Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Counterpulsation”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 955 records · Page 53Linked to original sources
PubMed1991

Autogenously lined skeletal muscle ventricles in circulation. Up to nine months' experience.

Skeletal muscle ventricles were constructed in fifteen dogs. After a delay period of 4 weeks the skeletal muscle ventricles were connected to the descending thoracic aorta with a polytetrafluoroethylene bifurcation graft (Gore-Tex bifurcation graft, W.L. Gore & Associates, Inc., Elkton, Md.). The aorta was ligated between the two limbs of the graft so that there was obligatory blood flow through the skeletal muscle ventricle. Nine skeletal muscle ventricles were lined with autogenously derived tissue, either pleura or pericardium, whereas six had no specific lining other than an induced fibrous reaction. The skeletal muscle ventricles were activated to contract during cardiac diastole. Aortic diastolic counterpulsation was achieved in all dogs, with ten surviving from 1 week to beyond 9 months. Thrombus eventually developed in all but three of the skeletal muscle ventricles, but no dog had clinical evidence of thromboemboli. The three thrombus-free skeletal muscle ventricles were lined with pleura, including the animal surviving beyond 9 months. These results indicate that canine skeletal muscle can provide aortic diastolic counterpulsation for 9 months without clinically apparent thromboembolic complications.

Animals↗
PubMedDate not supplied

Myocardial oxygen consumption. Comparison between left atrial pulsatile synchronous and asynchronous bypass.

This controlled study was undertaken to quantitate the effect of R-wave synchronization (counterpulsation) on myocardial oxygen consumption (MVO2) as reflected by the tension time index (TTI) during pulsatile left atrial to aortic bypass. Pulsatile ventricular assist devices were implanted in eight anesthetized, fully hemodynamically instrumented animals. After baseline measurement of TTI, heart rate, cardiac output, mean aortic and left atrial pressures, pulsatile left atrial to aortic bypass was instituted. Measurements were then continuously recorded during both left atrial pulsatile synchronous (LAPS) and asynchronous (LAPAS) bypass periods of pumping. Heart rate and mean aortic pressure were controlled throughout the experiment. TTI = 1819 +/- 95 mmHg-sec (control); 987 +/- 127 mmHg-sec (LAPAS); and 763 +/- 89 mmHg-sec (LAPS). The results indicate TTI, and therefore MVO2, is reduced significantly from control levels by either LAPS or LAPAS bypass. However, R-wave synchronization (counterpulsation) offers no further benefit in reducing TTI over the less complex LAPAS or full-to-empty mode pumping.

Animals↗
PubMed1983

'Pulsatile' left atrial-femoral artery bypass. A new method of preventing extension of myocardial infarction.

A left atrial-femoral artery (LA-FA) bypass system was designed to deliver synchronous pulsatile blood flow. We compared it with nonpulsatile LA-FA bypass in its effectiveness to limit infarct extension after ligation of the left anterior descending coronary artery at its origin in 35 dogs. Nonpulsatile LA-FA bypass resulted in a 70% reduction in the size of infarct. The addition of synchronous diastolic counterpulsation (P-LA-FA) further reduced the size of infarct, when compared with that in controls (95%) or animals that underwent LA-FA bypass (83%). Both LA-FA and P-LA-FA bypasses limited infarct extension and reduced mortality after acute coronary occlusion through effective unloading of the left ventricle. The addition of diastolic counterpulsation to LA-FA bypass led to further significant infarct reduction, when compared with LA-FA bypass alone. These effects were most likely secondary to improvements in myocardial blood flow distribution.

Animals↗
PubMed1985

Balloon pump support of the failing right heart.

This report reviews a clinical experience with pulmonary artery counterpulsation with a balloon pump in a patient with pulmonary embolization superimposed upon severe trivalvular rheumatic heart disease. This patient underwent a pulmonary embolectomy and triple-valve replacement requiring a pulmonary artery balloon pump for bypass discontinuation and postbypass hemodynamic support. The field of right heart counterpulsation is briefly reviewed, and the technical details of the implantation and management of the device are elaborated.

Cardiomegaly↗
PubMed1995

Skeletal muscle ventricles: improved left ventricular performance associated with a prolongation of ventricular relaxation.

