Heart Failure - The condition Flashcards
At the end of systole, ventricular relaxation begins suddenly,
which results in rapidly decreasing _____
intraventricular pressures
The degree of tension on the muscle walls of the ventricles
when they begin to contract
Preload
LV dilation, hypertrophy, and changes in
cardiac compliance modify ____
preload.
____- The load or pressure against which the ventricles (especially the left ventricle) exert their contractile force and must
overcome in order to eject the stroke volume
Afterload
The fraction of the End-Diastolic Volume that is ejected is called the _____
Ejection Fraction
The actual volume of blood that
is ejected during ventricular
contraction is called the _____
Stroke
Output Volume (stroke volume)
_____ is the amount of blood (the volume) that the heart ejects with each ventricular contraction
Stroke volume
The End-Diastolic Volume minus the End-Systolic Volume
Stroke volume
Explain what preload means in the myocardial cells
The stretching in turn causes the muscle to contract with increased
force because the actin and myosin filaments are brought to a more
optimal degree of overlap for force generation.
Frank-Starling Mechanism = ____
The greater the heart muscle is stretched
during filling, the greater the force and volume of contraction
_____ is the volume ejected by each ventricle in 1 minute
Cardiac Output
Cardiac Output (CO) is the product of ____
Heart Rate and Stroke Volume
○ In other words, CO = HR x SV
There are four main factors that affect the CO
○ Heart Rate
○ Contractility
○ Preload
○ Afterload
Cardiac causes of Heart failure:
○ Myocardial damage- Myocardial infarction, myocarditis, cardiomyopathy
○ Valvular disorders- Especially aortic/mitral valve stenosis/regurgitation
○ Arrhythmias- Bradyarrhythmias and tachyarrhythmias
○ Conduction defects- Especially AV blocks and LBBB
○ Reduced substrate availability- Ischemia with CAD
○ Infiltrative or matrix disorders- Amyloidosis, hemochromatosis, chronic fibrosis
Systemic causes of Heart failure:
○ Increased demand for Cardiac Output- Anemia, hyperthyroidism, Paget disease
○ Increased Afterload- Aortic stenosis and systemic hypertension
____-sided heart failure is more common than ____-sided
Left; right
Left-sided heart failure common causes
○ Most commonly caused by ischemic heart disease and/or hypertension.
○ Other important causes
include mitral or aortic valve
disease, cardiomyopathy, and
congenital heart disorders.
CARDIO-FAIL-3,4
Etiology of right-sided heart failure
○ Most commonly caused by left-sided heart failure.
■ Commonly seen along with left heart failure (biventricular).
■ Most heart failure patients have signs/symptoms of both.
○ Other important causes
include pulmonary
hypertension (Cor
Pulmonale), pulmonary
emboli, RV infarction,
valvular disease, and
congenital heart disorders
There are four main systems that respond in various ways when the
body encounters decreased Cardiac Output secondary to the
developing Heart Failure. These include:
○ Cardiac Response
○ Hemodynamic Response
○ Renal Response
○ Neurohormonal Response
Reduced CO with lower SBP in HF triggers arterial baroreflexes, leading to___
■ This triggers a neuronal response via the Autonomic Nervous
System that increases sympathetic tone and decreases
parasympathetic tone- VASOCONSTRICTION.
■ Heart rate and myocardial contractility also increase,
venoconstriction occurs, and Na and H2O are retained.
Renal Response to cardiac dysfunction
○ Cardiac dysfunction results in decreased renal blood flow / GFR.
○ This activates the Renin-Angiotensin-Aldosterone System (RAAS).
■ The end result of this massive hormonal cascade is Na and H2O
retention, increased intravascular volume, and increased BP
Angiotensin II worsens HF by causing ____
vasoconstriction, stressing the heart
Angiotensin II triggers ADH secretion (Vasopressin), which _____
increases water reabsorption, thereby increasing preload and stressing the heart
Angiotensin II also increases sympathetic activity on the heart (triggers
norepinephrine release), which likely contributes to _____
cardiac remodeling
Angiotensin II also increases Aldosterone production, which not only
enhances Na reabsorption, but also encourages ____
cardiac remodeling.
Neurohormonal Response
○ Brain (B-Type) Natriuretic Peptide (BNP) is released from the stretched
ventricles and can enhance renal excretion of Na.
