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Flashcards in Shock and Acute Heart Failure Deck (33)
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1

Where does the sarcoplasmic reticulum interface with the sarcolemma membrane?

At T-tubule

2

What are L-type calcium channels involved in?

within T-tubule, open in resposne to membrane depolarization

3

The small inward calcium current activates what receptor on SR?

ryanodine receptor

4

What does activiation of ryanodine receptor activate?

trigger large amounts of calcium from SR, which binds to troponin C; leads to conformational change in the actin thin filament. Mosin binding sites are exposed and myocyte contraction occurs.

5

What occurs in diastole with calcium in cardiac contraction?

rapid reuptake of calcium and myosin binding ceases

6

What is the venous return curve?

Reflect circulatory volume, peripheral vascular resistance and venous and arterial compliance

7

What is the frank-starling relationship?

connects force and muscle fiber length; more bridge made to cycle, more contractile force will be generated, further stretch more bridge connections available

8

What are factors that influence cariac output?

hear rate and contractility and extrinsic(preload and afterload)

9

What is the equation for wall tension?

La Place: Wall stress=(pressure*radius)/wall thickness

10

What is a compensatory mechanism for chamber dilation?

ventricular hypertrophy

11

Elevated filling pressures impede what in failing hearts?

impede adequate cardiac output

12

What is inotropic drugs do?

used to stimulate contractility and increase dilation; ; stim icrease in intracellular calcium

13

What are the two types of inotropic drugs?

Beta agonists such as dobutamine, epinephrine and norepi

phosphodiesterase inhibitors which degrade cAMP; milrinone

14

What are techniques to measure hemodynamics?

swan-ganz catheter; based on fick principle

15

What is CO equal to as far as measuring oxygen consumption?

CO=O2 consumption/((arterial O2)-MVO2)

16

What are the symptoms of warm and wet heart failure?

increased weight, elevated JVD, peripheral edema, dyspnea/orthopnea/rales

17

What are the symptoms of cold and dry heart failure?

dry mucous membrane, tachy, hypotensions, cold extremities

18

What are the symptoms of cold and wet heart failure

most severe;
hypotension, tachy
cold extremities
elevated JVD
dyspnea/orthopnea

19

What is an echocardiogram?

used to determine LVEF; in heart falilure by doppler measurment of flow

20

What percentages ndicate the different levels of heart failure normally?

45-50 mild
35-44 moderate
less than 35 is severe

21

What is a swan-ganz catheter physically and where is it placed?

catheter with ballon that goes through right atrium, ventricle and into the pulmonary artery

measure PCWP directly

22

In what pts is swan-ganz catheter used

pts with refactory sxs or severe disease

23

What lab tests are often gotten for acute heart failure?

chest xray
basic metabolic panel
Nt-pro BNP
tropoonin level
ECG

24

What are treatments of acute heart failure?

loop diuretics-furosemide
IV admin is recommended as a bolus or continuous infusion
also thiazide diuretics

afterload reduction by nitroprusside, nitroglycerine, nesteride

inotropes

mechanical support

25

What are the stages of shock?

inital
compensatory
progressive
refactory

26

What are the signs of initial shock?

hypo-perfusion
tissue hypoxia
lactic acidosis

27

What are the signs of compensatory heart failure

cytokine relase, hyperventilation for CO2 removal, endogenous catecholamine release

28

What are progressive stage of shock

failing compensatory mechanisms, worsensing capillary leakage, metabolic acidosis, increased blood viscosity, microsludging, MODS

29

What is refactory stage of shock?

irreversible organ damagge, cell death degradation of ATP to adenosine

30

What is SIRS?

systemic inflammatory response syndrome
tachypnea
WBC90 minutes
Temp Fever or hypothermia