Cardiovascular Disorders Flashcards
(244 cards)
1
Q
acute hypoxemia on ECMO; 3 possibilities
A
- patient
- MV
- ECMO circuit
2
Q
acute hypoxemia on ECMO if it’s the ECMO circuit
A
- large clot in oxygenator
- poor O2 source
- significant recirculation
3
Q
indications for surgery for tricuspid endocarditis
A
- failure of medical therapy (persistent bacteremia or enlarging vegetation)
- large vegetation, > 1 cm
- fungal endocarditis
- HF d/t TR
4
Q
when should you worry about fungal endocarditis in IVDU?
A
delayed growth of Candida species in BCs
5
Q
causes of dampened (smooth contours) arterial line waveform
A
- air bubbles
- catheter kinking
- tubing kinking
- intraluminal thrombus
6
Q
what is a distinguishing feature of a properly functioning arterial line system?
A
presence of 1-3 beats of pressure overshoot or oscillation
7
Q
four phases of myocyte action potential
A
- phase 4 (repolarization) = resting potential
- phase 0 (rapid depolarization) = Na+ influx
- phase 1 = K+ efflux
- phase 2 (plateau) = Ca++ influx
- phase 3 (repolarization) = K+ efflux
- phase 4 (repolarization) = resting potential
8
Q
arrhythmias are initiated and maintained by what 3 main mechanisms?
A
- automaticity
- afterdepolarizations
- reentry
9
Q
which arrhythmias are a/w automaticity?
A
- sinus tachycardia
- atrial premature complexes
- some atrial tachycardias
10
Q
afterdepolarizations are a/w an increase in cellular
A
Ca++ accumulation
11
Q
afterdepolarizations are a/w an increase in cellular Ca++ accumulation, leading to what?
A
repeated myocardial depolarization
- EADs if between phase 2 and phase 3 of the action potential (prolongs action potential and QT on ECG)
- DADs if between phase 3 and phase 4 of the action potential
12
Q
which arrhythmia may be related to early afterdepolarization?
A
initiation of torsades de pointes
13
Q
which arrhythmias may be related to delayed afterdepolarization?
A
- digoxin toxicity
- catecholamine-induced ventricular tachycardia
14
Q
which arrhythmias are a result of reentry?
A
most supraventricular and ventricular tachycardias
15
Q
class 1 antiarrhythmics
- work on what phase of the action potential
- block what channel
A
- phase 0
- Na+ channel blocker
16
Q
what are the class 1A antiarrhythmics?
A
- quinidine
- procainamide
- disopyramide
17
Q
when are the class 1A antiarrhythmics used?
A
- AF
- AFl
- SVT
- ventricular tachyarrhythmias (VTs)
18
Q
what are the class 1B antiarrhythmics?
A
- lidocaine
- tocainide
- mexiletine
19
Q
when are the class 1B antiarrhythmics used?
A
VTs
20
Q
what are the class 1C antiarrhythmics?
A
- flecainide
- propafenone
- moricizine
21
Q
when are the class 1C antiarrhythmics used?
A
life-threatening SVT and VTs
22
Q
quinidine distinguishing characteristic
A
moderate anticholinergic
23
Q
quinidine AEs
A
- cinchonism (blurred vision, tinnitus, headache, psychosis)
- cramping and nausea
- enhances digitalis toxicity
24
Q
procainamide distinguishing characteristics
A
- weak anticholinergic
- relatively short half-life
25
procainamide AE
lupus-like syndrome (25-30%)
26
disopyramide distinguishing characteristic
strong anticholinergic
27
disopyramide AE
negative inotropic effect
28
lidocaine distinguishing characteristic
good efficacy in ischemic myocardium
29
tocainide distinguishing characteristic
orally active lidocaine analog
30
tocainide AE
pulmonary fibrosis
31
mexiletine distinguishing characteristic
- orally active lidocaine analog
- good efficacy in ischemic myocardium
32
flecainide used for
SVT
33
flecainide AE
can induce life-threatening VT
34
propafenone used for
SVT and VT
35
propafenone AE
can worsen HF d/t beta and Ca++ channel blockade
36
moricizine distinguishing characteristic
also has class 1B activity
37
what are the class 2 antiarrhythmics?
