lecture 12: Cardiac failure

Question 1

What is heart failure?

Answer 1

occurs when the heart cannot supply sufficient blood to the vital organs of the body: results in Coronary Artery Disease, Hypertension, Dilated Cardiomyopathy.

Question 2

What is a Cardiac reserve?

Answer 2

Refers to the difference between cardiac output at rest vs. maximum capacity. Athletes have large cardiac reserve (5-6 times resting heart rate output). People with CHD do not have significant reserve volume. CHD is characterized by an inability to increase CO.

Question 3

what is the equation for cardiac output?

Answer 3

HR x SV

Question 4

what is ejection fraction?

Answer 4

the volume of blood pumped out by the ventricles with each heartbeat.

Question 5

name the two types of heart failure?

Answer 5

1. systolic ventricular dysfunction

2. diastolic ventricular dysfunction

Question 6

explain systolic ventricular dysfunction as a result of heart failure?

Answer 6

the Contractility is impaired so the ejection fraction is DECREASED so CO is decreased

Question 7

explain diastolic ventricular dysfunction as a result of heart failure?

Answer 7

the diastolic filling is decreased so EDV is decreased so CO is decreased.

Question 8

Causes of systolic ventricular dysfunction?

Answer 8

Impaired contractile function → MI, ischemia, cardiomyopathies

Question 9

What’s the ‘fall out’ of decreased contractility?

Answer 9

End diastolic volume? → INCREASED
Atrial volume? → INCREASED
Systemic and pulmonary circulation? → INCREASED WITH CONGESTION
BACKING UP → E.g. LEFT systolic dysfunction heart failure = pulmonary congestion

Question 10

Causes of Diastolic Dysfunction and HF?

Answer 10

Impaired diastolic filling → E.g Pericardial effusion, hypertrophy (chamber size); delays in relaxation (aging, ischemia); heart rate increase (tachycardia increases disease progression

Question 11

What is going to happen to the pressure of the left ventricle?

Answer 11

INCREASED (COMPENSATORY)

Question 12

Can you see the potential for pipe clogging?

Answer 12

Yes, pressure is high, hard for fluids to get into the ventricle

Question 13

What are the implications for the lung?

Answer 13

Congestion

Question 14

most common cause of right-sided failure?

Answer 14

Left-sided failure causes right-sided failure (most common cause)

Question 15

PATHOPHYSIOLOGY of Right-Sided Heart Failure

Answer 15

Right ventricle output is decreased or lost.

Question 16

What might the effect be on total cardiac output, right ventricle pressure, right atrial pressure, and systemic pressure when you have right-sided heart failure?

Answer 16

increased for all.

Question 17

most common cause of hypertension?

Answer 17

most common cause of hypertension is left-sided heart failure

Question 18

pathophysiology of left-sided heart failure (LSHF)

Answer 18

decreased in the output of the right ventricle. with this there is an increase in all pressure and cardiac output is increased as well.

Question 19

effect of LSHF on tissue perfusion?

Answer 19

decrease.

Question 20

effect of LSHF on pulmonary fluid?

Answer 20

build up

Question 21

Why does increased pulmonary pressure result in pulmonary edema?

Answer 21

When you have left ventricular failure, blood starts to accumulate in the left ventricle, left atrium, pulmonary circulation. Pressure starts to increase in pulmonary circulation (normally 10mm Hg). If it exceeds the capillary osmotic pressure (usually 25mm Hg) then there will be a possibility of fluid moving into the interstitial fluid; edema.

Question 22

list the respiratory manifestation of heart failure?

Answer 22

pulmonary edema which leads to fluid in lungs and lungs stiffness and impaired gas exchange.

Question 23

what is circularory shock?

Answer 23

inability to properly perfuse tissues.

Question 24

obstructive Shock

Answer 24

due to obstruction of blood flow outside of the heart.

Question 25

Distributive shock

Answer 25

excessive vasodilation causing the impaired distribution of blood flow

Question 26

types of distributive shock?

Answer 26

septic and anaphylactic shock

Question 27

septic shock

Answer 27

Infection with a microorganism resulting in the production of a massive amount of cytokines.
Increased vascular permeability → decreased blood pressure.

Question 28

anaphylactic shock

Answer 28

Response to an allergen, antigen or drug, resulting in a inflammatory response and the production of histamine → Vasodilator