congestive heart failure Flashcards
what are the two intrinsic mechanisms of heart rate regulation?
-frank-starling law
-right atria dilation
the force or tension developed in a muscle fibre depends on the extent to which the fibre is stretched
frank-starling law
what hormones does the sympathetic nervous system release in terms of heart rate regulation
epinephrine and norepinephrine
what hormones does the sympathetic nervous system release in terms of heart rate regulation
acetylcholine
______ is a complex syndrome in which abnormal heart function results in clinical signs and symptoms of low cardiac output and/or pulmonary or systemic congestion (e.g. pulmonary edema)
heart failure
_____ is the amount of blood leaving the left ventricle
cardiac output
______ is the pressure in the right side of the heart as blood returns to the heart
cardiac preload
_______ is the pressure the heart must pump against within the arterial system to eject blood (peripheral vascular resistance)
cardiac afterload
what’s the average cardiac output for an adult
5L/min
what are the determinants of cardiac output
heart rate and stroke volume
what is equation for ejection fraction
stroke volume/end diastolic volume
left ventricular failure categories
pathology: anemia, hyperthyroidism, valve defects, hypertension, asymmetric ventricular hypertrophy
inappropriate overloads placed on the heart
left ventricular failure categories
pathology: mitral stenosis, pericardial disease
restrictive filling of the heart
left ventricular failure categories
pathology: MI, coronary artery disease
myocyte loss
left ventricular failure categories
pathology: poisons, viral and bacterial infections
decreased myocyte contractility
right ventricular failure categories
pathology: congenital (shunts, obstructions), idiopathic pulmonary hypertension
precapillary obstruction
right ventricular failure categories
pathology: hypoxia induced vasoconstriction, pulmonary embolism and COPD
cor pulmonale (disease of heart caused by lungs)
right ventricular failure categories
pathology: right ventricular infarction
primary right ventricular failure
right ventricular failure categories
pathology: left cardiac heart failure
congestive heart failure
what 4 categories cause left ventricular failure
- myocyte loss
- decreased myocyte contractility
- inappropriate overloads placed on the heart
- restrictive filling of the heart
what 4 categories cause right ventricular failure
- precapillary obstruction
- congestive heart failure
- primary right ventricular failure
- cor pulmoanle
what is the pathophysiology of left ventricular heart failure at the hemodynamic level?
systolic and diastolic dysfunction
what is the pathophysiology of left ventricular heart failure of the neural-humoral level
- activation of compensatory mechanisms
- cytokines
- endotelin and vasopressin
what is the pathophysiology of left ventricular heart failure at the cellular level
hypertrophy and remodelling
______ is usually the result of an MI. evidenced by low ejection fraction and reduced ionotrpohy (contractility) during ventricular systole. impaired contractility is caused by loss of cardiac muscle cells, b-receptor down regulation and reduced ATP production
systolic dysfunction
______ is usually caused by hypertension and ischemic heart disease. more likely to develop in the elderly, in women and in those without a history of MI. decreased myocardial relaxation that renders the ventricle non complaint decreasing filling. low CO with normal ejection fraction
diastolic dysfunction
what is the first mechanism to occur when there is low cardiac output therefore the heart is failing
sympathetic nervous system is activated
favourable effects for this neural-humoral change: increased heart rate, increased contractility, vasoconstriction = increased venous return and increased filling
increased sympathetic activity
favourable effects for this neural-humoral change: salt and water retention = increased venous return
increase in renin-angiotensin-aldosterone and
increase in vasopressin
favourable effects for this neural-humoral change: may have roles in myocyte hypertrophy and left ventricular remodelling
increase in interleukins (IL-1) and TNF alpha
favourable effects for this neural humoral change: vasoconstriction = increase venous return
increase in endothelin
unfavourable effects for this neural humoral change: arteriolar constriction = after load = increased workload = increase in o2 consumption
increase in sympathetic activity
unfavourable effects for this neural humoral change: vasoconstriction = increased afterload
increase in renin-angiotensin-aldosterone and
increase in vasopressin
unfavourable effects for this neural-humoral change: apoptosis
increase in interleukins (IL-1) and TNF alpha
unfavourable effects for this neural humoral change: increased afterload
increase in endothelin
what changes may happen at the cellular level during heart failure?