- nadolol
- propranolol
- sotalol
- timolol
- acebutolol
- atenolol
- betaxolol
- bisoprolol
- esmolol
- metoprolol
38
nadolol distinguishing characteristic
long acting
39
propranolol distinguishing characteristic
- membrane stabilizing activity
- prototypical beta-blocker
40
timolol distinguishing characteristic
primary used for glaucoma
41
acebutolol distinguishing characteristic
intrinsic sympathomimetic activity
42
betaxolol distinguishing characteristic
membrane stabilizing activity
43
esmolol distinguishing characteristic
ultra-short acting
44
metoprolol distinguishing characteristic
membrane stabilizing activity
45
class 3 antiarrhythmics
- work on what phase of the action potential
- block what channel
- phase 3
- K+ channels
46
what are the class 3 antiarrhythmics?
- amiodarone
- dronedarone
- bretylium
- sotalol
- ibutilide
- dofetilide
47
amiodarone therapeutic uses
- VT
- VF
- AF and AFl (off-label)
48
amiodarone distinguishing characteristic
- very long half-life (25-60 days)
- has class 1, 2, 3, and 4 activity
49
amiodarone AEs
- pulmonary fibrosis
- hypothyroidism
- bradycardia and AVB
50
dronedarone therapeutic uses
- AF (non-permanent)
- AFl
51
dronedarone distinguishing characteristic
- structurally related to amiodarone
- CI in severe or recently decompensated symptomatic HF
52
dronedarone AE
risk for severe liver injury
53
bretylium therapeutic uses
life-threatening VT and VF
54
bretylium distinguishing characteristic
initial sympathomimetic effect (NE release) followed by inhibition which can lead to hypotension
55
sotalol therapeutic uses
- VT
- AF
- AFl
56
sotalol distinguishing characteristic
also has class 2 activity
57
ibutilide therapeutic uses
- AF
- AFl
58
ibutilide AE
can cause life-threatening ventricular arrhythmias
59
dofetilide therapeutic uses
- AF
- AFl
60
dofetilide distinguishing characteristic
- very selective K+ channel blocker
61
dofetilide AE
can cause life-threatening ventricular arrhythmias
62
what are the class 4 antiarrhythmics?
- verapamil
- diltiazem
63
what are the 3 classes of CCBs?
1. dihydropyridines
2. phenylalkylamine (non-dihydropyridine)
3. benzothiazepine (non-dihydropyridine)
64
what are the dihydropyridine CCBs?
- amlodipine
- felodipine
- isradipine
- nicardipine
- nifedipine
- nimodipine
- nitrendipine
65
which CCB is the phenylalkylamine class?
verapamil
66
which CCB is the benzothiazepine class?
diltiazem
67
how do CCBs work as antiarrhythmics?
- decrease firing rate of aberrant pacemaker sites w/i the heart
- decrease conduction velocity, especially at AV node
- prolong repolarization, especially at AV node
68
initial treatment of RV infarction
ivf w/o overdistention of RV
69
treatment of RV infarction if no improvement w/ ivf
inotrope
70
clinical findings of primary RCM
skeletal myopathy
71
What causes endomyocardial fibrosis (EMF)
h/o parasitic infestation, hematologic malignancy, or AI d/o
72
clinical findings of amyloidosis
- macroglossia
- periorbital ecchymosis
- orthostatic hypotension
73
clinical findings of drug-induced
h/o chloroquine or hydroxychloroquine use
74
What causes post-radiation RCM?
