Give a brief overview of the pathophysiology of heart failure
* The mechanical and biochemical forces alter the size, shape, and function of the ventricles
* The myocardial contractility is affected
* The ability of the heart as a pump is affected
* Not enough oxygenated blood is pumped out to meet the body's metabolic requirements
* Ineffective emptying
* Increased ventricular or atrial pressures
* Increase in sodium and water retention, decreased cardiac output, and circulatory and pulmonary congestion
What is systolic dysfunction?
* it occurs when the left ventricle is unable to pump sufficiently because of the inability of the heart to contract
* systolic dysfunction leads to increased vascular resistance and increased afterload
What is diastolic dysfunction?
* it leads to pulmonary vascular congestion-there is abnormal cardiac filling.
* diastolic heart failure-inability of the heart to pump sufficiently because inability of the heart to fill
What is heart failure?
* it is a complex clinical syndrome that can result from any structural or functional cardiac disorder that impairs the ability of the heart to pump blood to meet the metabolic requirements of tissue oxygenation
* it is the inability of the heart to provide sufficient blood (output) to meet the perfusion and oxygenation requirements of the tissues
List the risk factors of congestive heart failure
* HTN systolic>140, diastolic >90mmHg
* high cholesterol ischaemic heart disease fasting bloods >5.5 mmol/L
* overweight/obesity BMI overweight 25-30 obese >30
* etho abuse
* insufficient physical activity
* FHx of heart disease
* congenital heart disease, stroke, thyroid disorders
List the causes for congestive heart failure associated by disorders of heart muscle that results in decreased contractile properties of the heart
* coronary heart disease leading to myocardial infarction
* valvular heart disease
* congenital heart disease
List the other causes of congestive heart failure
* PE, chronic lung disease
* haemorrhage and anaemia
* transfusions or infusions
* increased body demands (fever, infection, pregnancy)
* drug induced
* physical and emotional stress
* dietary excessive sodium intake
List the systolic clinical signs of congestive heart failure
* impaired ability of the heart to contract
* weakened muscle, enlarged heart size
* inability of heart to empty
* Left ventricular ejection fraction (LVEF) <40-45%
List the diastolic clinical signs of congestive heart failure
* inability of the heart to relax is impaired
* stiff, thickened myocardial wall but normal size
* inability of heart to fill
Describe the clinical signs of left sided heart failure
* The left ventricle is weakened or overloaded and results in pulmonary congestion.
* left sided failure usually is the cause of right sided failure
Describe the clinical signs of right sided heart failure
* The right ventricle is impaired resulting in systemic venous overload.
* May occur independently from conditions affecting the right ventricle only
List the 4 functional classes associated with congestive heart failure
class I - no abnormal symptoms with activity
class II - symptoms with normal activity
class III - marked limitation due to symptoms with less than ordinary activity
class IV - symptoms at rest and severe limitations in functional activity
List the 4 stages of heart failure classification
stage A - presence of risk factors for heart failure
stage B - presence of structural heart disease but no symptoms
stage C - presence of structural heart disease along with signs and symptoms
stage D - presence of structural heart diseases and advanced signs and symptoms
What is left sided heart failure (forward failure)?
* inability of the left ventricle to fill or pump out blood to meet tissue needs
* congestion occurs mainly in the lungs from blood backing up into pulmonary veins and capillaries
* SOB, dyspnea on exertion, paroxysmal nocturnal dyspnea, orthopnea, pulmonary oedema
* cough may be dry, unproductive, usually at night
* fatigue from low cardiac output, nocturne, insomnia, dyspnea, catabolic effect of chronic failure
* insomnia, restlessness
What is right sided heart failure (backward failure)?
* inability of the right ventricles to fill or pump out blood into pulmonary circulation
* signs and symptoms of elevated pressures and congestion in systemic veins and capillaries
* oedema of ankles, unexplained weight gain (pitting oedema is obvious only after retention of at least 4.5kg of fluid)
* liver congestion may produce upper abdominal pain
* distended jugular veins
* abnormal fluid in body cavities (pleural space, abdominal cavity)
* anorexia and nausea from hepatic and visceral engorgement
* nocturia diuresis occurs at night with rest and improved cardiac output
What are the signs and symptoms of left sided heart failure (low output/pulmonary congestion)?
* paroxysmal nocturnal dyspnea
What are the signs and symptoms of right sided heart failure (systemic venous congestion)?
