[Twelve years' experience with Carbomedics bileaflet valves]

The authors report long-term results of a cohort of patients who underwent valve replacement with a Carbomedics bileaflet mechanical prosthesis. The influence of patient age on the results was examined. Three hundred and ninety patients were operated between 1988 and 2000. Complete follow-up was available in 98.5% of cases. For aortic valve replacement, the total experience was 1,061 person-years. The hospital mortality was 2.3%. Global actuarial 12 year survival was 74 +/- 7%. The actuarial probability of absence of thrombo-embolic complications at 12 years was 95 +/- 3%, and of absence of haemorrhagic complications 89 +/- 4%. For mitral valve replacement, the total experience was 610 person-years. The hospital mortality was 3.4%. The global actuarial 12 year survival was 78 +/- 5%. The actuarial probability of absence of thrombo-embolic complications at 12 years was 79 +/- 9% and of absence of haemorrhagic complications 82 +/- 5%. The results of survival and prosthesis-related complications were comparable to those reported in the literature with second generation mechanical prostheses, with the exception of thromboses of the mitral valve for which a higher linear rate was observed. Multivariate analysis showed an increased (x 2.3) risk of haemorrhage after 60 years of age irrespective of the site of implantation of the prosthesis. In patients over 60 years of age, the risks of long-term anticoagulant therapy should raise questions concerning the modality of follow-up and the indications. The use of biological prostheses is a possible alternative.

Indications of coronary artery bypass graft in 2003

During the last 3 decades, coronary artery bypass grafting (CABG) emerged, was developed and has progressed. Additionally, recent surgical innovations have been introduced aimed at reducing the trauma without deviating from the efficiency of conventional procedure. At the same time significant evolution in preventive, medical treatment and percutaneous procedures has been observed. The introduction of new treatment has improved the result in medically treated patients. Percutaneous procedures emerged and were developed. New technologies and advances available to adjunctive medical therapies have appeared and have impacted the effectiveness initially established for percutaneous coronary intervention (PCI). Larger use of stent permits a significant decrease in restenosis and the introduction of coated stent will probably improve the

RESULTS

Indication is a moving field. Continuing improvement in medical treatment, technical procedure and development of less invasive surgery modifies the place of each treatment and continuing evaluation and comparison are necessary. Introduction of new treatment, aimed at treating ischemic cardiomyopathy like transmyocardial revascularization, cell transplantation or gene therapy will probably modify indications in the future.

Inhibitory activity of antibodies against the human atrial 5-HT(4)receptor

Antibodies directed against the second extracellular loop of G protein-coupled receptors have been shown to exert "agonist-like" activities. In order to test the hypothesis that this is a general phenomenon, antibodies were raised in rabbits against a synthetic peptide corresponding to the second extracellular loop of the newly sequenced human cardiac 5-HT(4)receptor. The antibodies were affinity-purified and shown to recognize the 5-HT(4)receptor in immunoblots of Chinese hamster ovary (CHO) cells expressing the receptor. The antibodies had no intrinsic effect but could depress the activation of L -type calcium channel induced by serotonin in human atrial cells. This antagonist-like effect was exerted both by intact IgG and by Fab fragments. These results are physiologically important since it has been shown that the 5-HT(4)receptor could be a target for autoantibodies in mothers at risk of giving birth to children with neonatal atrio-ventricular block.

Analysis of the distribution of histologic myocardial lesions during acute cardiac rejection. Experimental study in rodents

BACKGROUND AND METHOD

Asymmetric distribution of histologic lesions have been reported in grafted hearts that could hamper the interpretation of right ventricular endomyocardial biopsy. Heterotopic heart transplantations were performed in rats (n=59) and guinea pigs (n=20). Grafted hearts were examined by a pathologist who established the degree of cardiac rejection in the four cardiac cavities.

RESULTS

Forty cardiac rejections were diagnosed in rats and ten in guinea pigs. An asymmetric distribution of histologic lesions was observed in 34 (68%) rejected hearts with greater lesions in the auricular myocardium than in the ventricular myocardium (n=25, 50%). One (n=18) or two degrees (n=7) differentiated the severity of rejection between atria and ventricles. Cardiac rejection score was significantly greater in atria than in ventricles (3.12+/-0.18 vs. 2.6+/-0.2 (P<0.01) in rats and 2.35+/-0.37 vs. 1.6+/-0.47 (P<0.001) in guinea pigs. There were histologic lesions of rejection in the auricular myocardium in seven cases, although the ventricular myocardium was completely normal. In nine (18 %) other grafted hearts the degree of rejection was equal in the auricular myocardium and ventricular septum but was greater than the degree of rejection noted in the right and left ventricular free walls.

