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At least 73 records · Page 4Linked to original sources
PubMed1985

Hemodynamic evaluation of stenotic cardiac valves: II. Modification of the simplified valve formula for mitral and aortic valve area calculation.

Since the introduction by Gorlin and Gorlin of the hydraulic formulae for calculating valve area, it has become the best parameter for quantitating valve stenosis. Recently Hakki et al proposed a simplified formula for valve area calculation that does not take into account either heart rate (HR) or left ventricular filling or ejection time. The purpose of this study was to analyze the validity of Hakki's formulae under different physiological conditions and to propose an easy correction to improve its accuracy. Our study suggests: (1) that an easy correction for heart rate in certain cases, dividing by 1.35 when HR less than 75 beats per min in mitral stenosis and when HR greater than 90 beats per min in aortic stenosis, significantly improves the accuracy and validity of Hakki's formulae (p less than 0.02 and p less than 0.05); (2) the instantaneous valve gradients (peak gradient for aortic stenosis and average of instantaneous early, middle, and late diastolic gradients for mitral stenosis) are as valid as mean planimetric gradients for valve area calculation. Thus the simplified formulae proposed in this study allow mitral and aortic valve area calculations by means of instantaneous gradients, cardiac output, and heart rate.

Adolescent↗
PubMed1998

Development of the papillary muscles of the mitral valve: morphogenetic background of parachute-like asymmetric mitral valves and other mitral valve anomalies.

OBJECTIVES: To understand papillary muscle malformations, such as in parachute mitral valves or parachute-like asymmetric mitral valves, we studied the development of papillary muscles. METHODS: Normal human hearts at between 5 and 19 weeks of development were studied with immunohistochemistry, three-dimensional reconstructions, and gross inspection. Scanning electron microscopy was used to study human and rat hearts. RESULTS: In embryonic hearts a prominent horseshoe-shaped myocardial ridge runs from the anterior wall through the apex to the posterior wall of the left ventricle. In the atrioventricular region this ridge is continuous with atrial myocardium and covered with cushion tissue. The anterior and posterior parts of the trabecular ridge enlarge and loosen their connections with the atrial myocardium. Their lateral sides gradually delaminate from the left ventricular wall, and the continuity between the two parts is incorporated in the apical trabecular network. In this way the anterior and posterior parts of the ridge transform into the anterolateral and the posteromedial papillary muscles, respectively. Simultaneously, the cushions remodel into valve leaflets and chordae. Only the chordal part of the cushions remains attached to the developing papillary muscles. CONCLUSIONS: Disturbed delamination of the anterior or posterior part of the trabecular ridge from the ventricular wall, combined with underdevelopment of chordae, seems to be the cause of asymmetric mitral valves. Parachute valves, however, develop when the connection between the posterior and anterior part of the ridge condenses to form one single papillary muscle. Thus parachute valves and parachute-like asymmetric mitral valves originate in different ways.

Adult↗
PubMed1984

Thrombosis of mechanical cardiac valves: a qualitative comparison of the silastic ball valve and the tilting disc valve.

A review of 817 mitral and aortic Silastic ball valve implantations with a follow-up of 3,554 total patient-years yielded only seven cases of valve thrombosis. Time-related risk was 0.4% per patient-year in the mitral position and 0.1% per patient-year in the aortic position. Four of five mitral and one of two aortic ball valve thromboses were successfully managed by valve rereplacement . At least five of the seven patients presented with a prodrome (lasting at least 3 months) of symptoms of progressive heart failure and, occasionally, embolic episodes due to gradually increasing prosthetic stenosis by thrombus. This lengthy time course is in contrast to the more frequent rapid catastrophic thrombosis that occurs with the Björk-Shiley tilting disc valve. Recognition of the prodrome of Silastic ball valve thrombosis provides an opportunity for life-saving surgical intervention.

Adult↗
PubMed1984

[Mitral commissurotomy or mitral valve replacement. Comparison of results of closed and open operative procedures in acquired mitral valve stenoses and combined mitral valve defects, predominantly stenosis].