h/o mediastinal radiation
75
clinical findings of hemochromatosis
- hyperpigmentation
- liver failure
- DM
76
What causes Anderson-Fabry
reduced alpha-galactosidase
77
clinical findings of Danon/Pompe/PRKAG2
skeletal myopathy
78
clinical findings of Friedreich's ataxia
- ataxia
- DM
79
clinical findings of constrictive pericarditis
- fluid overload; ranges from peripheral edema to anasarca
- decreased CO in response to exertion
80
if;
- fever
- AMS
- AF w/ RVR
- HF
after coronary angiography, consider what condition?
thyroid storm
81
Jod-Basedow syndrome
thyroid storm in a patient w/ subclinical hyperthyroidism precipitated by administration of iodinated contrast
82
clinical hallmarks of cardiac amyloidosis
- biventricular HF
- pAF
- carpal tunnel syndrome
83
3 main types of amyloidosis
1. amyloid light-chain (AL) amyloidosis
2. amyloid A (AA) amyloidosis
3. amyloid transthyretin (ATTR) amyloidosis
84
AL amyloidosis diagnosis
measuring serum immunoglobulin light chains and finding a monoclonal spike
85
what test is highly sensitive for ATTR amyloidosis in the presence of HF w/ a compatible TTE?
technetium-labeled bone scintigraphy compared w/ the bone signal
86
what class of medications used to treat non-small cell lung cancer can cause myocarditis?
checkpoint inhibitors, eg pembrolizumab
87
how to distinguish between true aortic stenosis and pseudostenosis?
dobutamine stress test
88
if dobutamine increases CO and the aortic valve gradient is unchanged, then calculated valve area will INCREASE, indicating what?
pseudostenosis
89
if dobutamine increases CO and the aortic valve gradient increases PROPORTIONALLY, then what is confirmed?
true aortic stenosis
90
if dobutamine does NOT increase CO (that is, the patient lacks contractile reserve), the test is what?
indeterminate regarding the severity of aortic stenosis
91
if a dobutamine stress test is indeterminate regarding the severity of aortic stenosis, what does that mean regarding prognosis?
POOR prognosis with or w/o valve replacement
92
what test is contraindicated in the presence of critical aortic stenosis?
exercise stress testing
93
dipyridamole administration w/ myocardial perfusion imaging may be used to diagnose what?
myocardial ischemia
94
is TEE good at evaluating AS?
no
95
how is aortic valve gradient calculated?
flow/AVA
- AVA = aortic valve area
96
what tachyarrhythmia should be considered when these 3 criteria are present?
1. wide complex tachyarrhythmia
2. irregularly irregular rhythm
3. varying widths of QRS complexes
preexcited AF or AF in a patient w/ an accessory conduction pathway AKA WPW syndrome
97
patients w/ WPW syndrome have an accessory conduction pathway that directly connects what to what?
atria w/ ventricles and bypasses the AV node
98
treatment for patients w/ preexcitation AF if signs/symptoms of hemodynamic instability; hypotension, chest pain, or confusion
urgent electrical cardioversion
99
treatment for patients w/ preexcitation AF w/o hemodynamic instability
medical treatment w/ ibutilide (class 3) or procainamide (class 1a)
100
what ETCO2 level is often the first indication that ROSC has been achieved?
abrupt increase to > 35 to 40 mmHg
101
normal aortic valve area
3 to 4 cm2
102
severe AS AVA (aortic valve area)
typically ≤ 1 cm2
103
what are the lateral leads?
1, aVL, v5-v6
104
what coronary arteries are a/w the lateral leads?
LCx or diagonal of LAD
105
what coronary arteries are a/w leads 1, aVL, v5-v6?
LCx or diagonal of LAD
106
what are the inferior leads?
2, 3, aVF
107
what coronary arteries are a/w the inferior leads?
RCA and/or LCx
108
what coronary arteries are a/w leads 2, 3, aVF?
RCA and/or LCx
109
what are the septal and anterior leads?
v1-v2 = septal
v3-v4 = anterior
110
what coronary arteries are a/w the septal/anterior leads?
