Effects Of Intra-aortic Balloon Pump Research Articles

Effects of intraaortic balloon pumping on acute myocardial infarction in 64 cases of cardiogenic shock, severe heart failure and mechanical heart failure.

Of the patients treated in the CCU of Nippon Medical School for acute myocardial infarction in the past 5 years and 8 months, 44 with cardiogenic shock, 11 with severe heart failure, 7 with ventricular septal perforation and 2 with mitral regurgitation were treated by IABP. The peak effect of IABP on the hemodynamics of patients with cardiogenic shock was noted 24 hours after starting on IABP. When hemodynamics were compared between surviving and dead groups, there was a significant difference in stroke volume index between the two groups. When left ventricular function was compared between them, it was suggested that patients whose left ventricular function does not respond to IABP for 48 hours or longer are more likely to die than responders. Twenty-four of 44 patients became independent of IABP, but no more than 13 patients (30%) survived for 6 months or longer. Isosorbide dinitrate (ISDN) was combined with IABP in 7 patients who had a persistence of heart failure in spite of IABP. Combination therapy with IABP and ISDN elicited a significant increase in cardiac index, a significant decrease in pulmonary capillary wedge pressure, mean pulmonary arterial pressure and total peripheral resistance and a pronounced improvement in left ventricular function, and all 7 patients became independent of IABP. In the patients with acute myocardial infarction complicated with ventricular septal perforation, the mean systolic arterial pressure was 87.7 +/- 8.3 mmHg, mean pulmonary capillary wedge pressure, 20.3 +/- 7.4 mmHg and pulmonary-to-systemic flow ratio, 3.12 +/- 0.95 before starting on IABP. When the hemodynamics at 3 hours of IABP were compared to the pre-IABP values, the right atrial pressure, pulmonary capillary wedge pressure and pulmonary-to-systemic flow ratio had a tendency to decline, but the changes were not statistically significant, except for the peak arterial pressure which showed a significant elevation at 3 hours of IABP. Three of the 7 patients became dependent on IABP, and 2 of the 3 patients were saved by emergency operation.

Effect of intraaortic balloon counterpulsation on regional myocardial blood flow and oxygen consumption in the presence of coronary artery stenosis: Observations in an awake animal model

The mechanism by which intraaortic balloon pumping ameliorates myocardial ischemia in patients with unstable angina pectoris is uncertain. Accordingly, the following study was performed to determine the effect of intraaortic balloon pumping on regional myocardial blood flow and myocardial oxygen consumption (MVO 2) distal to severe coronary artery stenosis. Nine closed chest conscious pigs were instrumented with a 7.5 mm long plastic stenosis which reduced vessel diameter by 82%. Measurements of hemodynamics, regional myocardial blood flow (microsphere technique) and MVO 2 were made (1) before intraaortic balloon pumping, (2) at the end of 15 to 20 minutes of intraaortic balloon pumping, and (3) 20 minutes after its discontinuation. Control endocardial blood flow (ml · min − 1 · g − 1) distal to the stenosis (1.04 ± 0.20, mean ± 1 standard deviation [SD]) was less than endocardial flow in myocardium perfused by the unobstructed circumflex coronary artery (1.67 ± 0 0.77, p < 0.01). Likewise, control distal zone epicardial flow (1.16 ± 0.36) was reduced in comparison with control circumflex zone epicardial flow (1.48 ± 0.60, p < 0.01 In response to intraaortic balloon pumping rate-pressure product declined versus control (10,300 ± 2,090 [SD] mm Hg · min − 1 to 9,110 ± 2,010, p < 0.005), whereas aortic mean diastolic pressure (mm Hg) increased versus control (109.0 ± 9.9 to 121.0 ± 13.8, p < 0.01). Distal coronary mean diastolic pressure did not change in response to intraaortic balloon pumping (61.9 ± 13.0 to 68.7 ± 16.5, p = NS). Likewise, endocardial blood flow (ml · min − 1 · − 1) distal to the stenosis did not change during intraaortic balloon pumping (1.00 ± 0.24) versus control (1.04 ± 0.20). In contrast, during intraaortic balloon pumping epicardial blood flow distal to the stenosis declined versus control (1.16 ± 0.36 to 1.01 ± 0.27, p < 0.05). Regional MVO 2 (ml · min − 1 · 100 g − 1) distal to the stenosis also decreased versus control in response to intraaortic balloon pumping (12.90 ± 3.55 to 10.30 ± 2.52, p < 0.05). Furthermore, regional MVO 2 correlated well ( r = 0.74, p < 0.002) with rate-pressure product. Thus, intraaortic balloon pumping reduces myocardial oxygen demand but does not improve blood flow distal to a severe coronary stenosis; (2) blood flow distal to a severe stenosis may fail to increase with intraaortic balloon pumping because (A) distal coronary mean diastolic pressure may not increase, and (B) blood vessels distal to the stenosis tend to autoregulate in response to a decline in myocardial oxygen demand; and (3) intraaortic balloon pumping ameliorates myocardial ischemia in patients with unstable angina pectoris primarily by reducing oxygen demand rather than by increasing oxygen supply.

