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Results for “Counterpulsation”

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PubMed2003

Changes of cerebral blood flow velocities during enhanced external counterpulsation.

OBJECTIVES: Intra-aortic counterpulsation is the most frequently used cardiac assist device. However, there are only few studies of the effects of counterpulsation on cerebral blood flow and these report conflicting outcomes. The new enhanced external counterpulsation (EECP) technique reproduces non-invasively the effects of intra-aortic counterpulsation. In this study, we evaluated effects of EECP on blood pressure (BP) and on cerebral flow velocity (CBFV). SUBJECTS AND METHODS: Twenty-three healthy controls and 15 atherosclerotic patients each underwent a 5-min session of EECP. Before, during and after EECP we monitored heart rate, beat-to-beat radial artery BP and CBFV. RESULTS: EECP induced a second increase in BP and CBFV during diastole with a significant increase of mean BP and a decrease of systolic BP in patients and controls. Mean CBFV increased in both groups during the first 5 s of EECP. After 3 min of EECP, diastolic CBFV was still higher than at baseline, but systolic CBVF was lower than at baseline; mean CBFV was as low as before EECP in the patients and lower than the baseline values in the controls. Three minutes after ending EECP, mean and systolic BP were lower in the patients than the corresponding baseline values. Otherwise, CBFV and BP values did not differ from baseline in patients and controls. CONCLUSION: Cerebral autoregulation ensures the constancy of cerebral blood flow even though EECP creates marked systemic changes. In the patients, the decrease of BP after EECP with maintained CBFV indicates an improved BPCBFV relation and a more economic autoregulation.

Adult↗

PubMed1989

Pulmonary artery counterpulsation to improve right ventricular function after heart transplantation.

The effectiveness of pulmonary artery counterpulsation in improving right ventricular function after heart transplantation was evaluated in a pig model. The balloon catheter was introduced through the anterior wall of the pulmonary artery distal to the pulmonary valve. A Millar catheter with a distal high-fidelity pressure transducer was placed in the right ventricle, where the peak rate of pressure rise, dP/dT, was measured. Pulmonary artery counterpulsation significantly improved right ventricular function, increasing both dP/dT and systolic pressure. A diastolic dip in pulmonary artery pressure and a fall in the early portion of the right ventricular pressure curve were seen. Inflation of the balloon caused a second (suprasystolic) wave in that curve. Improved right ventricular function was also seen when normal pig hearts were counterpulsated after occlusion of the right coronary artery and following increased afterload due to occlusion of a main pulmonary artery. There were no changes in central venous or systemic pressure. The results indicate that pulmonary artery counterpulsation may be valuable when the transplanted heart has a poorly functioning right ventricle.

Animals↗

PubMed1991

[Hemodynamic study of external counterpulsation with left and right cardiac catheters in 15 cases].

The hemodynamic changes of 15 cases during external counterpulsation with left and right cardiac catheters were reported. The results showed that the diastolic pressure at the root of the aorta was remarkably increased, the peak value (countercurrent pressure) was 8.02 +/- 2.05 kPa higher than the diastolic pressure before counterpulsation; the aortic systolic pressure during counterpulsation was slightly decreased with a mean value of 0.81 kPa; there was no apparent change in the central venous pressure and pulmonary arterial pressure; pulmonary arterial wedge pressure was slightly reduced during counterpulsation. All the above data are useful in showing the improvement of cardiac and brain perfusion volume and clarifying its mechanism.

Adult↗

PubMedDate not supplied

Physiologic and pathologic evaluation of chronic extra-aortic counterpulsation with latissimus dorsi flap. Preliminary results.

