another Sx of angina is chest pain occurring at rest. The clinical implication of unstable angina is that the Pt. may be at risk of an impending myocardial infarction. (Miller, 416)
4
Q
Which are exposed to higher pressures during LV contraction? Sub-endocardial or sub-epicardial vessels?
A
Sub-endocardial. Therefore, it is more susceptible to ischemia in the presence of coronary artery stenosis, pressure overload, hypertrophy, and pronounced tachycardia. (Thurman III, slide 5).
5
Q
There is a greater amount of LV coronary flow during (systole or diastole).
A
Diastole
6
Q
What occurs to the LV coronary artery blood flow during systole?
A
During systole, the left coronary artery blood flow to the subendocardium ceases d/t compression of the subendocardial vessels by the myocardium. Flow to the epicardial vessels are not affected to the same extent.
7
Q
Name the factors that determine myocardial O2 SUPPLY.
A
Heart Rate, Coronary Perfusion Pressure, Arterial Oxygen Content, Diameter of Coronary Vessels
8
Q
Name the factors that determine myocardial O2 DEMAND.
A
Basal Metabolic Requirements, Heart Rate, Wall Tension, Contractility
9
Q
The myocardium extracts about ____% of O2 from arterial blood.
A
65-80% (she says to remember 75%)
10
Q
What is the most important factor that negatively affects mVo2?
A
Heart Rate. Doubling the HR doubles the myocardial O2 consumption. So tachycardia is bad for Pts with coronary artery disease.
11
Q
The difference between maximal and resting coronary blood flow is termed what?
A
Coronary Reserve
12
Q
What is the normal heart size for males and females (in grams)
A
Females 230- 280g, Males 280-340g
13
Q
What is the normal coronary blood flow?
A
225-250ml/min or 4-7% of CO (slightly different that previously, but this is from “a chart in naglehout”
14
Q
Normal Myocardial 02 Consumption
A
65-70% Extraction according to NH, 75-80% according to Barash. Again…she says go with 75% (8-10ml O2/100g/min)
15
Q
Normal Autoregulation (ie MAP of coronary arteries within the heart in mmHg)
A
60-140 mmHg (MAP)
16
Q
Coronary Filling mostly occurs during…
A
Diastole (80-90%)
17
Q
Determinants of Myocardial Oxygen Consumption
A
Myocardial Contractility
Myocardial Wall Tension (Preload)
Heart Rate
MAP (Afterload)
18
Q
What is the formula for determining O2 Content in plasma (ml O2/ml plasma)???
A
O2 content (ml O2/ml plasma)=(PaO2 x 0.003) + (1.36 x Hgb)(O2 Sat/100)
19
Q
Calculate the Plasma 02 Content using the following parameters.
Hbg 13
Sat 98%
PaO2 88
A
17.6 (88 x 0.003) + (1.36 x 13)(98/100) (0.264)+(17.68)(0.98) 0.264 +17.3264 17.5904 17.6
20
Q
Coronary blood flow is autoregulated at 60-140mmHg. What occurs when the MAP falls outside of these limits?
A
It becomes PRESSURE DEPENDENT
now CBF determined by MAP - RAP
21
Q
Coronary perfusion pressure is determined by the difference between…….
A
aortic pressure and ventricular pressure
22
Q
Formula for calculating CPP
A
Arterial diastolic pressure - LVEDP
23
Q
heart is bound anteriorly by
A
sternum/costal cartilages of 3rd, 4th, + 5th ribs
24
Q
heart is bound inferiorly by
A
diaphragm
25
apex points this way
anteriorly/inferiorly toward left 5th intercostal space
26
S1 best heard here, or S3, S4 if present
PMI
27
what are the layers of pericardium
fibrous (tough and dense)
| serous
28
2 layers of serous pericardium
parietal and visceral (epicardium)
29
pericardium is pierced by these vessels
SVC, aorta, pulm trunk
30
this layer of the heart is made of fibrocollagenous - tough, dense layer, forms outer layer of pericardial sac. continues superiorly with great vessels and adventitia & pretracheal fascia
fibrous pericardium
31
fibrous pericardium.. anteriorly attaches to ____ thru ____ ligaments
sternum
| sternopericadial
32
fibrous pericardium.. posteriorly fuses with ___ ___ of the _____.
central tendon
| diaphragm (stabilizes heart and chest)
33
Layers from Fibrous pericardium to heart chamber
```
FP
parietal layer of pericardium
pericardial cavity
epicardium (visceral layer)
myocarium
endocardium
heart chamber
```
34
amount of serous fluid in pericardial cavity
10-35 ml
35
if CVP is 18 what is the pericardial cavity pressure
18 - 5 = 13 mmHg
36
Pericardial blood supply
branches of internal thoracic arteries, bronchial, esophageal & superior phrenic arteries
37
Pericardial venous drainage from these veins
azygos and pericardiophrenic veins which join internal thoracic vein
38
Has sarcomere with actin and myosin. Cardiac Muscle, Skeletal muscle, or Both.
Both
39
Capable of contraction
| Cardiac Muscle, Skeletal muscle, or Both.
Both
| Cardiac longer, Skeletal shorter
40
T-tubule system and SR
| Cardiac Muscle, Skeletal muscle, or Both.
Both
41
Which has more mitochondria?
| Cardiac Muscle or Skeletal muscle
Cardiac Muscle
42
Which has more O2 requirements?
| Cardiac Muscle or Skeletal muscle.
Cardiac Muscle
43
Which extracts more O2 from the blood?
| Cardiac Muscle or Skeletal Muscle
Cardiac - 75%, Skeletal only has 25% extraction of O2.
44
Has Intercalated discs?
| Cardiac Muscle, Skeletal muscle, or Both.
Cardiac
45
Functions aerobic or anaerobic?
| Cardiac Muscle, Skeletal muscle, or Both.
Skeletal. Cardiac is Aerobic only and requires constant supply of O2.
46
Myocardium are like smooth muscles in that they are interconnected so that action potentials can rapidly spread to adjacent cells. What is the name of this characteristic?
Syncytial- Thus the action potential propagation and the muscle contraction occurs as a "all or none" response.
47
Name the 3 types of cardiac muscle
1. Atrial muscle
2. Ventricular muscle
3. Excitatory and conductive muscle fibers
Atrial and ventricular muscle contract like skeletal muscle, excitatory and conductive muscle contract poorly and have fewer contractile fibrils.
48
Cell membranes separating individual cardiac muscle cells.
What are intercalated discs?
49
The area where intercalated discs fuse
Gap Junctions. (Allows for rapid diffusion of ions).