Skeletal muscle ventricles (SMV) have been shown to pump blood effectively in both acute and chronic models. In this study SMVs were placed in circulation in series with the descending thoracic aorta to function as diastolic counterpulsators. The SMVs were stimulated to contract at a 1:2 ratio with the heart. The R-wave delay and the burst duration were varied, both as a percentage of the total R-R' interval to determine the effect of the SMV on left ventricular (LV) relaxation in relation to other parameters of LV function. Optimal hemodynamic benefit was obtained using a 40% R-wave delay and a 30% burst duration. At these settings, the time constant of LV relaxation (tau) increased from a control value of 29.1 +/- 1.6 to 39.8 +/- 2.1 msec (P < 0.001). The tension time index decreased from a control value of 15.24 +/- .31 to 13.88 +/- .7 mm Hg-sec-1 (P < 0.001). The endocardial viability ratio, an indicator of myocardial blood flow, improved from 1.12 +/- .11 to 1.55 +/- .16 (P < 0.001) and LV dP/dt increased from 1555 +/- 180 to 2320 +/- 210 mm Hg-sec-1 (P < 0.05). In conclusion, this study demonstrates SMV diastolic counterpulsation results in improved LV performance which is associated with a prolongation of LV relaxation. A 40% R-wave delay interval and a 30% burst duration were the stimulation parameters which benefitted myocardial function optimally in this study.

Animals↗
PubMed1988

Myocardial oxygen tension during left ventricular bypass.

The effect of an assist pump on the heart was evaluated on the basis that myocardial gas tensions reflect the balance between oxygen supply and consumption in local regions of the myocardium. A left ventricular assist device (LVAD) was implanted in dogs between the left ventricle (LV group), or the left atrium (LA group) and the aorta. The assist pump was driven in a counterpulsation mode. A silicone catheter for mass spectrometry was inserted into the myocardium to monitor continuously myocardial oxygen and carbon dioxide tensions (PmO2, PmCO2). Coronary sinus blood flow (CSBF) was measured by completing an extracorporeal flow loop between the coronary sinus and the jugular vein. During LVAD counterpulsation, the LV pressure was reduced and diastolic arterial pressure (i.e. coronary perfusion pressure) was increased. Total LV bypass was obtained in the LV group, and partial LV bypass in the LA group. In the LV group, PmO2 was 18.3 +/- 1.9 mmHg with pump-off and increased to 26.4 +/- 3.0 during LV bypass (N = 10, p less than 0.005). PmCO2 was 45.3 +/- 1.8 mmHg with pump-off and decreased to 40.2 +/- 1.5 during bypass (N = 10; p less than 0.005). CSBF significantly decreased during LV bypass from a control value of 24.1 +/- 2.74 ml/min/100g to 16.3 +/- 1.69 in LV group (N = 10; p less than 0.001). It was 43.4 +/- 8.0 ml/min/100g in the pump-off and 31.9 +/- 7.2 during LV bypass in the LA group (N = 7; p less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1991

Induction of transverse polarity by blue light: an all-or-none response.

Phototropic stimulation induces a spatial memory. This was inferred from experiments with maize (Zea mays L.) coleoptiles involving opposing blue-light pulses, separated by variable time intervals, and rotation on a horizontal clinostat (Nick and Schafer, 1988b, Planta 175, 380-388). In those experiments, individual seedlings either curved towards the first or towards the second pulse, or they remained straight. Bending, if it occurred, seemed to be an all-or-none response. Intermediates, i.e. plants, bending only weakly, were not observed. In the first part of the present study it was attempted to create such intermediates. For this purpose the strength of the first, inducing, and the second, opposing, pulse was varied. The result was complex: (i) Individual seedlings maintained the all-or-none expression of spatial memory. (ii) However, on the level of the whole population, the time intervals at which a given response type dominated depended on the fluence ratio. (iii) Furthermore, the final curvature was determined by the fluence ratio. These results are discussed in terms of a blue-light-induced transverse polarity. This polarity initiates from a labile precursor, which can be reoriented by an opposing stimulation (indicated by the strong bending towards the second pulse). The strong curvatures towards the first pulse over long time intervals reveal that, eventually, the blue-light-induced transverse polarity becomes stabilised and thus immune to the counterpulse. In the second part of the study, the relation between phototropic transduction and transverse polarity was characterised by a phenomenological approach involving the following points: (i) Sensory adaptation for induction of transverse polarity disappears with a time course similar to that for phototropic sensory adaptatation. (ii) The fluence response for induction of transverse polarity is a saturation curve and not bell-shaped like the curve for phototropism (iii) For strong counterpulses and long time intervals the clinostat-elicited nastic response (Nick and Schafer 1989, Planta 179, 123-131) becomes manifest and causes an "aiming error" towards the caryopsis. (iv) Temperature-sensitivity of polarity induction was high in the first 20 min after induction, then dropped sharply and rose again with the approach of polarity fixation. (v) Stimulus-summation experiments indicated that, for different inducing fluences, the actual fixation of polarity happened at about 2 h after induction. These experiments point towards an early separation of the transduction chains mediating phototropism and transverse polarity, possibly before phototrophic asymmetry is formed.

