L27-heart Failure Flashcards
What is heart failure
Failure of heart to pump blood at a rate commensurate with requirements of metabolizing tissues
Common end point for many cardiac diseases
Poor prognosis
What are the 3 causes of heart failure
Inapp workload
Impaired myocyte contraction
Restricted filling of ventricles
What are the 2 cases of inapp workload
1-volume overload
2-pressure overload
Cases of volume overload
Hypervolemia
Regurgitation/incompetent valves
Cases of pressure overload
Hypertension
Pulmonary/aortic stenosis
What is dilated cardiomyopathy
causes the heart chambers (ventricles) to thin and stretch, growing larger leading to systolic heart failure
Describe mitral stenosis
Restriction and narrowing of mitral valve
Impairment of left ventricular filling
What is hypertrophic cardiomyopathy
disease in which the heart muscle becomes thickened (hypertrophied)
What is restrictive cardiomyopathy
refers to a set of changes in how the heart muscle functions(impaired relaxation). These changes cause the heart to fill poorly (more common) or squeeze poorly (less common). Sometimes, both problems are present.
Fibrosis/amyloidosis
What are the causes of restricted filling of ventricles
Mitral stenosis Hypertrophic cardiomyopathy Impaired relaxation: Restrictive cardiomyopathy Pericardial constriction(thickening)
Describe ischemic heart disease
Coronary atherosclerosis
Damage to myocardium and scar tissue formation
What causes systolic dysfunction
Inadequate myocardial contractile function: Ischemic heart disease Dilated cardiomyopathy Increased preload: Mitral/tricuspid regurge Aortic/pulmonary regurge
What causes diastolic dysfunction
Restricted filling: Mitral or tricuspid stenosis Hypertrophic cardiomyopathy Impaired relaxation: Restrictive cardiomyopathy Constrictive pericarditis
Result of combined systolic and diastolic dysfunction
Increased after load:
Hypertension
Aortic valve stenosis
Concentric hypertrophy
Difference between systolic and diastolic heart failure
Bp,myocardial hypertrophy,ESV,EDV
Systolic Bp:low-normal-high Myocardial hypertrophy:eccentric:longer muscle fibers ESV:high EDV:high
Diastolic: Bp:low-normal-high Myocardial hypertrophy:concentric:thicker muscle fibers ESV:low EDV:normal or low
How does frank starling mechanism correlate to cardiac output
When EDV inc Dilatation of ventricle occurs Inc cardiac myofiber stretching Inc force of contraction Inc cardiac output
Describe compensated heart failure
▪️Patient may remain asymptomatic or minimally symptomatic
Mechanism of compensation:
▪️Inc in preload to restore resting stroke vol to normal levels
▪️Combination of sympathetic nervous system and renin angiotensin system
▪️Compensatory hypertrophy
▪️Limitation on ability to inc stroke vol above resting levels
▪️Manifests as exercise limitation
Describe decompensated heart failure
▪️When compensatory mechanisms fail to inc cardiac output
▪️Plateau:further inc in EDV does not produce a corresponding inc in force of contraction of ventricle resulting in ▪️inadequate cardiac output
▪️Patients develop symptoms
▪️Outcome:may rapidly lead to death
What are the outcomes of heart failure
▪️Right sided(cor pulmonale): pulmonary hypertension
Lung diseases
▪️Biventricular: right sided heart failure due to left sided heart failure
▪️Left sided: ischemic heart disease
Systemic hypertension
Mitral or aortic valve disease
Primary diseases of myocardium(ex amyloidosis)
Most common form of heart faiulre
Left ventricle systolic failure
Effects of left sided heart failure
Raised pulmonary capillary pressure Raised left atrial pressure Left ventricular preload is increased Backward failure Forward failure inadequate cardiac output Renal hyoperfusion Activation of renin angiotensin system Hypoxic encephalopathy(irritability and coma) Accumulation of nitrogenous wastes