Influence of vascular parameters on the effectiveness of intra-aortic balloon pumping: a model study.

The intra-aortic balloon pump has been widely used as a temporary heart-assist device. In this investigation, a nonlinear mathematical model of the arterial system and intra-aortic balloon pump was studied analytically. Thus, the influences of a number of vascular parameters on the effectiveness of intra-aortic balloon pumping (IABP) were determined. The effects of changes in vascular parameters of the model on a number of performance indexes were investigated. These performance indexes (aortic mean diastolic pressure, aortic end diastolic pressure, cardiac output, coronary flow and phase differences between the fundamental Fourier components of aortic root pressure and flow) were used as the criterion for an evaluation of the effectiveness of the assist pump. The following vascular parameters were perturbed by four steps (±10%, ±20%) from the values in the standard model: heart rate, peripheral resistance, left ventricular pressure, aortic elastance, aortic radius, arterial wall thickness, and aortic length. This model was evaluated for a wide range of balloon-pump phase-control settings (assisted case) and for the unassisted case (when the pump is disabled). It is concluded that changes in heart rate, peripheral resistance and left ventricular pressure cause the most significant changes in pump performance.

Effect of intra-aortic balloon pumping on myocardial blood flow distal to a severe coronary artery stenosis

Effect of intra-aortic balloon pumping on myocardial blood flow distal to a severe coronary artery stenosis

Experimental and clinical studies on the effects of Intra-aortic Balloon Pumping

Experimental and clinical studies on the effects of Intra-aortic Balloon Pumping

The effect of intraaortic balloon pumping (IABP) on peripheral circulation

The effect of intraaortic balloon pumping (IABP) on peripheral circulation

Effect of intra-aortic balloon pumping and calcium antagonist for reducing coronary reperfusion injury.

Open heart surgery under aortic cross-clamping is often required, but coronary reperfusion injury after release of aortic cross-clamping is unavoidable irrespective of applications of various protective methods to the myocardium. The anterior descending branch of the left coronary artery of mongrel adult dogs was occluded for 2 hours and then reperfused. The protective effects of intra-aortic balloon pumping (IABP) and of a calcium antagonist "diltiazem hydrochloride" (diltiazem) on the decreased reperfusion of ischemic, border and normal areas were examined by measuring the regional myocardial blood flow (RMBF) using a radioactive microsphere method. Diltiazem could increase significantly the RMBF in the border area. IABP induced a significant increase in the RMBF of the same area more than Diltiazem, with the increase in the endocardial layer tending to be superior to that in the epicardial layer. The results suggested that diltiazem is very effective for reducing the coronary reperfusion injury. It is also suggested that IABP is even more effective than diltiazem because it increases the RMBF significantly and, moreover, has a tendency to increase the blood flow in the endocardial layer which is poor in collateral vessels and thus vulnerable to ischemia.

Effects of intra-aortic balloon pumping on regional and total coronary flow in patients with coronary disease

Effects of intra-aortic balloon pumping on regional and total coronary flow in patients with coronary disease

Mechanism of the beneficial effect of intra-aortic balloon pumping in patients with refractory angina

Mechanism of the beneficial effect of intra-aortic balloon pumping in patients with refractory angina

The Effects of Intraaortic Balloon Counterpulsation on Myocardial Infarct Size

The left anterior descending coronary artery was ligated in 6 baboons. Subsequently, 3 animals were supported with long-term (24-hour) intraaortic balloon pumping (IABP), and 3 were on coronary occlusion alone. Animals were studied hemodynamically and with unipolar electrocardiographic mapping acutely and then were studied after a week and killed. A histological measurement of infarct size was made. The use of IABP had no influence on the area of ischemia determined by unipolar mapping or on infarct size measured quantitatively at a week. Similarly, there were no acute hemodynamic differences between the two groups. The only significant difference noted was a reduction in systolic pressure in IABP animals during balloon pumping and a significantly higher left ventricular systolic pressure a week following infarction in animals treated with IABP. The data indicate no significant effect of IABP on altering infarct size in animals with acute coronary ligation in the absence of cardiogenic shock.