Cell Polarity↗
PubMed1998

Rescue therapy with C1-esterase inhibitor concentrate after emergency coronary surgery for failed PTCA.

Administration of C1-esterase inhibitor (C1-INH) attenuates myocardial necrosis and sustains normal cardiac performance after myocardial ischemia and reperfusion in animal experiments. We report on our first experience of C1-INH application as rescue therapy in patients undergoing emergency surgical revascularization after failed percutaneous transluminal coronary angioplasty. Three patients were treated, because post-operative hemodynamic stabilization could not be achieved despite prolonged reperfusion periods, high-dose inotropic support, inodilators and aortic counterpulsation. As there was no surgical or medical option remaining, C1-INH was administered starting with a 2000 unit bolus, followed by 1000 U 12 and 24 h after surgery. C1-INH therapy resulted in rapid hemodynamic stabilization of all patients; weaning from aortic counterpulsation and epinephrine support was possible within 1 day. All patients survived and were discharged from hospital. In this group of patients suffering from severe reperfusion injury after coronary surgery, C1-INH seemed to be an effective adjuvant therapy to restore myocardial function by blocking the complement cascade. These results should encourage the performance of controlled studies on the effects of prophylactic C1-INH substitution therapy in patients undergoing coronary surgery at high risk conditions.

Aged↗
PubMed1985

Effects of pulsed external augmentation of diastolic pressure on coronary and systemic hemodynamics in patients with coronary artery disease.

The purpose of this study was to define the effects of pulsed external diastolic pressure augmentation on coronary and systemic hemodynamics in 14 men with coronary artery disease and normal left ventricular function. Coronary sinus and great vein blood flow (thermodilution) and systemic hemodynamics were measured before, during, and after timed lower extremity compression, augmenting peak diastolic pressure to within 5 mm Hg of systolic pressure. Systolic and diastolic pressure-time indices were calculated from the high-fidelity micromanometer left ventricular-aortic recordings. External counterpulsation increased mean arterial pressure (108 +/- 11 [1 SD] to 114 +/- 12 mm Hg, p less than 0.01) and the diastolic pressure-time index (440 +/- 51 to 498 +/- 82 units, p less than 0.01), with no change in the systolic pressure-time index, absolute coronary sinus, or great cardiac vein blood flow. External diastolic pressure augmentation did not affect heart rate, right heart hemodynamics, cardiac output, or calculated myocardial oxygen consumption. An unanticipated finding was a greater than or equal to 10% reduction in peak systolic pressure during external diastolic pressure augmentation in 8 of 14 patients. Despite minimal changes in absolute myocardial blood flow and oxygen consumption, the increase in the diastolic pressure-time/systolic pressure-time index ratio suggests that subendocardial perfusion may be favorably influenced by diastolic pressure augmentation and may explain the previously reported clinical benefits of external counterpulsation in some patients with ischemic heart disease.

Adult↗
PubMed1992

Frequency of long-term lower limb ischemia associated with intraaortic balloon pump use.

Lower limb ischemia is a frequent complication of intraaortic balloon pump (IABP) use. The incidence and risk factors for acute ischemia have been well-defined, but little is known about long-term ischemic complications. This prospective study evaluated the incidence, nature, progression and predisposing factors for long-term lower limb ischemia in 151 patients who were previously treated with the IABP. These persons were interviewed and their lower extremities examined 12 to 20 months after undergoing IABP counterpulsation. Limb ischemia, characterized primarily by ipsilateral discomfort and diminished pulses, occurred in 18% of those evaluated. Evidence of ischemia worsened over time in 14%. Logistic regression analysis, which was based on variables found to be significant in bivariate analysis, revealed that the occurrence of limb ischemia acutely, cardiogenic shock as an indication for IABP insertion, and smoking (at the time of hospitalization or having quit < 10 years previously) were risk factors for long-term lower limb ischemia. The adjusted odds ratio for acute limb ischemia was 8.89 (95% confidence interval 2.80 to 28.21), for cardiogenic shock 3.59 (95% confidence interval 1.01 to 12.75), and for smoking 2.87 (95% confidence interval 1.10 to 7.46). Increasing numbers of patients are undergoing IABP counterpulsation and a greater proportion of these are surviving their acute event and resuming active lives. It is essential to recognize that detrimental consequences of this device can persist long after hospitalization.

