Heart Failure Flashcards
List the 4 key phases of the cardiac cycle
- Isovolumetric Relaxation
- Filling Phase
- Isovolumetric contraction
- Ejection Phase
(1 + 2 diastole 3 +4 systole)
Equation for BP
BP = CO x TPR
Equation for CO
CO = SV x HR
List the 3 mechanisms in HF that act to preserve BP
- Frank Starling
- Neurohormonal (SNS, RAAS, ADH)
- Ventricular hypertrophy (remodelling)
Explain the Frank Starling Mechanism
- In HF there is ↓ CO and SV
- leads to ↓emptying, ↑EDV
- results in ↑stretch, ↑ SV, ↑emptying and CO
UP TO A POINT
Explain SNS activation in HF
Baroreceptors in carotid sinus and aortic arch detect ↓ CO and ↑ SNS outflow:
- ↑cardiac contractility
- ↑ vasoconstriction (arteries and veins)
- ↑ Heart rate
Explain RAAS activation in HF
Explain ADH activation in HF
- Osmoreceptors in hypothalamus detect high osmolarity
- ADH released from posterior pituitary
- ↑ H2O retention
- ↑ intravascular volume and preload
What is heart failure?
Failure of the heart to generate sufficient CO to meet the metabolic demands of the body
What are the types of heart failure?
R vs L
Systolic vs Diastolic
List 4 symptoms of Right sided heart failure
- Ankle swelling
- Weight gain
- Abdominal distension and discomfort
- Anorexia / nausea
List 4 signs of Right sided heart failure
- Raised JVP
- Pitting ankle/sacral oedema
- Tender smooth hepatomegaly
- Ascites
List 4 symptoms of left sided heart failure
- Shortness of breath on exertion
- Orthopnoea
- Paroxysmal nocturnal dyspnoea
- Nocturnal cough (± pink frothy sputum)
List 4 signs of left sided heart failure
- Tachypnoea
- Bibasal fine crackles and wheeze
- Cyanosis
- Prolonged CRT
- Hypotension
List 3 less common signs of left heart failure
- Pulsus alternans (alternating strong and weak pulse)
- S3 gallop rhythm (filling of a stiffened ventricle)
- Features of functional mitral regurgitation
List 4 causes of Systolic heart failure
- Ischaemic heart disease
- Dilated cardiomyopathy
- Myocarditis
- Infiltration (e.g. in haemochromatosis or sarcoidosis)
List 4 causes of diastolic heart failure
- Hypertrophic obstructive cardiomyopathy
- Restrictive cardiomyopathy
- Cardiac tamponade
- Constrictive pericarditis
What is high output cardiac failure?
CO is normal, but there is an increase in peripheral metabolic demands which exceed those that can be met with maximal cardiac output
List 4 causes of high output cardiac failure
- Anaemia
- Arteriovenous malformation
- Paget’s disease
- Pregnancy
- Thyrotoxicosis
- Thiamine deficiency (wet Beri-Beri).
What classification system is used for heart failure?
New York Heart Association (NYHA) Classification of Heart failure
Grades severity of exertional dyspnoea
Explain the NYHA classification
Class I - no limitation in physical activity
Class II - slight limitation of physical activity
Class III - marked limitation in physical activity
Class IV - inability to carry on any physical activity
Investigations for heart failure?
(In order)
- NT-proBNP
- ECG
- FBC
- Chest X-ray
- Echocardiogram
What is NT-proBNP?
List 3 of its actions
Released by ventricles in response to myocardial stretch. Works to balance effects of RAAS:
- ↑excretion of Na and H2O
- vasodilation
- ↓ renin and AT II
What values of NT-proBNP, in GP, require specialist referral?
What investigation is performed by the specialist to confirm diagnosis?
- BNP > 2000ng/L - urgent 2 week referral
- BNP 400-2000ng/L - 6 week referral
Referred to specialist for trans-thoracic echocardiogram
What is the purpose of an Echocardiogram in HF?
