Heart Failure Flashcards
(28 cards)
What is heart failure?
When the heart is unable to pump sufficient blood to
meet metabolic needs of the body.
What is the usual cause of heart failure?
- Impaired ventricular contractility
- Increased afterload
- Impaired ventricular filling
Chronic heart failure may be classified into the following two categories:
- heart failure with reduced EF
- heart failure with preserved EF (usually a result of diastolic dysfunction)
Describe ventricular stroke volume.
SV is a function of preload, afterload, and contractility; SV rises when there is an increase in preload, a decrease in afterload, or augmented contractility.
How is cardiac output (CO) represented?
heart rate (HR) x stroke volume (SV)
What does ventricular end-diastolic volume represent?
Represents preload and is influenced by the chamber’s compliance.
What does ventricular end-systolic volume represent?
Depends on afterload and contractility but not on preload.
What are the body’s compensatory mechanisms in heart failure that initially maintain circulatory function?
1) Preload augmentation with increased stroke volume via the Frank-Starling mechanism
2) Activation of neurohormonal systems
3) ventricular hypertrophy
*these compensations eventually become maladaptive, contributing to adverse ventricular remodeling and progressive deterioration of ventricular function
What is standard pharmacological therapy of symptomatic heart failure with reduced EF?
- ACE inhibitor, beta-blocker, and sometimes an aldosterone antagonists
- For patients who do not tolerate an ACE inhibitor, ARB or the combination of hydralazine plus nitrates
What invasive therapies can be offered to patients with heart failure with reduced EF who meet specific criteria?
- an implantable cardioverter-defibrillator and/or
- cardiac resynchronization therapy (biventricular pacing)
For refractory end-stage heart failure, what should be considered in select patients?
- cardiac transplantation
- mechanical circulatory support
What is the standard therapy for heart failure with preserved EF?
Primarily diuretics to relieve pulmonary congestion. Such therapy must be administered cautiously to avoid excess reduction of preload and hypotension.
What is systolic dysfunction?
- abnormality of ventricular emptying due to impaired contractility or excessive afterload
- HF with reduced EF
What is diastolic dysfunction?
- abnormalities of diastolic relaxation or ventricular filling
- HF with preserved EF
What are the causes of left-sided heart failure with systolic dysfunction?
- CAD
* myocardial infarction
* transient myocardial ischemia - Chronic volume overload
* Mitral regurgitation
* Aortic regurgitation - Dilated cardiomyopathy
- Excess Afterload (Pressure Overload)
* Aortic stenosis
* Uncontrolled hypertension
What are the causes of left-sided heart failure with diastolic dysfunction?
- Impaired Ventricular Relaxation
* Left ventricular hypertrophy
* Hypertrophic cardiomyopathy
* Restrictive cardiomyopathy
* Transient myocardial ischemia - Obstruction of Left Ventricular Filling
* Mitral stenosis
* Restrictive pericarditis or cardiac tamponade
Describe right-sided heart failure.
- RV receives and ejects blood volume at lower pressures
- RV fails with a sudden ↑ afterload, ↑ resistance to ejection, most commonly caused by LV failure
- Isolated RV failure with normal LV function uncommon
What are the causes of right-sided heart failure?
Cardiac Causes
- Left-sided heart failure
- Pulmonic valve stenosis
- Right ventricular infarction
Pulmonary disease
- Chronic obstructive pulmonary disease
- Interstitial lung disease
- Chronic lung infection
Pulmonary vascular disease
- Pulmonary embolism
- Primary pulmonary hypertension
What are the signs and symptoms of LV heart failure?
- fatigue
- confusion
- diaphoresis (sweating)
- tachycardia
- tachypnea
- dyspnea
- orthopnea
- crackles in lung sounds
- pulmonary edema
- chronic dry cough
- loss of appetite
- weight gain
- decreased urine output
What are the signs and symptoms of RV heart failure?
- fatigue
- peripheral edema
- jugular venous distention
- hepatomegaly
- abdominal distention
- weight gain
- decreased urine output
What are the diagnostic procedures used to diagnosis heart failure?
- Chest X-Ray
- 12 Lead ECG
- Echo – Measures cardiac
- Cardiac Cath
- Nuclear Imaging (MPI)
- RNEF - Radio Nuclide Ejection - - BNP Assays
What is the renin-angiotensin-aldosterone system (RAAS)?
- (RAAS) is a critical hormone system that regulates blood pressure, fluid balance, and electrolyte levels in the body, primarily through the actions of renin, angiotensin II, and aldosterone
- Decreased renal artery perfusion due to decreased CO, stimulates secretion of renin from the kidneys
- Renin splits angiotensinogen to
form angiotensin I, which is
then cleaved by angiotensin-converting enzyme (ACE) to form
angiotensin II (AII) - Angiotensin II, a potent
vasoconstrictor increases
intravascular volume to maintain BP and increase aldosterone secretion
What is anti-diuretic hormone (ADH)?
- Antidiuretic hormone (ADH), is secreted by posterior pituitary
- Mediated by arterial baroreceptors and ↑ levels of AII
- ADH adds to ↑ intravascular volume by promoting water
retention which results ↑ LV preload and ↑ CO - ADH also contributes to systemic vasoconstriction
What are natriuretic peptides?
- Natural “beneficial” hormones secreted in heart failure in
response to ↑ intracardiac pressures - ANP (atrial natriuretic peptide) - stored in atrial cells,
released in atrial distention - BNP (B-type natriuretic peptide) - produced when
ventricular myocardium subjected to hemodynamic stress - Results in excretion of Na+ and water, vasodilatation,
inhibition of renin secretion and antagonism of effects of AII on
aldosterone and vasopressin secretion - Usually not sufficient to counteract vasoconstriction and
volume-retaining effects of other activated hormone systems
