1
Cures For A Broken Heart

• Cardiogenic Shock, IABP, Vasopressors, Inotropes
  Cardiologists
• Daniel Orr

2
The Problem

• Definition
• Decreased cardiac output and evidence of tissue
  hypoxia in the presence of adequate intravascular
  volume.
• Clinically
• Cool, mottled extremities, poor capillary return
• Clouded sensorium
• Hypotension
• Oliguria
• Pulmonary Congestion
• Exclusion of other causes

3
The Problem

• Definition
• Haemodynamic criteria
• SBP lt90mmHg gt30min
• CI lt2.2L/min m2
• PCWP gt15mmHg

4
The Problem

• Incidence
• Range 5 10 patients presenting with AMI
• Does not account for out of hospital arrests/death

5
The Trigger

• Cause Epidemiology
• Myocardial Infarct
• Majority of cases Pump failure
• Include right ventricular infarct
• Mechanical Events
• Acute MR
• Rupture IVS or free wall
• Myocardial Dysfunction
• Myocarditis, Cardiomyopathy, Septic Shock,
  Prolonged CPB

6
Risk Factors Evolution

• Shock
• More likely in those with anterior and previous
  infarct, old, the diabetic, PVD, CVA
• Time Course
• Of those reaching hospital minority of patients
  in shock 10
• 7 hours typical delay between infarct and
  symptomatic shock

7
The Breakdown

• Pathophysiology
• Described as a downward spiral of events of
  compounding events
• Key Elements
• Primary Pump Failure
• Sympathetic Nervous System Activation

8
The Breakdown

• Pathophysiology
• Pump Failure
• Both systolic diastolic components
• Systolic
• Reduction in stroke volume, therefore cardiac
  output
• Remainder of myocardium hypercontractile,
  increasing O2 consumption
• Significant dependence on coronary flow,
  potentially already compromised by disease
• All worsen ischaemia

9
The Breakdown

• Pathophysiology
• Pump Failure
• Diastolic
• Perfusion reduced by hypotension and SNS induced
  tachycardia
• Increased EDP additionally reduces perfusion
• Increased wall stress increases O2 consumption
• All worsen ischaemia

10
The Fallout

• Pathophysiology
• Sympathetic Activation
• Attempt to maintain organ perfusion
• Results
• Tachycardia
• Increased circulating catecholamines
• Activation of RAA system
• Consequences
• Increased myocardial O2 demand via HR,
  contractility, afterload
• Increased preload via RAA
• Worsening ischaemia Pulmonary consequences

11
The Fallout

• Pathophysiology
• Tissue Hypoxia
• Results in increased products of anaerobic
  metabolism including lactate, and a decrease in
  pH
• Worsens myocardial performance
• The Latest
• Systemic inflammatory response
• Cytokines, interleukins, inducible NO synthase
• Consequences for genesis, treatment outcome

12
Assessing The Damage

• Symptoms Signs
• Emergency - Time is muscle (or Tissue)
• Signs of inadequate tissue perfusion
• CVS including elevated JVP, pulmonary oedema,
  extra heart sounds, murmur, arrhythmia
• Echo - wall motion, papillary muscle, valvular
  function
• Invasive monitoring

13
Damage Control

• Initial Management
• General Supportive
• Infarct
• Shock

14
Damage Control

• Initial Management
• General Supportive
• Correct hypoxia / acidosis
• Relieve pain
• Correct electrolytes

15
Damage Control

• Initial Management
• Infarct
• Aspirin
• Clopidogrel
• Heparin
• GPIIb/IIIa inhibitors
• NSTEMI

16
Damage Control

• Initial Management
• Infarct
• Thrombolysis / PTCA / CABG / VR
• Avoidance of agents with negative inotropic
  effects - beta blockers, calcium channel blockers

17
Damage Control

• Initial Management
• Shock
• Volume resuscitation, especially if cause is due
  to RV infarction
• Guided by Sats, MAP, CO, PCWP - aim for lowest
  value to give highest CO. Often 18-25mmHg
• Pulmonary oedema
• Diuretics
• Vasodilators

18
Invasive monitoring

• All modalities should be considered
• Arterial line - almost universal
• Central line - required for administration of
  inotropes
• PA catheter / PiCCO
• Refractory hypotension
• Mechanical complications cause
• Vasopressor / Inotropic agents

19
Putting The Squeeze On

• Vasopressors Inotropes
• Vasopressors
• Agents that produce vasoconstriction
• Mostly sympathomimetics, catechol and
  non-catecholamines
• Directly acting agents
• Inotropes
• Agents that increase myocardial contractility
• Sympathomimetics
• Phosphodiesterase inhibitors
• Others