LAD
111
what coronary arteries are a/w leads v1-v4?
LAD
112
what is the key to distinguishing AF in a patient w/ LBBB from VT?
irregular R-R interval
113
complications of aortic dissection
- ***rupture into pericardium***
- acute MI, 3%
- aortic insufficiency, 32%
- stroke, 5%
- BP differential, 15%
- paraplegia, 1%
- mesenteric ischemia, 5%
- renal ischemia, 8%
- lower extremity ischemia, 3%
114
which P2Y12 inhibitor is a/w dose-related episodes of dyspnea (unknown mechanism), and ventricular pauses?
ticagrelor
115
AF, in patients, w/ what condition can have profound effects on hemodynamic stability?
structural heart disease
116
most reliable view on pocus to measure RV size
apical 4-chamber view
117
what is a normal RV size?
≤ 2/3 LV
118
what is the most appropriate sequence of resuscitation for cardiac arrest in a patient w/ pulseless VT or VF and is w/i 10 days of cardiac surgery?
- shock x 3
- check for rhythm and pulse
- CPR
- call cardiac surgeon for sternotomy
- amiodarone 300 mg iv
- prepare chest for resternotomy
- repeat shock every 2 min
- perform resternotomy w/i 5 min by any trained personnel
119
VF is the cause of cardiac arrest in what percentage of cardiac surgery patients?
25 to 50%
120
what causes of cardiac arrest should be considered in post cardiac surgery patients, especially in patients in whom a SBP > 60 mm Hg is not achieved during effective CPR?
- cardiac tamponade
- intrathoracic bleeding
121
what dose of epinephrine should be given during a cardiac arrest in a post cardiac surgery patient?
50 to 300 mcg iv (0.05-0.3 mg)
122
why should reduced doses of epinephrine be given during cardiac arrest in a post cardiac surgery patient?
the usual dose, 1 mg iv, can precipitate severe HTN and bleeding in patients who regain ROSC
123
90% of Duchenne muscular dystrophy (DMD) patients > 18 yoa have what heart problem?
dilated cardiomyopathy
124
treatment for DMD-related cardiomyopathy
glucocorticoids
125
what percentage of mitral and tricuspid flow velocities indicates cardiac tamponade, reflecting ventricular interdepence?
- > 30% variation in mitral
- > 60% variation in tricuspid
126
how to calculate pulmonary vascular resistance (PVR)?
mean pulmonary artery pressure - pulmonary artery wedge pressure / CO
mPAP - PAWP / CO
PAWP = left atrial pressure (LAP)
127
how to calculate systemic vascular resistance (SVR)?
mean arterial pressure - right atrial pressure / CO
MAP - RAP / CO
128
CHB a/w IWMI is located where in 90% of patients?
proximal to the His bundle
129
CHB a/w AWMI is more often located where?
distal to the AV node
130
CHB a/w AWMI is usually symptomatic and a/w?
high mortality rate
131
normal intracardiac and vascular pressures (mm Hg)
- RA
0-4 (varies w/ respiration)
132
normal intracardiac and vascular pressures (mm Hg)
- RV
25/4
133
normal intracardiac and vascular pressures (mm Hg)
- PA
25/10
134
normal intracardiac and vascular pressures (mm Hg)
- LA
8-10
135
normal intracardiac and vascular pressures (mm Hg)
- LV
120/10
136
normal intracardiac and vascular pressures (mm Hg)
- aorta
120/80
137
normal TAPSE (tricuspid annular plane systolic excursion)
> 16 mm
138
treatment of RVMI
- antiplatelet therapy
- reperfusion therapy
139
treatment of shock d/t RVMI is aimed at raising RV stroke volume by doing what?
