Lecture 17 - Heart Failure Flashcards
Failure of the cardiovascular system is defined as
failure to supply adequate amounts of blood to meet cellular metabolic demands
what is circulatory failure often caused by
decreased cardiac output due to dysfunction or disease
decreased stroke volume
myocardial failure
low output
systolic pumping failure
increased stroke volume
high output
perfusion demands are not met (PDA, sepsis, anemia)
what is heart failure
inability of the heart to function within normal diastolic pressures (eject or fill)
T/F: fluid retention is classified as congestive heart failure
TRUE
diastolic dysfunction
- decreased ventricular filling, normal contraction
- impaired relaxation
systolic dysfunction
- ventricular filling normal, dysfunction during contractions
- failure of pumping
“forward” failure
- poor peripheral perfusion
- depressed contractility
- elevated venous pressures (passive congestion of organs)
“backward” failure
- increased pulmonary pressure leading to congestion
what are the general clinical signs of heart failure
- exercise intolerance
- syncope (or collapse)
- pale/gray membrane color and prolonged perfusion
- decreased atrial pulse
- arrhythmias
clinical signs of right-sided heart failure
- dependent edema
- fluid wave in abdomen
- GI distress
- impaired liver function
- jugular v distension
clinical signs of left-sided heart failure
- exercise intolerance
- cyanosis/hypoxia
- cough w frothy sputum
- dyspnea/tachypnea/orthopnea
- decreased lung sounds
pulmonary edema occurs due to the disruption of ____ ____ that cause hydrostatic pressure to be ______ than lymphatic pressure
starling forces; greater
ascites is due to the ____ of hydrostatic pressure causing capillaries to be ____ and ____ the formation of hepatic lymph
increase; “leaky”; increase
what are the 5 common causes of heart failure
- increased afterload (stenotic valves)
- increased preload (valve insufficiency)
- myocardial disease (DCM, HCM)
- Constrictive disease (pericardial effusion, pericarditis)
- arrhythmia
myxomatous mitral valve disease
- thickened and irregular mitral valve (“leaky”)
- regurgitation creates a murmur
- volume overload leads to left-sided heart failure
dilated cardiomyopathy (DCM)
- reduced pumping of the left ventricle
- dilation of ventricle thins walls
- connected to breeds (Doberman), grain-free diets, etc.
Hypertrophic cardiomyopathy (HCM)
- left ventricular concentric hypertrophy (thickened walls leading to decreased chamber size)
- outflow tract obstruction creates a murmur
T/F: HCM is the most common heart disease in cats
TRUE
define cardiac remodeling
results in changes of cardiac size, shape, and/or function
what are the 3 characteristics of eccentric hypertrophy
- volume overload
- increased diastolic pressure
- sarcomere addition in series
what are the 3 characteristics of concentric hypertrophy
- pressure overload
- increased systolic pressure
- sarcomere addition in parallel
what are the 3 things the SNS and renin-angiotensin-aldosterone system do
- increased HR
- vasoconstriction
- sodium and water retention
what is activated in response to decreased output and BP
sympathetic nervous system and RAAS
what happens in response to increased myocardial wall stress
cardiac remodeling
what are the 3 major adaptive compensatory mechanisms
- frank-starling mechanism
- neurohormonal activation
- myocardial remodeling and hypertrophy
how does the frank-starling mechanism compensate
increase preload to increase stress, contractility and CO
what does chronic activation of RAAS cause
progression of cardiac and kidney disease
T/F: chronic RAAS and SNS activation increases myocardial oxygen demand
TRUE
what causes fibrosis
chronic RAAS activation
what senses blood pressure differences
arterial baroreceptors