■ However, in patients with HF, the effect is blunted by decreased renal
perfusion and receptor downregulation (from chronic stimulation)
○ Because of the intense Sympathetic activation that occurs in response to
decreased cardiac output, Beta-1 adrenergic receptors on the heart are
downregulated over time, which further impairs myocyte contractility
and heart rate management
Systolic vs. Diastolic heart failure
● In Systolic Dysfunction, the ventricle contracts poorly and empties inadequately, which leads to increased diastolic volume/pressure and reduced ejection fraction
● In Diastolic Dysfunction, ventricular filling is
impaired due to impaired ventricular relaxation, which results in reduced end-diastolic volume and increased end-diastolic pressure
Left-Sided HF Presentation
■ Dyspnea (due to pulmonary venous congestion)
■ Fatigue (due to low cardiac output)
■ As HF worsens, the dyspnea can occur at rest, even at night (often causing nocturnal cough)
■ Orthopnea - Dyspnea that occurs shortly after lying flat and is relieved promptly by sitting up (common as HF advances)
Common signs of left heart failure on exam include:
■ Diffuse, sustained, laterally displaced PMI
■ S3 gallop- Very common in HF - Due to rapid ventricular
filling and poor ventricular function (“Sloshing-in”)
● Think volume overload
■ S4 gallop- Less common - Due to increased ventricular wall resistance and decreased compliance (“A-Stiff-Wall”)
■ Basilar crackles/rales (with pulmonary edema)
■ Basilar dullness to percussion (if pleural effusion)
Right-Sided HF Presentation: patient history
○ In right heart failure, patients most commonly report…
■ Lower extremity edema (due to systemic venous congestion)
■ Fatigue (due to low cardiac output)
○ Sometimes patients report a sensation of fullness in the abdomen
or neck, again due to systemic venous congestion.
○ Hepatic congestion can cause RUQ abdominal pain.
○ Stomach and intestinal congestion can cause anorexia and a
sensation of abdominal bloating
Physical Exam Findings: Right-sided HF
■ Peripheral pitting edema in lower extremities
■ Enlarged and sometimes pulsatile liver
● With hepatojugular reflux
■ Abdominal swelling / Ascites
■ Jugular Venous Distention
■ Possible S3 along right sternal border
■ Possible RV lift/heave
Clinical suspicion for heart failure should be high in patients with a
history of _____
MI, HTN, or Valvular Disorders
○ Suspicion should be moderate in any patient who is elderly and/or
has diabetes mellitus
When there is clinical suspicion of Heart Failure, diagnostic studies to order include:
○ Chest X-ray, EKG, and Echocardiogram
○ Other than Serum BNP, blood tests are not used for diagnosis
Chest X-ray in heart failure can reveal several findings
○ Enlarged cardiac silhouette due to Cardiomegaly
○ Pleural effusion(s)- Will be transudative
○ Pulmonary edema (especially during exacerbations)
○ Findings suggestive of chronic pulmonary venous congestion
■ Kerley B lines
Echo use in Heart Failure
Echocardiography can help to evaluate the chamber dimensions, valvular function, ejection fraction, wall motion abnormalities,
and LV hypertrophy
Serum BNP Levels are generally ____ in heart failure
high
____ is released from the ventricular walls during ventricular
stretching, which happens with volume overload.
BNP
____ is an inactive polypeptide that
is created when BNP is cleaved during breakdown
N-Terminal Pro-BNP (NT-Pro-BNP)
_____ findings are not diagnostic of heart failure, but many abnormal
findings can be suggestive of underlying disease processes.
EKG
Free water retention is disproportionately higher, so a _____ often develops in HF, especially in the scenario of volume overload
hypervolemic hyponatremia
A sudden worsening of chronic heart failure, known as an exacerbation,
can occur when _____
something changes in the normal routine that places increased demand on the already weakened heart
How does “Congestive Heart Failure” develop?
● A sudden worsening of chronic heart failure, known as an exacerbation, can occur when something changes in the normal routine that places increased demand on the already weakened heart
● Cardiac-related elevation of pulmonary and/or systemic venous pressures may then result in organ congestion
Medication Non-Adherence in Heart failure exacerbation
○ A common cause of exacerbations is when patients with diagnosed
heart failure simply do not take their medication as prescribed.
○ Could be due to confusion, misreading labels, side effects, cost, etc
Causes of heart failure exacerbation
● Medication Non-Adherence
● Excessive Dietary Sodium Intake
Other important triggers of exacerbations include:
○ Alcohol consumption
○ Infections, like pneumonia
○ Uncontrolled hypertension
○ Increased metabolic demand (Anemia, Hyperthyroidism)
○ Arrhythmias and MI
American College of Cardiology / American Heart Association
(ACC/AHA) classifies heart failure into____
4 stages: A, B, C, and D
○ Stage A and B are “at risk of HF,” while C and D have HF
Common signs of left heart failure with vitals and inspection:
■ Tachycardia
■ Hypotension
■ Respiratory distress
■ Cyanosis
■ Confusion/agitation (due to hypoxia/
hypoperfusion)
Sometimes we estimate the degree of orthopnea by learning _____
how
many pillows the patient sleeps on at night to address the
orthopnea that occurs with lying flat.
Both Orthopnea and PND occur due to _____
pulmonary congestion
_____ - Dyspnea that occurs shortly after lying flat and is relieved promptly by sitting up (common as HF advances)
Orthopnea