CONCLUSION

The distribution of histologic lesions of acute cardiac rejection in rodents was heterogeneous in grafted hearts which exhibited greater lesions in the atria than in ventricles. This should be taken into consideration in the evaluation of new methods of detection of cardiac rejection and in the diagnosis of acute cardiac rejection in humans.

Severe and early alteration of action potential during acute cardiac rejection in rats

INTRODUCTION

Alteration of cardiac action potential and its adaptation to heart rate could contribute to cardiac dysfunction and arrhythmias during acute cardiac rejection.

METHODS AND RESULTS

Heterotopic heart transplantation was performed in allogeneic and syngeneic rats in which the action potentials of right and left ventricles were measured at 1, 2.5, 3.3, and 5.7 Hz successively using standard microelectrode techniques and compared with nontransplanted hearts. For each frequency, we measured action potential amplitude, action potential duration, transmembrane resting potential, and Vmax. In the right ventricle, at 1 Hz in the presence of rejection (n = 40), a significant increase was observed in action potential duration at 20%, 50%, and 70% repolarization (82.5%, 75.6%, and 70.8%, respectively) and in action potential amplitude (+17.9 mV), and the resting potential was decreased (-5.3 mV). A lack of adaptation of action potential duration to the driving frequency was observed in the rejecting heart group in contrast to controls (n = 20) and nonrejecting hearts (n = 13). Similar results were observed in the left ventricle and surprisingly in the native hearts (n = 11) of recipients with allografted rejecting hearts in the abdominal position.

CONCLUSION

Action potential and its adaptation to the driving frequency is considerably altered during acute rejection. A humoral factor could contribute to cardiac dysfunction.

Twelve-year experience with Carpentier-Edwards PERIMOUNT pericardial valve in the mitral position: a multicenter study

BACKGROUND AND AIMS OF THE STUDY

The study aim was to assess the durability of the Carpentier-Edwards PERIMOUNT pericardial bioprosthesis in the mitral position.

METHODS

This seven-center retrospective clinical study involved the follow up of 333 patients who underwent isolated mitral valve replacement and 102 patients who underwent double (mitral and aortic) valve replacement with the PERIMOUNT pericardial valve between 1984 and 1989. Mean patient age at implant was 60.7 +/- 11.6 years; 41.1% were males. The most common etiology was rheumatic heart disease (53.9%) and the most common mechanism mitral insufficiency. All patients but six were followed for an average of 7.2 +/- 3.6 years after surgery; total follow up was 3071.7 patient-years (pt-yr).

RESULTS

The total operative mortality rate was 7.6%; this included a valve-related mortality rate of 0.2%. The late mortality rate was 5.2% per pt-yr, of which 1.4% per pt-yr was considered valve-related. At 11 years, the overall actuarial survival rate was 53.3 +/- 2.8%, and actuarial freedom from valve-related death 83.9 +/- 2.6%. At follow up, 80% of patients were in NYHA class I or II, and 74% showed improvement. Twenty-eight incidences of deterioration requiring explant were observed. At 11 years the actuarial freedom from explant due to structural failure was 84.9 +/- 3.1%. Rates of structural failure decreased with age: the actuarial freedom from explant due to structural failure was 78.1 +/- 4.8% for patients aged < or = 60 years, 89.4 +/- 4.4% for those aged 61-70 years, and 100% for those aged over 71 years.

CONCLUSION

The Carpentier-Edwards PERIMOUNT pericardial bioprosthesis is a reliable choice when a tissue valve is required, especially in patients over 60 years of age.

[Incidental discovery of a giant myxoma]

The authors report a case of very large myxoma of the left atrium, original in terms of its mode of discovery, its very calcified appearance, in a totally asymptomatic elderly patient. A complete ultrasound assessment, catheterization, and coronary angiography allowed assessment of the morphology, topography, blood supply and cardiac repercussions of this tumour. Myxoma of the left auricle is the commonest cardiac tumour, with multiple clinical features and presentations. This benign tumour arises from embryonic vestigial remains, usually in the fossa ovale. The present case is original by its unusual mode of discovery in a totally asymptomatic patient.

