William S. Pierce

Ventricular-Assist Pumping in Patients with Cardiogenic Shock after Cardiac Operations

A ventricular-assist pump was used to support the circulation in eight patients who could not be separated from cardiopulmonary bypass after open-heart operations. In five patients with left ventricular failure, the systemic circulation was maintained with pumping from the left atrium to the aorta for 7.0 +/- 1.8 days (mean +/- S.E.M.); three of these patients were well four to 17 months after surgery. In two patients with biventricular failure, right and left ventricular bypass supported the circulation, but neither patient survived. One other patient had isolated right ventricular failure; pumping from the right atrium to the pulmonary artery maintained the pulmonary circulation for 2.2 days. This patient lived for 18 months. Use of the ventricular-assist pump in our patients provided complete support of the systemic or pulmonary circulation or both. Profoundly depressed ventricular function is potentially reversible if technical problems in employing the pump can be avoided.

Heterotopic prosthetic ventricles as a bridge to cardiac transplantation. A multicenter study in 29 patients

Heterotopic prosthetic ventricles were used to support the circulation in 29 candidates for heart transplantation who were expected to die before procurement of a donor heart. Twenty-one of these patients (average age, 36 years) underwent successful transplantation after 8 hours to 31 days of circulatory support. The other eight patients died because their condition could not be stabilized for transplantation, despite restoration of blood flow. Fourteen patients received biventricular support; 15 received only left ventricular support, with pharmacologic assistance of right heart function. Before transplantation, blood flow from the left prosthetic ventricle averaged 2.8 +/- 0.4 liters per minute per square meter of body-surface area, and from the right prosthesis 2.4 +/- 0.4 liters, as compared with an average flow of 1.6 +/- 0.5 liters per minute per square meter before implantation. Of the 21 patients who received heart transplants, 20 were discharged from the hospital after a median of 31 days. Nineteen patients were alive at 7 to 39 months, and 11 of the first 12 were alive at one year. We conclude that heterotopic placement of prosthetic ventricles as a bridge to transplantation provides an effective method of temporarily supporting cardiac function in critically ill patients without removing the natural heart. The early survival rate after transplantation is similar to that with elective cardiac transplantation.

Aortic valve replacement and combined aortic valve replacement and coronary artery bypass grafting: predicting high risk groups

To determine which groups of patients are at highest risk for operative or late mortality, 259 consecutive patients who underwent operation between 1978 and 1984 were studied; 170 underwent aortic valve replacement and 89 underwent aortic valve replacement combined with coronary artery bypass grafting. Multivariate analysis of risk factors selected emergency operation and patient age older than 70 years as the strongest predictors for operative death. Although patients having aortic valve replacement and coronary artery bypass grafting had a higher operative mortality rate (13.5 versus 3.5%), the combined operation had no independent predictive effect on early or late results. At a mean follow-up time of 48 months after surgery, 72% of the survivors of operation were living, 10% were lost to follow-up and 18% were dead. Seventy-seven percent of long-term survivors were in New York Heart Association functional class I or II. The incidence of thromboembolism, paravalvular leak, bacterial endocarditis and hemorrhage each occurred at a rate of less than 1% per patient-year. The factors associated with late death were preoperative age, male sex, left ventricular end-diastolic pressure, cardiac index and functional class. Despite an increase in operative mortality, patients undergoing emergency operation were not at higher risk of late death. Operative mortality is concentrated among several high risk groups. For patients undergoing elective operation, operative mortality is low, especially if the patient is less than 70 years old. Late results are good for all groups of patients undergoing operation, including those who are at greater risk of dying at operation.

Survival and Complications Following Ventricular Assist Pumping for Cardiogenic Shock

Thirty patients (pts) have undergone ventricular assist pumping for up to 25.4 days (mean 6.8 days). Twenty-eight pts could not be weaned from cardiopulmonary bypass (CPB) after open heart operations and two pts sustained myocardial infarctions (MI), with cardiogenic shock unresponsive to medical therapy previous to surgery. Twenty-two pts required left ventricular assistance (LVA); 55% (12/22) were weaned from the pump and 32% (7/22) survived. Two pts required right ventricular assistance (RVA); both were weaned from the pump and survived. Six pts required right and left ventricular assistance (BVA) and none survived. Postoperative survival for program years 1976 through 1979 (14 pts) was 14% (2/14). Postoperative survival for program years 1980 through 1982 (16 pts) was 44% (7/16), reflecting improved pump insertion techniques (left atrial cannulation) and pt management. Since 1980, 12 pts have required LVA, nine have been weaned from the pump, and six pts have survived (50%). One pt has required RVA and has survived, and three pts requiring BVA did not survive. Seven pts have been alive and well 5, 9, 14, 19, 24, 30 and 36 months after surgery. Five are NYHA functional Class I status and two pts are NYHA Class II status. Current data indicates that single ventricular assistance in pts who cannot be weaned from CPB is “reasonable and therapeutic treatment to extend life.”