1012 closed operations for mitral stenoses, mitral restenoses and combined mitral and aortic stenoses were performed from 1963 to 1981. Moreover 888 operations were performed at the mitral valve from 1973 to October 1983 as open heart procedures: 676 cases of mitral valve replacement (MVR) including 7 cases of coronary artery operations; 4 cases both of mitral, aortic and tricuspidal valve replacement or mitral and tricuspidal valve replacement; 9 cases of valve reinsertion; 20 cases of open commissurotomy and 4 cases of annular plastic according to Wooler. The functional results after open operation are quite better than those after closed procedures. The rate of reoperations after MVR is only 3% but after closed operations more than 25%. In this way we believe the open operation to be the better way of treating acquired mitral stenosis. In our opinion the closed method may be used in cases of late pregnancy and in those centres having an insufficient capacity for open heart surgery to be performed.

Aortic Valve↗
PubMed1991

Testing the hydrocephalus shunt valve: long-term bench test results of various new and explanted valves. The need for model for testing valves under physiological conditions.

13 new and 19 explanted hydrocephalus shunt valves were tested under perfusion for two weeks, using a modified ASTM test. Some manufacturers seem to have problems with quality control. Our results show large deviations in pressure-flow-characteristics in different valves, in some cases leading to an extremely high pre-shunt pressure. Test results almost corresponding to manufacturer's specifications were found in diaphragm valves and in some ball and spring valves. Results from slit valves usually varied widely, some being good, but others bad (much too high a pressure) or dangerous with even possibly fatal characteristics. Whilst laboratory performance may not correlate with clinical results, due to different impact of cerebrospinal fluid (CSF) pressure and flow on hydrocephalus shunting systems, manufacturers should provide devices that meet their supposed specifications. We developed an apparatus allowing simulation of different CSF production rates, CSF outflow resistances, CSF pressure waves caused by arterial and venous pulsation, breathing and coughing, and hydrostatic differential pressure caused by body position changes. This model enables testing of shunt valves under almost physiological conditions, thus closing the gap between conventional bench test results and clinical performance of hydrocephalus shunt valves.

Blood Flow Velocity↗
PubMed1984

Surgical treatment of ruptured mitral valve chordae. A comparison between valve replacement and valve repair.

Sixty-five patients were treated for ruptured mitral valve chordae from January, 1976, to December, 1981; 21 patients underwent valve reconstruction (group A) and 44 underwent valve replacement (group B). Both groups had a mean age of 62 years with an overall male: female ratio of 2:1. Eighty-one percent of group A and 73% of group B presented in clinical class III/IV (NYHA). Chordal rupture was spontaneous in 76% (group A) and 61% (group B) respectively, with posterior leaflet chordal involvement in most patients. The operative mortality was 6.8% (3 deaths) in group B with no early death in group A (p less than 0.001). More than 85% of both groups were in class I/II (NYHA) postoperatively. The actuarial survival at 5 years was 85% in group A and 78% in group B. No emboli occurred in group A while an actuarial incidence of freedom from emboli of 76% at 5 years was observed in group B (p less than 0.046). One patient (4.8%) in group A was reoperated for failed valve repair. The patients with repaired valves were assessed by echocardiography. The peak rates of dimension change of the left ventricular cavity were in the normal range in all but 3 patients, while the left ventricular and end-diastolic dimensions were significantly reduced (p less than 0.005). We conclude that valve reconstruction provides an improved functional result in patients with ruptured mitral chordae in addition to an increased event-free survival.

Actuarial Analysis↗
PubMed2003

Valve adaptation as a cause of disc opening reduction in mechanical heart valves: the case of the Lillehei-Kaster valve.

At fluoroscopy a decreased disc motion in mechanical heart prostheses is often a sign of valve thrombosis. On occasion, however, despite an exhaustive diagnostic work-up, common causes of prosthetic valve thrombosis are not found. In these cases the valve disc abnormalities are thought to be due to functional changes. We here report our experience with 5 consecutive patients carrying the Lillehei-Kaster prosthesis who had this fluoroscopic finding that was lately attributed to "valve physiologic adaptation". The time of onset, differential diagnosis and clinical/hemodynamic impact of valve adaptation are discussed.

Aged↗
PubMed1989

Late results of aortic valve replacement with Bjork Shiley prostheses: a comparison of standard aortic valve prosthesis with reversed mitral valve prosthesis implanted in aortic position.