- changes in Ca handling: need for Ca for contraction of the heart
- changes in a adrenergic receptors: sensitivity/# of alpha and beta receptors can change
- changes in contractile apparatus: due to large ineffective myocytes
- changes in myocyte structure: left ventricular remodelling
________ is the process by which ventricular size, shape and function are regulated by mechanical, neuro-humoral and genetic factors. related to myocyte hypertrophy, apoptosis, and fibrosis; the end result of body attempt to compensate
left ventricular remodelling
angiotensin II, TNF alpha and norepinephrine cause _______ related to left ventricular remodelling.
myocyte hypertrophy
TNF alpha and hypertrophy cause _______ related to left ventricular remodelling
apoptosis
fibroblast activation (endothelin) and collangenases (myocyte slippage) cause _______ related to left ventricular remodelling
fibrosis
are these backward effects associated with left ventricular failure or right ventricular failure
- dyspnea
- orothopnea
- basilar crackles
- cough
- cyanosis
- paroxysmal nocturnal dyspnea (sensation of sob awakens pt often after 1-2 hours of sleep, usually relieved in the upright position)
left ventricular failure
are these the forward effects associated with left ventricular failure or right ventricular failure
- fatigue
- restlessness
- increased heart rate
- faint pulses
- confusion
-anxiety
-oliguria (production of abnormally small amounts of urine)
both LVF and RVF
are these the backward effects of left ventricular failure or right ventricular failure
- hepatomegaly (enlarged liver)
- ascites (fluid collects in abdomen)
- splenomegaly (enlarged spleen)
- anorexia
- jugular vein distention (bulging of major veins in neck)
right ventricular failure
what are some other signs and symptoms of CHF?
- chest pain
- S3 gallop (S3 sound unique to heart failure)
-nocturia (urinating at night) - anascara (swelling of the whole body)
- hepatojuguylar reflex (press on liver to see jugular veins enlarge)
- abdominal pain
know the different classifications of heart failure based on the New York heart association
class I - no limitations; ordinary physical activity does not cause fatigue, sob, palpitations or angina
class II- mild limitations; comfortable at rest. ordinary physical activity (carry heavy packages) may result in fatigue, sob, palpitations and angina
class III- marked limitation; comfortable at rest. less than ordinary physical activity (getting dressed) leads to symptoms
class iv - severe limitation; symptoms of heart failure or angina are present at rest and worsened with activity
how is CHF diagnosed
- past medical history
- physical examination
- lab and radiology findings
__________ is another valuable diagnostic test for CHF. looks at CBC, liver biochemistry, cardiac enzymes, brain natriuretic peptide (BNP) and thyroid function
blood tests
______ is another valuable diagnostic test for CHF. used to establish the presence of systolic and/or diastolic impairment of the left or right ventricle
echocardiography
______ + ______ are released from the atria and ventricles in response to increased wall stress. patients with HFrEF (heart failure with reduced ejection fraction) tend to have higher levels than pts with HFpEF (heart failure with preserved ejection fraction), whereas levels may be falsely low in obesity. valuable in differentiating between cardiac and pulmonary causes of sob
BNP and NT-pro-BNP
list some examples of Framingham’s major criteria for diagnosing CHF
- paroxysmal nocturnal dyspnea
- neck vein distention
- rales
- cardiomegaly
- acute pulmonary edema
- increased venous pressure
- positive hepatojugular reflex
list some examples of Framingham’s minor criteria for diagnosing CHF
- extremity edema
- night cough
- dyspnea on exertion
- hepatomegaly
- pleural effusion
- tachycardia
- weight loss
regarding Framingham’s criteria, what needs two be established for a clinical diagnosis of CHF
need at least one major and two minor criteria
what is the pharmacological treatment for CHF
BAADDA
B- beta blocker
A- ACE inhibitor
A- ARB
D- diuretic
D- digoxin
A- aldactone
this med is used if volume overloaded; decreases preload, BP and edema
diuretic
this med iOS used if still have symptoms and low K+. also decreases Na retention
aldactone (spironolactone)
this drug decreases HR and enhances contractility
digoxin
these two drugs are vasodilators and counteracts RAAS
ACE inhibitor and ARB’s
this med is used if stable and no fluid overall; may feel weak and tired for a few days, then stable. reduces HR and NP through SNS to decrease oxygen consumption of the heart muscle
beta blockers
what are some non-pharm recommendations for CHF
- 1.5-2L of fluids a day
- exercise
- sodium restriction
- close supervision and follow up
- flu and pneumonia vaccines
