Heart Failure Flashcards
What is congestive heart failure?
When the heart is unable to pump blood at a rate that meets the requirements of the tissue or can do so only from high pressures
What are underlying structural abnormalities which can cause heart failure?
LV systolic dysfunction Valvular heart disease Pericardial constriction or effusion LV diastolic dysfunction/HF with sys function or normal EF Tachycardia or bradycardia MI Restrictive cardiomyopathy (amyloid, hypertrophic CM) RV failure: primary or secondary PHT
What are the causes of LVSD?
Ischaemic heart disease (MI) Severe AV disease or MR Dilated cardiomyopathy Hypertension HIV, lyme's disease
What are the symptoms of congestive heart failure?
Dyspnoea
Fatigue
Oedema
Reduced exercise capacity
What are the signs of CHF?
Oedema Tachycardia Raised JVP Chest crepitation or effusion 3rd heart sound Displaced apex beat
Why carry out an CXR?
Signs of: Pul. oedema Cardiomegaly Effusion Sternal wires (previous op)
What bloods should be carried out?
FBC Fasting glucose U+Es Urinalysis TFT
What investigations should be carried out?
CXR Bloods Echo Radionucleotide scan L ventriculogram (angiogram) CMRI ECG (HF unlikely is normal) BNP level - Amino acid peptide elevated in HF Response to therapy (diuretics) MUGA scan for LVEF
What tests are used to show evidence of cardiac dysfunction?
Echo
Radionecleotide scan
L ventriculogram (angiogram)
CMRI
Name types of diuretic drugs
Furosemide and bumetanide
Name types of ACEi drugs
Ramipril, enalpril snd lisinopril
What are the ranges of LV ejection fraction?
Effected by disease - anaemia, sepsis etc Normal: 50-80% Mild: 40-50% Moderate: 30-40% Severe: <30%
How does heart failure affect cardiac output?
HF does not mean reduced CO - EF might lower but might be tachcardic to compensate
Is heart failure the final diagnosis?
No, there is underlying structural abnormality and cause:
HF due to LVSD due to IHD
HF due to severe aortic stenosis
What percentage of people in the UK suffer from HF?
1-2%
What is the prognosis in the first year of developing HF?
Poor: 30-40% mortality
How many inpatient bed days are caused by HF and what is the readmission rate over the nest 3 months?
1 million inpatient bed days
50% readmitted
What are the factors that are contributing to the increase in prevalence of heart failure?
Treatment of acute myocardial infarction - prev MI increases risk of CHF
Ageing population
Increased prevalence of: hypertension, CHD, obesity, diabetes, high cholesterol
What does displaced apex beat indicate?
Enlargement of the heart
What is the 2/3 criteria for heart failure to be diagnosed?
- Symptoms or signs of HF (rest or exercise)
and - Objective evidence of cardiac dysfunction
and (in doubtful cases) - Response to therapy (diuretics)
What are the 2 investigations that can be carried out for screening for congestive heart failure?
ECG - if normal then rules out LVSD
Brain natriuretic peptide - the amino acid is elevated in HF, low BNP excludes HF
What does raised brain natiuretic peptide indicate?
Heart failure or left ventricular systolic dysfunction, and indicates the need for echo/cardiac assessment
What is the order of investigations and examination for the diagnosis of HF?
- Symptoms of signs suggest CHF
- FBC, fasting blood glucose, U+Es, urinalysis, TFT and CXR
- BNP and ECG
- If BNP elevated or ECG abnormal
- Refer for echocardiography
What is way to diagnose LVSD?
- Clinical history: MI, DM, HBP, post partum, alcohol
- ECG, CXR, and always an echo
- Coronary angigraphy (if chest pain, <70)
- Cardiac MRI: infarction/inflammation/fibrosis
What is an echo an essential investigation for HF?
Shows: LVSD Valvular dysfunction Pericardial effusion / tamponade Diastolic dysfunction LVH Atrial/ventricular shunts / congenital heart defects PHT/ R heart dysfunction
What are the investigations done to assess LVEF?
MUGA and MRI
What are the pros and cons of MUGA in measuring LVEF over echo?
Easier to obtain accurate figure
Greater reproducibility
But
Ionising radiation
No additional structural info
What are the pros of using MRI to measure LVEF?
Greater reproducibility
Added into about:
Aetiology - fibrosis, infiltration, oedema
Valves
What are the cons of using MRI to measure LVEF?
Time consuming
Patient compliance - long breath holds, claustrophobic, ability to lie flat
Specialist centres
Long waiting lists
What classification if used to grade heart failure?