[Echocardiographic Doppler study of left ventricular filling in the diagnosis of minimal or moderate rejection in cardiac transplantation]

The study of left ventricular filling by Doppler echocardiography may be a non-invasive diagnostic method of detection of acute rejection of cardiac transplants. The aim of this study was to assess the value of the method for diagnosis of minimal to moderate rejection (grades 1 to 3 of the Billingham classification). A total of 466 Doppler echocardiographic studies were performed in 23 cardiac transplantation patients (21 men, mean age 49.3 +/- 10 years) with endomyocardial biopsy as the reference method for the diagnosis of rejection. Over a follow-up period of 18.5 +/- 10 months, 22.7% of biopsies showed minimal or moderate rejection. The Doppler measurements of the isovolumic relaxation period and peak early diastolic (E) velocity with respect to the mitral velocity-time integral were no different in cases of acute rejection. The only difference observed was in the mitral half-pressure time which was much shorter in cases of rejection. However, after drawing a ROC graph, the accuracy of this parameter was insufficient for diagnosing rejection irrespective of the threshold of variation considered (23% sensitivity for a 20% shortening and 36% sensitivity for a 10% shortening). The authors conclude that Doppler echocardiographic study of left ventricular filling is of limited value for the diagnosis of acute minimal or moderate rejection in cardiac transplant patients. The half-pressure time may be a useful complement to endomyocardial biopsy or when biopsy investigations are performed less frequently.

[Paradoxical embolism and thrombosis trapped in the foramen ovale. Role of transesophageal echocardiography]

The authors report a case of paradoxical embolism presenting with syncope and a transient cerebrovascular accident. A large thrombus was observed entrapped in the foramen ovale during transthoracic echocardiography and confirmed at transoesophageal echocardiography. Despite the recent cerebrovascular event surgery was successfully performed. This clinical situation, and a review of the literature illustrate the diagnostic value of transoesophageal echocardiography, the finding of an intra-atrial thrombus being a possible surgical indication when the clinical context is favourable.

Influence of age on valve related events with Carpentier-Edwards pericardial bioprosthesis

Age is the most important factor for the durability of biological valves. With an original design the Carpentier-Edwards pericardial valve showed improved results at 10 years. The influence of age on valve related complications is studied with a 10 year follow up on 807 valvular replacements.

METHODS

Between January 1984 and December 1993, 807 patients underwent valve replacements with a Carpentier-Edwards pericardial bioprosthesis. Patients, 193 were younger than 60 years, 284 between 60 and 70 years and 330 patients were older than 70 years. All patients but seven were followed up for an average of 4.18 years after their operation and total follow up was 3373 patient years. Patients were divided into three groups of age: group I, less than 60 years; group II, 60-70 years; group III, over 70 years. A retrospective comparison was made between age groups.

RESULTS

At 11 years, valve related complications included 97 patients with 27 valve related deaths. Rates of valve related death increase with age linearized rate were 0.3, 0.6 and 1.2%, respectively. No difference was observed for rates of all valve related morbidity: 2.6, 2.4 and 3.5%, respectively. Risk of thromboembolism increased with age, linearized rates were: 0.3, 0.7 and 1.3%. Risk of deterioration and reoperation decreased with age, rates of deterioration were 0.8, 0.1 and 0%. Other valve related events had the same incidence in all groups. No statistical difference was observed between group II and group III for deteriorations and reoperations.

CONCLUSIONS

The performance of the Carpentier-Edwards pericardial valve is the same at 10 years in group II and III. This study supports the clinical use of this tissue valve in patients over 60 years. The results in group I are satisfactory, nevertheless, a more durable biological valve is needed for young patients.

