5.10 Right Ventricular Failure

Question 1

Q10 — Right ventricular failure
A 69-year-old obese female presents with a significant history of obstructive sleep apnoea with presenting features of right ventricular failure. She has been using a CPAP machine for the last 4 years.

a) What are the signs of acute right ventricular failure?

Answer 1

● Signs due to a low cardiac output.

● Signs due to systemic venous congestion.

● Signs of hypoperfusion —
deranged liver function,
raised urea,
creatinine and lactate.

● Decreased venous oxygen saturation.

Question 2

b) What are the signs of chronic right ventricular failure?

Answer 2

● Ascites

● Exertional dyspnoea.

● Reduced exercise tolerance.

● Ankle swelling.

Question 3

c) Describe one investigation that will help in the early diagnosis
for right ventricular failure.

Answer 3

Transthoracic echocardiogram (TTE).

Question 4

d) Discuss the pathophysiology of right ventricular failure.

Answer 4

● Volume or pressure overload or reduced contractility.

● Dysfunction triggered by injury or stress.

● Acute —
MI, pulmonary embolism.

● Chronic —
pulmonary hypertension,
congenital cardiac disease.

● Multiple compensatory mechanisms —
hypertrophy,
extracellular matrix expansion,
reduction in wall stress,
upregulation of neurohormonal systems.

● Increased preload —
tricuspid regurgitation, atrial septal defects.

● Increased afterload —
pulmonary hypertension,
pulmonary embolism.

● Decreased contractility —
RV infarction,
arrhythmias,
sepsis.

Question 5

e) How can obesity lead to right ventricular dysfunction?

Answer 5

● Obesity —
an independent risk factor for cardiovascular disease.

● Increased cardiac output.

● Obesity-hypoventilation syndrome.

● Obstructive sleep apnoea.

● RV dilatation,
increased RV wall thickness
seen in young obese patients.

Question 6

f) What is the mechanism of right ventricular failure in
obstructive sleep apnoea?

Answer 6

● Apnoeic episodes leading to
hypoxic pulmonary vasoconstriction.

● Remodelling of pulmonary microcirculation results.

● Increased pulmonary vascular resistance,
pulmonary hypertension,
RV dysfunction.

● Negative intrathoracic pressure,
increased venous return,
increased preload in the RV.

● Coexisting cardiovascular disease and hypoxaemia

Question 7

g) List the management strategies for a patient admitted with
right ventricular failure.

Answer 7

1 ● Identify the cause and treat it.

2 ● Optimise heart rate:
- higher rate;
- aim for sinus rhythm.

3 ● Optimise rhythm:
- cardioversion if there are new-onset rhythm problems;
- amiodarone +/- cardioversion

4 ● Optimise preload:
- filling;
- small fluid boluses 50ml with CVP monitoring;
- if overfilled, loop diuretics;
- haemofiltration if needed.

5 ● Augment contractility and maintain perfusion:
- inodilators — dobutamine, milrinone;
- vasopressors — noradrenaline.

6 ● Minimise afterload:
- prevent hypoxia, acidosis, hypercapnia;
- reduce PEEP;
- inhaled or IV pulmonary vasodilators.

7 ● Surgical management — mechanical circulatory support:
- balloon pump;
- ECMO;
- ventricular assist devices.