What Role Should the Intra-aortic Balloon Have in Cardiac Surgery

Intra-aortic balloon pumping (IABP) to assist the failing circulation has become widely applied and accepted since its introduction in 1968. The elective, preoperative use of IABP for patients undergoing cardiac surgery has now become the controversy. The purposes of this report are to examine our experience with IABP and to determine its appropriate role in high-risk patients. IABP was utilized in 75 of 2333 (3.2%) adult cardiac surgical patients at Emory University Hospital from January 1976 through June 1978. IABP was required for refractory shock following cardiopulmonary bypass (CB) in 53 patients, for preoperative cardiogenic shock after acute myocardial infarction (CSMI) in nine and was electively placed prior to CB in 13. Sixty-two patients (81%) were able to separate from CB with IABP and pharmacologic support and were assisted 24-432 hours (median 64 hours). Fifty-five (73%) were weaned from IABP. Fifty (67%) are hospital survivors; late deaths have occurred in six patients (8%). Hemodynamic effect of IABP was demonstrated by comparison of pumping 1:1 to 1:8 mode in five balloon-dependent patients after CB. IABP was found to decrease systolic blood pressure, left ventricular filling pressure and peripheral resistance (p < .05). It increased diastolic and mean blood pressure, cardiac index and the endocardial viability ratio (p < .05). The post-CB use of IABP resulted in highest salvage when utilized to support failing hearts that required surgery despite recent preoperative infarction or when intraoperative ischemic injury had occurred. Poorest results were in patients with extensive chronic myocardial damage. Except in the case of preoperative cardiogenic shock, it was impossible to establish statistically reliable criteria for patients in whom elective preoperative insertion was found to be necessary. Careful surgical and anesthesia management with good monitoring can be used instead of preoperative IABP in the majority of (if not all) hemodynamically stable patients regardless of risk classification.

Effects of intraaortic balloon pumping on organ perfusion in cardiogenic shock

Effects of intraaortic balloon pumping on organ perfusion in cardiogenic shock

Peripheral Hemodynamics in Assisted Circulation with Intra‐Aortic Balloon Pumping in Patients with Cardiogenic Shock

Seven patients treated for cardiogenic shock were studied with and without intra-aortic balloon pumping (IABP). Calf and forearm blood flows were determined with a Dohn plethysmograph and arterial pressures were registered intra-arterially and in the great toe and thumb with the cuff method. During IABP, an augmented flow was registered in the arms and legs and accurate arterial BPs could also be determined from the extremities. The findings demonstrate a beneficial effect of IABP on peripheral flow, expecially in patients who could be weaned off the pump.

Effect of intra-aortic balloon pumping on nutrient coronary flow in normal and ischemic myocardium

The effects of intra-aortic balloon pumping (IABP) on myocardial flow distribution were studied in 50 dogs. Cardiac output was controlled by right heart bypass. In each dog the following parameters were measured with and without IABP during normal coronary perfusion and after regional ischemia was induced by anterior descending coronary vein flow by timed collection, and endocardial/epicardial flow ratios by a previously reported thermal washout technique. In nonischemic myocardium, IABP significantly (p less than 0.05) increased mean coronary sinus flow 11.5 percent +/- 5.8 percent (S.D.) and the mean endocardial/epicardial ratio, 17.3 percent +/- 0.28 percent. In the regionally ischemic myocardium, IABP significantly (p less than 0.05) increased mean segmental coronary vein flow 13.9 percent +/- 1.23 percent but decreased the endocardial/epicardial ratio 29.9 percent +/- 1.1 percent. We conclude that in the dog, IABP enhances subendocardial blood flow in perfused but not in ischemic myocardium. Contrary to common suppositions, the increase in collateral blood flow with IABP preferentially supplies epicardial layers in segmental ischemic zones, but may be shunted from the subendocardium.