This study attempted to evaluate the efficacy of chronic extra-aortic counterpulsation with a latissimus dorsi neuro vascular flap. Five dogs had a preliminary procedure consisting of the creation of a latissimus dorsi flap and a thoracotomy in which the flap was wrapped around the descending aorta just distal to the left subclavian artery. An epicardial lead was placed on the left ventricle and a nerve stimulating lead placed around the thoraco-dorsal nerve. Three weeks later, both leads were connected to a cardiomyostimulator programmed to function in a counterpulsation mode with a 1:2 assist frequency. Hemodynamic measurements were made at 6 and 8 and 10 and 12 weeks and the dogs were sacrificed. Three dogs had all sets of hemodynamic measurements made. Two of the three dogs demonstrated diastolic augmentation at 6 and 8 and 10 and 12 weeks average 20 to 25 mmHg. The third dog failed to demonstrate any change. All dogs were sacrificed at 12 weeks and specimens were submitted for histologic evaluation. The muscle flap was preserved in all animals. The aorta subjacent to the flap showed, (1) normal intima with no evidence of disruption or thrombus in all animals, (2) in the animals in whom counterpulsation was observed, there appeared to be thinning of the media in the aorta subjacent to the muscle flap, and (3) no evidence of distal emboli. This study demonstrated that chronic counterpulsation can be obtained with a latissimus dorsi flap. The actual hemodynamic benefits are not determined from this study. The medial thinning in the aortic wall may limit the long-term benefit of this procedure.

Animals↗

PubMedDate not supplied

Maintenance of circulation during ventricular fibrillation with the simultaneous use of two "counterpulsation" devices.

Two valveless, single orifice counterpulsation devices, with pumping stroke volumes of 65 ml each, were implanted on the ascending aorta and pulmonary artery of seven open chest anesthetized dogs. After completion of the preparation, ventricular fibrillation was induced. The devices were synchronized to pump simultaneously at a rate of 85-100 bpm. The combined use of the counterpulsation devices provided maximal aortic pressure of 111.4 +/- 25.1 mmHg during ventricular fibrillation for a period of 15-60 min. The mean left ventricular pressure was 17.7 +/- 4.4 mmHg, and the cardiac index 64.5 +/- 23.6 ml/kg/min. Cardioversion of ventricular fibrillation to sinus rhythm restored normal hemodynamics. The counterpulsation device implanted on the ascending aorta was not able to maintain circulation for more than 5 min after the induction of ventricular fibrillation, if used alone. In conclusion, the use of two counterpulsation devices implanted on the ascending aorta and pulmonary artery was able to maintain circulation in experimental animals during ventricular fibrillation.

Animals↗

PubMed1994

[Evaluation of the addition of counterpulsation to the partial left ventricular-femoral bypass for limitation of evolving myocardial infarction].

The effect of adding counterpulsation to a partial left ventricular bypass was evaluated in a canine model of acute myocardial ischemia by using a myocardial staining method. To establish a left ventricular bypass, a catheter consisting of bypass tube (90 cm in length and 15 Fr in inner diameter) and an accompanying intraaortic balloon as a single apparatus (Integrated Cardioassist Catheter; ICAC) was introduced into the left ventricle via the abdominal aorta. The left ventricular bypass was adjusted to 1 L/min. with or without counterpulsation with the aid of a centrifugal pump and IABP console. The use of the ICAC that provided pulsatile left ventricular bypass tended to raise the mean aortic pressure and cardiac output. Reduction of the tension time index was noted with the use of the ICAC in contrast to the control. And increment of the DPTI/TTI ratio was observed with the use of the ICAC in contrast to the control and partial left ventricular bypass alone. While the percentages of the region at risk were similar [17.3 +/- 9.5% (control), vs. 16.4 +/- 3.4% (partial left ventricular bypass alone) vs. 16.9 +/- 5.2% (ICAC)], the percentages of infarct sizes were reduced due to the use of counterpulsation. [61.9 +/- 12.2% (control), vs. 57.5 +/- 3.9% (partial left ventricular bypass alone) vs. 16.8 +/- 6.0% (ICAC)]. These results revealed that the addition of counterpulsation alleviates afterload reduction to the partial left ventricular bypass and was more beneficial to the reduction of the infarct size than partial left ventricular bypass alone.

Animals↗

PubMed1981

Counterpulsation and dobutamine. Their use in treatment of cardiogenic shock due to right ventricular infarct.

A patient had right ventricular infarction complicated by cardiogenic shock. Volume expansion along with high doses of dopamine hydrochloride successfully alleviated hypotension in this patient. However, he had persistent mental obtundation and low cardiac output, and adverse chronotropic responses to high doses of dopamine developed. Counterpulsation effectively maintained an adequate arterial pressure and dopamine therapy was discontinued. Counterpulsation, however, failed to augment cardiac output. Simultaneous use of dobutamine hydrochloride along with counterpulsation was associated with a noticeable increase in cardiac output. To our knowledge, this is the first reported case of right ventricular infarct complicated by shock in which the simultaneous use of counterpulsation and dobutamine therapy resulted in a substantial increase in cardiac output.

