Congestive Cardiac Failure or Congestive Heart Failure (CHF)- B. Pharma 2nd Semester Pathophysiology notes pdf

Congestive Cardiac
Failure of Congestive Heart Failure (CHF)

Contents

       Congestive Cardiac Failure

       Types

       Pathogenesis

Objectives
 

At the end of this PDF Notes, student will be able to

       Define  congestive heart failure

       Discuss the types of congestive
heart failure

       Explain the pathophysiology of
congestive heart failure

       Discuss the signs and symptoms of it

CONGESTIVE CARDIAC FAILURE

      
A clinical syndrome

      
Result from any disorder that
impairs the ability of the ventricle to fill with or eject blood

      
Rendering the heart unable to pump
blood at a rate sufficient to meet the metabolic demands of the body

       Heart failure can result from any disorder that reduces ventricular
filling (diastolic dysfunction) and/or myocardial contractility (systolic
dysfunction)

Etiology of 

Congestive Heart Failure

Systolic dysfunction (decreased
contractility)

       Reduction in muscle mass (e.g. myocardial infarction)

       Dilated cardiomyopathies

       Ventricular hypertrophy

       Pressure overload (e.g. systemic or pulmonary    HT, aortic or pulmonic valve stenosis)

       Volume overload (e.g., valvular regurgitation, shunts, high-output
states)

Diastolic dysfunction (restriction in
ventricular filling)

       Increased ventricular stiffness

       Ventricular hypertrophy (e.g. hypertrophic cardiomyopathy)

       Infiltrative myocardial diseases (e.g. amyloidosis, sarcoidosis,
endomyocardial fibrosis)

       Myocardial ischemia and infarction

       Mitral or tricuspid valve stenosis

       Pericardial disease (e.g. pericarditis, pericardial tamponade)

Types of Heart Failure

       Acute and chronic heart failure

       High output and low output HF

       Left sided, right sided and biventricular HF

       Forward and backward HF

       Systolic and diastolic HF 

Acute heart failure 

       Heart is not able to pump the blood effectively

       Also called as Decompensated heart failure

       Compensatory mechanisms  of human
body cause increase in CO by stimulation of β1  receptors and 
also RAA-system

       Both mechanism leads to vasoconstriction

       Treatment with Inotropic drugs becomes necessary

Chronic heart failure

       Failure of compensatory mechanism

       Heart needs to undergo surgery for its repair

       Further controlled by administration of drugs

High output HF:

       There is high demands of the body, which are not met even with increased
cardiac output

       e.g.: anemia, pregnancy

Low output HF:

       There is decreased contractility of heart leading to decreased cardiac
output

       e.g.: cardiomyopathy, valvular disease

Left sided (left ventricular) HF

        Excess fluid accumulates upstream

        Reduction in left ventricular
output

        Increase in left atrial pressure

        Increase in pulmonary venous
pressure

Ø  Acute increase in left atrial pressure causes pulmonary congestion and
pulmonary edema e.g.: MI

Ø   Gradual increase in left atrial
pressure causes reflex pulmonary hypertension but no pulmonary edema

e.g. : aortic stenosis

Right sided (right ventricular) HF:

         Excess fluid accumulates
upstream behind the failing right ventricle  

         Reduction in right ventricular
output

         Results in systemic venous
congestion

  
Ex: pulmonary valvular stenosis, multiple pulmonary emboli 

Systolic HF:

       Characterized by an abnormality of ventricular contraction

       As seen in ischemic heart failure and dilated cardiac myopathy

Diastolic HF:

       Characterized by an impaired ventricular relaxation

       Increased ventricular stiffness resulting in diastolic dysfunction

e.g.: ischemia, left ventricular
hypertrophy

Pathophysiology of 

Congestive Heart Failure

Preload: Pressure that fills the left ventricle during
diastole

      
Main Determinant– left ventricular compliance and venous
return

      
Small increase in end-diastolic volume

      
large increase in cardiac output

      
Primary compensatory mechanism in normal heart

      
Ability of heart to alter the force of contraction depends  on preload

Afterload: Pressure against which the left ventricular contracts and is measured
as the mean aortic pressure 

  • Main determinants – total peripheral resistance
    and left ventricle size 

  • Left ventricular dysfunction – an inverse
    relationship exist between afterload and stroke volume

  • An increase in afterload causes a decrease in
    stroke volume

Key components of the pathophysiology of
cardiac remodelling

Compensatory Mechanisms

Cardiac compensatory mechanism:

Ø  Ventricular dilation

Ø  Ventricular hypertrophy

Peripheral compensatory mechanisms:

Ø  Increased sympathetic activity

Ø  Activation of renin angiotensin aldosterone system

Ø   Increased release of arginine
vasopressin

Renin Angiotensin Aldosterone system

Clinical Presentation – Signs of 

Congestive Heart Failure

       Pulmonary edema

        Pleural effusion

        Tachycardia

        Cardiomegaly

       Peripheral edema

        Jugular venous distension

        Hepatojugular reflux

        Hepatomegaly

Symptoms of 

Congestive Heart Failure

          Dyspnea

       Orthopnea

       Paroxysmal nocturnal dyspnea

        Exercise intolerance

        Tachypnea

       Ascites, Mental status changes

       Cough

        Fatigue

        Nocturia

        Hemoptysis

        Abdominal pain, Anorexia, Nausea,
Bloating

SUMMARY

       CHF
is a clinical syndrome that impairs the ability of the ventricle to fill with
or eject blood

       Heart
is unable to pump blood at a rate sufficient to meet the metabolic demands of
the body

       It can be classified as:  Acute
and chronic heart failure,

       High output and low output heart failure,

       Left sided, right sided and biventricular heart failure,

       Systolic and diastolic heart failure

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