* peripheral oedema
* weight gain
* abdominal discomfort
List the common symptoms of heart failure
SOB, decreased exercise tolerance, tiredness/fatigue/lethargy, interrupted sleep due to difficulty breathing, swelling of ankles/feet/legs, weight gain (rapid), persistent cough, faintness/dizziness, rapid/irregular heart beat, swelling of the tummy area, SOB on exertion, paroxysmal nocturnal dyspnoea, orthopnoea
What are some of the investigations that should be undertaken to assist with the diagnosis of heart failure?
ECG, CXR, blood (FBC, electrolytes, LFT, TFT), urinalysis, Echo
What are the goals of therapy associated with congestive heart failure?
1. reduce symptoms
2. prevent hospitalisation
3. improve quality of life
4. slow the progression of the disease
5. improve survival (where possible) - decrease death due to progressive pump failure, decrease sudden cardiac death
6. minimise health costs
What are the treatment approaches for those with stage A (at high risk, no structural disease) CHF?
* treat HTN
* treat lipid disorders
* encourage regular exercise
* discourage alcohol intake
* ACE inhibition
What are the treatment approaches for those with stage B (structural heart disease, asymptomatic) CHF?
* all measures under stage A
* ACE inhibitors in appropriate pt's
* beta-blockers in appropriate pt's
What are the treatment approaches for those with stage C (structural heart disease with prior/current symptoms of HF) CHF?
* all measures under stage A
* drugs: diuretics, ACE inhibitors, beta-blockers, digitalis, dietary salt restriction
What are the treatment approaches for those with stage D (refractory HF requiring specialised interventions) CHF?
* all measures under A, B, C
* mechanical assist devices
* heart transplant
* continuous (not intermittent) IV inotropic infusions for palliation
* hospice care
What do diuretics do in the management of chronic heart failure?
symptomatic improvement of congestion, fluid overloaded patients (spironolactone is recommended)
What do beta-adrenergic blockers do in the management of chronic heart failure?
decrease myocardial workload and protect against fatal dysrhythmias by blocking norepiephrine effects of the sympathetic nervous symptom
What do angiotensin converting enzyme (ACE) inhibitors do in the management of chronic heart failure?
improve symptoms, exercise capacity, inhibit the adverse effects of angiotensin II (potent vasoconstriction/sodium retention)
What does digoxin do in the management of chronic heart failure?
improves symptoms, exercise capacity, and fewer admissions to hospital
What drugs are useful in the treatment of both hypertension and HF?
* ACE inhibitors
* beta blockers (carvedilol or long acting metoprolol)
* angiotensin receptor blocker
* treatment of lipid disorders
What are some complications that are associated with chronic heart failure?
* cardiac dysrhythmias
* myocardial failure and cardiac arrest
* digoxin toxicity from decreased renal function and potassium depletion
* pulmonary infarction
What are the most frequent non-cardiac causes of worsening CHF?
* recent co-prescribed drugs
* renal dysfunction
* thyroid dysfunction
What are the most frequent cardiac causes of worsening CHF?
* Supraventricular tachycardia
* worsening mitral valve, tricuspid valve
* uncategorised ischemia/MI
* excessive preload reduction
What is the definition of polypharmacy?
* The use of prescription or non-prescription (over the counter) medication that have no legitimate indication
* the use of multiple medications to treat the same condition
* the simultaneous use of interacting medications
* an inappropriate medication or dosage and
* the use of a medication to counteract the side effects of another medication
What are some strategies to address the issues of polypharmacy?
* collaboration between GP and acute sector
* review medication list
* electronic prescribing & linking of case profiles
* limiting over prescribing (different drug name but same action)
* pt education
* pt compliance
Describe how diet therapy can assist in the non-pharmacological management of CHF
*restricted sodium diet (dietary sodium should be limited to below 2000mg/day)
* restricted fluids diet
* saturated fat intake should be limited in all people
* high fibre diet recommended
* discourage alcohol: contributes to total fluid intake and may increase body weight due to its caloric load
* poor nutrition may benefit from vitamin supplementation particularly thiamine
* caffeine: excessive caffeine intake may exacerbate arrhythmia, increase HR and increase BP
What is the goal in encouraging physical activity and exercise in those with CHF?
* to increase stamina & improve tolerance
What lifestyle changes should be encouraged among patients with CHF?
* reduce salt intake
* healthy diet
* weight control
* alcohol intake
What is the definition of cardiac rehabilitation?
* the sum of activities required to ensure pt's the best possible physical, mental and social conditions so that they may resume and maintain as normal a place as possible in the community
What is the goal of cardiac rehabilitation?
* to help participants develop knowledge, skills and confidence to improve and sustain achievable health and functional activity
* to improve confidence
* to understand condition
* to increase energy levels
* to learn what I can do and how far to go
* to take up specific activity
* to have a practical need met