Assisted Circulation↗

PubMed1986

Portable intraaortic balloon counterpulsation: clinical experience and guidelines for use.

Intraaortic balloon (IAB) counterpulsation is a proven treatment for patients with refractory ischemia or cardiogenic shock; however its use has been largely limited to tertiary centers due to the difficulties and risks encountered in transporting patients with this device in place. We report our initial experience with 11 patients who underwent IAB counterpulsation at a community hospital utilizing a portable transport IAB system. All 11 patients had successful IAB insertion, resulting in prompt stabilization. Immediate transportation during uninterrupted IAB counterpulsation was successfully accomplished in each case using routine ambulance vehicles, allowing for the prompt initiation of further tertiary care. The role of portable IAB counterpulsation in the community hospital and guidelines for the implementation of this portable IAB system are outlined.

Adult↗

PubMed1993

Complications associated with percutaneous placement and use of intraaortic balloon counterpulsation.

In-hospital and late complications related to percutaneous placement of 240 intraaortic balloon pump catheters in 231 consecutive patients from March 1985 through June 1990 were reviewed. Mean age was 64 +/- 11 years and 34% were women. Average duration of counterpulsation was 44.2 hours. Indications for counterpulsation included complications of myocardial infarction (34.6%), prophylactic placement before high-risk coronary angioplasty (20.0%) or open heart surgery (12.9%), complicated coronary angioplasty (18.3%), end-stage cardiomyopathy (5.4%) and miscellaneous (8.8%). Early major complications occurred in 11 cases (4.6%) and included limb ischemia requiring surgery (n = 9), bleeding requiring arterial repair (n = 1) and septicemia (n = 1). Other complications included hematoma requiring transfusion (n = 7), limb ischemia resolving with balloon catheter removal (n = 12), and superficial wound infection (n = 1). Overall in-hospital complication rate was 13% (31 of 240). Peripheral vascular disease and diabetes were found to be significant predictors of limb ischemia (p = 0.01 and p = 0.02, respectively). Follow-up information was obtained in 97% of patients with a mean duration of 19 months: 2 patients (1.1%) required vascular surgery for femoral false aneurysms and 1 patient experienced new onset of claudication. In conclusion, compared with previous experience, contemporary intraaortic balloon counterpulsation with percutaneous placement of smaller size (8.5Fr to 10.5Fr) catheters is associated with improved complication profile. This will further enhance the current trend for an expanding role of intraaortic balloon counterpulsation in complex interventional procedures.

Adult↗

PubMed1977

Improved survival after coronary bypass surgery in patients with poor left ventricular function: role of intraaortic balloon counterpulsation.

The operative mortality rate of aortocoronary bypass surgery in 23 patients with poor left ventricular function (ejection fraction 0.30 or less) operated on in 1973-74 was 34.7 percent. The incidence rate of operative myocardial infarction was 30.4 percent. In an attempt to improve survival, intraaortic balloon counterpulsation was used therafter in 25 similar patients. Counterpulsation was instituted preoperatively and continued intra- and postoperatively for 2 to 5 days. Preoperative studies revealed an "unloading" effect of the left ventricle, with significant reductions of systolic arterial blood pressure, end-diastolic pulmonary arterial pressure and end-diastolic left ventricular volume and pressure. Metabolic improvement was demonstrated by the lesser production of myocardial lactate after pacing-induced tachycardia when the ventricle was balloon-assisted. Intraoperatively, blood flow through the vein graft was found to increase with counterpulsation. The rate of operative myocardial infarction was reduced to 4 percent and the mortality rate to 8 percent. In patients who have sustained a significant loss of functioning myocardium, the beneficial hemodynamic and metabolic effects of intraaortic balloon counterpulsation appear to prevent furhter, possibly critical, myocardial damage in the perioperative period.

Assisted Circulation↗

PubMed1984

Pulmonary artery balloon counterpulsation for right ventricular failure: I. Experimental results.

