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.

Beta-adrenergic receptor changes during coronary artery bypass grafting.

To evaluate whether the function of beta-adrenergic receptors, essential to the biologic activity of catecholamines, is altered during coronary artery bypass grafting, we measured, in 16 patients undergoing myocardial revascularization, the density and the affinity of lymphocyte beta-adrenergic receptors before anesthesia induction (control) and at the end of cardiopulmonary bypass. Variations in the density and affinity of beta-adrenergic receptors were determined in vitro. Repeated determinations of plasma epinephrine and norepinephrine concentrations were also performed. Overall, no significant modification was observed in mean density and affinity of beta-adrenergic receptors at the end of cardiopulmonary bypass when compared with control values. However, a significant decrease (p less than 0.05) in affinity for isoproterenol was found in the six patients who had high catecholamine levels during cardiopulmonary bypass. In contrast, no significant modification of beta-adrenoreceptor affinity for isoproterenol was observed in the 10 patients who did not have this degree of adrenergic activation. In addition, beta-adrenoreceptor affinity for isoproterenol was decreased in the three patients in whom intraaortic balloon pumping was mandatory after discontinuation of cardiopulmonary bypass. We suggest that this decreased affinity of lymphocyte beta-adrenergic receptors could be related, at least in part, to a sustained adrenergic activation occurring in some patients during cardiopulmonary bypass.

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.

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.

Management of giant coronary artery aneurysm with fistulization into the right atrium.

A giant right coronary artery aneurysm communicating with the right atrium is reported. Its diagnosis using echocardiography, computed tomography of the chest, and angiography is illustrated. The operative management of this rare cardiac pathology is described. The role of operation in such a large aneurysm is emphasized.

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.

Bicaval pulmonary connection in tricuspid atresia using an extracardiac tube of autologous pediculated pericardium to bridge inferior vena cava.

From August 1989 to April 1991, four children, 1.5 to 4 years old with type IIb tricuspid atresia underwent total right heart bypass by means of a bicaval pulmonary connection using an extracardiac conduit of pediculated pericardium between the inferior vena cava and the main pulmonary artery. The tube was made from a large rectangular flap of the patient's own pericardium, pediculated along the right border, ensuring a vascular supply. The diameter of the tube, calibrated on a Hegar probe, equals that of the inferior vena cava, and the length is adapted to bridge the gap between the inferior vena cava and the main pulmonary artery. All four patients had an uneventful postoperative course. Assisted ventilation was stopped on the next morning and the chest tubes removed on the 2nd or 3rd day. The liver was only moderately enlarged and no pleural effusions developed. Sinus rhythm was permanent. Echocardiographic monitoring 6-10 months after the hospital discharge showed patent tubes, no collapse during the cardiac cycle, and no wall thickening and a laminar flow. The advantages of the pediculated pericardial tube are that no prosthetic material is used. There is no thrombogenicity or antigenicity. These tubes retain a growth potential, and we believe that this material is suitable for use in young patients.

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)

[Subaortic fibromuscular tunnel following resection of accessory mitral tissue. Surgical treatment]. / Tunnel fibro-musculaire sous-aortique développé après résection de tissu mitral accessoire. Traitement chirurgical.

When accessory mitral valve tissue obstructs the left ventricular outflow tract resection is considered a sufficient and definitive procedure. We report the unusual case of a child who had undergone such resection at the age of 4 years and who developed, over a few years, a recurrent subvalvular aortic obstacle consisting, this time, in a fibromuscular tunnel. In a second operation performed at the age of 12, a septal patch was inserted to widen the subaortic channel which was approached through a trans-septal infundibular route. Control examination showed a satisfactory pressure gradient and a sinus rhythm.

[Functional capacity after cardiac transplantation]. / Capacité fonctionnelle après transplantation cardiaque.

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.

[Coronary-cardiac fistula as a cause of tricuspid endocarditis treated by mitral homograft]. / Fistule coronaro-cardiaque à l'origine d'une endocardite tricuspide traitée par homogreffe mitrale.

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.

[Repair of rheumatic mitral lesions by transfer of a segment of the posterior valve with its chordae onto the anterior valve]. / Réparation de lésions mitrales rhumatismales par transfert d'un segment de la valve postérieure avec ses cordages sur la valve antérieure.

