Right Ventricular Infarction
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Direct answer
Right ventricular infarction is necrosis of the right ventricular wall, usually caused by proximal right coronary artery occlusion during an inferior myocardial infarction. It classically causes hypotension with clear lung fields and a raised jugular venous pressure, and ST elevation in the right-sided lead V4R confirms it. Because the right ventricle depends on preload, nitrates and diuretics are harmful, and intravenous fluid is the first-line treatment.
What you must remember
- Culprit artery: proximal right coronary artery occlusion, which supplies the right ventricular free wall and usually the inferior wall as well.
- Diagnostic lead: ST elevation of 1 mm or more in V4R, so right-sided leads belong in every inferior infarct with hypotension.
- Classic picture: hypotension, raised jugular venous pressure and clear lung fields in a patient with an inferior infarct.
- Preload dependence: the failing right ventricle cannot fill against high pressure, so any fall in venous return drops the output.
- Drugs to withhold: nitrates, morphine and diuretics, since each one lowers preload and can precipitate profound hypotension.
- Fluid first: a crystalloid bolus of about 250 to 500 mL repeated in aliquots, reassessing blood pressure, JVP and lungs after each.
- Heart block: AV nodal ischaemia causes bradycardia and heart block, which may need atropine or temporary pacing.
Recognising and treating the right ventricle
A 60-year-old man with a proximal inferior infarct has a systolic blood pressure of 80 mmHg, a JVP that rises on inspiration and clear lung fields on auscultation. The steps below set out how to confirm the picture and treat it safely.
- Confirm the picture. Look for inferior ST elevation with hypotension and a raised JVP, and check that the lung fields are clear.
- Record right-sided leads. Put V4R on the chest, and treat ST elevation of 1 mm or more as confirmation of right ventricular involvement.
- Stop preload-reducing drugs. Hold nitrates, morphine and diuretics, since each one drops the already low preload.
- Give fluid. Run a crystalloid bolus in aliquots and reassess blood pressure, JVP and lung fields after each one.
- Add support if needed. Use dobutamine if hypotension persists after filling, and atropine or temporary pacing for heart block.
Reperfusion by primary PCI remains the definitive treatment, and the right ventricle often recovers once the culprit artery is opened. Early restoration of flow is therefore the aim alongside the haemodynamic support.
Where the exam tries to catch you
Right ventricular infarct stems are built to tempt the student into the usual chest pain drugs, so the traps below focus on the reflexes to avoid.
- Trap: nitroglycerin is given for chest pain in an inferior infarct with hypotension. Correct: nitrates drop preload in right ventricular infarction and can precipitate profound hypotension, so they are withheld.
- Trap: a raised JVP with hypotension is treated with diuresis for presumed failure. Correct: the right ventricle is preload-dependent, so diuretics worsen the state and fluid is given instead.
- Trap: bradycardia after an inferior infarct is treated as benign. Correct: AV nodal ischaemia causes heart block, so atropine or temporary pacing may be needed.
Frequently asked questions
Which ECG lead confirms right ventricular infarction?
ST elevation of 1 mm or more in lead V4R, a right-sided precordial lead, is the most useful marker of right ventricular infarction. Right-sided leads should be recorded in every inferior infarct that is accompanied by hypotension.
Why are nitrates contraindicated in right ventricular infarction?
Nitrates dilate the venous capacitance vessels and reduce venous return to the right ventricle. The preload-dependent right ventricle then cannot maintain output, so profound hypotension follows.
What is the first-line treatment for hypotension in right ventricular infarction?
Intravenous crystalloid fluid is the first-line treatment, given in repeated small boluses while the JVP and lung fields are monitored. Inotropes such as dobutamine are added only if hypotension persists after adequate filling of the right ventricle.
Why are the lungs clear in right ventricular infarction?
The failing right ventricle delivers less blood to the left heart, so pulmonary venous pressure does not rise and congestion is absent. This is why the triad of hypotension, raised JVP and clear chest is classic for the condition.
Which conduction disturbance is common in inferior infarction with right ventricular involvement?
Atrioventricular block is common in inferior infarction, because the AV node is usually supplied by the right coronary artery. It presents as bradycardia and may need atropine or temporary pacing.