[Intermediary results with the CarboMedics bileaflet valvular prosthesis]

From December 1988 to December 1995, 212 patients underwent valve replacement with a CarboMedics bileaflet valve in our institution (103 aortic valve replacements, 72 mitral valve replacements, and 37 double valve replacements). Fifty-five percent were male patients. Mean age was 53.8 +/- 12.7 years. Forty seven percent of patients were in NYHA clinical status III or IV. Operative mortality was 3.7% (8/212). All patients but eight were followed-up for an average of 2.9 years after their operation and total follow-up was 617 patient-years. At the time of the study, more than 90% of patients were in NYHA class I or II, 26% were in atrial fibrillation and 100% of patients received anticoagulation treatment. There were 15 late deaths. After 7 years, the actuarial survival rate was 84 +/- 7%. Three patients died of valve-related causes. Valve-related complications included 5 thromboembolic episodes (0.8% patient-year), 18 anticoagulant-related complications (2.9% patient-years), 3 endocarditis (0.5% patient-year), and 4 reoperations (0.6% patient-year). After 7 years, freedom from thrombo-embolic complication was 97 +/- 2%, from anticoagulant-related complications was 88 +/- 6%, from endocarditis was 96 +/- 4%, and from reoperation was 95 +/- 5%. We conclude that the 7-year results compare with other bileaflet valves. More follow-up and larger studies are mandated to give definite conclusions.

[Treatment of congenital heart diseases with pulmonary artery cerclage. Immediate and medium term results in 51 patients]

The aim of this study was to assess the results of pulmonary artery banding in a retrospective study of 51 consecutive children treated from January 1980 to December 1993. The study population was 24 girls and 27 boys with an average age of 6.2 months, of average weight of 4.01 kg. The cardiac conditions treated were ventricular septal defects in 24 cases (isolated and associated with one or more cardiovascular malformations or multiple), complete atrioventricular canal in 12 cases (isolated or associated with several cardiovascular malformations), single ventricle in 7 cases, double outlet right ventricle in 3 cases, transposition of the great arteries with ventricular septal defect in 2 cases, tricuspid atresia in 2 cases, and a complex lesion with double discordance in one case. The average duration of banding was 2.35 years (n = 49). Hospital morality of banding was 1.9% (1/51). Late mortality was 14.8% (7/47). Twenty-one patients (42.8%) had complications of banding. The survival rates of children who underwent banding was 86.8% at 1 year and 80.6% at 11 years. The low hospital mortality leaves a role for pulmonary artery banding as a palliative procedure in congenital heart disease in which early correction is impossible or carries and unacceptable risk. Complications of banding justify attempts to improve the technique, by making adjustable bands.

Detection of acute cardiac allograft rejection with high resolution electrocardiography: experimental study in rats

BACKGROUND AND METHODS

To diagnose early acute cardiac rejection, we evaluated high-resolution electrocardiography in rats. Heterotopic heart transplantations were performed in allogeneic animals, either treated with cyclosporine or untreated, and in syngeneic animals. High-amplification electrocardiograms were recorded daily, under anesthesia, with two intra-abdominal leads. After amplification (x 5000 to 20,000), the electrocardiographic signal was acquired and analyzed with P-Clamp software. We measured the amplitude (millivolts) and duration (milliseconds) of the auriculogram (P wave) and the ventriculogram (QRS wave), the duration of auriculoventricular conduction (milliseconds; PQ interval) and the heart rate. Twenty-five grafted hearts were fully studied in recipients not treated with cyclosporine (allogeneic n = 16, syngeneic n = 9).

RESULTS

In the allogeneic group, acute cardiac rejection was always accompanied by an early and progressive increase in P wave duration and PQ interval, whereas an increase in QRS duration was subsequently recorded. No significant change in P wave, PQ interval, or QRS wave duration was recorded in the syngeneic group, which showed no histologic rejection lesions. A decrease in P wave and QRS wave amplitude was recorded in both groups of animals. In the allogeneic group treated with cyclosporine (n = 21), grafted hearts were removed early (4.5 +/- 0.5 days): 10 cardiac grafts were rejected and 11 were not. An increase in P wave duration > or = 20% was associated with mild rejection in most cases. The sensitivity and specificity of this electrocardiographic sign were excellent (100%). The auricular (right and left atria) and the ventricular (right and left ventricles) tissues were evaluated histologically. In the allogeneic groups (n = 26), the histologic lesions during acute rejection were greater in the auricular myocardium than in the ventricular myocardium. Rejection in the atrial and ventricular myocardium was most often differentiated by one degree according to the Billingham classification.

CONCLUSIONS

We concluded that acute cardiac rejection in rats is associated with early conduction disturbances in the atrial myocardium which can be shown by high-resolution electrocardiography.

