Different forms of support of the failing heart consist of Cardiopulmonary Bypass Pumps/ ECMOs, internal or external Counterpulsation and the various modes of Auxiliary heart pump.
Intraaortic balloon pump (IABP) is a form of internal counterpulsation, acting as an assisting circulatory support device. Diastolic augmentation during inflation potentially contributes to coronary, cerebral, and systemic circulation.
Development of the idea of counterpulsation
The possibility to alter timing of pressure events during a heartbeat was conceived by Kantrovitz et al. [
3]. External counterpulsatrion simulated when the hemidiaphragm wrapped around the distal portion of the thoracic aorta and stimulated during each diastole. The diastolic pressure was increased significantly as compared with control studies.
Simultaneously other researchers [
4‐
6] experiment counter pulsation. They used femoral access to remove blood during systole and then replace it during diastole. Some haemodynamic impact was observed but the practical application of the technique failed to pursue.
Preliminary studies with an intraaortic balloon pump took place in 1961 by S. Moulopoulos and associates [
7]. Latex tubing was tied around the end of a polyethylene catheter with multiple side holes. The distal end of the catheter was occluded so that the tubing could be inflated and deflated through the side holes in the catheter. The tubing, the catheter and the balloon formed a closed system that was filled with carbon dioxide; air pressure was applied intermittently to the tube in the cylinder and the carbon dioxide was expelled to inflate the balloon. The stroke was triggered with the aid of a timing circuit from the electrocardiogram (ECG) of the animal. The stroke length and the delay after the R wave of the electrocardiogram were preset so that the latex tubing was inflated during diastole and remained deflated during systole. Testing their balloon pump in a mock circulation and canine aorta concluded that it was possible to increase the diastolic blood flow in the arterial system and lower the end diastolic arterial pressure.
The concept of external counter pulsation was introduced by Dennis et al. [
8] in 1963. This had become feasible by application of a G-suit (a diastolic leg compression method) covering over the lower extremity to mid abdomen, which sequentially inflated during diastole and deflated during systole, synchronous with the cardiac action.
The first clinical application of a successful treatment with IABP was reported in 1967. Intra aortic balloon pumping was advocated successfully in a 45 year old female who had sustained a myocardial infarction and was hypotensive, comatose and anuric in severe cardiogenic shock.
By the early 1970s and after a series of successfully treated patients with cardiogenic shock (The Kantrowitz-team had treated 30 patients) the IABP had been convincingly promised to be helpful in acute low cardiac output state following left ventricular failure.
Buckley et al. [
9] looked at the hemodynamic benefit of the IABP and reported the results of treating the first eight patients in cardiogenic shock and confirmed that balloon inflation in diastole augments coronary perfusion and deflation just before systole markedly reduces resistance to the left ventricular ejection and thereby reduces cardiac work and myocardial oxygen consumption.
Mundth and co-workers [
10] reported as early as 1970 a case of a patient who sustained cardiogenic shock following myocardial infarction who was stabilised with Intraaortic balloon counterpulsation; subsequently underwent coronary revascularisation and with the support of the balloon pump has had an uneventful recovery. This was the first report whereas the application of the intraaortic balloon pump extended successfully to support heart failure post coronary artery surgery.
Jacobey et al. [
11] following the principles of counterpulsation in 1971 reported encouraging results for the treatment of cardiogenic shock in 18 patients with counterpulsation using an ascending aortic cannula.
In 1971 Feola and associates [
12] looked upon the therapeutic impact of intraaortic balloon pump on a heart failure animal model. Three levels of successively worsening heart failure (by means of decrease in cardiac output and aortic pressure and elevation of the left ventricular end diastolic pressure) were reproduced. Institution of the IABP support followed by normalisation of left ventricular end diastolic pressure and left atrial pressure increased the stroke volume and ejection fraction as well as improvement of coronary and peripheral flow and so tissue perfusion. They concluded that intraaortic balloon pumping is an effective means of circulatory support providing that is being used early in the sequence of coronary occlusion -myocardial infarction -acute left ventricular failure. It is most effective in states of mild to moderate left ventricular failure. There was no effectiveness of the balloon pumping during the situation whereas cardiogenic shock with sustained hypotention for more than 30 min and 50 % drop in cardiac output, had been ensued.
Krakauer et al. [
13] in the beginning of 1971 reported the experience with the intraaortic balloon in 30 cases treated for cardiogenic shock due to acute myocardial infarction refractory to conventional pharmacological treatment. They stated that counterpulsation could beneficially affect hemodynamic measurements. Ventricular end-diastolic pressure can be decreased, thereby reducing myocardial tension with a proportionate decrease in myocardial oxygen consumption. The coronary arterial perfusion pressure is increased and this together with reduced myocardial tension and decreased systolic ejection time permits enhancement of coronary blood flow. They concluded that the group of patients treated with balloon support early following the onset of the shock had a significant better prognosis.
In 1972 Bregman and coworkers [
14] developed a dual chamber balloon consisting of a large proximal and a small distal balloon which inflated first; the idea was to block distal blood flow and augment flow proximally to the brain and coronary arteries.
The development of catheters and balloons of polyurethane material enable prolonged periods of counterpulsation.
In 1973 two different groups [
15,
16] reported the successful utilization of IABP in patients who were unable to be weaned from cardiopulmonary bypass. Therefore, IABP support opened a new era in the perioperative management of patients with ventricular dysfunction during cardiac surgery.
By 1976 more than 5000 patients with post-cardiotomy low cardiac output had received IABP treatment in United States.
Continuous evolution brought a method of insertion of the balloon catheter percutaneously without the need for surgical cut down [
17,
18]. Invasive Cardiologists then adopted this method; that transformed the entire field of IABP due to the aggressive expansion of indications for use of this device to different subsets of patients with advanced coronary artery disease unresponsive to medical management.
During the past decade major mechanical and engineering developments have allowed optimal timing of counterpulsation and on-line monitoring of blood pressure and cardiac output.