Cardio - Cardiogenic Shock

Question 1

Define Cardiogenic Shock

Answer 1

Evidence of tissue hypoperfusion Secondary to…Primary Cardiac Failure….After correction of preload(Extreme end of decompensated failure)

Question 2

How would you diagnose cardiogeneic shock

Answer 2

SBP <90mmHg or a decrease in MAP by >30mmHg
HR > 60
Oliguria
With/without evidence of congestion

Question 3

Pathophysiology of heart failure

Answer 3

Can by DIASTOLIC or SYSTOLIC
Diastolic —> impaired function —> Rising LVEDP —> pulmonary congestion —> Hypoxia —> ishaemia
Systolic —> Low CO and SV —>. Hypotension —> low coronary perfusion —> Ischaemia —> low systemic perfusion —> Compensatory vasoconstrict + fluid retention

COMMON FINAL PATH IS ISCHAEMIA AND VASOCONSTRICTION —> Progessive myocardial DYSFUNCTION

Question 4

Causes of heart failure?

Answer 4

ACS
Arrythmias
Valves: regurg (chordae rupture, endocarditis)
Decompensated aoritc stenosis
Tampanade - Trauma, surgery, aortic dissection, effusion/pericarditis
High output failure —> anaemia, thyroid storm
Viral - Coxsackie/Adenovirus. —> MYOCARDITIS
Decompensated causes —> Hypertensive disease —> disastolic heart failure
Dilated cardiomyopathy —> Alcohol, Drugs (coke), Peripartum Restrictive —> infiltartion, sarcoid, amyloid etc Congenital HOCM

Question 5

Presentation of cardiogenic shock

Answer 5

CVS Cool peripheries Prolonged CRT Tachy or brady Arrythmias High if SVR raised, Low if decompensated Myocardial ischaemia RVF - oedema, raised JVP, RUQ pain
Resp - tachypnoea, hypoxaemia, pulmonary oedema
Neuro - low GCS/mental state
Renal - oliguria

Question 6

Approach to treating cardiogenic shock

Answer 6

Reduce myocardial demand AND improve myocardial oxygen delivery
DEMAND: — reduce HR or reduce after load (vasodilators/diueretics, sedation, beta blockers??)
DELIVERY: — Improve myocardial perfusion (Vasodilators, Inotropes (may increased consumption)
Increase O2 carriage —> FiO2, blood transfusion

Question 7

Management of Acute HF

Answer 7

ABCDEA / B - 100% intuabate, NIV if needed
C - iv access and bloods 250mls fluid bolus, warm, cautious Echo/CVPIntoropic options

Question 8

What investigations

Answer 8

Bloods: FBC, U&E, LFT, TFT, Troponins, BNP, clottingMicro: viral serology, culturesCardiac - Echo, 12 lead ECGRadiology - CXR

Question 9

Inotropic Options| Vasodilator options

Answer 9

Goals is to reduce demand (afterload) and improve delivery
Use of INOTROPES, VASODILATORS, VASOPRESSORS AND MECHANICAL
Adrenaline —> low dose —> b1/2 - tachy, inotropic, dilation High dose —> a1, constrictionDobutamine —> B1, tachy with inotropy, and dilation (consider norad to offset) B2 (some, dlation)
VASODILATORS
PDE3 inhib - Milrinone/enoximone —> increased cAMP, lower PVR/SVR, inotrope and lusitrope)
good in diastolic failure
GTN - NO donor - VENOdilation
VASOPRESSORS Vasopressin V1 - vasoconstriction V2, water retention Norad a1Levosimendin
IABP/VAD

Question 10

How does levosimendin work

Answer 10

Sensitises troponin C to calcium —> inotropy
Opens K(atp) channels, increases perfusion, reduce preload and afterload
INCREASES CONTRACTILITY WITHOUT INCREASING DEMAND

Question 11

How does the IABP work

Answer 11

Works on a principle of Countercurrent pulsation
Goal is to improve oxygen delivery whilst reducing oxygen demand
Inserted into femoral artery
Balloon is distal to the left subclavian artery
Helium pushed into balloon in diastole —> augments diastolic BP —> improves perfusion to coronary
Deflates in systole —> reduces afterload.

Question 12

Describe how the pump inflates and deflates in terms of timing in IABP

Answer 12

Either ECG, or via the invasive BP trace.
ECG: BP
Inflation - middle T wave dicrotic notch
Deflation - peak of R wave just before systolic upstroke

Question 13

Contra-indications to IABP

Answer 13

1) aoritic regurg
2) 2) aortic dissection
3) 3) severe PVD

Relative Arterial tortuousity LV outflow obstruction Sepsis
Can’t be anticoagulated - coagupathic or HIT

Question 14

Complications of an IABP

Answer 14

Vascular: Failure Bleeding Pseudoaneurysm Perforation
Balloon: Mesenteric/renal ischaemia (balloon position) Left upper limb and cerebral iscahemia (position too high) Helium embolus Haemolysis Thrombocytopenia

Question 15

What is a VAD

Answer 15

Surgical placed Mechanical device
Supports Left (LVAD), Right (RVAD) or both (BiVAD) ventricles
BiVAD is uncommon as RHF usually due to LV failure and will therefore improve
Reduce myocaridal work —> ventricles rest rest there is forward flow and perfusion
Impella - Centrifugal flow
Used as a bridge gto recovery instead of VA ecmo in heart failure bridge to transplant long term heart failure

Question 16

Complications of a VAD

Answer 16

Bleeding post insertion
Product transusions
Re-exploration
Cardiac tampanade
Decreased VAD flow, increased CVP, reduced MAP, rising inotropes
Immediate decompression
Haemodynamic disturbance, specially if hypovolaemic
RV failure RV dilates, high atrial pressures (20mmHg), reduced contractiliy
Tricuspid regurg
Fluid overload
Infection
Intra-cardiac thrombosis due to decreased VAD flows

Question 17

Describe how you would perform transcutaneous pacing?

Answer 17

place pads in AP position (black on anterior chest, red on posterior chest)
connect ECG leads
set pacemaker to demand
turn pacing rate to > 30bpm above patients intrinsic rhythm
set mA to 70
start pacing and increase mA until pacing rate captured on monitor
if pacing rate not captured at a current of 120-130mA -> resite electrodes and repeat the above.
once pacing captured, set current at 5-10mA above threshold