50
The heart is how many syncytiums?
2
* Atrial syncytium, which constitutes the walls of the 2 atria.
* Ventricular syncytium, which constitutes the walls of the 2 ventricles.
51
On a cellular level, name the three components of the heart.
1. Cardiac muscle tissue (contracting cardio-myocytes)
2. Conduction tissue (conducting cells)
3. Extracellular connective tissue
52
What is a group of cardio-myocytes with its extracellular matrix (connective tissue)?
Myofiber
53
Myofibrils are connected to adjacent myofibrils via
Collagen strands
54
What 3 elements make up the structure of the myocyte?
Sarcolemma
Mitochondria
Sarcomere
55
What is the external membrane of the cardiac myocyte?
Sarcolemma
| Contains ion channels, ion pumps, exchangers, G-protein coupled and other receptors, transporter enzymes and T tubules.
56
What part of the myocyte generates large amounts of high-energy phosphates?
Mitochondria
57
What is the fundamental contractile unit of the cardiac muscle?
Sarcomere
58
Cardiomyocytes are between ____um and ____um in length.
20um-140um. Atrial are shorter and ventricular are longer Atrial are 20 micrometers, ventricular at 140 micrometers
59
What is the rod-like bundle forming the contractile element of the cardiomyocyte?
Myofibril
60
The contractile proteins make up ____% of the myofibrillar protein.
80%
61
The ____ & _____ proteins make up the remaining 20% of the myofibrillar protein.
regulatory and structural
62
Separates cardiac intracellular and extracellular space
Sarcolemma
63
Contains ion channels, ion pumps and exchangers, G-Protein coupled and other receptors, and transporter enzymes.
Sarcolemma
64
The Sarcolemma is the _____ membrane of the cardiac muscle cell.
EXTERNAL
65
What forms specialized intracellular junctions between cells?
T Tubules
66
The sarcolemma surrounds the cardiomyoctes and invaginates into the myofibrils through tubular networks called.... allows for rapid, uniform impulse transmission
Transverse tubules (T Tubules)
67
The cardiomyocyte sarcoplasmic reticulum is subdivided into these 2 types.
Longitudinal and Junctional
68
Which type of SR is involved in the uptake of calcium? (helps initiate relaxation)
Longitudinal
| think long relaxing nap
69
The junctional SR contains
Large calcium release channels....Ryanodine receptors (RyRs).
70
The sarcomere is the fundamental ________ unit of the myofibril.
contractile
71
Regarding the cardiac cycle, which of the following is FALSE.
a. LV systole has three phases
b. Isovolumic contraction occurs after mitral valve closure.
c. The decrease in ejection fraction (EF) is proportional to the decrease in LV function.
d. Isovolumic contraction occurs in both the LV and the RV.
e. Diastasis allow free blood flow through the left atrium.
D. True isovolumic contraction does not occur in the RV b/c of the sequential nature of inflow followed by outflow during RV contraction. See page 258, Barash for further explanation).
72
Each of the following is a characteristic of cardiac AND skeletal muscle fibers, EXCEPT?
a. both sarcolemma contain Na+ channels
b. Impulses reach the myocytes through "T transverse tubules"
c. Mitochondria are highly abundant in both types of fibers
d. Actin and myosin are the contractile proteins
e. They use transporter enzymes to regulate intracellular ion concentrations.
C. Unlike the skeletal muscle cell, the cardiac myocyte is densely packed with mitochondria, which are responsible for generation of large quantities of high-energy phosphates (e.g. adenosine triphosphate) that are required for the heart's phasic cycle of contraction and relaxation.
73
Which sarcomere band contains thin filaments only, which decrease in width as the cell contracts?
"I" band
74
What sarcomere band is an overlap of thick and thin fibers, and lengthens as sarcomere shortens?
"A" band
75
What defines the border between 2 adjacent sarcomeres? (hint, each "I" band is bisected by this)
Z line
76
What band lies in the middle of the "A" band, and consists of thick filaments constrained by myosin-binding protein C?
Central "M" band
77
Found beneath the sarcolemma, wedged between the myofibrils, contain enzymes promoting ATP, and is the powerhouse of the cardiac myocyte.
Mitochondria
78
What part of the cardiac myocyte contains the genetic information?
Nucleus
79
What is the fluid-filled microenvironment of the cardiac myocyte?
Cytosol
80
Name the 3 different types of intercellular junctions.
1. Gap junctions
2. Spot desmosomes
3. Sheet desmosomes
81
Which type of intercellular junction provides the mechanical linkage, has adhesion sites and anchors the filament cytoskeleton?
Spot desmosomes
82
Which intercellular junction anchors the contractile apparatus and is AKA fascia adherens?
Sheet desmosomes
83
Which type of intercellular junction is responsible for electrical coupling and transfer of small molecules between cells.
Gap Junctions
84
Name the 3 functional categories of the cardiomyocytes.
1. Excitation system
2. Excitation Contraction Coupling System (ECC)
3. Contractile System
85
action potential in the muscle cell that triggers contraction, begins with depolarization and spread of the electrical excitation.
ECC System (excitation contraction coupling system)
86
What is the "key player" in the ECC system? Hint- electrolyte.
Ca++
87
Which is where cellular action potential originates in the special conduction tissue; impulses propagates to individual cells to initiate an events leading to the contraction
Excitation System
88
This system "basically" consists of the sarcomere
Contractile system
89
Which structures of the heart have "fast-response action potentials"?
His bundle, Purkinje system, and the Atrial and Ventricular Cardiomyocytes
90
Which structures of the heart have "slow-response action potentials"?
Pacemaker cells found in the SA + AV nodes
91
Which ion is responsible for establishing a resting membrane potential?
Potassium
92
The heart is bound anteriorly by the...
Sternum and costal cartilages of the third, fourth, and fifth ribs.
93
The heart is bound inferiorly by the...
Diaphragm.
94
Where is the "point of maximal impulse"?
The apex- L 5th intercostal space, midclavicular line.
95
Which heart sounds are best heard at the apex of the heart?
S1, S3, and S4
96
The superior aspect of the cardiac silhouette is formed by the.....
transverse and ascending aorta
97
The anterior surface of the cardiac silhouette is almost entirely composed of the....
Right Ventricle
98
The outer portion of the pericardium is called the...
Fibrous pericardium
99
What is the inner pericardium portions called?
The visceral portion, which is in intimate contact with the outer surface of the heart, and the outer parietal portions, which adheres to the fibrous pericardium.
100
The pericardial cavity is a potential space between which two layers?