- optimizing preload
- decrease afterload
- RV contractility
- RVAD
- venoarterial extracorporeal support
140
should fluid loading be used to treat shock d/t RVMI?
no, and it may even depress CO thru ventricular interdependence
141
should MV w/ PEEP be used to treat shock d/t RVMI?
no, as it tends to increase RV afterload, which depresses SV, and may exacerbate shock
142
type 1 MI
spontaneous MI
143
type 2 MI
MI 2/2 ischemic imbalance
144
type 3 MI
MI resulting in death w/o biomarkers
145
type 4a MI
MI related to PCI
146
type 4b MI
MI related to stent thrombosis
147
type 5 MI
MI related to CABG
148
In a patient who has unexplained dyspnea, what conditions are you looking for when doing a RHC?
- RV dysfunction
- biventricular dysfunction
- congenital heart disease
- pulmonary arterial HTN
- pericardial disease
- intracardiac shunting
149
absolute CIs to RHC
- mechanical TV
- RVAD
150
relative CIs to RHC
- coagulopathy
- arrhythmias
- LBBB
151
unusual pattern of ST elevation in leads v1 and v2
Brugada syndrome
152
increased r/o
- syncope
- cardiac arrest
- sudden death
often occurs during sleep, rest, or enhanced vagal tone
Brugada syndrome
153
channelopathy w/ loss of function of cardiac sodium channels
Brugada syndrome
154
syndrome of polymorphic VT a/w prolonged QT
torsades de pointes
155
first-line tx for torsades de pointes
magnesium 1-2 g IV or IO diluted in 10 mL of fluid over 5-20 minutes
156
AE if magnesium sulfate is administered too rapidly
hypotension
157
electrolyte d/o's that can contribute to prolonged QT and TdP
- hypokalemia
- hypomagnesemia
158
medications a/w long QT syndrome and TdP (12 items listed)
- methadone
- procainamide
- quinidine
- sotalol
- amiodarone
- haloperidol
- erythromycin
- levofloxacin
- trimethoprim-sulfamethoxazole
- azole antifungals
- vasopressin
- tacrolimus
159
other risk factors for TdP besides electrolyte d/o's and medications
- bradycardia
- liver dysfunction
- renal dysfunction
- heart disease
- recent AF
160
genetic d/o characterized by myofibril disarray, fibrosis, and myocardial hypertrophy
hypertrophic cardiomyopathy (HCM)
161
HCM patients are prone to dynamic outflow tract obstruction in the following settings
- decreased preload
- decreased afterload
- increased contractility
162
the best way to increase BP in HCM w/ outflow tract obstruction is to ensure the following
- adequate volume repletion
- selective alpha agonist, such as phenylephrine
163
which medications can increase outflow tract obstruction and decrease BP?
- epinephrine
- norepinephrine
- dobutamine
- dopamine
164
which medical therapy is counterproductive and inappropriate in patients w/ CHF d/t HCM?
diuresis
165
what factors commonly affect recirculation in VV-ECMO?
- cannula configuration
- cannula positioning
- pump speed
- ECMO blood flow rate
- direction of ECMO blood flow
- changes in intrathoracic pressure
- changes in intracardiac pressure
- changes in intraabdominal pressure
166
what will increasing pump speed or ECMO blood flow rates lead to in a patient on VV-ECMO w/ recirculation?
worsen recirculation
167
besides recirculation, persistent hypoxemia on VV-ECMO can be d/t
- small cannula size limiting ECMO blood flow rate
- patient positioning
- low ratio of ECMO flow to native CO (worse in septic patients)
- metabolic rate/O2 consumption
- malfunctioning components of the circuit (eg oxygenator)
168
VA-ECMO is used in which patients?
hemodynamic instability from LV or RV cardiogenic shock
169
dopamine is a/w increased risk of what compared to norepinephrine?
tachyarrhythmias
170
most important thing to do when removing a central venous catheter
placing the patient in a Trendelenburg or flat position
171
what are the deleterious consequences of LV not ejecting blood while on ECMO?
