Heart Failure Flashcards
How is heart failure defined?
An abnormality of cardiac structure or function
In heart failure, what does the heart fail to do despite normal filling pressures? Heart failure can be caused by myocardial failure or what other condition?
Deliver oxygen at a sufficient rate
Nearly-normal cardiac functions (High Output Failures)
While heart failure always leads to circulatory failure, what non-cardiac conditions can also lead to circulatory failures?
Hypovolaemic and septic shock
What compensatory mechanisms are activated in heart failure?
- Increase in blood volume
- Increased cardiac filling pressure
- Increased heart rate
- Increased cardiac muscle mass
What are the consequences of the compensatory mechanisms activated in heart failure?
Progressive declined contraction and relaxation
From a hemodynamic standpoint, heart failure can be secondary to what? In heart failure, is cardiac output usually above or below the normal range?
Systolic or diastolic dysfunction
Below normal range
What ejection fraction value is typical of acute failure resulting from myocardial infarction? How does diastolic dysfunction affect ejection fraction?
<45%
Ejection fraction may be normal
In “high-output” failure, why is increased cardiac output insufficient?
The demands of the body are too great
How is ejection fraction (EF) related to heart failure terminology?
- Reduced ejection fraction: EF <40%
- Mildly impaired EF: EF 40-49%
- Preserved ejection fraction: EF ≥50%
What are some ways that heart failure is related to time-course?
New onset
Transient
Chronic
How can heart failure be related to progression?
Acute
Stable
Worsening
How is heart failure related to location?
Left heart
Right heart
Combined
How can heart failure be related to Cardiac Output?
High output failures
Low output failures
What are some more specific signs of heart failure?
- Elevated jugular venous pressure
- Hepatojugular reflux
- Third heart sound (gallop rhythm)
- Laterally displaced apical impulse
- Cardiac murmur, Tachycardia
- Ankle swelling, venous congestion (oedema)
What are some typical symptoms of heart failure?
- Breathlessness
- Orthopnoea
- Paroxysmal nocturnal dyspnoea
- Reduced exercise tolerance
- Fatigue, tiredness, increased time to recover after exercise
In heart failure pathophysiology, what do the systemic responses in the renin–angiotensin–aldosterone and sympathetic nervous systems cause?
Further myocardial injury
What protective function does the natriuretic peptide system have in heart failure?
Counterbalance detrimental effects
What happens when compensatory mechanisms in heart failure become overwhelmed?
A failure ensues
What are the main adaptations that occur in heart failure?
- Increase preload (Frank-Starling mechanism)
- Alterations in myocyte regeneration and death
- Myocardial hypertrophy (cardiac remodelling)
- Activation of neurohumoral systems
What is the Frank-Starling mechanism?
Increase preload to sustain cardiac performance
In heart failure, what are the Favourable and Negative Impacts of ↑ Sympathetic Activity?
- Favourable Impact: ↑ HR, ↑ Contractility, ↑, →Vesocon. ↑Venous return, ↑Filling Pressure
- Negative Impact: Arteriolar Vasocon→ Afterload → ↑ Workload → ↑ Vasocon.
In heart failure, what are the Favourable and Negative Impacts of ↑ Renin-Angiotensin-Aldosterone System?
- Favourable Impact: Salt & Water retention ↑ Venous Return
- Negative Impact: ↑ Vasocon. ↑ Afterload
In heart failure, what are the Favourable and Negative Impacts of ↑ Vasopressin?
- Favourable Impact: Salt & Water retention ↑ Venous Return
- Negative Impact: ↑ Vasocon. ↑ Afterload
In heart failure, what are the Favourable and Negative Impacts of ↑ Interleukins & TNFα?
- Favourable Impact: Potential role in myocyte hypertrophy
- Negative Impact: Apoptosis