Mitral homografts for total tricuspid valve replacement: comparison of two techniques.
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Adult↗
Biomedical subjects
Y Pansard
Publications and source records attributed to Y Pansard.
[Dual chamber rate responsive pacing and chronotropic insufficiency. Comparison of double and respiratory sensors].
Late responsive DDD pacemakers are the most technically advanced devices presently available. These pacemakers are particularly useful in patients with chronotropic insufficiency when the sinus node is incapable of accelerating during exercise. The latest pacemakers have two sensors to reproduce optimal physiological sinus acceleration. The aim of this study was to analyse the performances of a new rate responsive pacemaker with a double activity and respiratory sensor, the interaction of which is automatically controlled by a sophisticated algorithm, in 12 patients (8 men and 4 women) with a mean age of 75 +/- 7 years. Analysis was based on the performance of the sensors used singly or in association: during three exercise stress tests with measurement of the VO2 max; during everyday activities using the data archived by the pacemaker and the answers to a simplified questionnaire on quality of life. The results showed that during exercise stress testing with measurement of VO2 max, the best performances were obtained with the double sensor or the respiratory sensor compared with the activity sensor alone, suggesting that these two sensors are more effective in intense exercise. This tendency was also observed in the analysis of the memory bank of the pacemaker which showed that the total duration of the faster heart rates was greater with the two sensors. On the other hand, the quality of life was not significantly different, whichever sensor was studied. Longer scale trials are necessary to appreciate the real value of these new double sensor pacing devices and to identify the best indications for their usage.
Aged↗
Tyrosine kinase and protein kinase C regulate L-type Ca(2+) current cooperatively in human atrial myocytes.
The effects of tyrosine protein kinases (TK) on the L-type Ca(2+) current (I(Ca)) were examined in whole cell patch-clamped human atrial myocytes. The TK inhibitors genistein (50 microM), lavendustin A (50 microM), and tyrphostin 23 (50 microM) stimulated I(Ca) by 132 +/- 18% (P < 0.001), 116 +/- 18% (P < 0.05), and 60 +/- 6% (P < 0.001), respectively. After I(Ca) stimulation by genistein, external application of isoproterenol (1 microM) caused an additional increase in I(Ca). Dialyzing the cells with a protein kinase A inhibitor suppressed the effect of isoproterenol on I(Ca) but not that of genistein. Inhibition of protein kinase C (PKC) by pretreatment of cells with 100 nM staurosporine or 100 nM calphostin C prevented the effects of genistein on I(Ca). The PKC activator phorbol 12-myristate 13-acetate (PMA), after an initial stimulation (75 +/- 17%, P < 0.05), decreased I(Ca) (-36 +/- 5%, P < 0.001). Once the inhibitory effect of PMA on I(Ca) had stabilized, genistein strongly stimulated the current (323 +/- 25%, P < 0.05). Pretreating myocytes with genistein reduced the inhibitory effect of PMA on I(Ca). We conclude that, in human atrial myocytes, TK inhibit I(Ca) via a mechanism that involves PKC.
Adolescent↗
Regulation of the transient outward K(+) current by Ca(2+)/calmodulin-dependent protein kinases II in human atrial myocytes.
Ca(2+)/calmodulin-dependent protein kinases II (CaMKII) have important functions in regulating cardiac excitability and contractility. In the present study, we examined whether CaMKII regulated the transient outward K(+) current (I(to)) in whole-cell patch-clamped human atrial myocytes. We found that a specific CaMKII inhibitor, KN-93 (20 micromol/L), but not its inactive analog, KN-92, accelerated the inactivation of I(to) (tau(fast): 66.9+/-4.4 versus 43.0+/-4.4 ms, n=35; P<0.0001) and inhibited its maintained component (at +60 mV, 4.9+/-0.4 versus 2.8+/-0.4 pA/pF, n = 35; P<0. 0001), leading to an increase in the extent of its inactivation. Similar effects were observed by dialyzing cells with a peptide corresponding to CaMKII residues 281 to 309 or with autocamtide-2-related inhibitory peptide and by external application of the calmodulin inhibitor calmidazolium, which also suppressed the effects of KN-93. Furthermore, the phosphatase inhibitor okadaic acid (500 nmol/L) slowed I(to) inactivation, increased I(sus), and inhibited the effects of KN-93. Changes in [Ca(2+)](i) by dialyzing cells with approximately 30 nmol/L Ca(2+) or by using the fast Ca(2+) buffer BAPTA had opposite effects on I(to). In BAPTA-loaded myocytes, I(to) was less sensitive to KN-93. In myocytes from patients in chronic atrial fibrillation, characterized by a prominent I(sus), KN-93 still increased the extent of inactivation of I(to). Western blot analysis of atrial samples showed that delta-CaMKII expression was enhanced during chronic atrial fibrillation. In conclusion, CaMKII control the extent of inactivation of I(to) in human atrial myocytes, a process that could contribute to I(to) alterations observed during chronic atrial fibrillation.