The effects of pulmonary artery balloon counterpulsation (PABC) as a circulatory assist for the failing right ventricle were investigated. Sixteen anesthetized dogs underwent instrumentation to measure cardiac output and to record pressures in both ventricles, the pulmonary artery, and the aorta. Autonomic control of the heart was surgically and pharmacologically ablated. A specially designed counterpulsation balloon was inserted through the right ventricular (RV) outflow tract into the pulmonary artery. Pulmonary hypertension, induced acutely by the microembolization of the pulmonary circulation with glass beads combined with infusion of serotonin, served as a model for development of acute RV failure. Immediate effects of PABC were investigated in 10 dogs during normal function and failure of the right ventricle at different levels of preload. After further embolization which caused progressive cardiogenic shock, the effects of 10 minutes of PABC, and of its withdrawal, were examined. In all cases, PABC immediately decreased RV preload and afterload. In the failing right ventricle, counterpulsation also significantly increased cardiac output. Progressive cardiogenic shock was successfully reversed by PABC; after 10 minutes of counterpulsation, increases in cardiac output (+53%), arterial pressure (+55%), and RV minute work (+62%) were observed, paralleled by a fall in RV preload (-22%). After PABC was discontinued, the circulatory status again began to deteriorate. We conclude that PABC effectively improves function of the failing right ventricle caused by acute pulmonary hypertension.

Animals↗

PubMed1986

Comparison of an implanted abdominal aortic counterpulsation device with the intraaortic balloon pump in a heart failure model.

The abdominal aortic counterpulsation device is a round pumping chamber with a valveless opening which is implanted retroperitoneally on the abdominal aorta. The Utah driver is connected to the device through an air conduit and is synchronized on the electrocardiographic signal to provide diastolic aortic augmentation. For comparison an intraaortic balloon was also driven by the Utah driver system. The abdominal aortic counterpulsation device (stroke volume = 30, 40 and 60 ml) and the intraaortic balloon pump (balloon volume = 20 ml) were tested in dogs with acute left ventricular failure. The abdominal aortic counterpulsation device was also tested in normal animals. In acute left ventricular failure the abdominal aortic counterpulsation device at a stroke volume of 30, 40 or 60 ml decreased left ventricular end-diastolic pressure by an average of 28.56 (p less than 0.001), 39.56 (p less than 0.001) and 44.14% (p less than 0.005), respectively; aortic end-diastolic pressure by 24.11 (p less than 0.001), 26.67 (p less than 0.001) and 19.57% (p less than 0.01); and aortic systolic pressure by 18.56 (p less than 0.002), 26.0 (p less than 0.001) and 22.43% (p less than 0.005). It increased cardiac index by 27.58 (p less than 0.02), 35.59 (p less than 0.005) and 43.42% (p less than 0.001) and it provided peak aortic diastolic augmentation of 64.5 (p less than 0.001), 69.78 (p less than 0.001) and 74.43% (p less than 0.001), respectively, above the control aortic end-diastolic pressure.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed2002

A new approach to assist postoperative heart failure in an animal model: juxta-aortic counterpulsation.

Aortic counterpulsation is a useful technique frequently used in postcardiotomy heart failure. An acute heart failure model in open chest sheep was chosen to evaluate hemodynamic improvement with a counterpulsation balloon pump in juxta-aortic position. This was achieved with a manufactured Dacron prosthesis and a balloon pump placed between the prosthesis and the aorta. Juxta-aortic balloon pump counterpulsation in acute experimental heart failure resulted in a significant improvement of hemodynamic parameters: increase of cardiac output (from 0.86 +/- 0.04 to 1.29 +/- 0.09 L/min, p < 0.05) and cardiac index (from 0.03 +/- 0.01 to 0.04 +/- 0.01 L/min per kg, p < 0.05), and decrease of systemic vascular resistance (from 89.76 +/- 6.69 to 66.56 +/- 6.02 mm Hg/L per min, p < 0.05). The extent of aortic diastolic pressure change evaluated through the diastolic and systolic areas beneath the aortic pressure curve (DABAC/SABAC) index before cardiac failure induction showed a significant increase compared with unassisted values (from 0.81 +/- 0.10 to 1.12 +/- 0.09, p < 0.05). Assisted values of DABAC/SABAC index after heart failure induction also showed a significant increase compared with unassisted values (from 0.78 +/- 0.21 to 1.17 +/- 0.38, p < 0.05). Treatment of experimental acute heart failure by juxta-aortic balloon pump counterpulsation allows an effective hemodynamic improvement in open chest sheep.

