Heart failure

• What is heart failure?

  A complex clinical syndrome in which the heart is incapable of maintaining a cardiac output adequate to accommodate metabolic requirements and the venous return
• New York Heart Association Classification

  • Class I: No symptoms with ordinary activity
  • Class II: Slight limitation of physical activity. Comfortable at rest, but ordinary physical activity results in fatigue, palpitation, dyspnoea, or anginal pain
  • Class III: Marked limitation of physical activity. Comfortable at rest, but less than ordinary physical activity results in fatigue, palpitation, dyspnoea or anginal pain
  • Class IV: Unable to carry out any physical activity without discomfort. Symptoms of cardiac insufficiency may be present even at rest.
• HF Classification: Evolution and Disease Progression

  • Stage A: Patient at high risk for developing HF with no structural disorder of the heart
  • Stage B: Patient with structural disorder without symptoms of HF
  • Stage C: Patient with past or current symptoms of HF associated with underlying structural heart disease
  • Stage D: Patient with end-stage disease who requires specialised treatment strategies
• Causes of heart failure?

  • Ischemic heart disease
  • Hypertension
  • Idiopathic cardiomyopathy
  • Infections
  • Toxins
  • Valvular disease
  • Prolonged arrhythmias
• Left ventricular dysfunction

  Systolic: Impaired contractility/ejection

  Diastolic: Impaired filling/relaxation
• Frank Starlings law

  CO = HR X SV

  • An increase in EDV increases the stretch on actin-myosin filaments, causing greater contraction and, therefore, increased stroke volume and decreased end-systolic volume.
  • If the heart is overstretched, a less forceful contraction occurs, decreasing stroke volume, increasing end-systolic volume, and raising the end-diastolic volume.
  • The graph becomes more linear. A large increase in EDV does not cause a larger increase in SV

  
• Symtomology?

  • Increase in ventricular end-diastolic pressure
  • Left atrial pressure increase
  • Pulmonary capillary pressure increases
  • Pulmonary congestion
• LV dysfunction - systolic and diastolic (symptoms)

  • Dyspnoea on exertion
  • Paroxysmal nocturnal dyspnoea (PND)
  • Tachycardia
  • Cough
  • Haemoptysis
  • Fatigue
• LV dysfunction - systolic and diastolic (physical signs)

  • Basilar Rales
  • Pulmonary oedema
  • S3 Gallop (systolic dysfunction)
  • Pleural effusion
  • Cheyne-stokes respiration
• RV failure - Systolic and diastolic (symptoms)

  • Abdominal pain
  • Anorexia
  • Nausea
  • Bloating
  • Swelling
• RV failure - systolic and diastolic (physical signs)

  • Peripheral oedema
  • Jugular venous distention
  • Abdominal-jugular reflux
  • Hepatomegaly
• Compensation?

  How does the body adjust to having this pain.

  • Frank-starling mechanism
  • Neurohormonal activation
  • Ventricular remodelling
• Compensatory mechanism (Frank-starling mechanism)

  • At rest, no HF
  • HF due to LV systolic dysfunction
  • Advanced HF
• Neurohormonal activation

  • Sympathetic nervous system
  • Renin-angiotensin-aldosterone system
  • Vasopressin (antidiuretic hormone, ADH)
• Compensatory mechanism 


  MAP = (SV x HR) x TPR
• Beta-Blockers

  • Beta-blockers decrease myocardial contractility and increase EF after 1-3 months of use
  • When combined with conventional HF therapy, beta-blockers reduce the combined risk of morbidity and mortality or disease progression.
  • Beta 1 - cardiac
  • Lowers blood pressure by reducing contractility of the heart
• Aldosterone antagonists

  • Reduces heart failure-related morbidity and mortality
  • Reserved for patients with NYHA class III-IV HF
  • Side effects include hyperkalaemia and gynecomastia. Potassium and creatinine levels should be closely monitored
• Angiotensin Receptor Blockers (ARBs)

  • Block AT1 receptors, which bind circulating angiotensin II
  • Examples valsartan, candesartan, losartan
  • Should be used to treat patients who are ACE intolerant or who develop angioedema
• Cardiac Resynchronization Therapy (CRT)

  Increases efficiency by improving the co-ordination
• LVAD & Transplant

  The biggest problem is the rejection

  • Patients immune system will attack it
  • Lack of donors
• ACE inhibitor

  Reduces blood pressure by preventing vasoconstriction
• Diuretic

  Reduces blood pressure by decreasing circulating blood volume