CV Flashcards
1
Q
How many nuclei do most myocytes have?
A
2
2
Q
What is the only way to increase cardiac mass?
A
hypertrophy (cannot increase in cell number, only cell size)
3
Q
CVP wave: v wave?
A
filling of right atrium from venous (v) system
4
Q
CVP wave: a wave?
A
atrial contraction
5
Q
CVP wave: c wave?
A
ventricular contraction causes AV valves to bow into atria
6
Q
CVP: what are the 3 waves (in order)?
A
a wave, c wave, v wave (alphabetical)
7
Q
What occurs at the time of the first heart sound?
A
closing of the AV valves
7
Q
Ejection fraction =
A
ejection fraction = SV/EDV
7
Q
Where does the coronary sinus drain?
A
right atrium
8
Q
What occurs at the time of the second heart sound?
A
closing of the aortic/pulmonary valves
8
Q
The majority of coronary blood flow occurs during which phase of the cardiac cycle?
A
diastole
9
Q
CPP (coronary perfusion pressure) =
A
CPP = dBP - LVEDP
10
Q
What are the 4 major proteins of a sarcomere?
A
actin, myosin, tropomysoin, troponin
11
Q
Which sarcomere protein has a “head” that attaches to the filament?
A
myosin
12
Q
Which sarcomere protein is the filament to which the “head” protein attaches?
A
actin
13
Q
How does calcium interact with the sarcomere?
A
calcium binds to troponin-C which then removes troponin-I’s inhibitory effect on tropomyosin, so it moves and exposes actin to myosin
14
Q
What are the 3 types of troponin?
A
troponin-C, troponin-I, troponin-T
15
Q
During cardiac myocyte depolarization, calcium first enters cell via which channels?
A
L-type (in cell membrane)
16
Q
Which calcium channels are on the sarcoplasmic reticulum and responsible for massive calcium release?
A
ryanodine recepetors
17
Q
Sequestration of calcium back into sarcoplasmic reticulum: active or passive process?
A
active (ATPase)
18
Q
How does acidosis effect calcium levels?
A
acidosis raises ionized calcium levels (H binds to albumin, displacing calcium)
19
Q
If you correct acidosis with bicarbonate, what must you make sure is corrected first?
A
iCal (alkalosis lowers ionized calcium levels)
20
Q
What is lusitropy?
A
rate of myocardial relaxation
21
Q
During inhalation: does heart rate increase or decrease?
A
increase (ventilation and perfusion are matched)
22
What is pulsus paradoxus?
a decrease in SBP >10 mmHg during negative pressure inhalation (exaggeration of normal physiology)
23
During a normal negative pressure inhalation, does blood pressure increase or decrease?
decrease (<10 mmHg; otherwise pulsus paradoxus)
24
What is systolic pressure variation?
an increase in SBP >10 mmHg during positive pressure
25
What percent of the blood volume is in the venous vasculature?
~75%
26
A vessel responds to an increase in transmural pressure or stretch by constricting. Name of response?
Myogenic response
27
What are the 4 major causes of tissue hypoxia (not hypoxemia)?
1 ischemic, 2 anemic, 3 hypoxemic, 4 histotoxic
28
Tissue hypoxia causes vasodilation in all vascular beds except which?
pulmonary circulation
29
Adenosine: vasodilator or vasoconstrictor?
vasodilator (A2AR)
30
Which (generally) vasoconstrictive medicine vasodilates the pulmonary vascular bed?
Vasopressin (use in PH)
31
Tissue hypoxia induces vasodilation through what kind of an oxygen-associated channel?
Potassium channel
32
Endothelin receptor B (ETb): vasodilates or vasoconstricts?
vasodilates
33
Endothelin receptor A (ETA): vasodilates or vasoconstricts?
vasoconstricts
34
Bosentan: dual (ETA and ETB) or selective (ETA) receptor antagonist?
dual
35
Ambrisentan: dual (ETA and ETB) or selective (ETA) receptor antagonist?
selective
36
Which is better for PH therapy: dual (ETA and ETB) or selective (ETA) receptor antagonist?
selective (ETB vasodilates, so if you block ETB, will promote vasoconstriction)
37
What is the resting membrane potential of a vascular smooth muscle cell?