[Rheumatoid aortic insufficiency. Apropos of a case treated by mechanical valve replacement. Review of the literature]

Rheumatoid valve lesions have been described for a long time in the literature. The authors report a case of rheumatoid aortic incompetence presenting with complete heat failure and treated semi-urgently by mechanical valve replacement. The pathological lesions observed on the aortic valves were pathognomonic of rheumatoid arthritis. Transthoracic echocardiography should be systematically proposed in the context of severe rheumatoid arthritis looking for valvular heart disease.

[Coronary embolism disclosing thrombosis on a Medtronic-Hall aortic valve prosthesis in aortic position]

A 32 year-old-man admitted to hospital on the third day of myocardial infarction, three months after aortic valve replacement with a mechanical Medtronic-Hall prosthesis. The embolic character of the disease was evident on coronary angiography which showed a large thrombus in the left main coronary artery. The thrombosis of the valve prosthesis was not detected by non-invasive investigations but at aortography, confirmed at surgery. Thrombolysis with rt-PA did not dissolve the clot and reoperation was necessary (valve replacement with aorto-coronary bypass grafting).

Pericardial valves in small aortic annuli: ten years' results

OBJECTIVE

The first generation of pericardial valves was withdrawn from the market because of too high a rate of premature failure. With an original design, the Carpentier-Edwards pericardial valve promised improved results, especially in small sizes.

METHODS

Ninety patients who underwent an isolated aortic valve replacement with a 19 mm Carpentier-Edwards pericardial bioprosthesis in our institution between July 1984 and December 1993 were followed up. The mean age was 72.2 +/- 10.1 years. Fifty percent of the patients were in NYHA clinical status III or IV. The operative mortality rate was 3.7% (3/90). All patients were followed up for an average of 4.45 years after their operation and the total follow-up was 398 patient-years.

RESULTS

At this time of the study, over 80% of the patients are in NYHA class I or II. There were nine late deaths. After 10 years the actuarial survival rate was 80 +/- 12%. Three patients died of valve-related causes (1 endocarditis, 1 structural failure and 1 sudden death). The actuarial rate of freedom from valve-related death was 93 +/- 6% at 10 years. Valve-related complications included two thromboembolic episodes (0.5% patient-year), one endocarditis (0.3% patient-year), one reoperation (0.3% patient-year) and one structural valve failure with calcification and stenosis (0.3% patient-year). After 10 years, freedom from reoperation was 99 +/- 1%, from valve failure 98 +/- 2%, from thromboembolic episodes 95 +/- 4% and from endocarditis 98 +/- 2%. The mean gradient was 18.8 mmHg and mean effective orifice area 1.1 cm2.

CONCLUSIONS

With a low rate of valve-related events at 10 years and a low rate of structural deterioration with no leaflet tear, this prosthesis is a reliable alternative for small aortic annuli.

[Influence of the valve position on the complications related to pericardial Carpentier-Edwards valve after 8 years]

Between July 1984 and December 1991, 541 Carpentier-Edwards pericardial prostheses were implanted in 536 patients (420 aortic and 121 mitral prostheses). The operative mortality was 2.9% for aortic and 3.3% for mitral valve replacement. All but 8 patients were followed up for an average of 3.9 years, making a total follow-up of 1930 patient-years. There were 61 deaths during follow-up (41 AVR, 20 MVR). The actuarial 8 year survival was 80 +/- 6% for AVR and 74 +/- 10% for MVR. There were 15 deaths related to the prostheses. The probability of absence of valve-related mortality was 97 +/- 3% for AVR and 92 +/- 6% for MVR (NS). The valve-related complications included 15 thromboembolic events (AVR: 12; MVR: 3), 10 endocarditis (AVR: 7; MVR: 3), 8 anticoagulant-related haemorrhages (AVR: 4; MVR: 4), 4 degeneration (AVR: 2; MVR: 2). There were no cases of cusp tear. The probability of absence of thromboembolic events at 8 years was 96 +/- 3% for AVR and 96 +/- 4% for MVR (NS), of absence of endocarditis 97 +/- 2% for AVR and 97 +/- 3% for MVR (NS) and of absence of valve degeneration 99 +/- 1% for AVR and 99 +/- 2% for MVR (NS). These results show that the position of the bioprosthesis had no influence on valve-related morbidity and that pericardium is a satisfactory tissue for the manufacture of mitral bioprostheses.

