Principles of action
- Myocardial ischemia can cause a fall in cardiac output
- Coronary blood flow may subsequently be reduced
- Compensatory mechanisms may further reduce cardiac output
- Cardiac performance can be improved by optimisation of
- Preload
- Afterload
- Heart rate
- Contractility
- Myocardial oxygenation
- Balloon pump provides haemodynamic support to the failing heart
- It reduces risk of cardiac ischaemia
- The intra-aortic balloon pump works by
- Increasing blood flow in the coronary arteries
- Reducing the work of the cardiac muscle
- Balloon is inflated in diastole
- Increases diastolic coronary artery perfusion pressure
- Increases myocardial oxygen supply
- Balloon is deflated in systole
- Reduces impedance to left ventricular ejection
- Reduces myocardial oxygen demand
Indications
- Perioperative myocardial ischaemia
- Acute mitral valve regurgitation
- Postoperative low cardiac output states
- Preoperative use in high-risk coronary artery surgery
- Refractory left ventricular failure
- Cardiogenic shock
- Impending myocardial infarction
Contraindications
- Severe aortic regurgitation
- Severe calcific aorto-iliac disease
- Severe peripheral vascular disease
- Aortic dissection
Mechanics of the pump
- Catheter is inserted through the femoral artery using a Seldinger
technique
- Tip of the balloon is placed about 2cm distal to left subclavian
artery
- Balloon pump timing is triggered from the ECG or arterial wave form
- Inflation occurs at the peak of the T wave at the end of systole
- Deflation occurs just before the R wave
- Correct timing of inflation and deflation is essential for optimum
diastolic augmentation
- Factors that reduce stroke volume lower diastolic augmentation
Complications
- Limb ischaemia
- Bleeding at insertion site
- Thromboembolism
- Balloon leak
- Thrombocytopenia
- Infection
- Aortic dissection
Bibliography
Baskett R J, Ghali W A, Maitland A et al. The
intra-aortic balloon pump in cardiac surgery. Ann Thorac Surg
2002; 74: 1276-1287.
Sanbom T A, Feldman T. Management strategies for
cardiogenic shock. Curr Opin Cardiol 2004; 19:
608-612.
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