The visceral and parietal pericardium.
101
The pericardial cavity normally contains __ - __ml (give range) of serous fluid, which provides lubrication for the free movement of the heart within the mediastinum.
10-25ml
102
The right coronary artery travels within this sulcus.
Coronary Sulcus (AV sulcus)
103
The LAD travels within this sulcus
Anterior interventricular sulcus.
104
What is the name of the place where the coronary and the posterior sulci meet?
Crux of the heart
105
What is the name of the heart's skeleton?
Annulus Fibrosus
106
T/F The annulus acts as an insulator to prevent aberrant electrical conduction from the atria to the ventricles so that AV conduction moves through on pathway only: the AV node to the AV bundle (bundle of HIs)
TRUE
107
What is the approx. muscle thickness of the RA?
2mm
108
What is the name of the rudimentary valve protecting the coronary sinus?
Thebesian valve.
109
What is the "Gorlin" formula used to calculate?
Valve area (cm2)
110
Nervous innervation to heart
vagus
phrenic
sympathetic trunk
111
Which phase of the action potential is the "plateau phase"?
Phase 2- Slow Ca++ channels open and allow an influx of Ca++
112
heart receives vagal fibers via this nervous tissue
esophageal plexus
| Left RLN
113
heart receives vagal fibers via this nervous tissue
esophageal plexus
| Left RLN
114
these arteries provide 80% of vascular supply to pericardium from pericardial phrenic branches
Internal thoracic a. (left and right)
115
pericardial pain: worsens and releived by
worse - lies on back or left
| relieved - lean forward
116
pericardial pain: worsens and releived by
worse - lies on back or left
| relieved - lean forward
117
most lymph drainage to these ducts
thoracic
right lymphatic
.. also bil mediasstinal & parasternal internal thoracic lymph nodal groups
118
double layer of pericardial lymphatic vasculature surrounds the ___ pericardium and is present in ___ and loose ____ tissue
perietal
fat
areolar
119
this occurs when systemic and pulm pressures equalize in tamponade to prevent chamber collapse and pericardium cannot distend anymore
```
ventricular interdependence
(also can say pulsus paradoxus)
```
120
define pulsus paradoxus
drop in SB > 10 mmHg with inspiration
121
define pulsus paradoxus
drop in SB > 10 mmHg with inspiration
122
becks triad
low bp
JVD
distand muffled heart sounds
*may not see in chronic
123
becks triad
low bp
JVD
distand muffled heart sounds
124
hallmark of pericardial tamponade
atrial & ventricular diastolic transmural pressure = 0 mmHg
125
pericardium typical max capacity
250 - 300 ml
126
describe filling of chambers during insp/expiration in ventricular dependence
inspiration: inc VR/filling to RIGHT heart bulges toward left
expiration: inc VR/filling to LEFT heart - bulges toward right
127
describe filling of chambers during insp/expiration in ventricular dependence
inspiration: inc VR/filling to RIGHT heart bulges toward left
expiration: inc VR/filling to LEFT heart - bulges toward right
128
how does CVP compensate for inc volume and intrapericardial pressures
inc CVP
| maintains gradient allowing heart filling
129
What is another name for the SA node?
Keith-Flack Node
130
transvalvular blood flow velocities during insp and exp
insp: tricuspid > mitral and LV
exp: mitral and LV > tricuspid
131
What is the primary electrolyte in effect during Phase 0 of the action potential?
Na+ Sodium channels open and Na+ moves from the ECF to the ICF.
132
Which phase of the action potential is the "plateau phase"?
Phase 2- Slow Ca+ channels open and allow an influx of Ca+
133
Which phase of the action potential is the early rapid repolarization phase where the sodium gates close and the rapid influx of sodium stops and the slower influx of Ca++ begins?
Phase 1
134
Which phase of the action potential is the terminal repolarization phase?
Phase 3
135
Calcium channel blockers exert their pharmacological effects during this phase of the action potential.
Phase 2
136
Which phase of the action potential is the diastolic repolarization phase?
Phase 4
137
the flexible carilaginous (fibrous connective) structure of cardiac skeleton compose of these
annuli of valves
aortic & PA roots
central fibrous body
Rt & Lt trigones
138
why is left heart collapse rare
inc stiffness/thickness of LV
| located posteriorly - not much fluid behind it
139
IF you do have LA collapse in tamponade why is this significant
HIGHLY SPECIFIC for tamponade
140
function of fibrous skeleton
valve support
prevent overstretching of valve
insertion point & anchor for muscle bundles
electrical insulation btw atria & ventricles
141
RCA in which sulcus
coronary sulcus
142
Circumflex in which sulcus
coronary sulcus
143
name location where coronary sulcus and posterior IVS meet
crux
144
the flexible carilaginous structure of cardiac skeleton compose of these
annuli of valves
aortic & PA roots
central fibrous body
Rt & Lt trigones
145
Where is the absolute refractory period lie in regards to the action potential phases?
Phase 0 to the middle of phase 3
146
Aortic stenosis and mitral regurgitation are (systolic/diastolic) murmurs?
Systolic
147
Mitral stenosis and aortic regurgitation are (systolic/diastolic) murmurs?
Diastolic
148
Mitral stenosis often occurs with mitral regurgitation and usually is at result what type of infection?
Strep
149
What murmur is a incompetent valve heard early in systole due to part of the valve prolapsing back into the atrium late in systole?
Mitral valve prolapse murmur
150
```
in RA... valve of coronary sinus
not a true valve
semicircular fold of membrane
lies at orific of coronary sinus
varies in size or completely absent
```
Thebasian valve
151
in RA... muscular trabeculi
extend anterolaterally from Crista Terrminalis to auricle
parallel ridges in atrium walls
mainly in RA - few in LA
do not contribute much to atrial contraction
can improve ability to inc volume in RA w/o creating wall stress
pectinate muscles
152
function of fibrous skeleton
valve support
prevent overstretching of valve
insertion point for muscle bundles
electrical insulation btw atria & ventricles
153
muscle wall thickness of RA
2 mm
154
RA receives blood from these 4 structures
SVC
IVC
coronary sinus
Thebasian cardiac veins (minute valveless cardiac veins)
155
LA thickness
3 mm
156
only portion of LA that is trabeculated
```
left auricle
(longer and narrower than right auricle)
```
157
ventricle muscles consist of these 3 things
interdigitating deep sinospiral
superficial sinospiral
superficial bulbospiral
158
valve of IVC is Thebasian or Eustachain?
Eustachain valve
159
valve of coronary sinus is Thebasian or Eustachain?