Can show the presence and degree of ventricular dysfunction
Measured by the ejection fraction
EF values indicative of systolic vs diastolic HF
< 40% (reduced EF) = systolic
> 40% but raised BNP (preserved EF) = diastolic
Blood tests in HF and why
- U+Es - renal function
- LFTs - hepatic congestion
- TFTs - hyperthyroidism
- HbA1C and lipid profile - modifiable risk factors
- BNP
List 5 chest x-ray findings in heart failure
(ABCDEF)
- Alveolar oedema (‘batwing’ perihilar shadowing)
- Kerley B lines (due to interstitial oedema)
- Cardiomegaly
- upper lobe blood diversion
- Pleural Effusions (bilateral transudates)
- Fluid in the horizontal fissure
What value indicates cardiomegaly on x-ray?
cardiothoracic ratio > 0.5
List 3 lifestyle modifications for HF
- Smoking cessation
- Salt and fluid restriction
- Supervised cardiac rehabilitation
Pharmacological management for HF
(ABAL)
- ACE inhibitor (eg. ramipril)
- Beta Blocker (eg. bisoprolol)
- Aldosterone antagonist (eg. spironolactone or eplerenone)
- Loop diuretics improves symptoms (eg. furosemide)
What is Entresto?
Valsartan/sacubitril
Used as an alternative to ACEi or ARBs
Who is eligible for Entresto
- Symptomatic heart failure
- Severe LVSD
- Stable renal function
- Good BP
- Already on decent dose of ACEi or ARB
Surgical/device management option for HF
Cardiac resynchronisation therapy in QRS > 130ms
What cannot be used alongside Entresto?
ACEi due to risk of angioedema
Requires minimum 36 hour washout period
Any of what 3 criteria must be fullfilled for an ICD
- QRS interval <120ms, high risk sudden cardiac death, NYHA class I-III
- QRS interval 120-149ms without LBBB, NYHA class I-III
- QRS interval 120-149ms with LBBB, NYHA class I
What is acute HF?
Sudden onset or worsening of the symptoms of HF due to a reduced CO that results from a functional or structural abnormality
What are the two ways in which acute HF may arise?
- De-novo AHF - no PMH of HF
- Decompensated AHF (66-75%) - a background history of HF
What causes De-novo AHF
Ischaemia → increased cardiac filling pressure and myocardial dysfunction
Results in reduced CO → hypoperfusion
Can cause pulmonary oedema
List one other cause of De-Novo AHF
- Viral myopathy
- Toxins
- Valve dysfunction
List 4 triggers of decompensated AHF
- Acute coronary syndrome
- Hypertensive crisis
- Acute arrhythmia
- Valvular disease
List 4 symptoms of AHF
- Breathlessness
- Reduced exercise tolerance
- Oedema
- Fatigue
List 4 signs of AHF
- Cyanosis
- Tachycardia
- Raised JVP
- Displaced apex beat
- Bibasal crackles +/- wheeze
- S3 heart sound
Initial Management of decompensated AHF
- Sit patient up
- O2 therapy (aim >94%)
- IV furosemide
- SC morphine
- Consider nitrites (it hypoxic or hypertensive)
Advanced management of AHF (pulmonary oedema)
(ITU setting)
- CPAP
- Intubation and ventilation
- Furosemide infusion
- Dopamine infusion
- Intra-aortic balloon pump - if in cardiogenic shock
- Ultrafiltration
List 4 s/e of Beta blockers
Bradycardia, hypotension, fatigue, dizziness
List 4 s/e of ACEi
Hyperkalaemia, renal impairment, dry cough, lightheadedness, fatigue, GI disturbances, angioedema
List 4 s/e of spironolactone
Hyperkalaemia, renal impairment, gynaecomastia, breast tenderness/hair growth in women, changes in libido
List 3 s/e of Furosemide
Hypotension, hyponatraemia/kalaemia
List 3 s/e of NO
Headache, palpitation, flushing
List 3 s/e of Digoxin
Dizziness, blurred vision, GI disturbances