Adult↗
PubMed1995

Resternotomy for bleeding after cardiac operation: a marker for increased morbidity and mortality.

Over a 2-year period from January 1, 1992, to December 31, 1993, of 2,221 patients undergoing cardiac operations in our unit, 85 (3.8%) were reopened for the control of bleeding (9 patients more than once). The incidence of resternotomy in coronary cases was 2.3%, but resternotomy was more than three times as likely in valve cases (odds ratio, 3.4; 95% confidence interval, 2.1 to 5.4). Previous cardiac operation was more common among resternotomy patients than among the remainder (18% versus 9%, respectively; p = 0.018). An identifiable source of bleeding was found in 57 of the 85 patients (67%), but a concurrent coagulopathy was common (45 patients). Resternotomy patients, as a group, had higher preoperative risk scores (Parsonnet) than did the other patients (p < 0.0001), stayed longer in the intensive care unit (p < 0.0001), and had greater requirements for intraaortic balloon counterpulsation (14% versus 3%) and hemofiltration (9% versus 3%) (p < 0.0001 and p < 0.01, respectively). Nineteen resternotomy patients (22%) died in the hospital, a proportion significantly greater than the risk assigned to this group of patients preoperatively (12.8%) (p = 0.008). In contrast, the observed mortality for the other 2,136 patients (5.5%) was significantly less (8.3%) (p < 0.00006). Multiple forward stepwise logistic-regression analysis confirmed resternotomy for excessive bleeding after cardiac operation to be a significant independent predictor of a prolonged stay in the intensive care unit (p < 0.0001), the need for intraaortic balloon counterpulsation (p < 0.0001), and death (p < 0.0001).

Aged↗
PubMed1995

Peripheral vascular complications in the Coronary Angioplasty Versus Excisional Atherectomy Trial (CAVEAT-I).

OBJECTIVES: In-hospital peripheral vascular complications of balloon angioplasty were compared with those of directional atherectomy in the Coronary Angioplasty Versus Excisional Atherectomy Trial (CAVEAT-I) to identify patients at risk and evaluate costs and outcomes. BACKGROUND: The incidence, costs and outcomes of peripheral vascular complications after coronary intervention have not been fully characterized as a function of randomly assigned therapy. METHODS: At 35 sites in the United States and Europe, 1,012 patients were randomized. Peripheral vascular complications were defined as the composite of pulse loss, pseudoaneurysm, hematoma > 4 cm in diameter or groin hemorrhage necessitating blood transfusion. Logistic models were derived to 1) predict these complications from baseline and procedural characteristics, 2) test the relevance of randomization assignment, and 3) assess their impact on hospital costs and long-term outcomes. RESULTS: Sixty-seven patients (6.6%) developed peripheral vascular complications, of whom 15 (22.4%) required a blood transfusion, 14 (20.9%) underwent vascular surgery, and 2 (3.0%) died. Both in-hospital deaths occurred in patients with peripheral vascular complications. There was no difference in composite peripheral vascular complication rates among patients randomized to angioplasty or atherectomy. Greater age, female gender, postprocedural heparin and intraaortic balloon counterpulsation were predictive of increased risk. In a representative 60% subset, mean hospital costs increased from $9,583 in patients without to $18,350 in those with peripheral vascular complications (p = 0.0001). The unadjusted mortality rate at 1 year was 7.5% for patients with peripheral vascular complications compared with 1.1% for all others (p = 0.0001). These complications identified patients at greater risk of death, myocardial infarction or repeat revascularization at 30 days and 1 year. The atherectomy group had a trend toward more frequent deaths and myocardial infarction. CONCLUSIONS: Directional atherectomy and balloon angioplasty had similar in-hospital peripheral vascular complication rates. Female gender, greater age, postprocedural heparin and intraaortic balloon counterpulsation were predictive of higher risk. The twofold increase in cost and sevenfold increase in long-term deaths highlight the need to prevent these periprocedural events and monitor patients closely.

Angioplasty, Balloon, Coronary↗
PubMed1987

The intra-aortic balloon pump as an adjunctive therapy for severe myocardial contusion.

The management of patients with post-traumatic myocardial contusion requires close electrocardiographic and hemodynamic monitoring. When complications such as cardiogenic shock occur, aggressive treatment using Swan-Ganz catheterization for monitoring of intravascular volume and cardiac inotropic support are necessary. Failure to restore hemodynamic stability using these measures is an indication for the use of intra-aortic balloon pump counterpulsation. A case of successful management of a patient with post-traumatic myocardial contusion complicated by refractory cardiogenic shock using intra-aortic balloon pump counterpulsation is presented. Use of the intra-aortic balloon pump improved cardiac output, eventually resulting in hemodynamic stabilization.