- stasis in LVOT and proximal aorta which leads to risk of thrombosis and systemic embolism
- LV continues to fill through the pulmonary and Thebesian veins which raises LV and pulmonary vascular pressure
172
what happens when the LV is overdistended in a patient w/ cardiogenic shock on VA-ECMO?
- pulmonary edema
- delay in LV recovery
173
treatment to decompress LV in cardiogenic shock on VA-ECMO
- inotropes
- intraaortic balloon counterpulsation (to reduce LV afterload)
- reducing ECMO pump speed (which lowers LV afterload)
- placement of LVAD
- transvenous or transseptal cannula drainage
- maintaining PEEP (reduces afterload)
174
what happens to LV afterload when you increase PEEP?
decreases
- increasing PEEP raises intrathoracic pressure
- decreases venous return to right heart
- overdistention of lungs can increase PVR --> RV failure --> decrease LV preload
175
underdamping (SBP is overestimated and DBP is underestimated) can be caused by
- excessively long tubing
- tubing that's too elastic
- excessive pressure bag inflation
- too many stopcocks
176
overdamping (SBP is underestimated and DBP is overestimated) occurs when the pressure waveform is flattened, can be caused by
- air bubbles in tubing
- clot in the catheter
- kinked tubing
- tubing that's too stiff
- tubing that's too short
- a catheter positioned against a blood vessel wall
- inadequate volume in pressure bag
177
how many oscillations are optimal after the end of a square wave test?
1-2
178
how many oscillations at the end of a square wave test represent overdamping?
no oscillations (response speed is too slow)
179
how many oscillations at the end of a square wave test represent underdamping?
> 2
180
LCx supplies
LA and LV
181
RCA supplies
RA and RV
182
LAD supplies
RV, LV, and interventricular septum
183
classic physical findings of RV infarction
- hypotension
- JVD
- clear lung fields
184
hypotension in patients w/ RV infarction results from what?
failure of dysfunctional RV to deliver adequate preload to the LV
185
what medications should be avoided in patients w/ RV infarction?
medications that decrease preload (eg nitrates, diuretics, morphine)
186
besides murmur, what are the findings of severe MR?
- pulmonary edema
- crackles on lung exam
- hypoxemia
187
heart block early after acute IWMI is usually d/t
ischemia in the AV node
188
when does heart block from acute IWMI usually resolve?
w/i 5 to 7 days
189
which therapy in CHF patients w/ LBBB has been shown to improve LV systolic performance, decrease MR, reduce LV remodeling, improve symptoms, and improve mortality?
resynchronization w/ biventricular implantable cardiac defibrillator (ICD)
190
guidelines recommend insertion of biventricular ICD in which patients?
EF < 35% and LBBB w/ QRS > 120 ms (optimally > 150 ms) who are symptomatic on guideline-directed medical therapy for HF
191
which coronary artery lies in close proximity to the mitral annulus and can be injured by suturing, distortion of the artery, coronary laceration, subintimal hematoma, or coronary embolization during MV repair?
left circumflex coronary artery (aka circumflex coronary artery)
192
when should an implantable defibrillator be placed for primary prevention after MI after revascularization if EF is < 40% on optimal medical therapy?
after 90 days to allow for potential ventricular recovery
193
mPAP equation
mPAP = mean pulmonary arterial pressure
2/3rd PADP + 1/3rd PASP
PADP = end-expiratory PA diastolic pressure
PASD = end-expiratory PA systolic pressure
194
hemopericardium in the setting of acute STEMI should suggest 1 of 2 diagnoses
- Stanford type A (proximal) aortic dissection into the right coronary cusp w/ subsequent pericardial dissection
- ventricular free-wall rupture
195
is TEE sensitive for proximal, type A, aortic dissection?
yes, very
196
how much fluid bolus do patients w/ hypotension and tamponade physiology need if they are fluid responders?
