PubMed Health⌕ Search

SEARCH · PubMed Health

Results for “CARDIAC VALVES”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

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

At least 451 records · Page 25Linked to original sources
PubMed1995

Hemolytic differences among artificial cardiac valves used in a ventricular assist pump.

Ventricular assist devices (VADs) required for cardiac support may produce clinically significant hemolysis. VAD valves differ in both mechanics and hemodynamics. Therefore, we examined a ball valve, a modified tilting disc (MTD) valve, a polyurethane trileaflet valve, and a Björk-Shiley monostrut valve to determine their degrees of hemolysis. The valves were tested in a Pierce-Donachy VAD which pumped fresh bovine blood through a mock loop. Blood samples were analyzed for hematocrit and plasma hemoglobin, from which the indices of hemolysis were calculated. A one-way analysis of variance indicated significant differences between certain valves. The MTD was the most hemolytic. No significant hemolytic difference was found between the trileaflet and monostrut valves despite their different designs. The monostrut valve and the MTD valve were hemolytically very different despite their similar design. This study suggests that the valve type significantly affects the hemolysis produced by the VAD.

Animals↗
PubMed1998

A new approach to cardiac valve replacement through a small midline incision and inverted L shape partial sternotomy.

OBJECTIVE: Minimally invasive cardiac surgery is becoming more popular as an alternative technique in some cardiac operations. We report our experience with an inverted 'L' ministernotomy in 25 patients and describe the technical details of this new approach. METHODS: From June 1996 to February 1997 we performed 25 ministernotomy approaches for cardiac surgery, 17 aortic and 7 mitral valve replacements and 1 atrial septal defect closure. A comparison group included all patients (n = 126) operated on for mitral or aortic valve replacement through a median sternotomy since June 1996. RESULTS: Ventilatory support, Intensive Care Unit stay and hospital stay were 8.3 h (SD = 4 h), 25 h (SD = 8 h) and 5.5 days (SD = 3 days) in the L ministernotomy group and 11.5 h (SD = 5), 53 h (SD = 11) and 9.1 days (SD = 4 days) in the median sternotomy group (P < 0 05). Mortality and morbidity are similar to conventional sternotomy (hospital mortality 4% vs. 5.5%; P not significant). CONCLUSIONS: We conclude that inverted L ministernotomy for cardiac surgery is a safe approach and can offer some advantages over the conventional approach.

Aortic Valve↗
PubMed1999

Intraoperative transesophageal echocardiography in minimally invasive cardiac valve surgery.

The minimally invasive procedure is a new surgical technique that uses a small sternal incision. Because of limited surgical exposure, removal of intracavitary air and visual assessment of cardiac function are not possible. We studied the utility of intraoperative transesophageal echocardiography (IOE) before and after cardiopulmonary bypass in 112 patients (mean age 53.1 +/- 15.2 years, 74 males) who underwent minimally invasive valvular surgery. Surgical procedures included 52 isolated mitral valve procedures (49 repairs, 3 prostheses), 58 isolated aortic valve procedures (16 repairs, 26 prostheses, 16 homografts), and 2 combined aortic and mitral valve repairs. Prepump IOE was useful to confirm valve dysfunction and assist determination of arterial cannulation site. Postpump IOE identified intracardiac air in all patients, which was defined as extensive in 58 (52%) cases. Postoperatively, new left ventricular dysfunction was noted in 22 (20%) patients, more often in the group with extensive air by IOE (17 [30%] of 58 patients) compared with those without extensive air (5 [10%] of 54 patients, P =.01). Second pump runs were required in 7 (6%) of 112 patients: 3 cases of residual aortic regurgitation, 1 case of residual mitral regurgitation, and 3 cases with new ventricular dysfunction. No deaths occurred. We conclude that IOE is essential in minimally invasive valvular surgery because it detects problems that require immediate remedy. IOE allows real-time assessment of ventricular filling, ventricular and valvular function, and intracardiac air.

Air↗
PubMed2006

[Video-assisted cardiac valve surgery].

