Agenda เอกราช อร ยะช ยพาณ ชย. - Cardiac physiology - Pathophysiology of shock - Pathophysiology of heart failure 9/6/2016

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1 6 September 2016 เอกราช อร ยะช ยพาณ ชย Heart Failure and Transplant Cardiology Agenda - Cardiac physiology - Pathophysiology of shock - Pathophysiology of heart failure 1

2 Cardiovascular system 1. What is the heart? 2. What is the function of the heart? 2

3 The cardiovascular system Cardiac output (CO) The blood flow thru the heart in 1 minute L/min Stroke volume x Heart rate Intrinsic heart mechanics properties Preload // Contractility // Afterload What is preload? 3

4 1 Preload

5 Frank-Startling Mechanism SV Preload Preload: Cellular level 5

6 Preload in clinical A load to the contractile unit before contraction A load = Molecular z-z line contractile protein Cellular myocardial cell length Heart Wall stress LV end diastolic pressure --- LVEDP LV end diastolic volume --- LV size RA pressure --- JVP Volume status What is afterload? 6

7 Afterload Afterload SV Afterload 7

8 Afterload in Clinical A load that the heart has to contract against o Systolic blood pressure o Systolic vascular resistant o vaso-constriction 8

9 What is shock? What is shock? The clinical syndrome from various causes that result in damages due to inadequate global tissue perfusion. Inadequate O2 delivery Usually have hypotension (MAP < 60 mmhg) Lead to a vicious cycle, due to Organ protective mechanism Cellular dysfunction functional and structural change. multiple organ failure and death. Adapt from harrison principles of internal medicine 18th edition 9

10 HYPOTENSION SHOCK Hypoperfusion: Cellular responses ATP depletion Aerobic to anaerobic Abnormal membrane function Cell dysfunction, swelling, death Inflammatory response Hematologic response 10

11 Hypoperfusion: Autonomic responses Sympathetic nervous system Baroreceptor, adrenal gland NE, epinephrine, dopamine, and cortisol release Vasoconstriction, HR, contractility, BP Renin-angiotensin-aldosterone system Water and Na absorption, vasoconstriction blood volume and BP ADH (vasopressin), cortisol, Multi organ dysfunction Renal failure Acute kidney injury Liver failure Ischemic hepatitis, shock liver DIC Respiratory distress or failure Cardiac depression 11

12 How many type of shock are there? 12

13 NEJM 2013 Type of shock Type of Shock Preload CO Afterload Cause Hypovolemic Cardiogenic Distributive Other type of shocks: Hypoadrenal, neurogenic, obstructive 13

14 Type of shock Type of Shock Preload CO Afterload Cause Hypovolemic Cardiogenic Distributive Other type of shocks: Hypoadrenal, neurogenic, obstructive Type of shock Type of Shock Preload CO Afterload Cause Hypovolemic Cardiogenic Distributive Blood or fluid loss (internal, external) Acute MI, acute HF Arrhythmia, cardiac tamponade pulmonary emboli Septic, anaphylaxis, inflammation, toxin Other type of shocks: hypoadrenal, neurogenic, obstructive 14

15 Type of shock JVP Central venous pressure Pulmonary capillary pressure Sign of hypovolumia Type of Shock Preload CO Afterload Cause Hypovolemic Cardiogenic Distributive Blood or fluid loss (internal, external) Warm vs. cold skin paleacute MI, acute HF Arrhythmia, Systemic vascular cardiac tamponade resistant pulmonary emboli Septic, anaphylaxis, inflammation, toxin Other type of shocks: hypoadrenal, neurogenic, obstructive S&S symptoms of hypoperfusion mental status Tachycardia BP urine cold skin Cr, Lactic acid. 15

16 Treatment Recognize shock Reverse the cause(s) In a timely fashion Support and prevent further end organ damage Restore perfusion ICU: Invasive monitor: Arterial line, foley cath, PA catheter (Swann-Ganz) Ventilation support: O2 support, Mechanical Ventilator/ Endotracheal tube Fluid resuscitation: Crystalloid > colloid. Cardiogenic shock Hemodynamic support: Inotrope, pressor, VAD Epinephrine Action Usual dose C 1 A 2 Note mcg/kg/min 1 mg iv bolus q 3 mins Norepinephrine mcg/kg/min Low dose = more. (like dobutamine) High dose = more. (like norepi) Use: ACLS, anaphylaxis, S/E: splanchnic vasoconstrict. Potent vasoconstriction. Moderate CO. HR effect (reflex bradycardia from increased MAP. Use: Septic shock. Dopamine Low Moderate High DA DA DA mcg/kg/min 2-10 mcg/kg/min mcg/kg/min Precursor to norepi but less, more effect. Dose-dependent effects. Dose is varied pt to pt. Use: Septic shock, 2 nd -line alternative to norepinephrine. Dobutamine 1 2 ( 1) 2-20 mcg/kg/min Milrinone PDE inh mcg/kg/min Isoproterenol mcg/min Phenylephrine mcg/kg/min 0 Not a vasopressor. Inotrope with a vasodilation. The net effect = CO + SVR, may not BP. Use: HF, cardiogenic. Similar to dobutamine more vasodilator, PA Use: HF, cardiogenic. Prominent chronotropic. Prominent vasodilation. Use: Bradycardia Pure vasoconstriction. May decrease SV. Vasopressin V unit/min 0 Pure vasoconstriction. Use: 2 nd -line in refractory vasodilatory shock.. S/E: coronary, mesenteric ischemia, skin necrosis. Na and pulm vasoconstriction 16