New York Association (NYHA)
Describe classifications of heart failure using the NYHA
I - no symptoms on usually activity
II - comfortable with rest or mild exertion
III - comfortable only at rest
IV - discomfort of physical activity
What symptoms are used to characterised chronic heart failure?
Progressive cardiac dysfunction SOB Fatigue Neurohormonal disturbances Sudden death
What is systolic heart failure?
Decreased pumping function of the heart, which results in fluid back up in the lung and heart failure
What is diastolic heart failure?
Thickening and stiffening of the heart muscle causing the heart to not fill up with blood properly, which causes fluid back up in the lungs and heart
Normal EF but not as much blood in the ventricle in the first place
What are the risk factors for HF?
CAD HPT Valvular disease Alcoholism Infection (viral) DIabetes Congenital heart defects Other: age, smoking, obesity, obstructive sleep apnoea
How can the risk factors lead to heart failure in general terms?
- Cause myocardial injury
- Pathologic remodelling
- Low ejection fraction
- Death or pump failure -> heart failure
Describe the pathophysiology of systolic dysfunction heart failure?
- Failing or damaged heart causes it to not follow Starling’s law
- So cardiac output decreases
- This activates RAAS and sympathetic system and circulatory volume increases and vasoconstriction
- This causes further dilation, CO drops further as the myocytes undergo hypertrophy and then fibrose causing further tweaking
What 2 drugs are given to improve symptoms?
Diuretics
Digoxin
What 3 drugs are give to improve symptoms and survival?
ACEi/ARBs
Spironolactone
Valsartan-sacubitril (ARNI)
What 2 drugs are given to improve survival?
Beta blockers
Ivabridine
What are the diuretics used for the treatment of symtpoms of heart failure?
Furosemide or Bumetanide
Which Beta Blockers are used to block detrimental hormonal changes (adrenaline) in heart failure?
Carvedilol
Bisoprolol
Metoprolol
Which 2 groups of drugs are available for the blocking of angiotensin II effects in heart failure? and give examples
ACE inhibitors - ramipril
ARBS - valsartan, losartan
What drug blocks the effects of aldosterone in heart failure?
Spironolactone
What is the action of the drug Neprolysin?
Prevents metabolism of ANP/BNP and enhances their actions
What do positive inotropes do and what is their action?
Improve ability of heart to pump by increasing availability of Ca in the myocyte - Digoxin
How are vasodilators useful in cardiac failure and give an example?
Reduces preload and after load - isosorbide mono or dinitrate
What is the action of loop diuretics (furosemide) in improving symptoms?
Removes excess salt and water by inducing diuresis (urine output) and block the Na-K-Cl transporter in the Loop of Henle, preventing reabsorption of sodium and water
What are the adverese drug reactions of furozemide?
Dehydration Hypotension Hypokalaemia, hypronatraemia Gout Imparied glucose tolerance, diabetes
What drugs do furosemide interact with?
Aminoglycosides Lithium NSAIDs Antihypertensives Vancomycin
What general actions of different drugs will reduce mortality in heart failure?
Angiotensin blockade
Beta receptor blockade
Aldersterone blockade
ANP/BNP enhancement
What is the effect of ACE inhibitors?
Block angiotensin converting enzyme, preventing conversion of angiotensin I to II
Reduces preload and afterload of the heart (by prevent vasoconstriction)
What are the adverse effects of ACEis?
First dose hypotension Cough Angioedema Renal impairment Renal failure Hyperkalaemia
What drugs do ACEis interact with?
NSAIDs
Potassium supplements
Potasium sparing diuretics
What is the action of ARBs?
Block angiotensin II receptor AT1 receptor Inhibits: Vasoconstriction Hypertrophy Increased sympathetic tone
What is the action of aldersterone antagonists and give example?
Potassium sparing diuretic which inhibits the actions of aldosterone by acting in the distal tube - spironolactone
What is the action of ivabridine?
Inhibits the If current in the SA node - slows depolarisation and thus heart rate
Why can anti-coagulants be useful in heart failure?
Dilated ventricle gives rise to thrombus formation and thromboembolic events - warfarin
Outline the therapeutic regime for heart failure
Furosemide ACEi ARB Sacubitril and valsartan (ARNI) B block +/- ivabridine Spironolactone Digoxin Warfarin
What are ways that are used to monitor benefit of drugs?
Symptomatic relief - SOB, fatigue
Clinical relief - Peripheral. oedema, ascites
Monitor weight (shows water retention)