Cardiogenic Shock

Cardiogenic Shock
Types of Shock
 Distributive/Septic Shock: variable cardiac output,
decreased SVR
 Hypovolemic Shock: decreased effective circulating
 Obstructive Shock: circulatory failure caused by
physical obstruction, e.g. cardiac tamponade or
pulmonary embolism
 Cardiogenic Shock: decreased cardiac output, pump
Definition of Cardiogenic Shock
Inadequate tissue perfusion resulting from cardiac
Clinical definition: decreased CO and tissue hypoxia in
the presence of adequate intravascular volume
Hemodynamic definition: Sustained SBP<90 mm Hg, CI
<2.2 L/min/m2, PCWP > 15 mm Hg
Subset of severe LV failure patients who have nonhypotensive cardiogenic shock: peripheral
hypoperfusion with preserved BP
Definition of Cardiogenic Shock
SBP < 90 mm Hg for at least 1 hour that is not
responsive to fluid administration alone
Secondary to cardiac dysfunction
Associated with signs of hypoperfusion or a CI <
2.2 L/min/m2 and a PAWP > 15 mmg Hg
Pathophysiology of CS: Downward Spiral
How to identify Cardiogenic Shock
 History
 Physical Exam
 Chest xray
 Echocardiogram
 Swan-Ganz Catheter
History: Who gets Cardiogenic Shock?
• Acute MI
Pump failure
Mechanical complications: VSD, Papillary septal rupture, free wall
rupture and cardiac tamponade
Right ventricular infarction
• Other conditions
End-stage cardiomyopathy
Myocardial contusion
Prolonged cardiopulmonary bypass
Septic shock with myocardial depression
Valvular disease: AS, AR, MS, MR
History: Who gets Cardiogenic Shock?
Physical Exam: Hemodynamic Profiles
in Heart Failure
Congestion at Rest
at Rest
Warm & Dry
Warm & Wet
Cold & Dry
Cold & Wet
Signs of congestion
Evidence of low perfusion
 Narrow pulse pressure
 Altered mental status
 Low serum sodium
 Cool extremities
 Hypotension with ACE inhibitor
 Renal insufficiency
Stevenson LW. Eur J Heart Fail. 1999;1:251
Rales (not always)
Physical Exam
  CO
Cold extremities, distant pulses, acidosis, SvO2. Try to
figure out whether a decrease in CO is due to hypovolemia or
due to pump failure.
Pump Failure
Distended neck veins, S3, cold extremities
 Preload (CVP)
Flat or absent neck veins, tachycardia.
 Preload (CVP)
 jugular vein distention, enlarged veins elsewhere
BP and mental state may be NORMAL.
Findings: Cold extremities, distant pulses
Hypotension is likely. Patient may be warm with full pulses
if CO is normal or elevated.
Other valuable studies:
 Spot Echo exam of the heart: addresses tamponade, CHF, ischemia,
 O2 saturation from CVP line or PICC line: provides indirect but meaningful
estimates of the adequacy of DO2, cardiac function.
 If STEMI, degree and severity of EKG should agree with severity
of clinical condition
 If ST elevations in precordial leads -> likely anterior MI -> LV
pump failure is likely cause
 If inferior STEMI -> need marked ST elevations with reciprocal
ST depressions on EKG. Check RV leads. If no reciprocal
changes or RV infarct, think mechanical problems such as
papillary muscle rupture
 Normal EKG (especially with arrhythmias): think myocarditis
• Overall and regional systolic function
• Mechanical causes of shock
• Papillary muscle rupture
• Acute VSD
• Free wall rupture
Degree of mitral regurgitation
Right ventricular infarction
Other causes of shock (tamponade, PE, valvular
Right Heart Catheterization
 If no right heart catheterization is performed:
PE, CXR and TTE must clearly demonstrate systemic
hypoperfusion, low CO and elevation of LA
pressure/PA pressure /RA pressure
 If the above is not clear, perform right heart
Right Heart Catheterization
• Exclude volume depletion, RV infarction,
mechanical complications
• Optimize therapy
• CO to guide use of inotropic agents
Filling pressures to guide use of vasopressors and
Titration to minimum dosage required to achieve
therapeutic goals and minimize increases in oxygen
demand and arrhythmogenic potential
 ACC Guidelines
 Vasopressors and Inotropes
 Diuretics
 Cardiac Catheterization
 Intra-aortic balloon pumps (IABPs)
 Left Ventricular Assist Devices (LVADs)
Therapy/Treatment: ACC Guidelines
Class I
1. Intra-aortic balloon counterpulsation is recommended for STEMI
patients when cardiogenic shock is not quickly reversed with
pharmacological therapy. The IABP is a stabilizing measure for
angiography and prompt revascularization. (Level of Evidence: B)
Intra-arterial monitoring is recommended for the management of
STEMI patients with cardiogenic shock. (Level of Evidence: C)
Early revascularization, either PCI or CABG, is recommended for
patients less than 75 years old with ST elevation or LBBB who
develop shock within 36 hours of MI and who are suitable for
revascularization that can be performed within 18 hours of shock
unless further support is futile because of the patient’s wishes or
contraindications/unsuitability for further invasive care. (Level of
Evidence: A)
Therapy/Treatment: ACC Guidelines
Fibrinolytic therapy should be administered to STEMI patients
with cardiogenic shock who are unsuitable for further invasive
care and do not have contraindications to fibrinolysis. (Level of
Evidence: B)
Echocardiography should be used to evaluate mechanical
complications unless these are assessed by invasive measures.
