Acute heart failure

Question 1

acute heart failure refers to

Answer 1

rapid onset or worsening of the signs and symptoms of heart failure
life-threatening condition in which the heart does not pump enough blood to meet the body’s needs
may present as new onset heart failure or as acute decompensation of chronic heart failure

Question 2

pathophysiology of acute heart failure

Answer 2

AHF involves the acute failure of the heart to pump blood to meet the body’s demand
two courses of pathology develop as a result:
1. congestion in the pulmonary or systemic circulation. pulmonary oedema develops when the left ventricle is unable to empty, which increases the hydrostatic pressure in pulmonary vasculature leading to pulmonary oedema and hypoxia. these patients are ‘wet’
2. hypoperfusion of vital organs as the cardiac output is reduced. these patients are ‘cold’

Question 3

AHF patients will be classified according to:

Answer 3

four heamodynamic profiles:
1. WET-WARM: signs of congestion without signs of hypoperfusion (50%)
2. WET-COLD: signs of congestion with signs of hypoperfusion (45%)
3. DRY-WARM: no signs of congestion with no signs of hypo perfusion
4. DRY-COLD: no signs of congestion with signs of hypoperfusion

Question 4

two pathologies in acute heart failure

Answer 4

1. congestion: pulmonary oedema develops with the left ventricle is unable to empty, which increases hydrostatic pressure in pulmonary vasculature
2. hypoperfusion: of vital organs as the cardiac output is reduced.

Question 5

causes of new-onset AHF

Answer 5

• acute myocardial dysfunction (e.g. ischaemia due to myocardial infarction)
• acute valve dysfunction
• arrhythmias

Question 6

causes of acute decompensation of CHF

Answer 6

• infection
• acute myocardial dysfunction (e.g. ischaemia due to myocardial infarction)
• uncontrolled hypertension
• arrythmias
• worsening chronic valve disease
• non-adherence with drugs/diet
• change in drug regimen

Question 7

symptoms of acute heart failure

Answer 7

dyspnoea
reduced exercise tolerance
ankle swelling
fatigue
pink frothy sputum
orthopnoea
paroxysmal nocturnal dyspnoea

Question 8

signs of pulmonary or systemic congestion

Answer 8

fine basal crackles (bilateral)
peripheral oedema (bilateral)
dull percussion at lung bases
raised jugular venous pressure (JVP)
hepatomegaloy
gallop rythm (S3 or S4 heart sounds)
murmur

Question 9

signs of hypoperfusion

Answer 9

hypoxia
tachypnoea and accessory muscle use
tachycardia
cyanosis
cold, pale, and sweaty peripheries
oliguria
confusion/agitation
synocope/pre-syncope
narrow pulse pressure

Question 10

DDx for AHF

Answer 10

asthma
chronic obstructive pulmonary disease (COPD)
pneumonia

Question 11

leading cause of AHF without established CHF

Answer 11

myocardial infarction

Question 12

a presentation of unilateral basal crackles, especially concurrent with cough and fever, is more likely to represent

Answer 12

a chest infection

Question 13

if there is a global wheeze you should consider

Answer 13

asthma, although there may be a wheeze in pulmonary oedema

Question 14

bedside investigations

Answer 14

may show hypoxia (often SpO2 < 90%)
tachycardia and taachypnoea
systolic blood pressure may be normal, elevated or reduced (hypotension is associated with cardiogenic shock and poor prognosis)
pulse pressure may be narrow (<25% of the sBP)
ECG rarely normal

Question 15

what might the ECG show in acute heart failure

Answer 15

the ECG is rarely normal
abnormalities eg. signs of ischaemia or arrythmias are very common in AHF and an alternate diagnosis should be considered if the ECG is completely normal

Question 16

lab investigations for acute heart failure

Answer 16

B-type natriuretic peptide (BNP)
arterial blood gas
baseline blood tests
cardiac troponin
thyroid-stimulating hormone (TSH)
D-dimer

Question 17

B-type natriuretic peptide BNP

Answer 17

a sensitive but non-specific marker of heart failure. AHF is unlikely/can be ruled out if:
- BNP is less than 100ng/litre
- NT-proBNP is less than 300ng/litre

Question 18

arterial blood gas

Answer 18

often shows type 1 respiratory failure, or type 2 respiratory failure in those with pre-existing chronic lung conditions