What is backward failure
One of the ventricles fails to pump out all of its blood that comes into it. Thus, the ventricular filling pressure and systemic or pulmonary edema increase+dyspnea
Leads to hemosiderin laden macrophages
What is pulmonary edema
Dec gas exchange resulting in arterial hypoexmia
What are the morphological changes in left sided heart failure in lungs
Grossly:heavy and congested
Microscopically: accumulation of edema
Fluid in the alveolar spaces
Heart failure cells:alveolar macrophages phagocytose extravasated RBCs from leaky capillaries
What are the morphological changes in left sided heart failure in heart
Grossly:depend on underlying cause
Left ventricular hypertrophy/dilatation
No hypertrophy due to mitral stenosis or restrictive cardiomyopathies
Microscopically: myocyte hypertrophy with interstitial fibrosis of variable severity
Clinical features of left sided heart failure
Onset is gradual but may be abrupt Dyspnea on exertion Orthopenea Paroxysmal nocturnal dyspnea Cough with blood tinged sputum Auscultation: Pulmonary crackles(edema) at base of lung Diminished s1+s2 and occurrence of s3 at apex Cyanosis
What is orthopnea
Dyspnea when recumbent
the supine position increases Venous return from the lower limbs and elevates the diaphragm
What is paroxysmal nocturnal dyspnea
Extreme dyspnea with the feeling of suffocation that wakes patient from sleep
What is cyanosis
Low organ perfusion decrease gas exchange
What are the effects of right heart failure
▪️Pressure back through the vena cava and peripheral veins and capillaries ▪️raised right atrial pressure
▪️combination of hepatic congestion and portal hypertension can lead to peritoneal transudates (ascites)
▪️backward failure
▪️pitting edema
Morphology of right sided heart failure in lung
▪️No pulmonary parenchymal edema or congestion
▪️Systemic venous congestion due to right sided heart failure to transudates(effusions) in to pleural space
Morphology of right sided heart failure in heart
▪️RA dilation
▪️RV dilation
▪️RV hypertrophy
▪️In cor pulmonale,myocardial hypertrophy and dilation generally
▪️Systemic venous congestion due to right sided heart failure can lead to transudates(effusions) in the pericardial spaces
What happens to liver (morphology) in right sided heart failure
▪️Congestive hepatomegaly: heavy and congested liver
▪️Cut section:congested central areas surrounded by peripheral paler,non congested parenchyma:nutmeg liver
▪️In severe long standing right sided heart failure,the central areas become fibrotic creating cardiac cirrhosis
▪️can also lead to elevated pressure in portal vein and its tributaries(portal hypertension)
▪️with vascular congestion,the spleen becomes tense and enlarged(congestive splenomegaly)
Clinical features of right sided heart failure
▪️distended jugular veins ▪️abdominal enlargement: Hepatic enlargement Splenic enlargement Ascites ▪️pleural/pericardial effusion ▪️peripheral/dependent/pitting edema Ankle swelling is specifically a characteristic of right heart failure(standing or seated) Sacral edema(supine)
Describe biventricular heart failure
RHF due to LHF
▪️Raised pulmonary artery pressures ▪️Raised pulmonary capillary pressure ▪️Backward failure ▪️Raised left atrial pressure ▪️Left ventricular preload is increased ▪️ventricular and atrial septal defect
Clinical picture of biventricular heart failure
▪️Dyspnea and fatigue ▪️Orthopnea ▪️Paroxysmal nocturnal dyspnea ▪️Cough with blood tinged sputum ▪️Pulmonary crackles(edema)at base of both lungs ▪️Diminished s1 and s2 and s3 occurs ▪️Cyanosis ▪️Distended jugular veins ▪️Abdominal enlargement: ▪️Hepatic enlargement ▪️Splenic enlargement ▪️Ascites ▪️Pleural/pericardial effusion ▪️Peripheral/dependent/pitting edema ▪️Ankle swelling ▪️Sacral edema(supine)