Thebasian valve
160
ridge of muscle in RA (superior portion)
| divides pectinate muscles and auricle from smooth surface of RA
crista terminalis
161
T/F
RV is highly compliant and is able to accomadate to acute changes in intraventricular volume to a greater degree than the LV
true
| Barash 240
162
```
valve of coronary sinus
not a true valve
semicircular fold of membrane
lies at orific of coronary sinus
varies in size or completely absent
```
Thebasian valve
163
collagenous band within subendocardium of RA that is part of fibrous skeleton
originates from central fibrous body
Tendon of Todaro
164
osteum/skeleton of coronary sinus, antero-septum leaflet commisure & tendon of Todaro
** anatomical landmark for location of AV node for EP studies, pacing **
Triangle of Koch
165
orientation of LV apex
anterior/inferior
166
LA thickness
3 mm
167
LV.
upper 1/3 portion is ___ endocardium.
lower 2/3 of septum are rest of ventricular wall have ____ _____
upper 1/3 - smooth
| lower 2/3 - trabeculae carneae
168
superior RV has a ____ appearnace as it approaches pulm orifice; called _____
conical
| infundibulum
169
infundibulum is aka
conus arteriosus
170
RV thickness
4-5 mm
171
RV relies on this for contractility
interventricular septum
| LV
172
T/F
RV is highly compliant and is able to accomadate to acute changes in intraventricular volume to a greater degree than the LV
true
173
RV outflow tract =
infundibulum
174
how many papillary muscles in RV and what are they
1. anterior (large)
2. posterior (large)
3. septal (smaller)
175
chordae tendineae consist of __ % collagen and __ % elastin.
80% collagen
| 20% elastin
176
orientation of LV
anterior/inferior
177
LV thickness
8-15 mm
178
normal valve area of tricuspid
7 cm2
| < 1.5 cm2 = symptomatic
179
per Stoelting, aortic valve has these 3 semilunar cusps
left
right
noncoronary
180
how many papillary muscles in LV
1. anterior
2. posterior
both large
181
this vessel must be carefully avoided during tricuspid valve repair or replacement surgery
proximal right coronary artery
| located in the atrioventricular groove (coronary sulcus)
182
LV contracts with this direction in shift
anterior and to right
183
this type of activation in LV causes long axis to shorten, reduce chamber diameter, and produce rotation of apex in an anterior-right direction
synchronous activation of LV
184
standard method to calculate valve area (cm2)
- Gorlin formula (done in cath lab)
| - noninvasive - echo
185
one of the most accurate ways of determining the presence of valvular pathology is to
calculate valve area
186
tricuspid valves size compared to mitral
thinner and more translucent
187
now many tricuspid leaflets
1. anterior
2. septal
3. posterior
unequal sizes
188
normal valve area for MV and when Sx start
norm 4-6 cm2
| sx when decreased by 1/2
189
MV - two major leaflets: anteromedial and posterolateral are connected by what
- where chordae and leaflets attached
*commisural tissue*
190
this is a lateral segment of myocardium stretching btw anterior and septal papillary muscles and separates the embryonic RV inflow and outflow tracts
moderator band
191
coronary sulcus is aka
atrioventricular groove
192
this vessel must be carefully avoided during tricuspid valve repair or replacement surgery
proximal right coronary artery
| located in the atrioventricular groove (coronary sulcus)
193
of mitral valve leaflets and names
1. anteromedial (oval)
2. posterolateral (crescent)
-
194
above (proximal) aortic valve is a dilation know as this
sinus of Valsalva
195
normal aortic valve area and when Sx occur
- 2.5 - 3.5 cm2
| - reduction by 1/3 to 1/2
196
MV posterior division
P1, P2, P3
197
MV anterior division
A1, A2, A3
198
epicardium composed of 3 things
mesothelium
tissue
fat
199
SNS effect inc myocardial BF due to inc in metabolic demand & predominant __ receptors activation
beta 2
200
MV - two major leaflets: anteromedial and posterolateral are connected by what
*commisural tissue*
201
LAD main branches
diagonals
septal perforators
RV branches
202
LCX main branches
sinus node artery (40-50%)
obtuse marginal
posterolateral
203
What is a normal LV pressure?
100-140/3-12 mmHg
204
LCA supplies these areas
LA
most of IV septum
LV (septal, anterior & lat walls)
205
What is a normal PCW (PAOP)?
6-12 mmHg
206
in this artery the coronary BF is continuous throughout cardiac cycle
Right coronary flow - reaches peak during systole bc RV pressures remain low and cause minimal compression
207
What is a normal LAP?
4-12 mmHg
208
for MV, the primary and secondary chordae are attached to what? whereas, the teriary chordae insert into..
leaflet edges
| distal posterior leaflet or myocardium adjacent to annulus
209
each semilunar valve has __ leaflets
- 3
| - translucent and macroscopically avascular
210
Bundle of His blood supply
dual BF from PDA & LAD
211
which papillary muscles are vulnerable to ischemic dysfunction
posteromedial (PDA) because coronaries taper here in the myocardium (poorer blood supply). yet LCX will contribute some BF to posteromedial muscle regardless of dominance
212
above aortic valve is a dilation know as this
sinus of Valsalva
213
how do PM branch to chords and so on
1 PM = 6 heads
1 head = 12 chordae tendineae
head = "fingers"
214
Sinuses of Valsalva of SL valves have ___ flow which prevents adherence of valve leaflets & aids closure (prevents occlusion of coronary ostia)
hydraulic
215
these cardiac veins traverse the myocardium & drain into RA (40%), RV & LV (lesser extent). Also may carry 40% of blood returned to RA
Thebasian veins (little dudes)
216
epicardium composed of 3 things
mesothelium
tissue
fat
217
SNS effect inc myocardial BF due to inc in metabolic demand & predominant __ receptors activation
beta 2
218
activation of SNS results in mobilization of these substances for energy use by myocardial cells.
fat-free acids
| glycogen
219
The electrical discharge during a cardioversion is timed to coincide with ________ wave
P, Q, R, S, or T?
R wave
220
vagal innervation
| sympathetic innervation
v - supraventricular
v - Purkinje
SNS - everywhere
221
preganglionic PNS fibers originate here
medulla
222
RCA supplies these areas (about 9)
```
SA & AV nodes
RA & RV
posterior 1/3 of interventricular septum
medial portion of posterior wall
part of LV (inferior wall)
posterior fascicle of LBB
internal septum
```
223
cell differences in conduction system
variable in shape
fewer myofibrils
pale staining of cytoplasm
224
LCX branches
sinus node artery (40-50%)
obtuse marginal
posterolateral
225
example of an accessory pathway that can bypass AV node, go thru skeleton, and establish conduction btw atria and ventricles
Bundle of Kent = supraventricular tachyarrhythmias as in WPW syndrome
226
Hypokalemia _____ resting membrane potential, while Hyperkalemia ______ resting membrane potential.
hypokalemia decreases, hyperkalemia increases.