Between 1976 and 1983, 435 patients underwent aortic valve replacement (AVR) with Bjork Shiley prostheses. Standard aortic Bjork Shiley prostheses (ABP) were used in 150 patients (Group I) and a reversed mitral Bjork Shiley prostheses in 285 (MBP in 250 and MBC in 35) patients (Group II). There was no significant difference in the number of the patients with valve calcification or the size of aortic root in the 2 groups. There was no significant difference in the early mortality in these two groups. The total follow up period in Group I was 912 years and 2130 years in Group II. The incidence of major aseptic prosthetic dehiscence and valve occlusion with tissue ingrowth were higher in Group I than in Group II. Reversed Bjork Shiley mitral valve prosthesis was successfully used in aortic position with reduced incidence of valve related complications.

Aortic Valve↗
PubMed2003

[Aortic valve replacement with a freestyle stentless valve using the modified subcoronary technique and hemiarch replacement for bicuspid aortic valve and ascending aortic aneurysma; report of a case].

An association between bicuspid aortic valve disease and ascending aortic aneurysma has long been recognized. Root replacement with a composite valve graft for such disease is a well-established technique. But it may involve serious technical difficulties, and may be a more time-consuming procedure than separate valve replacement and graft replacement. We performed an aortic valve replacement with Freestyle stentless valve using the modified subcoronary technique and hemiarch replacement for a 72-year-old man with severe aortic stenosis and ascending aortic aneurysma. Angiographic studies after surgery showed no residual aortic regurgitation (AR) and no deformity of aorta. This technique is an acceptable option for an aortic disease and ascending aneurysma in elderly patients.

Aged↗
PubMed2000

[Aortic valve replacement for aortic valve stenosis due to congenital bicuspid aortic valve with abnormal positioning of coronary orifice, pseudotendon, and persistent left superior vena cava, report of a case].

A patient was a 65-year-old female who had a complaint of palpitation was diagnosed aortic valve stenosis due to congenital bicuspid aortic valve with pseudotendon by the echocardiographic examination. We suspected left single coronary artery by the aortography and the coronary artery angiography. Aortic valve replacement and resection of pseudotendon was performed with Carbomedics supra-annular aortic valve (21 A). During surgery, persistent left superior vena cava was detected. High-posterior take-off right coronary artery was casually detected at aortic closure. Ventricular fibrillation due to insufficient supply of cardioplegic solution at right coronary area frequently occurred after cardio-pulmonary bypass and percutaneous cardiopulmonary support was required. The patient was discharged 32 days after the operation. Preoperative and intraoperative evaluation was important in the case of aortic valvular disease.

Aged↗
PubMed1994

Mitral valve anatomy and morphology: relevance to mitral valve replacement and valve reconstruction.

An endoscope was used to study the anatomy and morphology of the native mitral valve inside an isolated pig heart working under physiological conditions. Annulus motion, valve leaflet function, and the anatomy of the chords and branching pattern are described. Anatomical and functional details relevant to mitral valve reconstruction and valve replacement are outlined. Because of the similarity with the human heart, we have assumed that the observations made in the pig heart also apply to humans.

Adult↗
PubMed1989

Mitral valve dimensions and motion in Marfan patients with and without mitral valve prolapse. Comparison to primary mitral valve prolapse and normal subjects.

To determine mitral valve and extravalvular findings associated with mitral valve prolapse (MVP) in patients with the Marfan syndrome, we compared mitral leaflet and anular dimensions and motion by computerized two-dimensional echocardiography in 53 Marfan patients (28 with M-mode echocardiographic MVP) to those in 48 adults with primary MVP and in 35 normal subjects. Mitral leaflet billowing occurred in 28 of 28 Marfan patients with M-mode MVP versus 24 of 48 with primary MVP (p less than 0.00005), 0 of 25 Marfan patients without M-mode MVP, and 0 of 35 normal subjects (both, p less than 0.0001). Billowing occurred on the first systolic frame in 8 of 28 Marfan-MVP patients, in whom posterior leaflet chordae arose abnormally from the posterior ventricular wall, and in no other subjects. These patients had large mitral valves and normal anular dynamics, whereas the remaining 20 Marfan-MVP patients had increased systolic anular expansion. Marfan-MVP patients were younger than those without MVP (29 +/- 12 vs. 38 +/- 15 years, p less than 0.02) and had lower body mass index (19.8 +/- 2.7 vs. 23.9 +/- 2.9 kg/m2, p less than 0.00005) and systolic blood pressure (120 +/- 20 vs. 133 +/- 20 mm Hg, p less than 0.05), similar to differences between primary MVP and normal subjects in body mass index (21.5 +/- 3.0 vs. 23.9 +/- 4.8 kg/m2, p less than 0.01) and systolic pressure (118 +/- 14 vs. 125 +/- 18 mm Hg, p less than 0.05). Marfan patients with and without MVP had similar arm span, arm span to height ratio, upper to lower segment ratio, and prevalence of ectopia lentis and thoracic bony abnormalities, but arachnodactyly was more frequent in those with MVP (82% and 48%, respectively; p less than 0.02). We conclude that 1) leaflet billowing occurs more uniformly in Marfan patients with MVP than in primary MVP, 2) MVP in Marfan patients may be due to either valve enlargement with distinctively abnormal chordal architecture or abnormal mitral anular distensibility, 3) Marfan patients with MVP have low body weight and systolic blood pressure, similar to primary MVP, and 4) Marfan patients with MVP more commonly have arachnodactyly but otherwise have similar skeletal and anthropometric characteristics to other Marfan patients.