Adult↗
PubMed1996

Myocardial revascularization for severe left ventricular dysfunction. Factors influencing early and late survival.

The results of coronary bypass surgery have been assessed in 102 patients with severe left ventricular dysfunction who had a preoperative left ventricular ejection fraction of < or = 0.35 (mean (s.e.m.) 0.29 (0.01)). Independent risk factors influencing operative mortality were obesity (P = 0.0290) and the need for preoperative intra-aortic balloon counterpulsation (P = 0.0010). Cox regression analysis using as its end-point 'cardiac-related death' demonstrated three variables; the need for preoperative intra-aortic balloon counterpulsation (P < 0.001), advanced age (P = 0.011), and obesity (P = 0.36). In a subset of 43 patients who did not have these risk factors, the 4-year cardiac-related death rate was 95.1 (3.4)%. The operative mortality and long-term survival can be expected to be satisfactory in patients with severe left ventricular dysfunction, provided they have a viable myocardium rather than myocardial fibrosis.

Aged↗
PubMed2004

Temporary assist device for postcardiotomy cardiac failure.

Postcardiotomy left ventricular failure (LVF) complicating a cardiac surgical procedure is usually managed with intraaortic balloon pump (IABP) counterpulsation. We report two cases of postcardiotomy LVF unresponsive to inotropic support and IABP counterpulsation that were managed successfully with the use of the TandemHeart percutaneous ventricular assist device (pVAD) (CardiacAssist, Pittsburgh, PA). The TandemHeart pVAD appears to be safe and effective as a bridge to recovery in the treatment of postcardiotomy cardiac failure.

Aged↗
PubMed1985

Late paraplegia as a consequence of intraaortic balloon pump support.

There have been several reports of paraplegia after intraaortic balloon counterpulsation in the surgical literature. In each instance, the paraplegia occurred during the period of counterpulsation support. We describe a patient in whom late paraplegia occurred three days after the removal of an intraaortic balloon catheter.

Aged↗
PubMed1983

Intraaortic balloon pump morbidity: a comparative analysis of risk factors between percutaneous and surgical techniques.

We reviewed our concurrent experience with percutaneous insertion versus surgical placement of the intraaortic balloon pump over a two-year period both to compare morbidity and to provide guidelines for the choice of method in particular patient groups and clinical settings. The effects on morbidity of sex, age, emergency placement, coexisting peripheral vascular disease, and duration of counterpulsation were determined. Sex was a highly significant factor, with low complication rates (3/29 or 10.3%) for percutaneous insertion in men and an inordinately high morbidity (12/17 or 70.6%) in women (Fisher exact test: p = 4.611 X 10(-5)). This difference may be due to the smaller size of the femoral artery in women. We conclude that percutaneous insertion is the preferred technique for most men but that direct exposure of the femoral artery should be employed in women. Given the serious morbidity encountered with each technique, there is no justification to broaden the indications for intraaortic balloon counterpulsation.

Assisted Circulation↗
PubMed1982

Delayed operative intervention in cardiogenic shock after myocardial infarction.

In a four-year period, 45 patients underwent counterpulsation for cardiogenic shock following myocardial infarction. Of these patients, 27 underwent angiography. Fifteen of them were not considered to be operative candidates because angiography demonstrated only single-vessel disease or diffuse distal coronary artery disease. Twelve patients were candidates for operation and were divided into three subgroups depending on the time of surgical intervention. One patient (Group 1) deteriorated while on counterpulsation, and underwent urgent angiography and operative intervention within 24 hours of balloon insertion. He is now in New York Heart Association (NYHA) Functional Class I. Group 2 consisted of 7 patients whose condition stabilized with use of the balloon but who could not be weaned. All underwent angiography from 7 to 14 days after insertion of the balloon. One patient died suddenly prior to operation. Six patients underwent coronary bypass from 8 to 21 days after balloon insertion. Five survived and are in NYHA Class II or III. Four patients were able to be weaned after angiography (Group 3). All had triple-vessel disease. Operation was undertaken six to eight weeks after infarction to treat persistent congestive heart failure or angina, or to improve chances of long-term survival. Two patients in this group survived. Our experience demonstrates that delayed intervention is an acceptable alternative to urgent operation.

Angiography↗