Heart Failure

Question 1

Outline the pathophysiology of Heart Failure

Answer 1

CO is inadequate for the body’s requirements

Systolic failure = inability of the ventricle to contract normally – reduced CO

Diastolic failure = failure of ventricles to relax and fill normally

CHF = L and R sided HF

Question 2

Outline the Aetiology of Heart Failure

Answer 2

Systolic failure = IHD, MI, cardiomyopathy

Diastolic failure = constrictive pericarditis, tamponade, restrictive cardiomyopathy, HTN

Question 3

What are the signs and symptoms of Heart Failure

Answer 3

LVF = dyspnoea, poor exercise tolerance, fatigue, paroxysmal nocturnal dyspnoea (PND), nocturnal cough (pink frothy sputum), wheeze, nocturia, cold peripheries, weight loss, muscle wasting

RVF = peripheral oedema, ascites, nausea, anorexia, facial engorgement, pulsation in neck/face (tricuspid regurgitation), epistaxis

Cyanosis

Decreased BP

Narrow pulse pressure

Displaced apex

Murmurs of mitral or aortic valve disease

Question 4

How would you investigate Heart Failure

Answer 4

ABG

ECG = look for evidence of MI, ischemia, ventricular hypertrophy

Bloods

• BNP = >100ng/L
• Troponin
• TFT
• U+Es

ECHO = look for evidence of MI, valvular disease

CXR = cardiomegaly, pleural effusion, kerley B lines, perihiliar batwing shadowing, fluid in the fissures

Question 5

How would you manage Heart Failure

Answer 5

Conservative

• Stop smoking
• Eat less salt
• Optimise weight and nutrition

Treat cause = dysrhythmia, valve disease

Treat exacerbating factors = anaemia, thyroid disease, infection, HTN

Avoid exacerbating factors = NSAIDs (fluid retention), verapamil (-ve ionotrope)

Medication
o Diuretics = furosemide (loop) – monitor U+Es
o ACEi = consider in all LVSD, if cough problems use ARB
o Beta-blocker = initiate after diuretic and ACEi
o Spironolactone = use in those still symptomatic despite treating with above
o Digoxin = for those with LVSD symptoms despite standard treatment
o Vasodilators

Question 6

What are the complications of Heart Failure

Answer 6

25-50% of pts die within 5 years of diagnosis

Question 7

How should acute HF be managed?

Answer 7

1. Oxygen
2. IV Furosemide + fluid restriction at 1.5L to offload
3. IV diamorphine
4. GTN infusion → CAREFUL → can drop BP → less commonly used
5. Dobutamine → dual action → reduces the afterload of the heart + increases the inotropic force of the heart
6. CPAP → type of NIV which delivers contrast + airway pressure to remove the extra fluid from the alveolar spaces

Question 8

What is left ventricular systolic dysfunction?

Answer 8

Increased LV capacity, thinning of wall/loss of muscle = necrosis/matric proteases = reduced LV CO, mitral valve incompetence seen with changes in the LV structure

neural-hormonal activation, cardiac arrhythmias

Question 9

What structural changes are seen in heart failure?

Answer 9

Loss of muscle, uncoordinated/abnormal myocardial contraction, changes in extra cellular matrix, cellular structure and function (first hypertrophy, then fibrosis, then necrosis), remodelling around weak/damaged areas

Question 10

Describe the involvement of the renin-angiotensin-aldosterone system in heart failure

Answer 10

Reduced renal blood flow = angiotensin II acting on AT1 receptors = potent vasoconstrictor, promotes LVH and myocyte dysfunction, promotes aldosterone release, promotes Na/H2O retention.

Angiotensin II acting on AT2 receptors = increase NO = vasodilation

Question 11

Explain the involvement of natriuretic hormones in heart failure?

Answer 11

Myocyte stretch = release of ANP/BNP = constricts renal afferent and vasodilates efferent arterioles, increased urinary Na excretion