-40 to -70 mV
38
Which organ has the highest OER?
heart (~60-70%)
39
Which organ has the lowest OER?
kidney (~10%)
40
How is coronary dominance defined? (right vs left dominant coronary circulation?)
whichever artery supplies the posterior descending coronary (posterior third of IVS)
41
Which is more common: right dominant or left dominant coronary circulation?
right dominant (70%)
42
Cardiac MVO2 can be estimated by what equation?
HR x SBP (pressure-rate product)
43
Left coronaries: perfused more during diastole or systole?
diastole
44
Right coronaries: perfused more during diastole or systole?
systole
45
Coronary perfusion pressure =
CPP = DBP - RAP
46
When MVO2 increases, how does the heart increase DO2?
by increasing capillary density (already at near max OER)
47
What does the heart use for energy?
fatty acids (70%) and carbs (30%)
48
What is the normal oxygen saturation of the coronary sinus?
30% (70% OER)
49
LVSWI (LV stroke work index) =
LVSWI = SI x (MAP-LAP) x 0.0136
50
Metabolic demand of the heart is lower during pressure work or volume work?
volume work
51
Activation of B2 adrenoreceptors: vasodilation or vasoconstriction?
vasodilation
52
Activation of a1 adrenoreceptors: vasodilation or vasoconstriction?
vasoconstriction
53
During CPR, what's more important for coronary blood flow - compression or decompression phase?
decompression phase
54
Cerebral blood flow (CBF) is reasonably constant over what range of cerebral perfusion pressures (CePP)?
50-150 mmHg (autoregulation)
55
Cerebral perfusion pressure (CePP) =
CePP = MAP - ICP
56
What part of the brain lacks a blood brain barrier?
choroid plexus
57
Hypercapnea-induced vasodilation in the brain: depends on pCO2 or pH?
pH
58
To avoid vascular steal in the brain, if a region vasodilates, what occurs upstream?
vasodilation of larger arteries ("flow-mediated vasodilation", reduces perfusion pressure)
59
Bronchial arteries/veins drain where?
To the pulmonary veins (causing an anatomic shunt)
60
Why are patients with bronchiectasis desaturated?
increased bronchial circulation leading to increased anatomic shunt
61
What's a normal systolic pulmonary artery pressure?
18-25 mmHg
62
What's a normal diastolic pulmonary artery pressure?
6-10 mmHg
63
What's a normal mean pulmonary artery pressure?
10-16 mmHg
64
How is pulmonary hypertension defined?
mPAP > 20 mmHg (as of 2018; previously 25)
65
Pulmonary vascular resistance (PVR) =
PVR (Woods units) = (mPAP-LAP)/Q
66
Why does a bolus of lasix cause pulmonary vasodilation?
lasix stimulates PGE1 production, relaxing postcapillary pulmonary venules
67
What are the 3 main classes of PH drugs?
1 prostacyclin analogs (+), 2 endothelin receptor antagonists, 3 PDE5 inhibitors
68
Increased sodium chloride delivery to the macula densa in the kidney has what effect?
afferent arteriole vasoconstriction (reduces GFR)
69
Adenosine acts as a vasoconstrictor (usually vasodilator) in what specific circumstance?
vasoconstricts the afferent arteriole when NaCl delivery is high (A1AR)
70
What's the normal PaO2 in the deep medulla?
only 10-15 mmHg (hence at risk for injury)
71
Prostaglandins: vasoconstrict or vasodilate?
vasodilate
72
What percent of the circulating blood volume is located in the splanchnic circulation?
~30%
73
Splanchnic circulation perfusion pressure =
SplPP = MAP - portal venous pressure (NOT CVP)
74
What is the normal toe temp?