Adolescent↗
Aortic valve replacement in relapsing polychondritis.
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Adult↗
The stentless Bravo 300 aortic porcine xenograft: supra-annular versus annular implantation.
The aim of the study was to compare the supra-annular and intra-annular implantation techniques by evaluating the differences in early haemodynamic outcome (gradients, effective orifice area, regurgitation). Since August 1991, 200 stentless Bravo model 300 valves have been implanted. Patients were divided into three groups of consecutive cases: group 1 (n = 50) represents exclusively intra-annular implantation; group 2 (n = 50) is a transitional period: and group 3 (n = 100) comprises only patients with supra-annular implantation. Significant differences were found (P<0.001) in low postoperative gradients (mean < or = 10 mmHg): 24% in group 1, 42% in group 2, and 95% in group 3. Comparing groups 1 and 3, gradients were lower and effective orifice area was augmented in all valve sizes in group 3. Trivial central regurgitation was present in groups 1-3 (6%, 12% and 0% respectively). Peripheral regurgitation was trivial in 6%, 8% and 0% and mild to moderate in 4%, 2% and 0% (P<0.001).
Animals↗
Tricuspid autograft for mitral-valve repair.
BACKGROUND: Transferring the posterior leaflet of the patient's own tricuspid valve with its subvalvular apparatus to the mitral valve is a new technique that allows a conservative approach to mitral-valve repair. The technique is based on the knowledge that the tricuspid valve can be remodelled from tricuspid to bicuspid, with a very low risk of significant dysfunction. METHODS: We describe six patients (age range 20-70 years) with mitral insufficiency in whom we have used the technique. FINDINGS: All patients survived the operation and were in sinus rhythm. Transoesophageal echocardiography before discharge showed trivial or no regurgitation at the site of mitral repair. Before operation, all patients were in New York Heart Association class III-IV; at follow-up after 6-13 months all patients were in class I-II. INTERPRETATION: Compared with using segments of mitral homografts in similar situations, the intraoperative availability of the tricuspid's viable natural chordae and valvular leaflet means that there are no immunological disadvantages to the procedure. With this new operation, the patient is his own tissue bank.
Adult↗
[Mitral valve repair by transfer of the posterior tricuspid leaflet and its chordae].
Mitral valve repair was performed in six patients by transferring the posterior tricuspid leaflet with its sub-valvular apparatus onto the mitral valve. This new technique considers the tricuspid valve as the patients own tissue bank where the posterior leaflet and eventually the adjacent part of the anterior leaflet is used as a "donor" valve, based on the knowledge that the right atrio-ventricular valve can be efficiently repaired with a very low risk of significant dysfunction. The mitral repair consists of incorporating the tricuspid autograft by securing the tricuspid papillary muscle to the mitral papillary muscle and by suturing the leaflet tissue where required. A mitral annuloplasty ring reinforces the repair. The tricuspid valve is subsequently repaired by annular plication and leaflet suture. A tricuspid ring is necessary to maintain efficient remodeling. The six patients ages ranged from 20 to 70 years. A etiology, was rheumatic in the first case and degenerative in the following. In three cases, sterilised endocarditis was responsible for ruptured chordae and leaflet destruction. The mitral insufficiency was located in a commissural area in 4 cases, and was due to a widespread posterior prolapse in 2. Post-operative control transesophageal echocardiography confirmed the excellent results of the repair and proved that, in selected cases, the tricuspid leaflet inserted onto the mitral apparatus is very efficient in correcting mitral insufficiency, without causing significant tricuspid impairment. With a 3 to 7 month follow-up, the results are stable.
