Intrapulmonary artery balloon pumping

Pulmonary artery balloon counterpulsation: safe after peripheral placement

Pulmonary artery balloon counterpulsation is a promising experimental technique for treatment of right ventricular failure. However, clinical application has been limited in that the only device presently available (the large-volume intraaortic balloon) must be placed within a synthetic graft. Because a balloon with a smaller volume (which could be placed through a peripheral vein and be contained entirely within the pulmonary artery) would make the technique feasible on a wider scale, we tested an 8-mL pulmonary artery balloon placed through the femoral vein in 12 dogs. Two groups of animals were compared. One group had the pulmonary artery balloon in place but not counterpulsating; the other had the pulmonary artery balloon in place and counterpulsating. Each group was studied for 12 hours. A variety of hemodynamic parameters were measured. Effective diastolic augmentation and systolic unloading were noted in all 6 dogs that underwent counterpulsation (5.0 +/- 1.1 mm Hg of diastolic augmentation and 9.5 +/- 1.6 mm Hg of systolic unloading). Pulmonary function, as measured by arterial blood gas sampling and pulmonary vascular resistance, was not impaired. Examination of the heart and lungs showed no detrimental pathologic effects of pulmonary artery balloon counterpulsation. Placement of the balloon through a peripheral vein with a guidewire was easy and uncomplicated. We conclude that pulmonary artery balloon counterpulsation is safe over an extended period of 12 hours in the canine model and that diastolic augmentation and systolic unloading can be produced.

Pulmonary artery balloon counterpulsation for intraoperative right ventricular failure

Two cases of severe low cardiac output and right ventricular failure after coronary artery bypass grafting necessitated pulmonary artery balloon counterpulsation after intraaortic balloon pumping and maximal inotropic/pressor support were unsuccessful in maintaining a satisfactory cardiac output. Hemodynamic improvement was sufficient to allow removal of the device 2 and 3 days postoperatively, with survival in 1 patient. Pulmonary artery counterpulsation is less morbid in comparison with other mechanical methods of right ventricular support and is applicable in right ventricular failure of intermediate severity.

A pediatric ventricular assist device: its development and experimental evaluation of hemodynamic effects on postoperative heart failure of congenital heart diseases

To evaluate the effectiveness of a pediatric ventricular assist device (VAD), hemodynamic effects of the VAD were investigated experimentally in two types of postoperative profound heart failure models of congenital heart disease. In the model I Fontan or modified Fontan operation model, right ventricular pump function was excluded surgically and a shunt between the right atrium and the pulmonary artery was constructed in four dogs. With a VAD between the left atrium and the aorta, pressure gradient across the lung and the cardiac output increased. Right ventricular failure was induced surgically and high pulmonary vascular resistance was made by injection of glass beads in five dogs in model II. Cardiac output increased and the right atrial pressure decreased when a VAD between the right atrium and the pulmonary arterial trunk was activated. In conclusion, the VAD will become a promising modality to manage pediatric profound heart failure cases.

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.

Successful use of a right ventricular assist device

Right ventricular failure caused by myocardial infarction may be refractory to treatment designed to support the systemic ventricle. A new type of right ventricular assist device driven by an impeller pump was successfully used for 79 hours after emergency revascularisation after right coronary occlusion. Despite renal failure requiring haemofiltration the patient has now fully recovered.

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.

Right ventricular failure. Pathophysiology and treatment

The cardiac surgeon is faced with RV failure in two main situations: in isolation or in patients with left-sided cardiac assist. Adequate volume loading, correction of acidosis and oxygenation, cardiac pacing, pharmacologic agents, and systemic intra-aortic balloon pumping allow stabilization in most of these patients. When these measures fail, some form of mechanical assistance of the right ventricle becomes necessary. Balloon counterpulsation in the pulmonary artery improves RV output but does not restore the systemic perfusion if the right ventricle is profoundly depressed. When the right ventricle is profoundly depressed, a mechanical assist pump is the only device capable of restoring systemic perfusion. Like the left ventricle, the right ventricle, given time and support, can recover enough function to allow weaning from the assist device and survival.

Pulmonary artery balloon counterpulsation for treatment of intraoperative right ventricular failure

Pulmonary artery balloon counterpulsation was used in 3 patients who underwent open-heart operation for the treatment of acquired cardiac lesions. This form of support was initiated because the patients could not be weaned from cardiopulmonary bypass even with intraaortic balloon counterpulsation and maximal pharmacological support. After pulmonary artery balloon pumping was instituted, cardiopulmonary bypass was successfully terminated in all 3 patients. One of them is alive and well one year after operation.

The hemodynamic effects and mechanism of action of pulmonary artery balloon counterpulsation in the treatment of right ventricular failure during left heart bypass

The efficacy of pulmonary artery balloon counterpulsation (PABC) was evaluated in improving right ventricular (RV) output during left heart bypass for global cardiac failure. In 13 pigs, a 40-ml balloon was positioned within a graft anastomosed to the pulmonary artery distal to the pulmonary valve, and left heart bypass was instituted from the left atrium to the carotid artery. Global myocardial failure was produced by an infusion of propranolol (range, 25 to 78 mg). In this model, RV output decreased despite volume loading to a right atrial pressure of 15 mm Hg and atrioventricular sequential pacing at 100 beats per minute. Pulmonary artery balloon counterpulsation increased both RV output (from 519 +/- 76 to 1,117 +/- 110 ml/min; p less than 0.01) and RV systolic stroke work (from 1.3 +/- 0.4 to 2.3 +/- 0.6 gm-m; p less than 0.01). Right atrial pressure decreased (from 15.5 +/- 0.9 to 10.7 +/- 1.0 mm Hg; p less than 0.01) in 8 of the pigs studied during RV failure. In 5 pigs, ventricular fibrillation occurred without a stable model of RV failure, and there was no cardiac output before or after counterpulsation. The mechanism of action of PABC was studied by placing a flow probe around a large branch of the right pulmonary artery. During RV failure, balloon inflation caused flow through the pulmonary circulation, and ventricular systole resulted in filling of the graft. During ventricular fibrillation, balloon inflation and deflation produced only a to-and-fro movement of blood in the pulmonary artery branch without net forward flow.(ABSTRACT TRUNCATED AT 250 WORDS)

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.