32-34C
75
What is normal capillary refill time?
less than 2 seconds
76
What cardiac lesion is commonly associated with narrowed pulse pressure?
aortic stenosis
77
MAP =
MAP = (CO x SVR) + CVP
78
MAP = (estimation with blood pressures)
MAP = dBP + 1/3 pulse pressure
79
Oscillometric BP (cuff): underestimates or overestimates dBP?
underestimates (algorithmic, not directly measured)
80
Cardiac tamponade: right atrial collapse occurs during which phase of the cardiac cycle?
systole
81
Cardiac tamponade: right ventricle collapse occurs during which phase of the cardiac cycle?
diastole
82
What is the best view during echo for EF measurements?
apical 4 chamber
83
EF =
EF = (EDV-ESV)/EDV
84
What is a normal EF?
>/= 55%
85
What is a mildly reduced EF?
41-55%
86
What is a moderately reduced EF?
31-40%
87
What is a severely reduced EF?
88
FS (fractional shortening) =
FS = (LVEDD - LVESD)/LVEDD
89
What is a normal FS (fractional shortening)?
28-46%
90
What is the best view during echo to measure FS (fractional shortening)?
parasternal long (with M-mode)
91
What is the normal RV to LV ratio?
0.65 to 0.9
92
What is the best echo view to see the bowing of the IVS in PH?
parasternal long
93
PASP (pulmonary artery systolic pressure) =
PASP = 4 x (TRv)^2
94
What is a normal PASP (pulmonary artery systolic pressure)?
<30 mmHg
95
What is the modified Bernoulli equation?
P = 4 x v^2 (used to calculate PASP from TRv)
96
RVSP (RV systolic pressure) =
RVSP = PASP + RAP
97
Bowing of IVS during diastole only: volume or pressure overload?
volume overload
98
Bowing of IVS during diastole AND systole: volume or pressure overload?
pressure overload
99
Do NIRS require pulsatility?
no
100
Peripheral vs central arterial waveform: how does it change?
systolic peak increases, dicrotic notch later, diastolic pressure lower (larger pulse pressure)
101
Accurate measurement of an arterial pressure is achieved by assuring the natural frequency of the measurement system is at least how many times higher than the natural frequency of the arterial pressure (ie, heart rate)?
at least 8 times higher than heart rate
102
Accurate measuring of heart rates of 120 bpm (2Hz) requires a natural frequency of the measurement system of at least what?
16 Hz (2 x 8 = 16)
103
What heart rate is 1 Hz?
60 bpm
104
What causes underdamping ("fling")?
excess tubing length or vasoconstriction
105
What causes overdamping (artificially low SBP)?
bubbles, kinks, clots, multiple stopcocks, highly compliant tubing
106
A "fast flush" test of an arterial waveform should yield what if the system is appropriately damped?
only 1 resonant wave
107
What is the phlebostatic axis?
external reference point of the atria
108
Where is the phlebostatic axis?
line drawn from 4th intercostal space and midaxillary line
109
Arterial and central venous pressure monitoring must be leveled to what?
phlebostatic axis (RA)
110
A transducer leveled below the heart: falsely high or low BP?
falsely high
111
A transducer at a level above the heart: falsely high or low BP?
falsely low
112
Dropping a transducer to the floor: will BP go high or low?
high
113
Raising a transducer to the ceiling: will BP go high or low?
low
114
Arterial line "zeroing": at what height should you zero?
ANY height; zeroing is zeroing to atmospheric pressure (no meaningful change in atmospheric pressure from floor to ceiling)
*ie, don't need to re-zero if you move it
115
For every 10 cm below the phlebostatic axis, the art line reading does what?
adds 8 mmHg
116
Where should you level the arterial line if you want to measure cerebral perfusion pressure?
tragus (ear)
117
Why does lowering an arterial line transducer raise BP?
the weight of the fluid on the transducer increases, adding to pressure reading
(NOT an increase in atmospheric pressure)
118
How is pulsus paradoxus defined?