The LionHeart LVD-2000 : a completely implanted left ventricular assist device for chronic circulatory support

Management of patients with end-stage cardiac disease remains a vexing problem. Limitations in medical management and a fixed supply of donor organs for cardiac transplant have a continued impact on this growing population of patients. Mechanical circulatory support has proved very successful as a means of bridging patients to cardiac transplant when all medical options have been exhausted. The development of a chronic system of circulatory support has been underway at the Pennsylvania State University for nearly 30 years. These efforts have been recently merged with the industrial partnership with Arrow International toward the development of the LionHeart LVD-2000 (Arrow International, Reading, PA) completely implanted left ventricular support system. We present an overview of the system, details of implantation, a review of preclinical studies, and a synopsis of the first European implants. Early results have demonstrated the system to be safe, effective, and reliable. Transcutaneous energy transmission and the compliance chamber have been validated.

Recurrent Pulmonary Emboli Secondary to Right Atrial Thrombus Around a Permanent Pacing Catheter: A Case Report and Review of the Literature

A case report and review of the literature.

Reduction of myocardial infarct size: comparison between left atrial and left ventricular bypass.

A controlled study was undertaken to quantitate and compare the effect of left ventricular bypass (LVB) and left atrial bypass (LAB on left ventricular infarct volume (LVIV). After baseline studies, the left anterior descending coronary artery in each of 30 mongrel dogs was ligated 1-1.5 cm from its origin. After baseline ischemic studies, control dogs (group 1--10 dogs), LAB dogs (group 2--10 dogs), and LVB dogs (group 3--10 dogs) were monitored for four hours. Final infarct size was determined by the nitroblue tetrazolium staining technique. Heart rate, mean arterial pressure, and total systemic flow (TSF) showed no significant difference between control and left heart bypass groups. In group 1, the LVIV was 27.7 +/- 6.5 g/100 g left ventricle (LV). In group 2, left heart bypass (LHB) flow was 90 +/- 4% of TSF. The pressure time index (PTI) was 2845 +/- 52 mm Hg-sec/min. The PTI demonstrated no significant difference from cntrols. In group 2, LVIV was 22.5 +/- 6.0 g/100 g LV. LVIV was reduced 18.8% from controls (p less than 0.08). In group 2, LHB was complete. Left ventricular decompression (group 3) resulted in a PTI of 328 +/- 76 mm Hg-sec/min. The PTI was significantly different (p less than 0.001) from groups 1 and 2. The LVIV was 12.6 +/- 5.1 g/100 g LV. LVIV was reduced 54.5% from controls (p less than 0.001) and 44.0% from group 2 (p less than 0.001). These results suggest that LVB may be useful, not only in supporting the circulation in the patient with myocardial infarct and cardiogenic shock, but also in limiting infarct size.

Results of mechanical ventricular assistance for the treatment of post cardiotomy cardiogenic shock

The voluntary submission of data on patients who receive mechanical circulatory assistance for post cardiotomy cardiogenic shock and acute myocardial infarction has resulted in an established data base for the ongoing evaluation of these devices. Since its inception in 1985, there have been 1,279 cases reported of implanted ventricular assist devices for post cardiotomy cardiogenic shock. The average duration of support for these devices is approximately 4 days. Those patients who underwent implantation of a centrifugal pump had significantly shorter periods of support when compared with the pneumatically supported group. Patients had similar periods of support when comparing clinical outcome. Approximately 70% of the reported cases underwent centrifugal assistance. The majority of reported cases were supported with isolated left ventricular assistance. There was no significant difference in overall outcome statistics when comparing type or mode of support. Approximately 45% of reported patients were weaned from circulatory assistance, and 25% of all patients survived to discharge. These numbers remain consistent with previously reported statistics. The results with acute myocardial infarction remain limited. Of the 96 reported patients, 26% were weaned from support and only 11.5% survived to discharge. This report continues to support the use and research for advancement of these devices toward the treatment of post cardiotomy cardiogenic shock.

Isolated Partial Anomalous Venous Connection: A Congenital Defect with Late and Serious Complications

The cases of 3 patients with partial anomalous pulmonary venous return with intact atrial septum are reported. The 2 adult patients had evidence of severe pulmonary artery hypertension with markedly increased pulmonary vascular resistance indicating advanced pulmonary vascular obstructive disease. This confirms earlier limited observations and emphasizes the potential for this congenital lesion to develop late, serious complications. In view of this potential, surgical repair of the anomaly should be considered whenever it is found. Descriptions of a successful operative approach are included.

Pathogenesis of Paradoxical Hypertension after Coarctation Repair

A recent review of 25 patients who had repair of coarctation of the aorta at the Milton S. Hershey Medical Center revealed a 56% incidence of paradoxical hypertension in the immediate postoperative period. Analysis of results from recent animal experiments helped us to formulate a logical explanation of the pathogenesis of this hypertension. Stimulation of sympathetic nerve fibers located between the media and adventitia of the aortic isthmus has two effects, both of which result in hypertension. The first effect is release of norepinephrine and consequential rise in systemic blood pressure. Second, this spinal reflex directly stimulates the juxtaglomerular cells to release renin and cause additional hypertension. An additional effect of this increased renin production might be the shunting of blood from mesenteric arteries, thus causing the abdominal symptoms of so-called post-coarctectomy syndrome. The inability of some patients to adapt to this spinal reflex may be related to the age of the patient when the coarctation was repaired. This probably explains the high incidence of persistent hypertension in patients who undergo coarctation repair after adolescence.