Adult↗
[Coronary-cardiac fistula as a cause of tricuspid endocarditis treated by mitral homograft].
The authors report a rare case which is interesting from three points of view: tricuspid valve endocarditis in a child complicating a fistula between the right coronary artery and right ventricle with negative blood cultures but a positive serology for Coxiella burnetii. This mutilating tricuspid endocarditis was complicated by multiple pulmonary embolism of the right lung. After two months of antibiotic therapy the coronaro-cardiac fistula was closed and the tricuspid valve replaced with a mitral homograft. All cases of blood culture negative endocarditis require serological investigation to detect intracellular organisms which are difficult to diagnose and justify specific prolonged antibiotic therapy. Control serological tests are essential in the long-term because of the risk of chronic infection, especially in cases with prosthetic intracardiac material. Treatment, based mainly on tetracyclines, should be continued for at least two years.
Anti-Bacterial Agents↗
[Repair of post-infarction left ventricular wall ruptures by biological glue and a flap from the pericardium. Results from 2 to 10 years].
The authors report their experience with a simple and efficient technique for repair of left ventricular free wall rupture complicating myocardial infarction. The technique consists, with the aid of cardiopulmonary bypass, in suturing a plaque of the patients own pericardium (6 to 8 cm in diameter) to the more normal tissue encircling the pathologic myocardium, and by injecting five ml of human fibrin glue as a cement under the pericardium to reinforce the remair and prevent leaking throughout the suture line. With a 10 year follow-up, we are able to be confident with the long term results. The five patients, at the time of operation were aged 46 to 74 years. The post-operative results and the annual echocardiographic controls have proved the technique to be sound without recurrences and without late complications such as pseudo aneurysms at the site of the repair.
Aged↗
[Exercise capacity after heart transplantation].
Independently of phenomena related to rejection, atherosclerosis of the grafted heart or high blood pressure, there exists a qualitative and quantitative degradation of response to exercise in heart transplant recipients. Maximal oxygen consumption is generally reduced to 40 to 60% of normal levels. There are several interactive mechanisms. Paradoxically, the transplanted heart is a clear demonstration of the fact that several other elements are involved in the organisms response to exercise. Indeed, ventilation, exercise load, peripheral circulation, muscle metabolism and neurohormonal response also play a role. Vasoactivity of the peripheral arteries limits distribution and extraction of oxygen during exercise. Noradrenaline, renin, atrial natriuretic factor, vasopressin and endothelin levels are normal at rest, but an overreaction occurs during exercise. The percentage of type I (oxidative) fibres is reduced in muscles. Cyclosporine has also been shown to have a toxic effect on mitochondria in muscles. The deinnervated transplanted heart is thus called upon to work in coordination with peripheral elements which have also undergone alterations. Consequently, response to exercise cannot be significantly increased above the level reached before transplantation. Usually patients are not greatly hindered in their daily activities and rarely complain of breathlessness. Nevertheless, an improvement would be appreciated. A coherent physical rehabilitation programme can increase maximal oxygen consumption by 25 to 30% in these patients, essentially via improvement in peripheral anomalies. It is more difficult to modify cardiac response.
Exercise↗
The O'Brien-Angell stentless porcine valve: early results with 150 implants.
From August 1991 to June 1994, 150 patients underwent aortic valve replacement with the O'Brien-Angell stentless porcine xenograft (Bravo Cardiovascular Model 300, Cryolife, Atlanta, GA). To establish trends we analyzed three consecutive groups of 50 patients. We found significant differences in low postoperative gradients (mean < or = 10 mm Hg): 24% in group 1, 42% in group 2, and 96% in group 3. Comparing groups 1 and 3, gradients were significantly lower in all valve sizes. The difference is credited to better supraannular positioning of the valve, which is the key to the learning curve. Trivial central regurgitation was present in the three groups at 6%, 12%, and 0%, respectively. Peripheral regurgitation was trivial in 6%, 8%, and 0%, and mild to moderate in 4%, 2% and 0%, respectively. Seventy-eight of 107 patients with an available follow-up exceeding 1 year had noninvasive controls. Two early cases with moderate perivalvular leaks evolved to moderately severe leaks. Two valves were explanted. The O'Brien-Angell stentless valve is easy to handle and correct supraannular positioning provides excellent hemodynamic results.