227
SA node: 2 cell types
P cells = pacemaker = pale & ovoid, large round nuclei
| Intermediate = transitional = elongated, conduct impulses
228
obstruction in these branching arteries of LAD (go across anterior wall of LV - can be large) can produce significant damage
diagonals
229
LCA supplies these areas
LA
most of IV septum
LV (septal, anterior & lat walls)
230
in LCA dominant population (__ to __ %) this artery supplies the PDA
10-15 %
| LCX
231
part of conduction system with mostly transitional myocytes (on histology) and insulated with sheath of connective tissue
AV bundle (Budle of His)
232
```
The most important ion currents during the ventricular action potential phases:
Phase 0
Phase 1
Phase 2
Phase 3
Phase 4
```
```
Phase 0: Sodium In
Phase 1: Chloride In
Phase 2: Calcium In
Phase 3: Potassium Out
Phase 4: Sodium Out
```
233
duration of S1 and S2
S1 - 0.14
| S2 - 0.11
234
split S2 may be heard d/t
- aortic valve closes sooner
- physiologically - P2 (pulm valve closure) is later on inspiration - normal
- best heard in young/pulmonic area
- on inspiration inc VR to RH + dec VR to LF = Aortic v. closes earlier bc of dec blood volume in LV
235
disease states with paradoxical split S2
- aortic stenosis
- hypertropic obstructive cardiomyopathy
- LBBB
236
Bundle of His blood supply
dual BF from PDA & LAD
237
which papillary muscles are vulnerable to ischemic dysfunction
posteromedial (PDA) because coronaries taper here in the myocardium
238
Which muscles last to be perfused
LV papillary
239
diseases with S4 sound
older patient with LVH (noncompliant ventricle)
diastolic heart failure
active ischemia
240
physiologically, S4 is due to this
during active LV filling (e.g. atrial contraction) blood is forced into a noncompliant LV - thus the sound of blood striking the noncompliant LV
241
S3 + S4 =
summation gallop
242
speed of conduction
dromotropic
243
inc SNS causes inc in HR which is a __ effect on heart
chronotropic
244
activation of SNS results in mobilization of these substances for energy use by myocardial cells.
fat-free acids
| glycogen
245
What is another name for the SA node?
Keith-Flack Node
246
how does SNS stimulation effect the AV node ERP (effective refractory period) and PR interval
- decreases
| - vagal stimulation does the opposite (ur welcome)
247
description of murmur sounds
harsh
blowing
musical
rumbling
248
preganglionic PNS fibers originate here
medulla
249
The SA and AV have action potentials a longer plateau than the ventricular. T/F
False- The SA and AV do not have plateau phases.
250
diseases with holosystolic finding
mitral regurge
| tricuspid regurge
251
disease with early diastolic; blowing or swishing
aortic regurge
252
how can you identify internodal pathways clinically
EP study
| * not myocyte histology (rare)
253
example of an accessory pathway that can bypass AV node, go thru skeleton, and establish conduction btw atria and ventricles
Bundle of Kent = supraventricular tachyarrhythmias
254
causes of aortic regurge
```
rheumatic
endocarditis
aortic disease (Marfan syn - connective tissue)
syphyllis
ankylosing spondylitis
aortic dissection
cardiac trauma
```
255
SA node: 2 cell types
P cells = pacemaker = pale & ovoid, large round nuclei
| Intermediate = transitional = elongated, conduct impulses
256
The LAD provides blood supply to which structures?
```
Anterior Interventricular septum
Apex of the Heart
L+R Bundle Branches
Anterolateral Wall
Papillary muscles of the MITRAL Valve.
```
257
prominent artery of SA which is a branch of RCA
conus artery
258
this part of conduction system is located in atria, is a preferential pathway btw SA and AV, composed of packed parallel myocarial fibers large pale-staining cells witih perinuclear clear zone, large nuclei, have transitional cells and spare myofibrils
internodal tracts
259
part of conduction beneath endocardium on right side of atrial septum, multiple nerve endings including vagus, causes delay in AP transmission
AV
260
part of conduction system with mostly transitional myocytes (on histology) and insulated with sheath of connective tissue
AV bundle (Budle of His)
261
determinants of both supply and demand
HR
| EDP
262
duration of S1 and S2
S1 - 0.14
| S2 - 0.11
263
split S2 may be heard d/t
aortic valve closes sooner
264
factors responsible for coronary autoregulation
```
myocardial consumption
metabolic vasodilation (SNS, adenosine - primary vasodilator substance)
```
265
What structures does the RCA supply?
```
Posterior Interventricular Septum
Posterior Left Bundle Branch
Interatrial Septum
And...most of the time...
AV node in 90% of population
SA node in 60% of population
```
266
disease states with paradoxical split S2
- aortic stenosis
- hypertropic obstructive cardiomyopathy
- LBBB
267
```
Match the structures with the coronary artery that supplies it.
Apex
AV Node
L atrial wall
(RCA, LCX, LAD)
```
Apex-LAD
AV Node- RCA
L atrial wall- LCX
268
features of cardiac t-tubule that make it different from skeletal t-tubule
cardiac: larger, broader, fewer #
269
when is S3 (sound at the beginning middle third of diastole) normal and abnormal
normal - children and adolescents
| heart failure in older
270
best patient position for S3
left lateral
271
in ECC, transient Ca++ removed by these 3 ways
1. active uptake into SR
2. Na Ca exchanger
3. binding of Ca to proteins
272
diseases with S4 sound
older patient with LVH
diastolic heart failure
active ischemia
273
what are the three types of ryanodine receptors
RyR1 - skeletal
RyR2 - heart
RyR3 - brain
274
About how thick is the walls of the Right Ventricle?
4-5mm
275
About how thick is the walls of the Left Atrium?
3mm
276
contractile apparatus: 6 major componenets
myosin
actin
tropomyosin
3 - protein troponin complex
277
How many papillary muscles in the LV?
Dos (anterior and posterior)
278
How many papillary muscles in the RV?
3
279
by itself, ____ is a weak inhibitor of actin-myosin interaction.. add _____, it becomes a major inhibitor
troponin I
| tropomyosin
280
What is the normal surface area of the Tricuspid Valve?
