Lecture 17 - Heart Failure

Question 1

Failure of the cardiovascular system is defined as

Answer 1

failure to supply adequate amounts of blood to meet cellular metabolic demands

Question 2

what is circulatory failure often caused by

Answer 2

decreased cardiac output due to dysfunction or disease

Question 3

decreased stroke volume

Answer 3

myocardial failure
low output
systolic pumping failure

Question 4

increased stroke volume

Answer 4

high output
perfusion demands are not met (PDA, sepsis, anemia)

Question 5

what is heart failure

Answer 5

inability of the heart to function within normal diastolic pressures (eject or fill)

Question 6

T/F: fluid retention is classified as congestive heart failure

Answer 6

TRUE

Question 7

diastolic dysfunction

Answer 7

• decreased ventricular filling, normal contraction
• impaired relaxation

Question 8

systolic dysfunction

Answer 8

• ventricular filling normal, dysfunction during contractions
• failure of pumping

Question 9

“forward” failure

Answer 9

• poor peripheral perfusion
• depressed contractility
• elevated venous pressures (passive congestion of organs)

Question 10

“backward” failure

Answer 10

• increased pulmonary pressure leading to congestion

Question 11

what are the general clinical signs of heart failure

Answer 11

• exercise intolerance
• syncope (or collapse)
• pale/gray membrane color and prolonged perfusion
• decreased atrial pulse
• arrhythmias

Question 12

clinical signs of right-sided heart failure

Answer 12

• dependent edema
• fluid wave in abdomen
• GI distress
• impaired liver function
• jugular v distension

Question 13

clinical signs of left-sided heart failure

Answer 13

• exercise intolerance
• cyanosis/hypoxia
• cough w frothy sputum
• dyspnea/tachypnea/orthopnea
• decreased lung sounds

Question 14

pulmonary edema occurs due to the disruption of ____ ____ that cause hydrostatic pressure to be ______ than lymphatic pressure

Answer 14

starling forces; greater

Question 15

ascites is due to the ____ of hydrostatic pressure causing capillaries to be ____ and ____ the formation of hepatic lymph

Answer 15

increase; “leaky”; increase

Question 16

what are the 5 common causes of heart failure

Answer 16

1. increased afterload (stenotic valves)
2. increased preload (valve insufficiency)
3. myocardial disease (DCM, HCM)
4. Constrictive disease (pericardial effusion, pericarditis)
5. arrhythmia

Question 17

myxomatous mitral valve disease

Answer 17

• thickened and irregular mitral valve (“leaky”)
• regurgitation creates a murmur
• volume overload leads to left-sided heart failure

Question 18

dilated cardiomyopathy (DCM)

Answer 18

• reduced pumping of the left ventricle
• dilation of ventricle thins walls
• connected to breeds (Doberman), grain-free diets, etc.

Question 19

Hypertrophic cardiomyopathy (HCM)

Answer 19

• left ventricular concentric hypertrophy (thickened walls leading to decreased chamber size)
• outflow tract obstruction creates a murmur

Question 20

T/F: HCM is the most common heart disease in cats

Answer 20

TRUE

Question 21

define cardiac remodeling

Answer 21

results in changes of cardiac size, shape, and/or function

Question 22

what are the 3 characteristics of eccentric hypertrophy

Answer 22

1. volume overload
2. increased diastolic pressure
3. sarcomere addition in series

Question 23

what are the 3 characteristics of concentric hypertrophy

Answer 23

1. pressure overload
2. increased systolic pressure
3. sarcomere addition in parallel

Question 24

what are the 3 things the SNS and renin-angiotensin-aldosterone system do

Answer 24

1. increased HR
2. vasoconstriction
3. sodium and water retention

Question 25

what is activated in response to decreased output and BP

Answer 25

sympathetic nervous system and RAAS

Question 26

what happens in response to increased myocardial wall stress

Answer 26

cardiac remodeling

Question 27

what are the 3 major adaptive compensatory mechanisms

Answer 27

1. frank-starling mechanism 2. neurohormonal activation 3. myocardial remodeling and hypertrophy

Question 28

how does the frank-starling mechanism compensate

Answer 28

increase preload to increase stress, contractility and CO

Question 29

what does chronic activation of RAAS cause

Answer 29

progression of cardiac and kidney disease

Question 30

T/F: chronic RAAS and SNS activation increases myocardial oxygen demand

Answer 30

TRUE

Question 31

what causes fibrosis

Answer 31

chronic RAAS activation

Question 32

what senses blood pressure differences

Answer 32

arterial baroreceptors