Fall in SBP >10 during negative pressure inspiration
119
Reverse pulsus paradoxus is also known as what?
systolic pressure variation (SPV)
120
The change in blood pressure that occurs during positive pressure ventilation is referred to as what?
systolic pressure variation (SVP; or "reverse pulsus paradoxus")
121
What factors are associated with increased infection of arterial catheters?
young age, femoral site, duration of use
122
Measured CVP is most accurate during which phase of the respiratory cycle?
end-expiration
123
CVP waveform: a wave?
atrial contraction
124
CVP waveform: c wave?
isovolumic ventricular contraction (tricuspid valve)
125
CVP waveform: x descent?
non-isovolumic ventricular contraction (tricuspid valve downward displacement as volume exits ventricle)
126
CVP waveform: v wave?
venous blood fills atria
127
CVP waveform: y descent?
atrium drained with opening of TV
128
What is the order of the CVP waves/descents?
a,c,x,v,y
129
What CVP wave occurs after the P wave of the EKG?
a wave
130
What CVP wave occurs after the QRS complex of the EKG?
c wave
131
What CVP wave occurs after the T wave of the EKG?
v wave
132
If shown a CVP waveform, what point should you use to best measure CVP?
a wave
133
Large a waves (CVP) occur when?
AV dissociation, tricuspid stenosis, poorly compliant RV
134
A wave (CVP) is lost when?
atrial fibrillation
135
Exaggerated c and v wave (CVP) occurs when?
tricuspid regurgitation
136
Y descent (CVP) is lost when?
tamponade physiology
137
The femoral site for a CVC is associated with increased risk of infection in which population?
postpubescent children
138
Qp/Qs =
Qp/Qs = (SatAo-SatRa)/(SatPV-SatPA)
139
Qp/Qs >1 indicates what?
L to R shunt
140
What Qp/Qs is considered clinically significant?
>2
141
What conditions will invalidate the results of calculated CO from thermodilution method?
shunts or tricuspid regurgitation
142
In thermodilution method of calculating CO, a large AUC indicates: increased or decreased CO?
decreased CO
143
In thermodilution method of calculating CO, a small AUC indicates: increased or decreased CO?
increased CO
144
A pulmonary artery catheter should be in which zone of the lung for the most accurate PCWP measurement?
base of the lung/west zone 3 (no alveolar distension)
145
Normal RA pressure?
5
146
Normal RV pressure (systolic and diastolic)?
25/0-10
147
Normal PA pressure (systolic and diastolic)?
25/5-10
148
Normal PCWP?
10
149
Normal LA pressure?
10
150
Normal LV pressure (systolic and diastolic)?
60-90/5-10
151
How would you know your PA catheter had moved from RV to PA?
systolic pressure the same, but diastolic pressure of PA is ~5 while RV is ~0
152
What measurement can be used in lieu of PCWP to assess LVEDP?
PA diastolic pressure (PADP)
153
How does a catheter that uses pulse contour analysis estimate CO?
assumes the AUC of the systolic portion of an arterial waveform equals the SV
154
How does a PiCCO catheter calculate CO?
uses pulse contour analysis (calibrates with thermodilution)
155
How does FloTrac determine CO?
uses pulse contour analysis (does NOT calibrate secondarily with thermodilution)
156
Why do you need the co-ox rather than the calculated oxygen sat from a normal blood gas for a central venous oxygen saturation?
co-ox actually measures, normal blood gas calculates; due to the steep O2-Hb curve, will be a big difference
157
Type A lactic acidosis (hypoxic) is associated with what lactate-to-pyruvate ratio?
elevated or >10:1 (normal 10:1)
158
Type B lactic acidosis (non-hypoxic) is associated with what lactate-to-pyruvate ratio?
10:1 (normal)
159
How can you differ type A vs type B lactic acidosis?
lactate-to-pyruvate ratio; type A, lactate is elevated (ratio elevated) vs type B, both are elevated (ratio maintaiend)
160
Elevation in the D-isomer of lactate occurs in what situations?
bacterial overgrowth (eg, short gut)
161
What is the difference between NT-proBNP and BNP?
NT-proBNP has a longer half life (1-2h vs 20 min) and is more stable
162
Cardiac cells: intracellular levels of Na, K, and Ca?