[Systemic pulmonary shunts in the neonatal period. Short and medium-term results]

Systemic pulmonary shunts were performed in 41 consecutive neonates with congenital cyanotic heart disease between 1981 and 1992. The lesions comprised pulmonary atresia with intact interventricular septum (16 cases), pulmonary atresia with ventricular septal defect (9 cases), tetralogy of Fallot (5 cases), transposition of the great arteries (3 cases) and different complex cardiac lesions (8 cases). A polytetrafluoroethylene tube was used in 40 neonates, 5 mm in diameter in 39 cases, anastomosed to be subclavian artery in 21 patients (group A) and on the ascending aorta or innominate artery in 19 patients (group B). A retrospective analysis of the results was undertaken in all patients with a mean follow-up period of 6.5 years (range: 19 months-12.5 years). There were 4 early deaths (9.7%) and 8 late deaths (19.5%) giving a total mortality of 29.2%. Of the late deaths, 4 occurred in the first year, 3 suddenly at home and 4 in relation with the surgical correction. Occlusion of the shunt was suspected in only one case. The actuarial survival rate was 78% at one year, 75.5% at 7 years and 66% at 10 years. Eleven of the 12 deaths were in children with pulmonary atresia with intact interventricular septum (8 cases) and complex cardiac malformations (3 cases). Early complications were observed in 15 of the 37 survivors of the initial procedure. Cardiac failure occurred in 83% of group B and 22% of group A (p < 0.01). The probability of shunt efficacy was 89% at 1 year, 63% at 2 years and 45% at 3 years.(ABSTRACT TRUNCATED AT 250 WORDS)

[Surgery of valve replacement with pericardial prosthesis]

The ideal artificial heart valve still does not exist among the various cardiac valves available to the clinician. Morbidity and mortality are directly related to the valve itself. Despite the promising hemodynamic results obtained in the 70s with pericardial prosthesis, these valves were progressively abandoned due to their poor long-term resistance. Based on an analysis of the causes of failures, modifications were made in the manufacturing method and current results with pericardial valves has greatly improved, inciting new interest in their clinical use. Today, the pericardium is recognized as a valid substitution material for bioprostheses. Results of long-term series should confirm current studies. Research is under way to determine how to improve pericardium longevity since tissue deterioration remains the limiting factor.

Electrocardiographic and electrophysiologic properties of cardiac allografts

The increasing number of heart transplant patients requires that physicians be able to recognize the electrocardiographic (ECG) and electrophysiologic properties of cardiac allografts. Cardiac allografts are characterized by modifications of resting ECGs and frequent arrhythmias in the postoperative period, and the loss of autonomic nervous control illustrated by permanent tachycardia and loss of heart rate variability during 24-hour ambulatory ECG recording. Some clinical and experimental observations suggest a mid-term reinnervation of the cardiac allograft, but this requires histologic confirmation. The electrophysiologic characteristics of the denervated myocardium are similar to those of the innervated myocardium at rest. However, supersensitivity to circulating catecholamines has been observed in cardiac allografts as in experimentally denervated hearts, which is responsible for a progressive increase in heart rate during exercise and a slow decrease during recovery. Supersensitivity of the denervated heart to acetylcholine may explain the high prevalence of donor sinus dysfunction due to impairment of its automaticity. More often, the sinus node dysfunction is transient and can be treated with an adenosine antagonist, such as theophylline, before permanent implantation of a pacemaker. In the case of pacemaker implantation, synchronization of the donor atria with the recipient atria is desirable, and an endocardial lead implantation is preferred. Several electrophysiologic changes have been observed during acute cardiac allograft rejection. From experimental studies, the most important of these are the disturbance of conduction in the atria and the atrioventricular node and a decrease in the amplitude of the ventricular potential. Initial studies on isolated myocytes show profound changes in membrane conductance during experimental cardiac rejection. The development of new noninvasive detection methods of cardiac allograft rejection, such as intramyocardial voltage electrogram monitoring and high-resolution ECG, could help early diagnosis.