(Level of Evidence: C)
Vasopressors and Inotropes
 Goal: optimize perfusion while minimizing toxicity
 Close monitoring of mixed venous saturation
 Invasive hemodynamic monitoring (arterial line, cardiac output
monitoring) to guide therapy
 Inotropes: shift Frank-starling curve to a higher plateau (increased
 Low output syndrome without shock: start with an inotrope such as
 Low output syndrome with shock: start with dopamine or
Vasopressors and Inotropes
Vasopressors and Inotropes
 Dobutamine: B1 and B2, inotropic but also causes
peripheral vasodilation
Good for non-hypotensive cardiogenic shock
Start with 5 ug/kg/min, don’t go higher than 20 ug/kg/min
 Dopamine: inotrope and vasopressor in hypotensive
cardiogenic shock
Up to 3 ug/kg/min – vasodilation and increase blood flow to
tissue beds, but no good evidence for “renal-dose dopamine”
Start at 5 ug/kg/min up to 15 ug/kg/min. Good inotropic and
chronotropic effect at doses between 3 and 10 ug/kg/min (B1)
Mild peripheral vasoconstriction beyond 10 ug/kg/min (A1)
Vasopressors and Inotropes
 Norepinephrine: primarily vasoconstrictor, mild
Increases SBP/DBP and pulse pressure
Increases coronary flow
Start 0.01 to 3 ug/kg/min
Good for severe shock with profound hypotension
 Epinephrine: B1/2 effects at low doses, A1 effects at
higher doses
Increases coronary blood flow (increases time in diastole)
Prolonged exposure -> myocyte damage
Vasopressors and Inotropes
 Milrinone: phosphodiesterase inhibitor, decreases
rate of intracellcular cAMP degradation -> increases
cytosolic calcium
Increases cardiac contractility at expense of increase
myocardial oxygen consumption
More vasodilation than dobutamine
Can be combined with dobutamine to increases inotropy
Start bolus 25 ug/kg (if pt is not hypotensive) over 10-20 min
then 0.25-0.75 ug/kg/min
May be proarrythmic, questionable in setting of acute MI
Vasopressors and Inotropes
 Vasopressin: causes vasoconstriction,
glyconeogenesis, platelet aggregation and ACTH
Neutral or depressant effect on cardiac output
Dose-dependent increase in PVR with resultant increase in
reflexive vagal tone
Increases vascular sensitivity to norepinephrine
Good for norepinephrine-resistant shock
 Mainstay of therapy to treat pulmonary edema and
augment urine output
 No good data regarding optimal diuretic protocol or
whether diuretics improve outcome in renal failure
 Lower doses of lasix are needed to maintain urine
output when continuous infusions are used
Start at 5 mg/hr, can increase up to 20 mg/hr
Cardiac Catheterization in Cardiogenic Shock
 ACC Guidelines: emergent coronary
revascularization is the standard of care for CS due
to pump failure (acute MI and shock)
 Most often demonstrates multi-vessel disease:
Left main disease 23%
3-vessel disease 64%
2-vessel disease 22%
1-vessel disease 14%
 Compensatory hyperkinesis: favorable prognostic
Intra-Aortic Balloon Counterpulsation
Arterial Pressure
SMH #619 2008
Intra-Aortic Balloon Counterpulsation
 Reduces afterload and augments diastolic perfusion
 Beneficial effects occur without increase in oxygen demand
 No improvement in blood flow distal to critical coronary
 No improvement in survival when used alone
 May be essential support mechanism to allow for definitive
Left ventricular assist devices
 Standard
 Percutaneous
Tandem Heart
Complete support
Transseptal puncture
Need good RV function
Complete support
Easy to insert
Also need good RV function
Left Ventricular Assist Devices (LVADs)
Components of the Left Ventricular Assist Device.
The inflow cannula is inserted into the apex of the
left ventricle, and the outflow cannula is
anastomosed to the ascending aorta. Blood returns
from the lungs to the left side of the heart and exits
through the left ventricular apex and across an
inflow valve into the prosthetic pumping chamber.
Blood is then actively pumped through an outflow
valve into the ascending aorta. The pumping
chamber is placed within the abdominal wall or
peritoneal cavity. A percutaneous drive line carries
the electrical cable and air vent to the battery packs
(only the pack on the right side is shown) and
electronic controls, which are worn on a shoulder
holster and belt, respectively.
Tandem Heart™
 Continuous flow
 Removes oxygenated
blood from LA via transseptal catheter placed
through femoral vein
 Returns blood via femoral
 Shown to
↓ LAP and PCWP
 ↓ MVO2
 ↑ MAP, CO
 Continuous flow
 Inserted into LV
through AV
 Blood returns to
descending aorta
 Not yet approved in
Outcomes in Cardiogenic Shock
 In-hospital mortality rate: 50-60% for all age groups
 Mechanical complications: even higher rates of
Ventricular septal rupture -> highest mortality (87% in
SHOCK Registry)
 RV infarction: SHOCK – mortality unexpectedly
high, similar to LV failure shock despite younger age,
lower rate of anterior MI and higher prevalence of
single vessel disease
 In hospital survival of diabetic patients in SHOCK
was only marginally lower than non-diabetic patients

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