Effects of a Selective Bypass of the Left Ventricle

Baird, Ronald J.; Labrosse, Claude; Lajos, Thomas Z.; Thomas, G.W.

doi:10.1161/01.cir.27.4.835

Cited by 23 publications

(3 citation statements)

References 10 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…During the cardiopulmonary bypass the heart was unloaded, which according to ex perimental studies decreases the myocardial oxygen need by 30-50% [2,10]. At the same time, some other factors may have an unfa vorable influence on the oxygen transport and delivery to all myocardial regions, e.g.…”

Section: Dilution During Bypassmentioning

confidence: 99%

Myocardial Oxygen Balance during Hemodilution in Patients Undergoing Coronary Artery Bypass Grafting

Jalonen¹,

Meretoja²,

Laaksonen³

et al. 1984

Eur Surg Res

View full text Add to dashboard Cite

The myocardial (arterial-coronary sinus) balance of oxygen and lactate was studied before a cardiopulmonary bypass and during the first 5 min of a normothermic bypass in two patient groups undergoing coronary revascularization for multiple coronary artery disease. The hemodilution (HD) group was hemodiluted before the bypass with dextran 70 (15 ml/kg; resulting mean hematocrit 32%) and further at the beginning of the bypass due to nonhemic priming of the oxygenator (mean hematocrit 15%). The control (C) group was not diluted before the bypass, and four units of red blood cells were included in the oxygenator priming (mean hematocrit 27% after the beginning of the bypass). The preoperative dilution produced a decline in the coronary sinus blood oxygen tension and oxygen saturation, but no change in the arterial-coronary sinus lactate balance. After the first 5 min of the bypass, the heart produced lactate in both the HD group and the C group, but the lactate production was more pronounced in the HD group. At the same time, the coronary sinus blood oxygen saturation was lower in the HD group than in the C group. Hypotension frequently accompanied the beginning of the bypass in both groups. It is concluded that the hemodilution to a hematocrit level of 32% in patients undergoing coronary revascularization for multiple stable coronary artery disease produces compensatory changes in myocardial oxygen extraction, but no changes of a generalized ischemia can be demonstrated. The hemodilution to a hematocrit level of 15 % produces myocardial ischemia in patients with a normothermic unloaded heart, adding to the effect of hypotension at the beginning of the bypass.

show abstract

Section: Dilution During Bypassmentioning

confidence: 99%

Myocardial Oxygen Balance during Hemodilution in Patients Undergoing Coronary Artery Bypass Grafting

Jalonen¹,

Meretoja²,

Laaksonen³

et al. 1984

Eur Surg Res

View full text Add to dashboard Cite

show abstract

“…179 * No. 6 [1][2][3][4] .r1. n -t to n n en 't ,t --n Cs enC e dee C*,en -C14 ,-dl 14 -u en en en -4 C en "t -,t …”

Section: Discussionunclassified

Comparative Effects of Left Atrial or Left Ventricular Bypass on Coronary Sinus Flow and Oxygen Usage in Dogs

Miller¹

1974

Annals of Surgery

View full text Add to dashboard Cite

Comparative coronary sinus flow rates and oxygen AV difference were studied in dogs undergoing left heart bypass with left atrial or left ventricular drainage at similar maximum obtainable flow rates. Left atrial bypass decreased the coronary sinus flow rates and oxygen consumption when compared with control values. These values were further decreased when left ventricular bypass was used. The oxygen consumption data were highly significant and give further evidence of increased effectiveness of complete bypass of the left ventricle in myocardial support systems.L EFT HEART BYPASS has been used both experimentallyl'7'10,13,14.17.l8 and clinically2'6'8'9'21 as a method of myocardial support. Although both the left atrial and left ventricular chambers have each been used as sites for decompression of the left side of the heart, the relative effectiveness of these two approaches in reducing myocardial oxygen consumption has not been clarified.20 The purpose of this study was to determine the comparative effectiveness of each site of drainage in reducing myocardial oxygen consumption during left heart bypass at comparable flow rates. MethodFourteen healthy mongrel dogs weighing 18 to 25 kg were used. Materials having contact with the blood were sterile; however, the experiments were conducted under clean rather than sterile conditions. Intermittent pentothal sodium was used intravenously for narcosis and oxygen was delivered by a positive-pressure ventilator. Animals were heparinized with 300 units/kg of aqueous heparin sodium (1000 units/ml).The right carotid artery was exposed and a #8 cardiac catheter inserted retrogradely into the left ventricular

show abstract

“…However, at least as important in delaying the development of partial LHB techniques was the view that LV functional recovery would not be possible except under conditions of virtually total LV bypass. This concept was based on experimental studies performed in animals with beating, nontraumatized hearts in which marked reduction of myocardial oxygen consumption (M902) was observed only when the LV was completely unloaded [3,4]. The studies demonstrated that nonpulsatile total LHB reduced MVO2 by approximately 50% while MVO2 reduction was only modest (20%) under conditions of partial LHB (50% of total flow).…”

Section: A Conventional Point Of Viewmentioning

confidence: 99%

A decade of experience with a left heart assist device in patients undergoing open intracardiac operation

et al. 1985

View full text Add to dashboard Cite

Over a decade has elapsed since the first clinical application of our left heart assist device (LHAD). The basic concepts underlying its development evolved from prior experience in which, given adequate support time, less than total left heart bypass (LHB) was found to result in gradual improvement of depressed left ventricular function. Hence, the long‐held view that functional recovery of the heart could occuronlyunder conditions of total LHB seemed unsupportable by clinical realities. As a result, a simple LHAD was devised. Requiring only special silicone elastomer cannulas, the system uses a roller (or other continuous flow) pump and diverts blood from the left atrium to the ascending aorta. We believe a major asset of the system is the ability to separate the patient subsequently from the LHAD without need to re‐enter the thorax. This is accomplished by permanently occluding each cannula lumen with an obturator, thereby allowing the biocompatible cannulas to remain permanentlyin situ.To date, 27 patients have undergone LHAD support. Of 18 patients who could be separated from the device, half (9) were discharged from the hospital. Seven remain alive and well, the longest now more than 10 years after the operation. Although rarely needed, broadening operative indications in patients with severely compromised left ventricular function suggests that there will be continued need for a method of LHB for the foreseeable future.

show abstract

Effects of a Selective Bypass of the Left Ventricle

Cited by 23 publications

References 10 publications

Myocardial Oxygen Balance during Hemodilution in Patients Undergoing Coronary Artery Bypass Grafting

Myocardial Oxygen Balance during Hemodilution in Patients Undergoing Coronary Artery Bypass Grafting

Comparative Effects of Left Atrial or Left Ventricular Bypass on Coronary Sinus Flow and Oxygen Usage in Dogs

A decade of experience with a left heart assist device in patients undergoing open intracardiac operation

Contact Info

Product

Resources

About