Effect of intra-aortic balloon pumping on the coronary blood flow in hypothermia

Effect of intra-aortic balloon pumping on the coronary blood flow in hypothermia

Effectiveness of intraaortic balloon pumping without cardiac surgery for patients with severe heart failure secondary to a recent myocardial infarction

Twenty-five patients with class III or class IV left ventricular failure (Myocardial Infarction Research Unit criteria) after a recent myocardial infarction were treated with intraaortic balloon pumping between December 1, 1972 and December 1, 1976. Three patients had no improvement and died during pumping. Two patients with improvement died during an attempt at weaning from circulatory assistance. Of 20 patients successfully weaned, 6 died within 3 months, 5 of these within 10 days after the weaning procedure. Of 14 patients who survived for more than 3 months, 13 were alive on February 15, 1977. Twelve of these 13 were in functional class II and 6 had resumed professional activities. Intraaortic balloon pumping proved an effective method for treating severe left ventricular failure after an acute myocardial infarction. Even without surgery, 14 of 25 patients survived 3 or more months after an acute infarction complicated by serious pump failure.

Oxygen conservation by propranolol and intra-aortic balloon pumping in the normal canine heart

This study examines the effects of myocardial-depressant doses of propranolol (PROP) on myocardial oxygen consumption (MVO 2) during intra-aortic balloon pumping (IABP). The objective was synergistic reduction of MVO 2 with support of cardiac output (CO) by IABP as a model for myocardial preservation during ischemia. Accordingly, conventional hemo-dynamics, MVO 2, and plasma catecholamines were measured in seven open-chest dogs during IABP and administration of 2 mg/kg of PROP. compared with appropriate controls, MVO 2 decreased from 5.83 ± 0.49 (SE) to 3.47 ± 0.27 ml/min/100 g of LV ( P < 0.01), and LV dp/dt decreased from 1795 ± 114 to 1012 ± 64 ( P < 0.01) mm Hg/sec. However, CO decreased from 2.7 ± 0.5 to 2.1 ± 0.3 liters/min ( P < 0.05). In general, CO was linearly related to MVO 2; it was not possible to reduce MVO 2 without similar decreases in CO. The principal effect of IABP in the PROP-depressed circulation was to increase LV contractility by raising coronary perfusion pressure, with a resultant increase in both CO and MVO 2 when compared to the effects of PROP alone. The results indicate that while myocardial-depressant doses of PROP can provide dramatic reductions in MVO 2 in the canine model, large reductions in CO are unavoidable, even with IABP. Measurements of plasma catecholamines indicate that an important mechanism of action of IABP is reflex-induced reduction of circulating catecholamines.

Effects of intraaortic balloon pumping on the acute mitral insufficiency and ventricular septal perforation

Effects of intraaortic balloon pumping on the acute mitral insufficiency and ventricular septal perforation

Therapeutic effects of intra-aortic balloon pumping on acute ischemic myocardium and our clinical experiences

Therapeutic effects of intra-aortic balloon pumping on acute ischemic myocardium and our clinical experiences

Nutrient myocardial blood flow in experimental myocardial ischemia. Effects of intraaortic balloon counterpulsation and coronary reperfusion.

This experimental study was designed to evaluate the effect of intraaortic balloon pumping (IABP) upon nutrient myocardial blood flow (NMBF) following acute myocardial ischemia in dogs, but also to determine whether IABP improves NMBF following revascularization. Localized myocardial ischemia was produced by ligation of one or two small branches of the circumflex coronary artery combined with a three hour snare occlusion of the left anterior descending coronary artery distal to the first septal branch. NMBF was measured by NaI131 washout at three points corresponding to the peripheral, intermediate, and central zones of the infarct. Occlusion of the coronary arteries reduced NMBF. Release of occlusion after three hours, or the equivalent of coronary artery revascularization, increased NMBF but did not restore it to control levels. The increase in flow was more marked in the peripheral zones of ischemia. IABP increased NMBF significantly both during and after release of occlusion. The effect was sustained after cessation of IABP only when the latter was maintained during the period of reperfusion. The results indicate that NMBF, defined by washout of a locally injected tracer, was improved by both IABP and reperfusion. The beneficial effect was maximal when the two techniques were combined.