250-500 mL
197
what should you think of and look for in a patient that had VF cardiac arrest, or has sinus bradycardia with no backup rate initiated in a patient w/ an AICD?
- failed AICD
- fracture of the AICD lead which can be seen on cxr
198
treatment for acute severe MR c/b cardiogenic shock 2/2 acute papillary muscle rupture 2/2 recent STEMI until surgical MVR
IABP insertion
199
- acute pulmonary edema
- acute hypoxemic respiratory failure
- cardiogenic shock
- occurs 2-7 days after STEMI
severe acute MR from acute papillary muscle rupture
200
management of acute papillary muscle rupture causing acute MR is aimed at what in order to direct blood flow across the aortic valve, which reduces MR, increases CO, and decreases pulmonary venous congestion?
reducing LV afterload
201
infusion of vasodilators, such as nitroglycerin, nicardipine, or nitroprusside, to reduce afterload are limited by what?
systemic hypotension
202
mitral valve transcatheter edge-to-edge repair to clip anterior and posterior leaflets of the MV is indicated in which patients?
- chronic primary MR w/ severe symptoms w/ high surgical risk
- chronic secondary (functional) MR
203
the definition of "electrical storm" varies, but in general the common definitions are
- patients w/ an implantable cardiac defibrillator vs those w/o
- recurrence of ventricular arrhythmias requiring treatment w/i a short period of time, usually > 2-3x w/i 24 hours
204
what are the fundamental principles in treating electrical storm?
- controlling the acute arrhythmia
- addressing the underlying problem
- managing the high sympathetic tone
- rarely, urgent ablation may be attempted
205
what are the usual antiarrhythmic therapies for sustained monomorphic VT?
- amiodarone
- dofetilide
- lidocaine
206
management for high catecholamine state observed in electrical storm (better than metoprolol)
propranolol
207
recommended medication for electrical storm in patients w/ Brugada syndrome
isoproterenol
208
what factors affect O2 delivery in patients on ECMO?
- integrity of ECMO circuit
- RV function
- oxygenation by the lungs
- O2-carrying capacity
209
O2 delivery capability in patients on ECMO is determined by what?
- blood flow
- Hb concentration
- inlet Hb saturation
- membrane lung properties
210
DO2 (rate of O2 delivery (mL/min)) formula
CO x (1.39 x [Hb] x SaO2 + (0.003 x PaO2))
CO = cardiac output (L/min)
1.39 = O2 binding capacity of Hb (1.39 mL/g)
SaO2 = Hb O2 saturation expressed as a decimal
0.003 = amount of dissolved O2 in the blood (mL)
211
ECMO promotes lung rest by
- minimizing shear stress and dynamic strain related to volutrauma (via low TV ventilation)
- minimizing static strain and barotrauma (through the lowest PEEP necessary to reach critical opening pressure of the alveoli)
212
a "spontaneous" wedge waveform indicates what?
incorrectly positioned catheter
213
incorrect positioning of a pulmonary catheter can lead to what complications?
- pulmonary infarction
- pulmonary artery rupture
214
what techniques can help predict volume responsiveness?
- TTE to estimate EF and/or SV
- change in IVC diameter
- pulse pressure variability
- SV variability
- SV index (SVI)
215
how can SV be measured?
- TTE
- flow analysis at the aortic root via Doppler US
- chest wall electrical bioimpedance
- flow-directed pulmonary artery catheter
- arterial pulse contour analysis
216
when techniques to predict volume responsiveness are combined w/ what, demonstrate high sensitivity and specificity?
passive leg raise maneuver or a 4 mL/kg fluid bolus
217
variation in IVC diameter w/ inspiration is evaluated w/ US and is dependent on what factors?
- CVP
- intrapleural pressure
- intraabdominal pressure
- IVC distensibility (compliance)
218
what is the formula for IVC diameter variation to predict volume responsiveness?
(Dmax - Dmin) / Dmin
D = measured IVC diameter
219
what % change in IVC diameter predicts volume responsiveness?
