5. Heart failure Flashcards
Definition of Heart Failure
Where the cardiac output (performance) can’t deliver the necessaryamount of blood to the tissues
does heart disease lead to heart failure
not always
Cardiac Output =
Heart Rate X Stroke Volume
Stroke volume is composed of
Preload
Afterload
Contractility
Preload definition
initial stretching of cardiac myocytes
left ventricular end diastolic volume
Increase in preload leads to
increased CO
increased congestion and O2 demand
Afterload definition
the load which the heart pumps against
determined by vascular resistance
Increase in afterload leads to
decreased CO
increased O2 demand
Hypertrophy
Contractility definition
ability of the heart to contract
Increase in contractility leads to
increased CO
increased O2 and energy demand
thus causing a decreased CO
Types of heart failure is based on
course
demand
grade
function
direction
anatomy
Heart failure based on course
Acute / Chronic
Heart failure based on Demand
Absolute / Relative
Heart failure based on Anatomy
Left / Right
Heart failure based on Function
Systolic / Diastolic
Heart failure based on Direction
Forward / Backward
Heart failure based on Grade
Compensation / Decompensation
What does the body prioritize in compensating for heart failure
Arterial BP in brain, heart, kidney
Venous BP at a low level
What is chonotropic effect
increased heart rate
what is inotropic effect
increased myocardial activity
what does myocardial damage lead to
increased congestion –> RAAS becoming permanently activated –> increased heart rate –> vasoconstriction and myocardial hypertrophy
cause of cardiac remodelling
autonomic nervous system
RAAS
inflammatory mediator
macroscopic cardiac remodelling
shape and size (concentric and eccentric)
microscopic cardiac remodelling
necrosis
apoptosis
fibrous tissue
how does heart failure cause inflammation
increased inflammatory mediators –> myocardial fibrosis
inflammatory mediators
paracrine molecules
interleukins
TNF alpha
effects of inflammatory mediators
cardiac cachexia
decreased myocardium contractility
myocardial hypertrophy
free radical synthesis
Left sided heart failure clinical signs
tachypneoa
cough
prerenal azotaemia
adam stokes syndrome
Right sided heart failure clinical signs
Ascites
Congested jugular veins
positive hepatojugular reflux
pleural fluid
Clinical Signs of Heart Failure
pale mm
prolonged crt
fatigue, weakness
exercise intolerance
weight loss
cachexia
tachycardia
Aim of medication against HF
treat cause
relieve the symptoms
slow/ stop progression
How to treat HF
decrease preload
decrease afterload
increase contractility
treat arrhythmias
treat neurohormonal overcompensation
How to decrease Preload
furosemide & torsemide
Amiloride
Vasodilators
Pimobendan
Chlorothiazides
How to decrease Afterload
Arterial Dilators - Amlodipine, Hydralazine
Pimodendan
Ace inhibitors
How to increase Contractility
Pimobendan
Digoxin
Phosphodiesterase Inhibitors
Emergency Treatment of HR
Priorities
Decrease Preload and Afterload
Increase contractility
Sedation - Butorphanol, ACP
O2 therapy