Na 10, K 140, Ca 0
163
Phase 0 of the cardiac action potential results from what channel/electrolyte?
rapid Na channels open (Na in) or Ca channels open (Ca in; in pacemaker cells)
164
Cardiac action potential: phase 0?
rapid depolarization
165
Cardiac action potential: phase 1?
early repolarization
166
Cardiac action potential: phase 2?
plateau repolarization
167
Cardiac action potential: phase 3?
late repolarization
168
Cardiac action potential: phase 4?
early/spontaneous depolarization
169
Which phases of the cardiac action potential are repolarization?
phase 1-3
170
Phase 1 of the cardiac action potential results from what channel/electrolyte?
Na channels close, K channels open (K out)
171
Phase 2 of the cardiac action potential results from what channel/electrolyte?
Slow calcium channels open (Ca in), K still open (K out)
172
Phase 3 of the cardiac action potential results from what channel/electrolyte?
Ca channels close, K still open (K out)
173
Phase 4 of the cardiac action potential results from what channel/electrolyte?
slow Na channels open (Na in)
174
The refractory period is defined by what phases of the cardiac action potential?
phases 1-3
175
Diastole is defined by what phases of the cardiac action potential?
phases 4-0
176
In the normal state, sinus node tissue demonstrates the fastest rate of which phase of the cardiac action potential?
phase 4 (early/spontaneous depolarization)
177
What are the 3 general mechanisms of arrythmias?
1 reentry, 2 increased automaticity, 3 triggered activity
178
What is the most frequent mechanism of arrhythmias?
reentry
179
Which arrhythmia mechanism involves "on/off" phenomenon and invariable rates?
reentry
180
Which arrhythmia mechanism is likely to terminate with adenosine?
reentry
181
Which arrhythmia mechanism involves "warm up" phenomenon and variable rates?
automaticity
182
An automatic arrhythmia occurs due to an increase of which phase of the cardiac action potential?
increased phase 4 (early/spontaneous depolarization)
183
Automatic arrhythmias result from variable rates of depolarization in specific areas of the heart called what?
ectopic foci
184
Triggered arrhythmias result from what?
abnormal afterdepolarizations (occur after normal cardiac depolarization, interrupting normal repolarization)
185
Infancy: a state of parasympathetic or sympathetic predominance?
parasympathetic
186
Vagus nerve causes release of what neurotransmitter at the sinus and AV nodes?
acetylcholine
187
Vagus-mediated acetylcholine release causes what effect on the action potential at the sinus and AV nodes?
decreases the slope (rate) of phase 4 depolarization (bradycardia)
188
Vagal-mediated bradycardia can be attenuated by what antagonists?
muscarinic receptor antagonists (aka anticholinergics; atropine and glycopyrrolate)
189
What is the dose of atropine?
0.02 mg/kg (min 0.1 mg, max 1 mg)
190
What maternal disease is associated with neonatal heart block?
SLE (SSA-Ro and SSB-La antibodies)
191
What does the first letter of the pacer setting mean?
chamber paced
192
What does the second letter of the pacer setting mean?
chamber sensed
193
What does the third letter of the pacer setting mean?
response to sensing
194
What does AAI pacing ensure?
a minimum atrial rate (requires AV synchrony)
195
What does VVI pacing ensure?
a minimum ventricular rate (asynchronous)
196
What does DDD pacing ensure?
a minimum synchronized rate
197
Sinus tachycardia involves increasing the rate of which phase of the cardiac action potential?
increased phase 4 depolarization
198
What are the supraventricular automatic arrhythmias?
sinus tachycardia, ectopic atrial tachycardia
199
What are the supraventricular reentry arrhythmias?
atrial fibrillation, atrial flutter, AVRT, AVNRT
200
WPW is what type of arrhythmia?
AVRT (reentry)
201
What are the supraventricular triggered arrhythmias?
chaotic atrial tachycardia, digoxin toxicity
202
SVT in infants and small children is usually: AVRT or AVNRT?
AVRT
203
Orthodromic AVRT: narrow or wide complex SVT?
narrow
204
Antidromic AVRT: narrow or wide complex SVT?
wide
205
SVT in older children: AVRT or AVNRT?
AVNRT
206
Delta wave is seen in which arrhythmia?
WPW
207
What does the delta wave represent?
early ventricular activation (no pause of AV node)
208
Vagal maneuvers cause the AV node to do what?
hyperpolarize (slows conduction)
209
Worrisome adenosine side effect?