BACKGROUND AND PURPOSE: Advances in the development of video-assisted systems for minimally invasive surgery now allow to perform cardiac surgery via a smaller anterolateral thoracotomy in order to reduce trauma, pain and improve cosmetics. In addition, due to sternal sparing, pulmonary function should improve resulting in reduced hospital stay and costs. However, only few centers worldwide abstain from spreading the ribs thus accepting considerable pain and reduced patient comfort. The minimally invasive approach described here uses a right-sided anterolateral incision (4-5 cm), a soft-tissue retractor and femorofemoral perfusion with endoclamping under continuous TEE (transesophageal echocardiography) control. It was the aim of this retrospective analysis to determine feasibility, safety and effectiveness of the method. PATIENTS AND METHODS: At the West German Heart Center Essen, 47 patients were operated using minimally invasive endoscopic techniques between January 2004 and April 2006 on the mitral valve (n = 31), mitral and tricuspid valve (n = 9), including mini-Maze procedure in two cases, as well as atrial septal defects (n = 5) and myxomas (n = 2). Mean age was 58 +/- 15.2 years (range 29-87 years), NYHA II-III, 20 patients were male. RESULTS: All but one patient survived (2.1%). Conversion to median sternotomy was necessary in three of the first twelve patients. After a mean follow-up period of 18 months all reconstructions and valves were competent, freedom from cardiac reoperation was 100%. On a visual analog scale 91% ot the patients reported no or mild postoperative pain, 96% felt they had an aesthetically pleasing scar. All but one patients would choose the same operation again. CONCLUSION: Videoscopically assisted, endoscopic cardiac surgery can be performed safely, but requires a learning curve and intense training. After evaluation of efficacy and safety it is now the authors' exclusive approach to isolated atrioventricular valve disease with an ideal pain-free and cosmetic result.

Adult↗
PubMed2004

DSCR1 gene expression is dependent on NFATc1 during cardiac valve formation and colocalizes with anomalous organ development in trisomy 16 mice.

The Down syndrome critical region 1 (DSCR1) gene is present in the region of human chromosome 21 and the syntenic region of mouse chromosome 16, trisomy of which is associated with congenital heart defects observed in Down syndrome. DSCR1 encodes a regulatory protein in the calcineurin/NFAT signal transduction pathway. During valvuloseptal development in the heart, DSCR1 is expressed in the endocardium of the developing atrioventricular and semilunar valves, the muscular interventricular septum, and the ventricular myocardium. Human DSCR1 contains an NFAT-rich calcineurin-responsive element adjacent to exon 4. Transgenic mice generated with a homologous regulatory region of the mouse DSCR1 gene linked to lacZ (DSCR1(e4)/lacZ) show gene activation in the endocardium of the developing valves and aorticopulmonary septum of the heart, recapitulating a specific subdomain of endogenous DSCR1 cardiac expression. DSCR1(e4)/lacZ expression in the developing valve endocardium colocalizes with NFATc1 and, endocardial DSCR1(e4)/lacZ, is notably reduced or absent in NFATc1(-/-) embryos. Furthermore, expression of the endogenous DSCR1(e4) isoform is decreased in the outflow tract of NFATc1(-/-) hearts, and the DSCR1(e4) intragenic element is trans-activated by NFATc1 in cell culture. In trisomy 16 (Ts16) mice, expression of endogenous DSCR1 and DSCR1(e4)/lacZ colocalizes with anomalous valvuloseptal development, and transgenic Ts16 hearts have increased beta-galactosidase activity. DSCR1 and DSCR1(e4)/lacZ also are expressed in other organ systems affected by trisomy 16 in mice or trisomy 21 in humans including the brain, eye, ear, face, and limbs. Together, these results show that DSCR1(e4) expression in the developing valve endocardium is dependent on NFATc1 and support a role for DSCR1 in normal cardiac valvuloseptal formation as well as the abnormal development of several organ systems affected in individuals with Down syndrome.

Animals↗
PubMed1997

Cardiac valve calcification: characteristics of patients with calcification of the mitral annulus or aortic valve.

AIMS: To determine whether mitral annular calcification and aortic valve calcification, with or without stenosis, are expressions of atherosclerotic disease. METHODS: The incidence of atherosclerotic risk factors was analysed in patients with mitral annular calcification and aortic valve calcification and in control patients from a prospective echocardiographic database of 8160 consecutive patients; 657 patients (8%) were identified with mitral annular calcification and 815 (9%) with a calcified aortic valve, of whom 515 (6.3%) had stenosis with a minimal aortic valve gradient of 16 mm Hg. In these patients, cardiac and vascular risk factors were compared with 568 control patients using multiple logistic regression analysis. RESULTS: Age (odds ratio (OR) varying from 5.78 to 104, depending on age class), female sex (OR 1.75), hypertension (OR 2.38), diabetes mellitus (OR 2.85), and hypercholesterolaemia (OR 2.95) were strongly and significantly associated with aortic valve calcification without stenosis, as were age (OR varying from 8.82 to 67, depending on age class), female sex (OR 2.22), hypertension (OR 2.72), diabetes mellitus (OR 2.49), and hypercholesterolaemia (OR 2.86) with mitral annular calcification. Age (OR varying from 1.11 to 7.7), hypertension (OR 1.91), and hypercholesterolaemia (OR 2.55) were strongly and significantly associated with stenotic aortic valve calcification. CONCLUSIONS: Mitral annular calcification and stenotic or non-stenotic aortic valve calcification have a high incidence of atherosclerotic risk factors, suggesting they should be considered as manifestations of generalised atherosclerosis.

Adult↗