Question 19

baseline blood tests

Answer 19

FBC, U&E, coagulation, CRP
anaemia may be a contributing factor

Question 20

cardiac troponin

Answer 20

to detect myocardial infarction (MI) as the underlying cause, however, troponins are often elevated in AHF patients without myocardial infarction

Question 21

thyroid-stimulating hormone

Answer 21

thyroid abnormalities may precipitate AHF

Question 22

D-dimer

Answer 22

performed if pulmonary embolism is suspected and well’s score is low (if Well’s score is high proceed to imaging)
note that D-dimer can be positive in AHF in patients without a pulmonary embolism

Question 23

imaging: chest x-ray appearance of AHF

Answer 23

abnormalities are present in 80% of patients in AHF
if the chest x-ray is normal, consider alternative diagnoses such as pulmonary embolism or exacerbation of asthma/COPD
it can help exclude other causes of dyspnoea such as pneumonia or pneumothorax

Question 24

what does the echocardiogram assess in AHF

Answer 24

transthoracic ultrasound scan
should be performed early in those with suspected AHF, especially if cardiogenic shock or life-threatening cardiac abnormalities are present
- biventricular systolic and diastolic function
- valve disease
- ventricular wall rupture
- pericardial effusionon
- intracardiac shunts: the presence of a dilated inferior vena cava with reduced respiratory variation is indicative of high venous pressure

Question 25

what is the relevance of a bedside lung ultrasound

Answer 25

may reveal extracardiac pathology such as pulmonary embolism or B-lines (consistent with interstitial oedema in pulmonary oedema)

Question 26

mnemonic to remember chest x-ray findings in heart failure is ABCDE

Answer 26

A: alveolar oedema (perihilar/bat-wing opacification)
B: Kerley B lines (interstitial oedema)
C: cardiomegaly (cardiothoracic ratio >50%) - may be difficult to assess on an AP film
D: dilated upper lobe vessels
E: effusions (i.e. pleural effusions - blunted costophrenic angles with meniscus sign)

Question 27

CHAMP conditions

Answer 27

these are the conditions that may have precipitated AHF, treat these urgently
acute Coronary syndrome
Hypertensive crisis
Arrythmias eg. atrial fibrillation, ventricular tachycardia, bradyarrhythmia
Mechanical problems eg. myocardial rupture as a complication of ACS, valve dysfunction
Pulmonary embolism

Question 28

when should oxygen be given

Answer 28

if the patient is hypoxic, titrate oxygen to maintain saturations between 94-98% (or 88-92% in those with COPD), patients often require 15L/minute)

Question 29

when to use loop diuretics

Answer 29

diuretics increase sodium excretion causing diuresis and decrease afterload
‘WET’ patients will require diuretics as the cornerstone of their management
furosemide IV initially to improve symptoms of congestion fluid overload
patients with chronic kidney disease and those already on oral diuretics will need a greater dose

Question 30

Nitrates

Answer 30

second most used in WET patients
cause venous and/or arterial dilatation to reduce the preload and/or afterload
given to patients with concomitant myocardial ischaemia or hypertension

Question 31

non-invasive ventilation

Answer 31

CPAP or BiPAP are used for those with cardiogenic pulmonary oedema, dyspnoea, and improves ventilation to reduce respiratory distress and drives fluid out of alveoli and into vasculature in those whose respiratory failure is not controlled with oxygen therapy given via a face mask

Question 32

cardiogenic shock

Answer 32

some cold patients whose AHF has led to a potentially reversible cardiogenic shock may present with haemodynamic instability
specialists may consider inotropes to increase cardiac output and peripheral perfusion, and vasodepressors to increase blood pressure and vital organ perfusion

Question 33

what is the aim of long-term management

Answer 33

pharmalogical treatment aims to increase cardiac output by optimising preload and contractility whilst decreasing afterload

Question 34

what do ACEi and ARBs do

Answer 34

decrease activation of the renin-angiotensin aldosterone system
contraindications include a history of angiooedema, bilateral renal artery stenosis, hyperkalaemia, severe renal impairment and severe aortic stenosis

Question 35

beta-blocker

Answer 35

decrease heart rate, myocardium oxygen demand and RAAS activation

Question 36

aldosterone antagonist

Answer 36

antagonise aldosterone increasing sodium excretion causing diuresis and decreased after load

Question 37

complications of AHF

Answer 37

• 40% die or are readmitted within a year
• AHF may cause arrythmias particularly atrial fibrillation
• increased risk of stroke and other thromboembolic disease following an episode of AHF