Ventricular fibrillation (from intense sympathetic activation in response to adenosine)
210
Adenosine dose?
0.1 mg/kg, then 0.2 mg/kg (max 12 mg)
211
What are the two most common drugs/classes for SVT treatment in children?
beta blockers, digoxin
212
What common adult medicine must be avoided in pediatric SVT treatment?
calcium channel blockers (verapamil)
213
Digoxin mechanism of action?
inhibition of Na/K ATPase
214
What drugs are contraindicated in WPW due to risk of ventricular fibrillation?
digoxin, calcium channel blockers (verapamil)
215
What is the drug of choice for WPW syndrome?
beta blocker
216
Which beta receptor mediates cardiac effects?
beta 1
217
Which beta blockers are cardioselective (B1)?
atenolol, esmolol, metoprolol
218
Which beta blockers are NOT cardioselective (B1 and B2)?
labetalol, propranolol
219
What is a common side effect of propranolol?
hypoglycemia
220
What arrhythmia is common following repair of anomalous pulmonary venous return?
atrial flutter
221
What must be ruled out BEFORE cardioverting atrial flutter or fibrillation?
presence of atrial thrombi
222
JET is caused by what?
enhanced automaticity of cells in the His-Purkinje complex
223
JET treatment involves cooling to what temperature?
35C
224
What medication is the preferred antiarrhythmic for JET?
amiodarone
225
An extra beat with a compensatory pause is likely: PAC or PVC?
PVC
226
Torsades de pointes is associated with what EKG finding (at baseline)?
long QT
227
What 3 medications predominate for use in ventricular tachyarrhythmias?
lidocaine, amiodarone, magnesium sulfate
228
What are class I antiarrhythmics?
sodium channel blockers
229
What are class II antiarrhythmics?
beta-blockers
230
What are class III antiarrhythmics?
potassium channel blockers
231
What are class IV antiarrhythmics?
calcium channel blockers
232
What class of antiarrhythmic is procainamide?
I (sodium channel blocker)
233
What class of antiarrhythmic is lidocaine?
I (sodium channel blocker)
234
What class of antiarrhythmic is phenytoin?
I (sodium channel blocker)
235
What class of antiarrhythmic is flecainide?
I (sodium channel blocker)
236
What class of antiarrhythmic is amiodarone?
III (potassium channel blocker)
237
What class of antiarrhythmic is sotalol?
III (potassium channel blocker; weak beta blocker)
238
What class of antiarrhythmic is diltiazem?
IV (calcium channel blocker)
239
What class of antiarrhythmic is verapamil?
IV (calcium channel blocker)
240
What is the loading dose of lidocaine?
1 mg/kg
241
What is a major side effect of lidocaine?
seizures
242
What drug causes blue skin discoloration?
amiodarone
243
What antiarrhythmic can cause interstitial pneumonitis?
amiodarone
244
Lidocaine is used in what type of arrhythmias?
ventricular arrhythmias (ONLY)
245
Lidocaine loading dose?
1 mg/kg
246
Amiodarone loading dose?
5 mg/kg (run over 30 minutes to avoid hypotension)
247
What is the formula for QTc?
QTc = QT/(square root of preceding RR interval)
248
What is a normal QTc?
<450 msec (460 in females)
249
What drug should be given for TdP arrhythmia?
magnesium
250
TNF alpha: pro or anti inflammatory?
pro
251
IL1B: pro or anti inflammatory?
pro
252
IL-6: pro or anti inflammatory?
pro
253
IL-8: pro or anti inflammatory?
pro
254
IL-10: pro or anti inflammatory?
anti
255
To define PH: what is the MPAP and PAWP?
MPAP >20, PAWP <15
256
What is the mechanism of Sildenafil?
PDE type 5 inhibitor
257
Which is better for a PH crisis, NE or vasopressin?
vasopressin (pulmonary vasodilator, systemic vasoconstrictor)
258
JET occurs most commonly after which surgeries?
VSD, AVSD, TOF
259
Persistent atrial ectopic tachycardia (AET) can lead to what?
arryhthmia-induced cardiomyopathy
260
Complete AV block occurs most commonly after which surgeries?