Since 1981, 100 patients have undergone mitral valve repair alone or in association with aortic or tricuspid valve surgery. The basic technique used was that described by Carpentier. However, in 13 of these patients, the repair was performed by a technical innovation consisting in transferring a one to two centimetres segment of the posterior leaflet with its chordae to the anterior leaflet. The lesions in which this particular technique was required were extensive chordal rupture of the anterior leaflet (5 cases), localised retraction of the surface of the anterior leaflet (2 cases), and perforation near the valve free edge due to endocarditis (1 case). The valvular disease was due to rheumatic fever in all cases. None of the patients had active endocarditis. The age of the patients varied from 4 to 60 years. Eight patients were under 15 years of age. Postoperative echocardiography and pulsed Doppler studies showed results comparable to the other patients who had undergone mitral valve repair although the valvular lesions were more severe in this particular group of patients. Only one patient had a poor operative result and had to be reoperated.

[Repair of post-infarction left ventricular wall ruptures by biological glue and a flap from the pericardium. Results from 2 to 10 years]. / Réparation des ruptures pariétales postinfarctus du ventricule gauche par colle biologique et plaque de péricarde. Résultats de 2 à 10 ans.

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.

[Early results of coronary surgery in patients between 71 and 80 years of age]. / Résultats immédiats de la chirurgie coronarienne entre 71 et 80 ans.

One hundred consecutive patients aged 71 to 80 without other cardiac pathology underwent coronary bypass surgery by the same surgical team between January 1986 and May 1989. These patients were recruited from a group of 687 patients undergoing coronary bypass surgery in the same period. The indication was always based on the severity of clinical symptoms resistant to medical therapy. Recent unstable angina despite triple therapy was a particularly common indication in this group of patients (61%). Preoperative coronary angiography showed a high incidence of triple vessel (62 cases) and left main stem disease (23 cases). Double vessel (12 cases) and single vessel disease (3 cases) were less common. Preoperative myocardial infarction was observed in 35% of cases; the site was nearly always on the inferior wall. In all, 230 bypasses were performed including 23 internal mammary artery bypasses (average 2.3 bypasses per patient). Six patients developed perioperative myocardial infarction confirmed by ECG and a rise in cardiac enzymes in 4 cases and by a rise in the cardiac enzymes alone in 2 cases. The mortality was low in this group of patients (3%). This was due to strict selection of patients in this age group and also to the improvement in the techniques of myocardial protection, anaesthesia and intensive care. Our results justify the operative indications in this group of patients in whom medical therapy has failed.

[Surgical treatment of infectious endocarditis on a native valve. Apropos of 71 cases]. / Traitement chirurgical de l'endocardite infectieuse sur valve native. A propos de 71 cas.

The results of surgery in a series of 71 patients operated upon for infective endocarditis on a native valve are presented. The patients' mean age was 35 years; the initial focus of infection was usually located in the mouth and the most frequent pathogens were staphylococci and streptococci. The aortic valve was most frequently involved. Only 26 patients underwent surgery after 40 days of antibiotic therapy; 34 were operated upon in a semi-emergency and 11 in an acute emergency. Pre-operative systemic embolism was common (20 cases), notably in the brain (17 cases), and 11 patients remained with sequelae. There was good correlation between the anatomical lesions found at surgery and the data obtained from pre-operative echocardiography. The operation was performed on one valve in 40 cases, on two valves in 20 cases and on three valves in 11 cases. Bioprostheses were used more often than mechanical prostheses. Hospital mortality was nil in patient who underwent elective surgery; it was 14.7 p. 100 in those operated upon in a semi-emergency and 27.3 p. 100 in those operated upon in an acute emergency. Nine patients developed late complications, mostly within 6 months of the operation; in particular, prosthesis disinsertion occurred in 4 cases, and progression of a pre-existing left cardiac failure was observed in 2 cases. In their conclusions the authors emphasize the reliability of echocardiography and the need for an early operation in cases with haemodynamic disorders in order to avoid severe myocardial failure and, if possible, systemic embolism and its fearsome sequelae.

[Hydatid cyst of the right heart and post-embolic pulmonary hypertension]. / Kyste hydatique du coeur droit et hypertension pulmonaire post-embolique.

A 22-year old man with hydatid cyst of the right ventricle presented, for about 10 years, with clinical signs of post-embolic pulmonary hypertension. Despite tumoral resection, the patient died post-operatively of his pulmonary hypertension. Post-mortem examination showed a hydatid cyst on the main pulmonary artery and fixed post-embolic pulmonary hypertension, but we were unable to determine whether we were dealing with old migrated cysts or blood clot emboli developed in contact with the cardiac tumour.

[Immediate postoperative results following conservative surgery of rheumatic mitral valve insufficiency in children]. / Resultats postopératoires immédiats après chirurgie conservatrice pour insuffisance mitrale rhumatismale chez l'enfant.