20
Putting The Squeeze On

• First Line
• Dopamine
• Noradrenaline
• Second Line
• Dobutamine
• Milrinone

21
Putting The Squeeze On

• First Line
• Dopamine
• Naturally occuring sympathomimetic amine, with
  effects at a, ß, and DA receptors
• Low dose ß effects predominate, high does a
• Both vasoconstrictor and inotropic effects
• Increases PCWP
• Risk of arrhythmia (gtNA latest NEJM)
• Tachycardia, increased O2 demand

22
Putting The Squeeze On

• First Line
• Noradrenaline
• Potent naturally occurring sympathomimetic amine
  and neurotransmitter, with effects at a ß
  receptors
• Predominant a effects
• Tissue necrosis
• Risk of arrhythmia
• Adrenaline - substitute for Dopamine

23
Putting The Squeeze On

• First Line
• Considerations
• Vasopressors typically increase SVR, with limited
  direct effect on CO
• Increased SVR may worsen CO - consider invasive
  monitoring

24
Putting The Squeeze On

• Second Line
• Dobutamine
• Synthetic catecholamine, predominantly ß effects
• Increases inotropy and chronotropy, often of
  benefit in cardiac failure
• May worsen hypotension
• Risk of arrhythmia
• Can be combined with Dopamine

25
Putting The Squeeze On

• Second Line
• Milrinone
• Selective PDE III inhibitor inotropic agent
• Increases CO via increased cAMP
• Additionally has vascular vasodilating effects
• Risk of hypotension and arrhythmia
• No studies to demonstrate benefit

26
Party Time

• IABP other VADs
• Benefit of improving coronary perfusion and
  cardiac performance
• Reduce myocardial ischaemia cardiac work
• Do not alter SVR

27
Party Time

• IABP
• Description
• Intravascular counterpulsation device used to
  augment cardiac function
• Haemodynamic Effects
• Displacement of blood into proximal aortic
  territory during diastole
• Increases coronary cerebral blood flow
• Reduction in afterload 2o to vacuum effect
• Reduces cardiac work

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Party Time

• IABP
• Consequences
• Improved myocardial O2 supply and reduced O2
  demand
• Improvement in end organ function, reduction in
  acidosis
• In cardiogenic shock used as adjunct to
  definitive treatment. In isolation does not
  improve mortality

30
Party Time

• IABP
• Uses/Indications
• Cardiogenic shock
• Including AMI mechanical lesions eg MR
• Support post PTCA
• Weaning from CPB
• Refractory unstable angina / High risk restenosis
  PTCA or thrombolysis

31
Party Time

• IABP
• Contraindications
• Absolute
• Moderate Severe Aortic Regurgitation
• Dissecting Aortic Aneurysm
• Relative
• PVD
• AAA

32
Party Time

• IABP
• Complications
• Vascular
• Limb ischaemia
• Vascular laceration
• Major Haemorrhage
• Non-Vascular
• Embolization
• Balloon migration ischaemia cerebral, renal
• Sepsis
• Balloon rupture

33
Party Time

• IABP
• Complications
• Other
• Haemolysis
• Thrombocytopaenia
• Peripheral neuropathy
• Practical
• Anticoagulation
• Post CABG
• AMI

34
Party Time

• IABP
• Practical
• Triggering
• ECG
• Pacing
• Arterial pressure
• Monitoring
• Peak diastolic will be higher than systolic
  (augmented)
• Continue to use MAP on IBP to guide tropes

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Party Time

• IABP
• Practical
• Modes - 11, 12, 14
• Size does matter
• Differing volume of balloon for height
• Weaning
• Stable haemodynamics typically after 24-48/24
• Reduce inflation ratio, off after 2/24 at 14

37
Finding Solutions

• Definitive Treatment
• Thrombolysis
• Revascularization
• CABG / VR

38
Finding Solutions

• Definitive Treatment
• Thrombolysis
• Evidence suggests benefit over placebo in
  cardiogenic shock, improved survival
• Use in combination with IABP
• PTCA and CABG superior
• Consider in patients who are high risk, in areas
  without angiographic services

39
Finding Solutions

• Definitive Treatment
• Revascularization
• Mainstay of AMI induced cardiogenic shock
• Early intervention preferable
• Improvement in both infarct and remote myocardium
• Response may be variable, and not immediately
  apparent

40
Finding Solutions

• Definitive Treatment
• CABG / VR
• Benefit demonstrated inlimited capacity in
  trials
• Relatively low mortalityrate
• Significant logisticalchallenges
• Typically limited to thosewith mechanical
  causesof cardiogenic shock

41
Going Back For Seconds

• Why Treatment Works
• Stunning
• Hibernation

42
Moving On

• Outcomes
• High mortality
• Limited scope forrecovery