7 cm2
281
RMP determined by these factors/forces
1. chemical (ion diff btw cell membrane)
2. electrostatic (i.e. negative pulls K+ ion into cell)
3. Na+/K+ pump
282
this equation calculates equilibrium potential if conc gradient is known and temp is 310 degrees Kelvin
Nernst =
| Em = (-61.5/FZ) x log [K]i / [K]o
283
Normal surface area of the Mitral Valve?
4-6 cm2
284
3 factors affect the calculation due to different ions in RMP
1. electric charge of each ion
2. permeability of the membrane to each ion
3. con gradient across membrane
285
this extra heart sound is during early diastole, high pitch, sharp snap or click, not affected by respiration; early mitral stenosis
MV opening snap
286
AP of cardiac muscle caused by opening of 2 types of channels. And.. are they fast or slow
1. voltage-activated FAST Na - open/close fast
2. L-type Ca SLOW - open slow/open longer - this prolongs depolarization = plateau phaase. Once slow Ca/Na ch closes. Rapid K out of cell = immediately restore RMP
287
plateau duration of atrial and also ventricular
a - 0.2 sec
| v - 0.3 sec
288
characteristics of murmurs depend on these factors
```
valve function
size of opening
rate of blood flow
vigor of myocardium
thickness/consistency of tissue
```
289
causes of murmurs
```
high output demand
dim strength of conraction
vigorous LV ejection
persistent fetal circ - PDA
(there are more - these stood out)
```
290
description of murmur sounds
harsh
blowing
musical
rumbling
291
disease with low frequency; diastolic rumble
mitral stenosis
292
disease with midsystolic (ejection); med pitch; harsh
aortic stenosis
293
phase 4 back to RMB at __ mV
-90 mV
294
phase of AP that CCB work on
phase 2
less Ca channel influx (less contraction) and more K efflux (cell more negative - resting) to bring to relaxation sooner i suppose
295
Dig effect on ion channels
inhibits Na/K = more Na intra cell
= more Ca intra cell
= inc contractility
296
this disease with systolic ejection murmur almost always due to congenital
pulmonic stenosis
297
cause of MR
rheumatic fever
MI
myxoma - tumor of connective tissue
rupture of chords
298
velocity of signal conduction (atrial and ventricular)
a and v muscle fibers = 0.3 to 0.5 m/sec
| purkinje = up to 4 m/sec
299
2 determinants of coronary perfusion (things that vary)
CPP - LV blood supply directly depended on CPP
| CVR - supply inversely related to resitance to flow - Poiseuille's Law
300
2 determinants of coronary perfusion (relatively constant)
vessel length
| viscosity
301
CPP usually determined by the diff btw ___ and ___ presssure
aortic
| ventricular (LVEDP)
302
SA node and other automatic cells have these phases of AP
phase 4
phase 0
phase 3
(phase 1 and 2 do not occur bc rapid depo does not occur)
303
HR BMP for AV node and ventricular cells
AV 40-60
| v 15-30
304
infuencing fx of mycardial O2 demand
64% pressure work
20% metabolic requirements
15% volume work
1% electrical activity
305
cardiac cycle lasts from
beginning of one beat to beginning of next
306
the difference btw pulmonary arterial blood and coronary sinus
O2 extraction
307
coronary BF determined primarily by
myocardial consumption
308
factors responsible for coronary autoregulation
```
myocardial consumption
metabolic vasodilation (SNS, adenosine - primary vasodilator substance)
```
309
3 ways to optimize CPP
1. low HR (avoid tachycardia)
2. normal to high diastolic pressure (avoid hypotension)
3. low LVEDP (avoid hypertension)
310
this layer of heart is subjected to greater intramural pressures during systole and is is most vulnarable to ischemia during decreases in CPP
endocardium
311
desmosomes are formed by ___ ___ in cell membranes linked by filaments
protein plaques
312
features of cardiac t-tubule that make it different from skeletal t-tubule
cardiac: larger, broader, fewer #
313
thin fibers of sarcomere contain these
actin
tropomycin
troponin C (complex)
314
thick fibers of sarcomere contain these
mysoin
| supporting proteins
315
in ECC, transient Ca++ removed by these 3 ways
1. active uptake into SR
2. Na Ca exchanger
3. binding of Ca to proteins
316
cardiac SR compared to skeletal and implication for contraction
less developed than skeletal - rely on T-tubule release of Ca, otherwise contraction would be weak
317
what are the three types of ryanodine receptors
RyR1 - skeletal
RyR2 - heart
RyR3 - brain
318
2 storage proteins in SR
calsequestrin
| calreticulin
319
this important protein senses and regulates iCa++
calmodulin
320
contractile apparatus: 6 major componenets
myosin
actin
tropomyosin
3 - protein troponin complex
321
light chains of myosin have 2 roles
1. regulatory - modulate myosin-act interaction
| 2. essential - undefined myosin activity
322
double stranded helical chain of G-actin monomer
F-actin
323
by itself, ____ is a weak inhibitor of actin-myosin interaction.. add _____, it becomes a major inhibitor
troponin I
| tropomyosin
324
summarize cross bridge cycling (C-BC)
-Ca++ released binds with Top C (C-BC starts)
-this decreases interaction btw Trop I + actin
(trop I covers up/inhibits actin so mysoin cant attach)
- once exposed mysoin binds to actin (facilitated via ATP hydrolysis + change in myosin head confirmation)
-power stroke of myosin head generated
325
RMP determined by these factors/forces
1. chemical (ion diff btw cell membrane)
2. electrostatic (i.e. negative pulls K+ ion into cell)
3. Na+/K+ pump
326
this equation calculates equilibrium potential if conc gradient is known and temp is 310 degrees Kelvin
Nernst =
| Em = (-61/FZ) x log [K]i / [K]o
327
equilibrium potentials of ions Na, K, Chl, Ca...and go..
