Week 6: Heart Failure Flashcards
what is heart failure
long-term chronic condition that gets worse over time
- inability of myocardium to pump enough blood to meet body needs
- abnormal clinical syndrome involving impaired cardiac pumping or filling, or both
- heart failure is a response to cardiac dysfunction
what are the most common causes of heart failure (11)
- coronary artery disease: MI
- hypertension
- valvular disease: rheumatic disease
- congenital heart disease
- pulmonary: HTN (right sided), PE
- infiltrative disorders
- pericardial disease (Restrictive)
- inflammatory (myocarditis)
- cardiomyopathy
- dysrhythmias
- medication non-compliance
review the normal circulation through the heart
- superior/inferior vena cava
- right atrium
- tricuspid valve
- right ventricle
- pulmonary valve
- pulmonary artery to lungs
- left atrium
- mitral valve
- left ventricle
- aortic valve
- aorta to body
what are the 3 major systems that are recruited when myocardial injury occurs
- sympathetic nervous system
- Renin-Angiotensin-Aldosterone System
- Natriuretic peptide system
what are the 4 compensation mechanisms
- elevation in SNS activity
- neural-hormonal response
- dilation of ventricle (Frank starling mechanism)
- ventricular hypertrophy
what does an elevation in SNS activity do
increases heart rate and contractility
what does the neural-hormonal response do
- increases blood volume and elevates preload
- increase in salt and water retention (RAAS)
- posterior pituitary gland secretes ADH
- production of endothelin - potent vasodilator
- proinflammatory cytokines are released by heart causing hypertrophy, contractile dysfunction, and cell death
what does the Frank starling mechanism do
- dilation of the ventricle
- increase pressures result in increased volume at the end of diastole
- increased stretch initially adaptive - eventual overstretch results in ineffective contraction
what is ventricular hypertrophy
- increase in muscle mass and cardiac wall thickness in response to overwork and strain
- develops overtime, generally following persistent or chronic dilation
what is the counter-regulatory mechanism
natriuretic peptide system
- impacts salt and water handling, pressure regulation, and may influence myocardial structure and function
natriuretic peptide system: what is BNP and ANP and what do they do
brain natriuretic peptide: natriuretic hormone primarily release from the heart - particularly the ventricles
atrial natriuretic peptide: hormone released by myocardial cells in atria
both are released in response to wall stress and volume expansion
both have diuretic, natriuretic, and hypotensive effects
both inhibit RAAS and impair systemic and renal sympathetic activity
what happens when the SNS, RAAS, NP systems regulate an issue for a prolonged amount of time? there are 4 outcomes
become maladaptive
- elevation of diastolic pressures transmitted to the atrial/pulmonary/systemic venous circulation promotes congestion and edema
- increase in LV afterload (vasoconstriction) can both directly depress cardiac function and enhance rate of deterioration of myocardial function
- increases in contractility, heart rate, and LV afterload can worsen or provoke coronary ischemia
- catecholamines, angiotensin 2, and aldosterone promote the loss of myocytes through apoptosis, and cause myocardial hypertrophy and fibrosis
explain acute vs chronic heart failure
acute
- sudden onset, no compensatory mechanisms
- days or hours
chronic
- ongoing process, months to years
- progressive worsening of ventricular function
chronic neuro-hormonal activation that results in ventricular remodelling
what are some clinical manifestations of chronic heart failure
- fatigue
- dyspnea
- tachycardia
- edema
- nocturia
- depression
- chest pain
- weight changes
explain left vs right heart failure
left
- left ventricular dysfunction
- disturbance of the contractile function of the left ventricle, resulting in low cardiac output state
right
- ineffective right ventricular contractile function
- backwards flow
explain systolic vs diastolic heart failure
systolic
- abnormality of the heart muscle that markedly decreases contractility during systole (ejection) and lessens the quantity of blood that can be pumped out of the heart
diastolic
- abnormality of the heart muscle that makes it unable to relax, stretch, or fill during diastole, ejection fraction can be normal
what are the 3 clinical heart failure syndromes
- heart failure reduced ejection fraction: HFrEF
- heart failure preserved ejection fraction: HFpEF
- heart failure mid-range ejection fraction: HFmEF
what are the 3 considerations for HFrEF
Heart failure reduced ejection fraction
- formally called systolic dysfunction (inability to pump)
- left ventricular ejection fraction < 40%
- aggressively treated with medical therapy and cause for etiology determined ASAP
what are the 3 considerations for HFpEF
Heart failure preserved ejection fraction
- Formally called diastolic dysfunction – inability to relax
- LVEF > 50%
- Treatment of symptoms
what are the 3 considerations for HFmEF
Heart failure mid-range ejection fraction
- “New” classification of patients.
- LVEF 40-49%
- Treatment pathway still under review, may be individualized
what are the complications of heart failure
- pleural effusions
- dysrhythmias
- left ventricular thrombosis
- hepatomegaly
- renal failure
explain the process of heart failure diagnosis
- suspected heart failure
- examine clinical history and physical assessment
- history: symptomos, functional limitation, prior cardiac disease, risk factors, comorbidities
physical: vitals, weight, volume, heart, lung, abdomen, vascular - do initial investigations
- chest radiograph
- electrocardiogram
- B-type natriuretic peptide
- lab work (CBC, electrolytes, renal function, urinalysis, glucose, thyroid) - assess ventricular function
- echocardiogram - additional diagnostic investigations
- radionuclide imaging
- cardiac catheterization
- cardiopulmonary exercise testing
- CMI, ST, endomyocardial biopsy
what are the clinical manifestations of right sided heart failure
- fatigue, weakness
- hypotension (severe disease)
- fluid overload
- weight gain
- anorexia
- peripheral edema, +/- JVP
- decreased saO2
- murmurs
- ascites/anasarca (massive, generalized body edema)
- hepatomegaly
- right heaves
- renal impairment
- tachypnea
- tachycardia
what are the clinical manifestations of left sided heart failure
- Fatigue, weakness
- Hypertension
- Hypotension – reflects severe disease
- Fluid overload
- Weight gain
- Pulmonary edema (crackles)
- Decreased SaO2
- Extra heart sounds (S3 and S4 )
- Peripheral edema
- Left Heaves
- Renal impairment
- Tachypnea
- Tachycardia
- Nocturia
- Dyspnea
- Orthopnea