Acute Disease↗

PubMed2005

The effect of intra-aortic balloon counterpulsation on left ventricular functional recovery early after acute myocardial infarction: a randomized experimental magnetic resonance imaging study.

AIMS: We sought to determine whether intra-aortic balloon pump (IABP) counterpulsation improves the recovery of left ventricular (LV) systolic function after reperfused acute myocardial infarction (AMI). METHODS AND RESULTS: Fourteen dogs underwent 90-min coronary artery occlusion followed by reperfusion. Seven animals were randomized to IABP counterpulsation immediately after reperfusion. Tagged, cine, and contrast-enhanced magnetic resonance imaging were used for regional and global LV functional assessment and MI characterization, respectively. Image acquisition was performed at 1 h, 6 h, and 24 h after reperfusion, during which the IABP device was paused. Animals randomized to IABP demonstrated an earlier improvement of LV ejection fraction when compared with controls (25+/-3 vs. 25+/-2% at 1 h, P=0.91; 36+/-3 vs. 26+/-2% at 6 h, P=0.015; and 38+/-3 vs. 35+/-1% at 24 h, P=0.34). Regional functional analyses revealed the same behaviour among non-infarcted risk regions, i.e., earlier circumferential systolic strain improvement in the IABP group than in controls (-5.4+/-0.4 vs. -5.3+/-0.5% at 1 h, P=0.86; -12.1+/-1.0 vs. -6.0+/-0.4% at 6 h, P<0.001; and -13.9+/-1.1% vs. -12.8+/-0.6% at 24 h, P=0.40). Importantly, however, the degree of LV functional recovery 24 h after reperfusion was similar whether IABP counterpulsation was used or not. CONCLUSION: IABP counterpulsation accelerates but does not significantly improve the recovery of LV systolic function after reperfused AMI.

Animals↗

PubMed1976

Similarities in coronary flow between external counterpulsation and intra-aortic balloon pumping.

The ability of external counterpulsation (Cardiassist) and intra-aortic balloon pumping (AVCO) to influence collateral coronary blood flow in ischemic myocardium was measured in anesthetized dogs. Cardiac output and heart rate (atrial pacing) were held constant on right-heart bypass. Both external counterpulsation and balloon pumping augmented peak diastolic pressure (30 mmHg and 38 mmHg, respectively), while mean aortic pressure, peak left-ventricular pressure, left-ventricular end-diastolic pressure, maximum left-ventricular dp/dt, hematocrit, and osmolality remained unchanged. Regional coronary blood flow was measured using 9-mum radioactive microspheres. External counterpulsation and balloon pumping begun immediately following ligation of the left-anterior descending coronary artery significantly increased collateral coronary blood flow 29 +/- 7.5% (SE, P is less than .01) and 20 +/- 8% (P is less than .05), respectively, to ischemic myocardium. This redistribution of collateral coronary blood flow produced by both methods of counterpulsation was primarily to the subepicardial region of the ischemic myocardium. The mechanism responsible for the measured increases in collateral coronary blood flow appears most likely to be an increased pressure gradient produced by diastolic augmentation.

Animals↗

PubMed2005

Nosocomial infections and balloon counterpulsation: risk factors and outcome.

Between February and September 2003, 136 (5.3%) of 2,558 patients undergoing cardiac surgery were supported with intra-aortic balloon counterpulsation. There were 71 infected (group 1) and 65 noninfected (group 2) patients. Risk factors for nosocomial infections were identified by univariate and multivariate analysis. On univariate analysis, significant risk factors were operation time, balloon pump duration, ventilation hours, duration of central venous catheter placement, amount of blood transfused, left ventricular ejection fraction<30%, intra- and/or postoperative intra-aortic balloon counterpulsation, surgery under cardiopulmonary bypass, combined procedures, re-exploration, and Acute Physiology And Chronic Health Evaluation (APACHE) II score. On multivariate analysis, ventilation hours and amount of blood transfused were independently associated with group 1. Respiratory tract infections were common in the balloon counterpulsation population (41.1%). Mortality was significantly higher in patients needing balloon pump support (19.9%) compared to controls (1.1%), but it was similar in groups 1 and 2. Recognition of risk factors for postoperative infection in patients undergoing cardiovascular surgical procedures with intra-aortic balloon counterpulsation may help to improve their prognosis and allow more organized surveillance.