The immediate post-operative results of conservative surgery were evaluated objectively in 31 children aged under 13 years referred to us for surgical correction of severe rheumatic mitral valve regurgitation. 16 patients had pure mitral regurgitation. In the others, lesions which required additional surgery were aortic regurgitation in 7 cases, tricuspid of the mitral valve and left ventricle was studied by two-dimensional TM-mode echocardiography. This examination was combined with a pulsed doppler study in search of a possible residual mitral regurgitation signal, with special attention to the depth at which it was recorded in the left atrium -- a semi-quantitative indication of the severity of residual leakage. Two mitral valve replacements were performed, and two early reoperations were needed for residual regurgitation developed between the 5th and 8th post-operative days. Three deaths occurred due to supra-systemic pulmonary arterial hypertension. The post-operative evaluation of mitral valvuloplasty results therefore involved 25 patients. In the absence of significant residual mitral regurgitation, two-dimensional echocardiography was inconclusive since the images obtained varied considerably according to the surgical procedures performed. There was a distinct reduction of end-diastolic diameters (43.5 +/- 5.9 versus 62.1 +/- 8.7 mm pre-operatively), reflecting the disappearance or marked decrease of the pre-operative ventricular volume overload consecutive to mitral regurgitation. The reduction of end-systolic diameters was also significant (31.2 +/- 6.7 mm versus 39.2 +/- 7.1 mm pre-operatively), though less pronounced than that of end-diastolic diameters, which explains the diminution observed in the percentage of fibre shortening, although the figures remained within normal limits (28.7 +/- 9.7 p. 100 versus 37.0 +/- 6.8 p. 100).(ABSTRACT TRUNCATED AT 250 WORDS)

[Extracardiac pulmonary bypass in the treatment of tricuspid atresia]. / Dérivation bicavo-pulmonaire extracardiaque dans le traitement de l'atrésie tricuspide.

Six patients aged 1.5 to 4 years with type 13 tricuspid atresia underwent extracardiac bicavopulmonary repair. This corrective procedure comprises control of palliative aorto-pulmonary anastomosis, the construction of an anastomosis between the superior vena cava and right pulmonary artery and the interposition of an extracardiac tube of autologous pediculated pericardium between the inferior vena cava and the main pulmonary artery. This tube, fashioned from a rectangular flap, remains attached along its right border, conserving its vascular pedicle with the pericardium. Its diameter is calibrated to that of the inferior vena cava. The postoperative course was uncomplicated: all children survived. Assisted respiration was discontinued 24 to 36 hours after surgery, and the pleural drains withdrawn after 48 to 72 hours. The rhythm remained sinusal. Central venous pressure ranged from 8 to 12 mmHg. Peripheral arterial situation was over 95%. At follow-up at 3 to 15 months, the children were very active, reflecting good exercise capacity. Holter monitoring was normal. Saturation was 94 to 97%. Doppler echocardiography showed laminar blood flow. This technique insures good venous drainage without any prosthetic thrombogenic material. In addition, the pediculated pericardium conserves a potential for growth, justifying its use in small children. Long-term evaluation is essential but the initial results are encouraging and encourage perseverance with this method.

[Mitral valve repair by transfer of the posterior tricuspid leaflet and its chordae]. / Réparations mitrales par transfert du feuillet postérieur de la valve tricuspide avec ses cordages.

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.

[Mitral stenosis with notable or important subvalvular changes. Complete open commissurotomies supported by chorda transfer]. / Rétrécissement mitral avec altérations sous-valvulaires notables ou importantes. Ouvertures commissurales complètes, soutenues par des cordages transposés.

Since 1983, 40 consecutive patients with mitral stenosis (MS) and significant disease of the subvalvular apparatus underwent open heart mitral commissurotomy (OHMC). The aim of the study was to evaluate the effects of an unrestricted dilatation of the two commissures followed by repair of the subsequent mitral regurgitation. The mitral regurgitation created by this procedure in 24 cases was corrected by transferring 2 to 6 chordae tendinae to the free border of the anterior and/or posterior leaflet in the commissural region. A central regurgitant lesion due to lack of coaptation of the valvular surfaces was treated by annuloplasty with a Carpentier prosthesis in 12 cases. The subvalvular abnormalities were treated by the conventional techniques of fenestration, resection and division of the papillary muscles. Thirty of the 38 survivors had no residual murmur, and 6 had a short low intensity systolic murmur. The 2D echocardiographic study showed no residual stenosis. The residual systolic murmurs were evaluated by pulsed Doppler and corresponded to very localised regurgitation. This extensive operative technique gives very good immediate valvular results which, associated with an adequate subvalvular procedure, are considered to be an important prognostic factor.