17 Sample A 55 yo M with hx of HTN, DM presents with crushing substernal CP, diaphoresis, hypotension, tachycardia and cool, clammy extremities An 81 yo F from a nursing home presents to the ED with altered mental status. She is febrile to 39.4, hypotensive with a widened pulse pressure, tachycardic, with warm extremities A 68 yo M with hx of HTN and DM presents to the ER with abrupt onset of diffuse abdominal pain with radiation to his low back. The pt is hypotensive, tachycardic, afebrile, with cool but dry skin N Engl J Med 2013; 369:

18 Cause of Hypovolemic Shock Non-hemorrhagic Vomiting Diarrhea Bowel obstruction, pancreatitis Burns Neglect, environmental (dehydration) Hemorrhagic GI bleed Trauma Massive hemoptysis AAA rupture Ectopic pregnancy, post-partum bleeding Cause of Septic shock Another lecture by it self Most common type of shock Hypoperfusion + infection + 2 SIRS (systemic inflammatory response syndrome) criteria S&S of hyperferfusion Temp > 38 or < 36 C HR > 90 RR > 20 WBC > 12,000 or < 4,000 Plus the presumed existence of infection 18

19 Sepsis Cardiogenic shock Hypoperfusion due to low cardiac output Low BP, high PCWP SBP < 90 mmhg CI < 2.2 L/m/m 2 PCWP > 18 mmhg 50% mortality rate 19

20 Pathophysiology Cardiac dysfunction Vicious cycle relaxation SV, Systemic flow contraction LVEDD, PCWP preload Pulmonary edema Hypoxia ischemia Coronary flow ischemia afterload Systemic hypopurfusion 20

21 Heart failure 21

22 Definition of HF 1. A syndrome caused by cardiac dysfunction 2. Leads to circulatory abnormalities and neurohormonal abnormality 3. Resulting in typical symptoms of Congestion Poor perfusion a. Common pathway from any causes b. Progressive, vicious cycle c. Systemic maladaptation 1 LVEDP dysfunction 2 Circulatory Abnormalities Neurohormonal abn. 3 Typical symptoms Dyspnea fatigue swelling 22

23 Cause of HF Circulation. 2013;128:e240-e327. Pathophysiology 23

24 24

25 J Am Coll Cardiol 2009;54:

26 Stage of HF S&S of HF Non specific, fatigue Dyspnea from increased breathing drive Reduction in exercise capacity (NYHA II-IV) Orthopnea, PND Edema, ascites, early satiety, N/V, confusion Apical shift, S3, S4, JVP, (+) HJ reflux, ascites, crepitation, edema 26

27 Treatment Self-care weight monitor, salt intake Diuretics to control symptoms Treatment To improve survival Betablocker ACE inhibitor or Angiotensin receptor blocker (ARB) Aldosterone blocker - spironolactone If channel inhibitor - Ivabradine Angiotensin receptor, neprilysin inhibitor(arni) Cardiac resynchronize therapy (special pacemaker) Implantable cardioverter Defibrillator End-stage HF Heart transplant Mechanical circulatory support Inotrope Palliative care - Valsartan/sacubitril 27

28 Circ Heart Fail.2008;1:63-71 Thank you 28

29 Back up slide Pressure volume Loop of the LV ESPVR (Ees) Ea A: MV close B: AV open C: AV close D: MV open Ees: end-systolic elastance (ESPVR: End systolic PV Relationship) EDPVR Ea: Arterial elastance EDPVR: End diastolic PV Relationship 29

30 Control flow Murphy E. O2 content Control volume Control pressure Investigation Lab: shock Cr, AST/ALT, WBC, acidosis Troponin ECG: MI: ST elevation, Q wave, TW inversion CXR: pulmonary edema Echocardiogram: function, etiology Pulmonary catheter (Swan-Ganz): DDx type of shock, intracardiac pressure, CO Coronary angiogram 30