HF And Therapeutics Flashcards
1
Q
Define heart failure
A
- Failure to pump blood at the rate to meet the metabolic demands (oxygen) of the tissues
- caused by abnormalities of any aspect of cardiac function with adequate cardiac filling pressure
- characterised by haemodynamic changes (systemic vasoconstriction and neurohumoral activation)
2
Q
List the common causes of HF
A
- coronary artery disease (MI)
- hypertension (resulting in hypertrophy of the ventricle)
- idiopathic
- toxins (eg. Alcohol, chemotherapy etc.)
- genetic
3
Q
What are the main types of heart failure?
A
- HF with reduced EF (less than 40%) = systolic HF
- HF with preserved EF (over 50%) = diastolic HF
- chronic (congestive)
- acute (decompensated)
4
Q
Describe the pathophysiology of HF
A
- myocardial injury causes LV systolic dysfunction
- the heart is not pumping as well and the body perceives this as a reduction in circulating volume and pressure
- the body’s compensatory mechanisms kick in
- activation of SNS (RAAS, AVP etc.) resulting in vasoconstriction and systemic Na and water retention
- but because not any volume is being lost (the cardiac output is just being reduced) this is maladaptive and worsens the dysfunction of the LV
5
Q
What are the symptoms of HF?
A
- dyspnoea (orthopnoea/PND)
- ankle swelling (can be abdomen and legs as well)
- fatigue/tiredness
6
Q
What are the signs of HF?
A
- peripheral oedema
- elevated JVP
- 3rd heart sound
- displaced apex beat (due to cardiomegaly)
- pleural oedema (lung crackles)
- pleural effusion
7
Q
Describe the NYHA classification of HF
A
- Class I = no symptoms/limitations in ordinary physical activity
- Class II = mild symptoms and slight limitation of ordinary activity
- Class III = marked limitation in activity as a result of symptoms, even during less than ordinary activity (only comfortable at rest)
- Class IV = severe limitations with symptoms even at rest, bed-bound
8
Q
Describe the route of diagnosing HF
A
- heart failure suspected (risk factors, symptoms/signs, abnormal ECG)
- NT pro-BNP taken (if low, HF excluded, if higher than cut-off - refer for echo)
- echo looks at EF and confirms HF (define HF phenotype)
- determine aetiology and commence treatment
9
Q
What are the class I recommendations for medications given to all HF patients?
A
- ACEi/ARB/ARNI
- BB
- MRA
- SGLT2i
- loop diuretic (symptomatic)
10
Q
Describe the mechanism of action of ACEis
A
Prevents the vasoconstriction and fluid retention initiate by the RAAS system in response to reduced cardiac output
11
Q
Describe the mechanism of action of ARNIs
A
- prevents binding of angiotensin II to receptor
- inhibits neprilysin responsible for breaking down BNP to augment natriuretic peptide action (increase vasodilation, diuresis and natriuresis etc.)
12
Q
What therapy can be given to selected patients and how is the decision made?
A
- devices implanted under the skin = CRT/ICDs
- used for reduced ejection fracture
- chosen depending on QRS duration and if LBBB
(CRDs = more severe NYHA classes) - VADs/mechanical circulatory assistance = severe cases
- transplant
13
Q
What drug therapy can be given for aortic stenosis?
A
- ivabradine (sinus node inhibition, ineffective in AF0
- hydralazine for African patients
14
Q
Describe the treatment for acute HF
A
- if cardiogenic shock - give circulatory support (usually ionotropes)
- if respiratory failure - give ventilatory suppport eg. CPAP, mechanical
- once stabilised, think aetiology (CHAMP - ACS, hypertension, arrhythmia, mechanical, PE)
- treat aetiology
15
Q
Describe features of warm + wet patients and the treatment
A
- pulmonary congestion
- orthopnoea/PND
- increased JVP
- gut congestion (hepatomegaly)
- treatment = vasodilation and diuretics
