Heart Failure Notes

Heart Failure

• Definition

  • Result of structural/functional cardiac disorder= CO inadequate

  • 2/1000 (UK); 1-3% (10% elderly); Poor prognosis 25-50% die <5yrs

  • Initially adaptive mechanisms compensate=maintain CO (AT REST)

  • Eventually cardiac function declines= more severe= DECOMPENSATED HF

• Pathophysiology Changes heart & peripheral vascular result of haemodynamic changes

  • Ventricular dilatation

  • Myocyte hypertrophy

  • Increased collagen synthesis

  • Altered myosin gene expression

  • Altered sarcoplasmic Ca-ATPase density

  • Increased ANP secretion

  • Salt and water retention

    • Activation of renin-angiotensin-aldosterone system= Loss of beneficial compensatory mechanisms--> Cardiac decompensation

  • Peripheral vasoconstriction (r-a-a--> Cardiac decompensation)

  • Sympathetic stimulation

• Development of CHF following IHD

• Chronic effects of CHF

• Systolic vs. Diastolic failure (COEXIST)

  • Systolic

    • Abnormal ventricle contractility= Decreased CO

    • EF <40%

    • Causes= IHD; MI; Cardiomyopathy

  • Diastolic

    • Abnormal ventricle relaxing and filling

    • Increased filling pressures >50%

    • Cause= Constrictive pericarditis; Tamponade; Cardiomyopathy; Hypotension

• Left sided vs. Right sided (Independently OR together as CONGESTIVE CARDIAC FAILURE)

  • LEFT HF (IHD most commonly affects LV)

    • Symptoms (PULMONARY CONGESTION)

      • Dyspnoea; Poor exercise tolerance; Fatigue; Orthopnoea; PND

      • Nocturnal cough (PINK FROTHY SPUTUM); Wheeze

      • Nocturia

      • Cold peripheries

      • Weight loss; Muscle wasting

  • RIGHT HF (COR PULMONALE; PULMONARY HYPOTENSION/EMBOLISM)

    • Symptoms & signs

      • Peripheral oedema; Ascites

      • Enlarged heart

      • Hepatomegaly

      • Nausea; Anorexia

      • Facial engorgement

      • Pulsation in neck and face (tricuspid regurgitation); Distended JVP

      • Epistaxis

  • CCF

    • LHF--> RHF

    • Greatly increased pulmonary vascular pressure

    • RV initially hypertrophies but eventually fails from pressure overload

• Acute vs. Chronic

  • Acute

    • New onset acute/decompensation of chronic

    • Pulmonary/Peripheral oedema

    • With/without signs of peripheral effusion

  • Chronic

    • Insidious

    • Venous congestion common but arterial pressure well maintained until late

• Low-Output vs. High-Output Failure

  • Low-output (CO decreased and fails to increase on exertion)

    • PUMP FAILURE

      • Systolic/diastolic HF

      • Decreased rate (B-blocker; Heart block; MI)

      • Negatively inotropic drugs (most antiarrhythmics)

    • EXCESSIVE PRELOAD

      • Mitral regurgitation

      • Fluid overload (NSAIDs cause)

      • Renal excretion impaired-> Fluid overload-> LVF (common if HF too)

    • CHRONIC EXCESSIVE AFTERLOAD

      • Aortic stenosis

      • Hypertension

  • High-output (output normal/increased in exertion. Fails when CO doesn't meet exertional needs. Normal heart too, but earlier if there is heart disease))

    • Anaemia; Pregnancy; Hyperthyroidism; Paget's; AV malformation;...

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