From the Guidelines
With inflation of the counterpulsation balloon during diastole, the mean arterial pressure will increase. This is because intra-aortic balloon counterpulsation (IABC) involves inflating a balloon in the descending thoracic aorta during diastole, which displaces blood volume in the aorta and increases diastolic pressure, thereby improving coronary perfusion since coronary arteries are primarily perfused during diastole 1. The key benefits of IABC include:
- Increased diastolic pressure
- Improved coronary perfusion
- Reduced afterload during systole, making it easier for the left ventricle to eject blood
- Overall increase in mean arterial pressure As stated in the guidelines on the diagnosis and treatment of acute heart failure by the European Society of Cardiology, IABC is a standard component of treatment in patients with cardiogenic shock or severe acute left heart failure that does not respond rapidly to fluid administration, vasodilatation, and inotropic support 1. The technique is contraindicated in patients with aortic dissection or significant aortic insufficiency, and should not be used in patients with severe peripheral vascular disease, uncorrectable causes of heart failure, or multi-organ failure 1. The inflation and deflation of the balloon are synchronized with the patient's cardiac cycle, with inflation occurring during diastole and deflation occurring during systole, to maximize the benefits of IABC while minimizing potential complications 1.
From the Research
Inflation of the Counterpulsation Balloon
- The inflation of the counterpulsation balloon during diastole increases the mean arterial pressure 2, 3.
- This is because the intraaortic balloon pump (IABP) displaces a blood volume during diastole, augmenting diastolic pressure and thus increasing mean arterial pressure 2.
- The rapid deflation of the balloon timed to the initiation of systole reduces the afterload of ventricular ejection and thus peak systolic pressure, which also contributes to the increase in mean arterial pressure 2, 4.
Effects on Mean Arterial Pressure
- The increase in mean arterial pressure is a result of the increased diastolic pressure and decreased systolic pressure 2, 3.
- This effect is beneficial in patients with heart failure or cardiogenic shock, as it can help to improve coronary perfusion and reduce myocardial oxygen consumption 5, 6.
- The timing of inflation and deflation of the balloon is crucial to achieve the desired therapeutic effects, and should be adjusted according to the arterial pressure waveform 5.