```
intra cell // extra cell // equilib pot
Na -- 10 145 60
K -- 135 4 -94
Cl -- 4 114 -97
Ca -- 0.0010 2 132
```
328
3 factors affect the calculation due to different ions in RMP
1. electric activity of each ion
2. permeability of the membrane to each ion
3. con gradient across membrane
329
membrane potential equilibrium of K+ =
-90 mV
| slide on K+ equilibrium potential
330
AP of cardiac muscle caused by opening of 2 types of channels. And.. are they fast or slow
1. voltage-activated FAST Na - open/close fast
2. L-type Ca SLOW - open slow/open longer - this prolongs depolarization = plateau phaase. Once slow Ca/Na ch closes. Rapid K out of cell = immediately restore RMP
331
plateau duration of atrial and also ventricular
a - 0.2 sec
| v - 0.3 sec
332
anti-arrhythmic that has inhibitory effect on phase 0 of cardiac muscle AP
lidocaine
| decreases Na influx
333
phase 0 Na channels open btw __- __ mV threshold potential
-70 & -65 mV
334
phase 0 __ mV is the membrane potential that is reached
+20 mV
335
phase 1 fast Na channels close at __ mV
+2 to +3 mV
336
phase 2 slow Ca open at __ to __ mV
-30 to -40 mV
337
phase 4 back to RMB at __ mV
-90 mV
338
phase of AP that CCB work on
phase 2
less Ca channel influx (less contraction) and more K efflux (cell more negative - resting) to bring to relaxation sooner i suppose
339
Dig effect on ion channels
inhibits Na/K = more Na intra cell
= more Ca intra cell
= inc contractility
340
absolute refractory period (time) in ventricles
0.25 to 0.3 sec
| this is close to duration of plateau time of AP
341
- time of relative refractory period (i suppose the total)
| - time of atrial and also ventricle RR
```
RR = 0.5 sec
atrial = 0.15 sec
ventr = 0.25 - 0.30 sec
```
342
velocity of signal conduction (atrial and ventricular)
a and v muscle fibers = 0.3 to 0.5 m/sec
| purkinje = up to 4 m/sec
343
SA node AP characteristics of myocardium
contractility
automaticity
conductivity
344
SA node has lower/higher RMP
higher
345
SA node more permeable to which ion = more than other atrial myocardial cells which is capable of raising MP close to threshhold pot (-55 to -60) that CAN INITIATE AP.
sodium
346
SA node adn other automatic cells have these phases of AP
phase 4
phase 0
phase 3
(phase 1 and 2 do not occur bc rapid depo does not occur)
347
HR BMP for AV node and ventricular cells
AV 40-60
| v 15-30
348
time of delay of impulse from atria to ventricles
> 0.1 sec
349
cardiac cycle lasts from
beginning of one beat to beginning of next
350
duration of sys or diastole with HR = 72
| answer in min/beat and sec/beat
reciprocal of HR
1/72 = 0.0139 min/beat
0.0139 x 60 sec = 0.833 sec/beat
351
during tachycardia compare dec in duration of systole to diastole
dec in diastole > dec in systole time
352
phases of diastole
prodiastole - SL valves close
isovolumetric relaxation
rapid v-filling
353
during isovolumetric relaxation of diastole this relaxation occurs during phases 2 - 4 of AP. give duration as well.
auxotonic relaxation
| 0.03 - 0.06 second
354
early filling of ventricles accounts for how much % of final SV
70-75%
355
period of diasole. aka time of "slow fillling"
| ... and how much % of total SV
diastasis
| <5%
356
aka for atrial kick, what wave on ECG, how much of final SV
final filling
P-wave (that was a hard one)
15-25% (20-30% per NH)
357
6 factors influencing diastolic function
1. magnitude of systolic volume
2. passive LV chamber stiffness
3. elastic recoil of ventricles
4. diastolic interaction btw RV and LV
5. atrial properties
6. prescense of CATs
358
** primary cause of heart failure w/ normal EF **
LV diastolic dysfunction
| aka diastolic HF
359
common causes of lV diastolic dysfunction (bunch of em)
>60 yo
acute MI
stunning, hibernation
remodeling
pressure-overlaod hypertrophy (aortic stenosis, HTN)
volume-overload hypertophy (regurge)
hypertrophic obstructive cardiomyopathy
dilated cardiomyopathy
restrictive cardiomyopathy (amyloidosis, hemochromatosis)
pericardial disease (tamponade, constrictive pericarditis)
360
determinants of ventricular diastolic fx (bunch)
```
rate and rhythm
LV sys fx
wall thickness
chamber geometry
myocyte relaxation factors
LV untwisting/recoil
diastolic suction magnitude
LA-LV pressure gradient
passive elastic properties of LV myocardium
viscoelastic effects (rapid LV fill, atrial systole)
LA & MV structure and fx
pulm venous blood flow
pericardial restraint
RV loading conditions and fx
ventricular interdependence
CBF and vascular engorgement
compression by mediastinal masses
```
361
ventricular ejection phases
1. rapid - first 1/3
| 2. reduced - last 2/3
362
(systolic fx slide) 3 factors combine with HR and rhythm to determine CO
1. preload
2. afterload
3. contractility
363
normal LV pressure during filling
10 mm Hg
364
normal volumes: give em to me (EDV, SV, ESV, EF)
EDV 110 - 120 ml
SV 70 ml
ESV 40-50 ml
EF 60%
365
all the waves of atrial pressures
a - atrial
c - TV closure (begin of v-contraction) - main cause of bulging of AV into atria.
v - passive a - filling (ending of v-contraction)
x - atrial diastole (trough of pressure)
y - atrial emptying (opening of TV)
366
RAP and LAP pressures inc during atrial contraction (a wave)
RAP inc 4-6 mmHg
| LAP inc 7-8 mmHg
367
pressure norms: RV, LV, PAP, PCW (PAOP), CVP, RAP, LAP
```
RV 15-30/2-8
LV 100-140/3-12
PAP 15-25/8-15
PCW (PAOP) 6-12
CVP 3-8
RAP 2-6
LAP 4-12
```
368
describes ventricular ejection
systolic upstroke
369
describes max pressure during systolic ejection
peak systolic press
370
describes rapid decline in atrial press as ventricular contraction ends
systolic decline
371
describes roughly the area under the arterial curve
MAP
372
describes closing of aortic valve
dicrotic notch
373
aka dicrotic notch
incisora
374
preload formula using PCW + PAD & based on what law
(LVEDP x LVEDR) / 2h
h= thickness of ventricle
Laplace (pressure x radius)/2x wall thickness
375
noninvasive ways to measure LVEDV
radionuclide angiography
| dynamic MRI
376
4 components determine LV afterload
1. aortic compliance
2. total arterial resistance
3. LVES wall stress
4. SV
377
formula to estimate LV afterload
SVR = [80(MAP - RAP)]/CO
| clinically can use SBP if aortic stenosis not present
378
RV afterload (RVA) compared to LV afterload
pulm-arterial circ more compliant (RVA)
| RV more sensitive to changes in afterload (maybe bc not as strong as LV)
379
LV diastolic pressure immediately before contraction (LV pressure loop)
diastolic pressure curve
380
systolic pressure achieved during contraction
systolic pressure curve
381
EF value assoc with significant LV impairment
EF < 40%
| norm (60-70%)
382
percentage of EDV ejected durign systole
EF
383
CI and CO formula
```
CI = CO/BSA
CO = HR x SV
```
384
CO determined by 4 factors:
intrinsic: HR & contractility
extrinsic: preload & afterload
385
norm CO and CI
Co ~ 5 L/min
| CI ~ 2.5 L/min/sqm surface
386
what does ol Frank Starlin say about CO
- change in intrinsic contractile performance is based on changes in preload.
