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F D Loop

Publications and source records attributed to F D Loop.

159 records · Page 9Linked to original sources
PubMedDate not supplied

Surgical treatment of coronary artery disease: pure graft operations, with a study of 741 patients followed 3--7 yr.

This report reviews the experience with bypass graft surgery in the pure form, without associated cardiac procedures, in 6828 patients operated upon from 1967 through 1974. The hospital mortality rate in this group was 1.4%. The incidence of definite perioperative myocardial infarction was 6.9% prior to 1971, and 4.1% in the past 3 yr. Graft patency in postoperative studies performed an average of over 12 mo after surgery was 83.6%, and 89% of patients had one or more functioning grafts. In a subgroup of 741 consecutive patients operated upon with pure graft techniques from 1967 through 1970, survival seemed to be improved when compared to another group of similar, but nonoperated patients. The average annual mortality rate was 3.3% per yr in the surgical group (including surgical mortality) compared to 8.8% per year in the medical group. Differences in survival were most striking in patients with isolated anterior descending, double and triple vessel involvement. In the 741-patient subgroup the incidence of new occlusions of grafted arteries was related to the severity of the lesion(s) for which the operation was performed, and unrelated to graft patency. Arteriographically demonstrated new occlusions of ungrafted arteries were infrequent, and few patients developed significant new lesions during the period of observation. Symptomatic improvement is related to completeness of revascularization as determined by postoperative arteriography.

Angiocardiography↗
PubMedDate not supplied

Muscle powered circulatory assist device for diastolic counterpulsator.

A diastolic counterpulsator that uses either skeletal muscle or pneumatic actuation was developed. The unit is positioned between the latissimus dorsi and the chest wall, without interference with collateral blood supply, and is connected in series with the descending aorta. The system was able to generate stroke volumes between 52 and 16 ccs against pressures of 60 and 140 mmHg, respectively. Stroke work at 200 msec stimulation averaged 2.8 X 10(6) ergs. Power output at an afterload of 100 mmHg, and at a rate of 60 bpm, was 0.51 W. Back-up pneumatic actuation provided by an intraaortic balloon pump resulted in a 46% increase in the endocardial viability ratio (EVR).

Animals↗
PubMedDate not supplied

New crisscross-shaped port design for universal serial pumps.

The long range goal is the development of a clinically useful, implantable, skeletal muscle powered cardiac assist device (MCAD). To accomplish this goal, two criteria must be met: good anatomic fit, and antithrombogenicity. Because of the relative locations of the latissimus dorsi (LD) muscle and aorta, there are two possible port arrangements: "crisscrossed" (C design), in which the ports are crossed to anastomotic sites, and "prong" shaped (P design), in which no crossover takes place. The purpose of this paper is to determine which of these designs is best from a fluid dynamic perspective, and hence has the best possibility for low thrombogenicity. Flow visualization (FV) techniques were used during two pumping conditions in a mock loop: worst case (MCAD off) and best case (MCAD driven optimally). Results of the MCAD off tests showed that both designs required immediate actuation (for example, an IABP console). However, FV studies under optimal conditions indicated superiority of the C design, most likely due to kinetic energy-induced rotary motion combined with a minimal interport distance. It is concluded that the C design provides ideal flow dynamics, even in valveless pumps, and also has application to valved devices.

Counterpulsation↗
PubMedDate not supplied

The old order changeth.

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Cardiac Surgical Procedures↗
PubMedDate not supplied

Cardiac rhythm and conduction disturbances in patients undergoing mitral valve surgery.

The occurrence and course of supraventricular rhythm and atrioventricular conduction disturbances were retrospectively compared in 206 patients with isolated mitral valve disease undergoing either valve replacement or ring annuloplasty (mitral repair) between January 1, 1985 and December 31, 1986. The replacement and repair groups were the same size and had approximately equal numbers of patients in sinus rhythm and atrial fibrillation preoperatively. The type of mitral valve operation did not affect the short-term outcome in terms of cardiac rhythm. For both groups, the incidence of patients crossing from sinus rhythm to atrial fibrillation and vice versa on the pre-discharge electrocardiography was equal, and both groups had a low incidence of clinically significant atrioventricular block.

Adult↗