VSD, AVSD, TOF
261
Define 1st degree AV block?
prolonged PR (>160ms)
262
Define 2nd degree (Mobitz type I) AV block?
"Wenckebach" progressive prolongation of PR before a blocked P wave
263
Define 2nd degree (Mobitz type II) AV block?
Blocked P wave with no change in PR interval
264
Define 3rd degree AV block?
complete dissociation of atrial and ventricular activity
265
What score is used to risk stratify congenital heart surgeries?
RACHS-2
266
Which ASD is amenable to cath intervention?
secundum ASD (only)
267
Postpericardiotomy syndrome occurs commonly after which procedure?
ASD
268
Postpericardiotomy syndrome occurs when in relation to cardiac surgery?
about 1 week after
269
A child 1 week out from cardiac surgery with fever and chest pain is worrisome for what?
postpericardiotomy syndrome (check for tamponade)
270
Which cardiac lesion is particularly associated with T21?
AVSD
271
What is a notable complication of aortic cross clamping to monitor for?
spinal cord ischemia (LE neurologic deficits)
272
Postcoarctectomy syndrome involves what?
hypertension, abdominal tenderness, feeding intolerance, GI bleeding
273
Type B IAA is associated with which diagnosis?
DiGeorge syndrome (22q)
274
"Restrictive" RV physiology is anticipated after which cardiac repair?
TOF
275
What does "restrictive" RV physiology mean?
diastolic dysfunction of RV
276
What is a common complication after truncus arteriosis repair?
PH crisis
277
TGA is treated with what surgical operation?
ASO
278
What is the biggest worrisome complication after ASO surgery?
coronary ischemia
279
"Torrential" pulmonary blood flow is seen in which cardiac lesion?
truncus arteriosus
280
What is the basic pathophysiology of TOF?
anterior malalignment of the conal septum
281
What are the cons of Sano vs BTTS?
Sano - ventriculotomy, BTTS - diastolic runoff/"coronary steal"
282
Why would hypercapnea be beneficial after a Glenn?
promotes cerebral blood flow, promoting SVC/Glenn blood flow
283
Why is the normal stress response inadequate in a post-op heart transplant?
loss of cardiac innervation (sympathetic surge blunted)
284
How to diagnose chylothorax from pleural fluid?
TG>110, cell count >1000 with >80% lymphocytes
285
What is a worrisome side effect of octreotide use for chylothorax?
NEC
286
Diets for chylothorax are rich in what?
MCTs (medium chain triglycerides)
287
An inotrope increases what?
contractility
288
A chronotrope increases what?
heart rate
289
A lusitrope increases what?
diastolic relaxation
290
Which adrenoreceptors are innervated by sympathetic nerves?
alpha1 and beta1
291
Which adrenoreceptors are "hormonal" (Epi agonists)?
alpha2 and beta2
292
Where are alpha1 receptors located (not located)?
vascular smooth muscle (NOT in coronary or cerebral circulation)
293
Alpha1 agonism causes what?
vasoconstriction
294
Alpha2 agonism causes what?
inhibition of NE release
295
Where are beta1 receptors located?
myocardium and kidney
296
Beta1 agonism causes what (in heart)?
increased inotropy, lusitropy, and chronotropy
297
Where are beta2 receptors located?
vascular smooth muscle, bronchial smooth muscle, lymphocytes and mast cells
298
Beta2 agonism causes what?
vasodilation, increased chronotropy
299
Where in the heart are beta2 receptors located?
atria (pacemaker)
300
How does dopamine work as a vasoactive?
stimulates NE release
301
Where are dopamine1 receptors located?
kidney and splanchnic vascular bed
302
Dopamine1 receptor agonism causes what (hemodynamic change)?
vasodilation
303
Dopamine2 receptor agonism causes what?
inhibition of NE release (similar to alpha2)
304
Norepinephrine activates what receptors?
alpha1 = beta1
305
Epinephrine activates what receptors?
beta2 > beta1 = alpha1
306
Phenylephrine activates what receptors?
alpha1
307
Isoproterenol activates what receptors?