> 18%
220
what 2 variables are required when evaluating for volume responsiveness based on IVC diameter variation?
- MV w/ > 8 mL/kg TV
- passive variation
221
how should a very high BMI be taken into consideration in regards to IVC diameter variation and volume responsiveness?
increased abdominal pressure could alter changes in IVC diameter
222
do arrhythmias alter the respiratory changes in IVC diameter?
no
223
what is a surrogate for SV variability that occurs w/ positive pressure ventilation?
pulse pressure variability
224
reproducibility in SV variability and pulse pressure variability requires what conditions to ensure adequate intrapleural pressure swings to alter venous return?
- TV of 10 mL/kg
- absence of arrhythmia, especially AF
225
what is the most frequent cause of pregnancy-related MI?
pregnancy-associated spontaneous coronary artery dissection (SCAD)
226
preferred initial treatment for pregnancy-associated spontaneous coronary artery dissection (SCAD) if hemodynamically stable and no signs of ongoing ischemia?
conservative medical management w/ aspirin and nitroglycerin
227
which patients w/ pregnancy-associated spontaneous coronary artery dissection (SCAD) should be considered for PCI?
- p/w ongoing or recurrent ischemia
- hemodynamic instability
- ventricular arrhythmias
- suitable coronary anatomy
228
which patients w/ pregnancy-associated spontaneous coronary artery dissection (SCAD) should be considered for emergency CABG?
- patients w/ left main dissections
- extensive dissections involving proximal arteries
- PCI failed
- not anatomically suitable for PCI
229
what is the only variable programmed by the operator in an LVAD (Heartmate 2)?
pump SPEED (rpm)
230
which setting on an LVAD is a direct measurement of the number of watts required by the device to pump blood at the set rpm?
pump POWER
231
what setting on the LVAD is a calculated number based on measured pump power and set pump speed?
FLOW
232
the actual blood flow through the LVAD pump is dependent on what factors?
- pump SPEED
- preload
- pressure differential between mean aortic pressure and LV chamber pressure
233
what happens to LVAD pump POWER when LV pump thrombosis occurs?
increases in response to increased resistance to flow w/i the device
234
what happens to flow if LVAD pump thrombosis is sufficiently severe?
can decrease
235
what happens to the LVAD in RV failure?
LVAD output might decrease because of decreased preload
236
the following indicate what issue?
- HF symptoms
- increased pump POWER
- low output LVAD alarms
- LV dilation
- aortic valve opening
- dark urine
- increased LDH
LVAD pump thrombosis
237
management of LVAD pump thrombosis in a hemodynamically stable patient
- fluid resuscitation
- heparin gtt
- +/- glycoprotein 2b/3a inhibitor
- +/- thrombolytic agent
238
when would LVAD pump thrombosis be managed w/ LVAD pump exchange?
- hemodynamically unstable patients
- failed medical therapy
239
- mechanical complication following acute MI
- usually occurs 2 to 7 days after
- pulmonary edema
- hypotension
- cardiogenic shock
- V waves in PCWP tracing (increased LA diastolic pressure)
papillary muscle rupture
240
- mechanical complication following acute MI
- pulmonary edema
- shock
- left-to-right shunt which increases pulmonary artery saturation
ventricular septal rupture
241
- mechanical complication following acute MI
- a/w elevation and equalization of right-sided and left-sided diastolic pressure w/o a V wave
free-wall rupture w/ tamponade
242
management of papillary muscle rupture
- vasoactive support
- afterload reduction if feasible
- mechanical circulatory support as a temporizing measure
- definitive therapy = surgical valve repair or replacement
243
what percentage of patients suffering inhospital cardiac arrest survive to hospital discharge?
25%
244
what are the essential components to achieve best components from inhospital cardiac arrest?
- early recognition
- highest quality BLS
- optimal ACLS
- optimal postcardiac arrest care (TTM)