Adult↗
Relief of complex left ventricular outflow tract obstruction with pulmonary autografts.
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Child↗
Left ventricular free wall rupture. Long-term results with a pericardial patch and fibrin glue repair.
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Aged↗
Cardiac valve replacement in relapsing polychondritis. A review.
Cardiac valve replacement is a rare but not exceptional eventuality in patients with relapsing polychondritis. One case requiring aortic and mitral valve replacement and its follow up is described. From the review of the literature an additional twenty patients who required cardiac valve replacement are analyzed. The mean delay between the first onset of relapsing polychondritis and operation was 6.51 years and the mean age at operation was 38.8 years. There was a preponderance of male patients (73.7%). Aortic and mitral valves were replaced in 100% and 28.5% of patients, respectively. During the four first postoperative years 23.8% of them were reoperated for periprosthetic leak or aortic aneurysm, and during the same period 52.6% died of a cardiovascular cause. Immunosuppressive agents should be employed in patients with relapsing polychondritis and cardiovascular involvement because they seem to be more effective than steroids in severe forms of the disease. Therefore, we recommend close and prolonged follow up: firstly because there can be early paravalvular prosthetic leakage due to the friability of the tissue to which it has been anchored; secondly because aortic aneurysms occur frequently in relapsing polychondritis, may be multiple, may involve all parts of the aorta and result in fatal rupture even in asymptomatic patients; and thirdly because there can be a fatal outcome due to other organ involvement, like airway obstruction, acute glomerulonephritis, or systemic vasculitis. Prophylactic composite graft replacement of the ascending aorta associated with replacement of the aortic valve and re-implantation of the coronary arteries could avoid the need for reoperation in these high risk patients.
Adult↗
Successful resection of giant intrapericardial lipoma.
We report a case of giant extracavitary cardiac lipoma weighing 4,800 g. The mode of presentation, the preoperative evaluation, and the radiographic features are presented. The surgical management of this very rare cardiac pathology is discussed. This is one of the largest cardiac tumors ever reported.
Adult↗
The O'Brien-Angell stentless valve. Early results of 100 implants.
From August 1991 to May 1993, 100 unselected consecutive patients in whom an aortic bioprosthesis was indicated underwent aortic valve replacement with the O'Brien-Angell stentless porcine xenograft (Bravo Cardiovascular Model 300). The indication was calcified aortic stenosis (AS) in 62 cases (isolated in 44, with associated cardiac lesions in 18), aortic insufficiency in 24 cases (isolated in 13 with associated cardiac lesions in 11), and redo operations in 14 cases. Forty-four percent of the patients were over 70 years of age. With the recommended supra-annular single running suture technique, the aortic cross-clamp times in isolated procedures ranged from 32 to 70 min, mean 39 min. Valve function was studied by echocardiography in 92 patients. Early post-operative transvalvular gradients were usually in the low range, below 15 mmHg in 68% of the cases. Isolated central valvular regurgitation was absent in 60.8%, "microscopic to trivial in 31.5% and mild to moderate in 1.2%. Perivalvular regurgitation was absent in 65.2%, microscopic to trivial in 26.2% and mild to moderate in 3.2%. Thirty-five of 40 patients with follow-ups exceeding 6 months had non-invasive controls. Transvalvular gradients showed a 30 to 40% reduction when compared to the immediate postoperative values. There were no new isolated central regurgitations but in two cases previously mild-to-moderate perivalvular leaks evolved to moderately severe leaks. Two valves were explanted, one for rupture of a Prolene 4/0 and one due to a slack Prolene 4/0 suture. We consider that the O'Brien-Angell stentless valve was easy to handle in all situations encountered.(ABSTRACT TRUNCATED AT 250 WORDS)
Adult↗
[Functional capacity after cardiac transplantation].
Cardiac transplantation has transformed the prognosis of NYHA Class IV severe cardiac failure. However, despite a "new heart", the exercise tolerance of transplanted patients remains poor for a long time. Cardiac denervation which decreases the chronotropic reserve, diastolic left ventricular dysfunction and intrinsic muscular abnormalities related to lack of training and to treatment are the underlying causes.
Cardiovascular Deconditioning↗