Heart Failure, Chronic Heart Failure, Congestive Heart Failure Flashcards
Cardiac Hemodynamics
What is the basic function of the HEART?
-is to pump blood
Cardiac Hemodynamics
Cardiac Output?
Cardiac Output: Amount pumped per minute
Cardiac Hemodynamics
Stroke Volume?
Stroke Volume: The Amount of Blood pumped out of the ventricle with each contraction
Cardiac Hemodynamics
formula of Cardiac Output (CO)
CO = Heart Rate(HR) x SV
Cardiac Hemodynamics
Preload?
Preload: The Amount of blood presented to the ventricle just before Systole
- Ventricular wall stretches to accommodate (compliance
- Venous return (Amount of blood entering ventricle during diastole) and elasticity determines preload
Cardiac Hemodynamics
Compliance/Elasticity decreases when:
- the muscle thickens (hypertrophic cardiomyopathy)
- There is increased fibrotic tissue within the ventricle
- Little or no compliance= stiff ventricle
Cardiac Hemodynamics
Non compliant ventricle has a?
Noncompliant ventricle has a higher intraventricular pressure than a compliant ventricle
Cardiac Hemodynamics
Higher Pressure increases?
Higher pressure increases the workload of the heart and leads to heart failure, if not corrected
Cardiac Hemodynamics
Afterload?
Afterload: The amount of resistance to the ejection of blood from the ventricle
- In order to eject blood, ventricle needs to overcome resistance caused by tension in the aorta and other vessels
- An increase in afterload causes the ventricle to work harder and decreases the amount of blood ejected
- When afterload increases, the workload of the heart must increase to overcome the resistance and eject blood
Cardiac Hemodynamics
Contractility?
The Force of the contraction is related to the status of the myocardium.
Significant loss of myocardial cells can decrease contractility and cause HF
Afterload can be reduced by medications to match the lower contractility and maintain adequate CO.
Cardiac Hemodynamics
Major Factors that determines Afterload?
Diameter and density of the great vessels
- Aorta
- Pulmonary artery
The Opening and competence of semilunar valves
- Pulmonic valve
- Aortic valve
When the valves open easily resistance is lower
When there is vasoconstriction, hypertension, narrow valve openings (stenosis) resistance
what is HEART FAILURE?
The inability of the heart to pump sufficient blood to meet the needs of the tissues for oxygen and nutrients. HEART FAILURE(HF)= CONGESTIVE HEART FAILURE (CHF)
Often referred to as CHF because many patients experience pulmonary or peripheral congestion.
Heart Failure sign and symptoms?
Currently heart failure is recognized as a clinical syndrome characterized by signs and symptoms of:
- Fluid overload
- Inadequate tissue perfusion
Fluid overload and decreased tissue perfusion result when the heart cannot generate a CO sufficient to meet the body’s demands.
The term HF indicates disease in which there is a problem with contraction of the heart (systolic dysfunction) or filling of the heart (diastolic dysfunction)
-May or may not cause pulmonary or systemic congestion
Facts about Heart Failure
Some cases reversible, depending on the cause
More often, HF is a progressive, life-long diagnosis managed with lifestyle changes and medications to prevent acute congestive episodes
5 Million in U.S. have HF
550,000 new cases diagnosed yearly
- Can affect all ages
- More often elderly
Heart failure is the most common reason for hospitalization of patients over 65 yrs
- The second most common reason for visits to doctors
- High rate of re-admissions
- Cost: $25 billion and rising
- Prevention and early intervention to arrest the progression are major health initiatives in U.S.
Types of Heart Failure?
Two types of HF, identified by assessment of left ventricular functioning, usually by echocardiogram.
- Systolic Heart Failure
- Characterized by a weakened heart muscle
- More common
- Diastolic Heart Failure
- Characterized by a stiff & noncompliant heart muscle making it difficult for the ventricle to fill
How to determine the type of Heart Failure?
- An assessment of the Ejection Fraction (EF) is performed .
- EF= an indication of the blood ejected with each contraction
- —-EF=Amount of blood at the end of diastole LESS the amount of blood at the end of systole and then calculating the percentage of blood that’s ejected
- —-Normal EF= 55-65% of ventricular volume (ventricle does not completely empty)
- In HF, the EF Fraction is normal in diastolic HF and severely reduced in systolic HF
Diagnosis and Assessment of Heart Failure?
- -The initial diagnosis and assessment of the severity and progression of CHF can be made using echo and exercise testing with gas analysis. The most commonly used echo measure is the EF. This is rated as:
- -45%–70%, normal
- -35%–45%, mildly impaired
- -25%–35%, moderately impaired
- -<15%, end-stage/transplant candidates
- -5% is compatible with life, but not long life
Classification of Heart Failure?
Ejection Fraction = The hallmark of HF
Severity classified according to the patient’s symptoms
Stage A: High risk for developing heart failure
- hypertension
- coronary artery disease
- diabetes mellitus
- family history of cardiomyopathy
Stage B: Asymptomatic heart failure
- previous myocardial infarction
- left ventricular systolic dysfunction
- asymptomatic valvular disease
Stage C: symptomatic heart failure
- known structure heart disease
- shortness of breath and fatigue
Stage D: refractory end-stage heart failure
- marked symptoms at rest despite maximal medical therapy( those who are hospitalized or cannot be safely discharged from the hospital without specialized intervention)
NY Heart Association Classification of Heart Failure?
Patient Symptoms
Class I (Mild) No limitation of physical activity. Ordinary physical activity does not cause undue fatigue, palpitation, or dyspnea (shortness of breath).
Class II (Mild) Slight limitation of physical activity. Comfortable at rest, but ordinary physical activity results in fatigue, palpitation, or dyspnea.
Class III (Moderate) Marked limitation of physical activity. Comfortable at rest, but less than ordinary activity causes fatigue, palpitation, or dyspnea.
Class IV (Severe)
Unable to carry out any physical activity without discomfort. Symptoms of cardiac insufficiency at rest. If any physical activity is undertaken, discomfort is increased.
Pathophysiology of Heart Failure?
- Heart Failure results from a variety of cardiovascular conditions which cause decreased contraction (systole) or decreased filling(diastole) or both
- Chronic Hypertension
- Coronary Artery Disease
- Valvular Disease - Significant myocardial dysfunction usually occurs before the patient experiences symptoms
- As heart failure develops, the body tries to cope by activating neurohormonal mechanisms – this results in the symptoms the clients usually exhibit
* The compensatory mechanisms of HF = ‘the Vicious Cycle of HF’ - As the heart’s workload increases, contractility of the myocardial muscle fibers decreases & hypertrophy of the heart results. The heart cannot respond to the increased load and the failure becomes worse.
pathophysiology of Systolic Heart Failure?
vasoconstriction(decreased)—>renin causes release of Angioten—> FLUID VOLUME OVERLOAD(Angiote)