Echocardiography↗
PubMed2003

Failure to prevent progressive dilation of ascending aorta by aortic valve replacement in patients with bicuspid aortic valve: comparison with tricuspid aortic valve.

BACKGROUND: Patients with bicuspid aortic valve (BAV) have been frequently complicated with ascending aortic dilation possibly because of hemodynamic burdens by aortic stenosis (AS) or regurgitation (AR) or congenital fragility of the aortic wall. METHODS AND RESULTS: To clarify if the aortic dilation could be prevented by aortic valve replacement (AVR) in BAV patients, we studied 13 BAV (8 AR dominant, 5 AS dominant) and 14 tricuspid aortic valve (TAV) patients (7 AR, 7 AS) by echocardiography before and after AVR (9.7+/-4.8 years). We also studied 18 BAV (11 AR, 7 AS) without AVR. Diameters of the sinuses of Valsalva, sinotubular junction and the proximal aorta were measured. The annual dilation rate was calculated by dividing changes of diameters during the follow-up period by the body surface area and the observation interval. We found that aortic dilation in BAV patients tended to be faster than that in TAV patients, although a significant difference was found only at the proximal aorta (0.18+/-0.08 versus -0.08+/-0.08 mm/(m2/year), P=0.03). BAV patients with and without AVR showed similar progressive dilation. AR dominant group showed tendency of more progressive dilation than AS dominant group in BAV, although it did not reach statistical significance. TAV patients did not show further aortic dilation after AVR. CONCLUSIONS: AVR could not prevent progressive aortic dilation in BAV. Since the aorta did not dilate in TAV, progressive aortic dilation in BAV seems mainly due to the fragility of the aortic wall rather than hemodynamic factors.

Adult↗
PubMed2006

Effect of the increase in valve area after aortic valve replacement with a 19-mm aortic valve prosthesis on left ventricular mass regression in patients with pure aortic stenosis.

OBJECTIVES: Although patients with aortic stenosis, who receive 19-mm valves, are at high risk for prosthesis-patient mismatch, most of them show a significant left ventricular mass (LVM) regression postoperatively. The aim of this study was to identify factors predicting postoperative relative LVM regression in this subgroup of patients. METHODS: A population of 44 patients operated on for pure aortic stenosis and receiving a 19-mm valve was studied by echocardiography at 1.4 +/- 0.5 years postoperatively. RESULTS: The mean relative LVM regression was -19.3 +/- 18.9%, the mean gradient drop was -31.6 +/- 13.3 mmHg, and the mean Delta increase in aortic area index (postoperative aortic area index minus preoperative aortic area index) was 0.30 +/- 0.14 cm/m. Thirty-two patients had an indexed effective orifice area of less than 0.8 cm/m. At multivariate analysis (r = 0.63; r = 40%; P < 0.0001) preoperative LVM (P = 0.006), hypertension (P = 0.018) and Delta aortic area index (P = 0.049) were independent predictors of relative LVM regression. CONCLUSIONS: Our study shows that, at least 1 year postoperatively, in patients receiving a 19-mm valve, LVM regression is influenced by several parameters, in particular preoperative LVM, hypertension and the magnitude of the increase in aortic area.

Aged↗