Aged↗

PubMed2006

Impedance cardiography for aortic balloon counterpulsation impact assessment on patients hemodynamics during acute myocardial infarction.

BACKGROUND AND OBJECTIVE: The evaluation of hemodynamics in patients with acute myocardial infarction is crucial. Intra-aortic balloon pumping or counterpulsation in patients with cardiogenic shock is supposed to be monitored exceptionally by invasive methods for assessment of hemodynamics. However, noninvasive methods might have place in monitoring these patients. The objective of the study was to evaluate the possibility of applying noninvasive methods for evaluation of hemodynamics during acute myocardial infarction complicated by cardiogenic shock and managed by intra-aortic balloon pumping. PATIENTS AND METHODS: A total of 16 patients were investigated according to the study protocol. Anterior acute myocardial infarction was diagnosed in 11 (68.75%) patients, inferior--in 4 (25%), circular--in 1 (6.25%). Primary percutaneous transluminal coronary angioplasty was successfully performed in 7 (43.75%) patients, unsuccessfully--in 1 (6.25%) patient, who died within the first 18 hours. Half of patients (50%) underwent cardiac surgery within the first two weeks. Mortality rate was 68.75% (11 patients). A prospective controlled study was carried out to compare two different methods--intermittent thermodilution (ITD) and impedance cardiography (ICG)--for simultaneous cardiac output measurements in patients with acute myocardial infarction complicated by cardiogenic shock and managed by intraaortic balloon counterpulsation. Statistical analysis was performed with Bland-Altman and linear regression. RESULTS: Correlation coefficient was calculated comparing cardiac output values derived from ICG and ITD; it ranged from 0.24 to 0.98 in separate patients. It was observed a weak correlation of ICG and ITD measurements before initiation of intra-aortic balloon pumping--0.24-0.27 in separate cases. The correlation improved during intra-aortic balloon pumping--0.58-0.98 and at the termination of intra-aortic balloon pumping--0.67-0.97. The observed correlation was more pronounced in patients not receiving high doses of inotropes and ranged 0.58-0.98 while for patients receiving high doses of inotropes correlation was less pronounced 0.29-0.5. CONCLUSIONS: Significant correlation of cardiac output values was observed between the impedance cardiography and intermittent thermodilution techniques during intra-aortic balloon counterpulsation. Noninvasive evaluation of hemodynamic indices by continuous monitoring of impedance cardiography during acute myocardial infarction, complicated by cardiogenic shock and managed by intra-aortic balloon counterpulsation is a reliable method for further application.

Acute Disease↗

PubMed1987

Comparison of left ventricular assist and intra-aortic balloon counterpulsation during early reperfusion after ischemic arrest of the heart.

In most centers, intra-aortic balloon counterpulsation and inotrope infusion are used for patients who require support to be weaned from cardiopulmonary bypass at the end of a cardiac surgical procedure. Where available, early institution of a left ventricular assist device is an alternative with possible advantages. In a canine model of left ventricular failure caused by 45 minutes of normothermic ischemic arrest, these two methods of support were instituted after an initial 30-minute reperfusion period. Both methods provided adequate support of the circulation (cardiac output greater than 2 L/min and mean arterial pressure greater than 50 mm Hg). After only 3 hours, however, significant differences were seen between the two groups. When the hearts were examined histologically, dogs in the group with intra-aortic balloon counterpulsation and inotrope infusion had significantly more necrosis than those in the group with a left ventricular assist device, 7.7% +/- 5.0% (mean +/- standard deviation) versus 2.0% +/- 1.3%. Decreases in compliance and systolic function were significantly greater in the group with intra-aortic balloon counterpulsation and inotrope infusion when compared with those supported with a left ventricular assist device. These findings suggest that even when support with intra-aortic balloon counterpulsation and inotrope infusion resulted in satisfactory hemodynamics, early institution of a left ventricular assist device was significantly more effective in preserving myocardial structure and function.

Animals↗