Beta1 > Beta2
308
Dobutamine activates what receptors?
Beta 1 = Beta 2, variable alpha1 effect (isomer)
309
Phenoxybenzamine mechanism of action?
alpha1 and alpha2 antagonist (irreversable)
310
Phentolamine mechanism of action?
alpha1 and alpha2 antagonist
311
Propranolol mechanism of action?
Beta1 and Beta2 antagonism
312
What are the Beta1-selective beta blockers?
atenolol, esmolol, metoprolol
313
Labetalol mechanism of action?
beta1 > alpha1 antagonism
314
Phosphodiesterase III enzyme does what?
Breaks down cAMP
315
Milrinone mechanism of action?
PDEIII inhibitor
316
Half-life of Milrinone?
2 hours
317
Epinephrine activates which cycle, which then increases lactate?
Cori cycle (gluconeogenesis)
318
Which vasoactive increases SVR but reduces PVR?
vasopressin
319
MVO2 is determined by what?
heart rate and stroke work
320
LVSW (LV stroke work) =
LVSW = (MAP - LAP) * SV
321
VasoDILATORS should be avoided in what patients?
Those with LVOTO (fixed obstruction)
322
Upon contact with hemoglobin, nitroprusside forms what?
cyanide and methemoglobin
323
Why does a patient desaturate after starting nitroprusside?
uncouples hypoxic vasoconstriction
324
How to treat cyanide toxicity from nitroprusside?
give thiosulfate and hydroxocobalamin (vitamin B12) to increase rhodanase activity
325
If a patient develops methemoglobinemia from nitroprusside, what medication should be avoided?
methylene blue (will release cyanide); instead do exchange transfusion
326
What medicine is used in patients with pheochromocytoma to limit severe hypertension?
phenoxybenzamine
327
Levosimendan mechanism of action?
Calcium-sensitizer (inodilator)
328
Tolvaptan mechanism of action?
vasopressin (ADH) receptor antagonist; increases free water excretion
329
Which calcium channel blocker has a greater action on vascular smooth muscle than heart?
Nicardipine
330
What common ICU medication increases the effect of esmolol?
morphine
331
What electrolyte derangement occurs in the setting of ACE inhibition?
hyperkalemia
332
Which is associated with increased hemolysis, acute renal failure, and need for inotropic support: roller pumps or centrifugal pumps in ECMO?
centrifugal pumps
333
Why do we use centrifugal pumps in ECMO?
cheaper, less anticoagulation, reduced priming volumes
334
IABP: when is it inflated?
diastole (enhances coronary perfusion)
335
What MCS provides both hemodynamic support and cardiac unloading in one device?
Impella (unloads LV, delivers to aorta)
336
The finding of complete heart block is often the presenting finding for what diagnosis?
L-transposition (ventricular inversion)
337
Normal AV delay length in children?
100-140 ms
338
How do you decide the output (mA) of a temporary pacer?
set at 2-3 times the pacing threshold
339
When a pacemaker sees electrical activity that it inappropriately recognizes as cardiac activity, thus inhibits pacing: oversensing or undersensing?
oversensing (sensitivity too HIGH)
340
When a pacemaker ignores cardiac activity and continues to pace inappropriately: oversensing or undersensing?
undersensing (sensitivity too LOW)
341
Post-op atrial wires are on which side of the chest?
right of sternum
342
Post-op ventricular wires are on which side of the chest?
(patient’s) left of sternum
343
Which is more dangerous by a temporary pacemaker: oversensing or undersensing?
undersensing (risk of R on T phenomenon); use LOWEST setting possible
344
If your pacemaker is oversensing, how fix?
increase the sensitivity threshold
345
If your pacemaker is undersensing, how fix?
decrease the sensitivity threshold
346
How do you fix pacemaker-mediated tachycardia?
increase the PVARP (post-ventricular AV refractory period)
347
What is the difference between the RA and LA pressure waveforms?
RA is a-wave dominant, LA is v-wave dominant
348
A mechanical mitral valve will cause the LA waveform to lose which wave?
c wave disappears (no bowing of cusps)