- inc preload = greater contractility force
387
preload can exist in these two ways
passive (flow from atria)
| active (atrial contraction)
388
CO formula accoring to Fick principle (which assumes normal resp fx)
```
CO = VO2/(Ca - Cv)
VO2 = O2 consumption in ml/min
Ca = arterial O2 content
Cv = venous O2 content
```
389
oculocardiac reflex via what efferent and afferent nerves
5 and dime
tri - afferent
vagus - efferent
390
traction on mesentery or gall bladder, or stimulation of vagus in other areas of body such as thorax/abdoment = bradycardia hypotension apnea
celiac reflex
391
"atrial stretch reflex" - increased volume of blood in heart.. SNS stimulation causes inc HR
Bainbridge reflex
392
(reflex) inc ICP -> SNS stimulation cause vasoconstriction in attempt to decrease ICP
Cushing reflex
393
chemoreceptors located in these two sites - response to hypoxia, hypercarbia and acidosis
central - medulla
| peripheral - carotid /aortic bodies
394
does wave of atrial recovery exist?
"too small"
395
duration of QRS
0.7 - 0.11 sec
396
characteristics of pathological q wave
> 1mm wide
> 2 mm deep
> 25 % of QRS size
present in V1-3
397
QT normal if
when 1/2 of R to R interval at normal rates
398
describe PR interval
p wave to QRS
399
describe RP segment
end of P to QRS
400
describe QRS interval
time from beginning to end of ventricular contraction
401
describe ST segment
end of ventricular activation (end of S) & begin of recovery (beg of T)
402
describe J point
junction of QRS & ST segment
403
describe QT interval
activation to recovery (beg of Q to end of T)
404
reasons for ST segment elevation
ischemia
pericarditis
aneurysma cordis
normal variant
405
reasons for ST depression
```
ischemia
LVH
digitalis
low K+/low Mg+
neurologic
```
406
causes of T-wave changes
```
ischemia
pericarditis
myocarditis
LVH/RVH
electrolyte changes (esp K+)
```
407
significant ST depression
> 0.5mm
408
significant ST elevation in standard vs precordial leads
standard > 1mm
| precordial > 2mm (healthy young black american > 4mm)
409
cause of ... depressed upsloping ST, low T wave , prominent U wave
low K+
410
cause of ... depressed , upsloping ST, "tent-like" symmetric wide T wave, apparent long QT
low K+ with T-U fusion, the most common pattern,
411
cause of ... wide QRS, horizontally depressed ST, low T wave amp, prominent U, long QT
class Ia drug: quin, proc, diso
412
cause of ... bowl-shape ST seg, low amp T wave, prominent U wave, short QT int
Digitalis
413
cause of ... "checkmark" shaped ST seg, T low to absent, 1 degree A-V bloc, QT int short
Digitalis (possible toxicity)
414
cause of ... long, straight ST seg, normal T, long QT int
low Ca+
415
cause of ... abbreviated ST segment, short or normal QT
high Ca+
416
ECG: arrow pointing direction of electrical potential
vector
417
mean QRS vector in degrees
+59
418
ECG (axis): length of arrow =
voltage of electrical potential
419
sum of vectors generating potential at one particular instant is called
instantateous mean vector
420
3 standard limb leads + 3 augmented leads is referred to as this system
Hexaxial reference system
421
3 things that cause LAD (left axis dev) in 90% of folks
normal varient
mechanical shift of heart
LVH
422
other causes of LAD (left axis dev)
```
LBBB
LAFB (left ant fascicular block)
congenital HD (eg ASD)
high K+
inferior MI
preexisting syndromes (eg WPW)
ventricular rhythm
pacemaker rhythm
```
423
causes of RAD (right axis)
```
normal
mechanical shifts
RVH
RBBB
LPFB (Left post fascicular block)
dextrocardia (heart apex points to right)
ventricular rhythm
lateral wall MI
preexcitation syndrome (WPW)
right heart strain (Cor Pulmonale, PE)
```
424
indeterminate axis causes (no mans land - "northwest axis")
ventriular rhythms
paced rhythms
lead misplacement
some congenital
425
2 most important risk factors for atherosclerosis
male
| inc age
426
often 1st sx of HD
angina pectoris
acute MI
sudden death (dysrhythmia)
427
"other causes of CAD"
CVA
PVD (undocumented CAD)
menopause
estrogen contraception (esp. smoking)
428
most common cause of stable MI (angina pectoris)
atherosclerosis
429
max compensatory dilation how much occusion % reached
70%
| BF only adequate at rest
430
ischemia releases these substances
adenosine
bradykinin
"other substances"
431
cardiac causes of acute CP
angina
rest or unstable angina
actute mi
pericarditis
432
vascular causes of acute CP
aortic dissection
PE
pulm HTN
433
pulmonary causes of acute CP
pleuritis/pneumonia
tracheobronchitis
spontaneous pneumo
434
GI causes of acute CP
```
reflux
esophageal spasm - severe substernal pressure
peptic ulcer
chole
pancreatitis
```
435
Musculoskeletal causes of acute CP
costochondritis
cervical disk disease
trauma or strain
436
infection causes of acute CP
herpes zoster
437
phych causes of acute CP
panic
438
characteristics that rarely cause myocardial ischemia
sharp pain x few seconds
| dull ache x hours
439
causes of angina / ischemic HD not related to lesion
spasm
vasculitis
trauma
ventricular hypertrophy
440
ace-inhibitors assist in what after MI
| prescribed to what comorbidity patients
ventricular remodeling
| DM, HF
441
coronary spasm w/ w/o plaque
printzmetal
| occurs usually at night, 5-15 min, ST elev during attack
442
cause of printzmetal
| tx
cold weather, stress, smoking!!!! (major), cocaine and vasoconstrictors. TREATMENT - Ca+ antagonist & nitrates
443
onset, frequency and duration of unstable angina
sudden inc severity
> 3x/day
> 30 min