[Surgical treatment of atrial fibrillation]

The persistence of atrial fibrillation with a controlled ventricular response with medical treatment or ablation of the His bundle, suppresses troublesome palpitations but leaves potential haemodynamic problems and the risk of thromboembolism. Surgical treatment of this arrhythmia, by leaving an anatomic bridge between the sinus and atrioventricular nodes, aims to allow acceleration of the ventricular rhythm on exercise whilst preventing by partial, total or selective exclusion of atrial tissues, the multiple intra-atrial reentries responsible for atrial flutter or fibrillation. The first method proposed was isolation of the left atrium (Cox, 1980) which allows acceleration of the ventricular rhythm during exercise, leaving little or no haemodynamic disturbance, but, in theory, the same risk of embolism. The second method, the "corridor" operation (Guiraudon, 1985) consists in isolating both atria, but significantly alters the haemodynamic efficacy without reducing the embolic risk, and hardly offers any advantage over ablation of the nodo-hisian pathway completed by implantation of a ventricular, rate responsive, pacemaker. The recently described "maze" procedure (Cox and Boineau, 1991) would seem to be more promising with judiciously chosen incisions (at the base of the atria, around the pulmonary veins, between the vena cavae, along the interatrial septum, etc.) and points of cryoablation in the region of the coronary sinus, allowing modulation of the ventricular response with activation of sufficient atrial tissue to prevent reentry and recurrence of atrial fibrillation without affecting haemodynamic efficacy. The results of this technique are encouraging in the hands of its inventors but require confirmation in larger series of patients.(ABSTRACT TRUNCATED AT 250 WORDS)

New procedure to replace the aortic valve with autologous pericardium: a clinical case

Primary tissue failure is a major problem with pericardial or porcine heterografts, and the causes of calcification of the tissue are not yet known. The deterioration of bioprostheses may be due in part to immunologic response. Using autologous tissue is a current approach of research. We present a case of replacement of the aortic valve using an original procedure with autologous pericardium.

[Partial pulmonary embolectomy without extracorporeal circulation. Apropos of a case]

The authors report a case of massive pulmonary embolism compromising the haemodynamic status of a 52 year old man with a formal contraindication to thrombolytic therapy. Unilateral pulmonary embolectomy was performed without cardiac pulmonary bypass, preceded by partial interruption of the inferior vena cava. Postoperative controls confirmed the success of the surgical procedure. Although the indications of surgical embolectomy are limited, especially without cardiopulmonary bypass, it may be considered for the treatment of certain cases of massive pulmonary embolism.

The Carpentier-Edwards pericardial aortic valve: intermediate results in 420 patients

From July 1984 to December 1991, 420 patients underwent isolated aortic valve replacement with a Carpentier-Edwards pericardial bioprosthesis in our Institution. Of the patients 71.5% were male, the mean age was 66.9 +/- 11.9 years and 48% were in NYHA clinical stage III or IV. The operative mortality rate was 2.9% (12/420). All patients but six were followed up for an average of 3.9 years after their operation and total follow-up was 1444 patient-years. At this time of the study, over 80% of the patients are in NYHA class I or II, 6% are in atrial fibrillation and 7% receive anticoagulation treatment. There were 41 late deaths. After 8 years the actuarial survival rate is 80% +/- 6%. Nine patients died of valve-related causes (three endocarditis, three thromboembolic complication, one structural failure, and two sudden deaths). The actuarial rate of freedom from valve-related death was 97% +/- 3% at 8 years. Valve-related complications included 12 thromboembolic episodes (0.8% patient-year), 7 endocarditis (0.5% patient-year), 4 anticoagulant-related complications (0.2% patient-year), 6 reoperations (0.4% patient-year) and 2 structural valve failures (0.1% patient-year). After 8 years, freedom from thromboembolic complication was 96% +/- 3%, from endocarditis 97% +/- 2%, from reoperation 98% +/- 2% and from valve failure 99% +/- 1%. There were only two structural deteriorations (calcification and stenosis) and one explanation. No leaflet tear was observed. We conclude that these intermediate results are better than those obtained with previous pericardial bioprostheses.

[Complete cusp rupture of Hancock pericardial bioprosthesis with systemic embolism. Apropos of a case]

The authors report the case of a systemic embolism of a cusp of a Hancock pericardial aortic bioprosthesis. This rare complication has not been previously reported to the authors' knowledge, and should lead to immediate valve replacement.

[Electrophysiological properties of the transplanted heart. Clinical applications]

With the improvement in the results of cardiac transplantation, more and more cardiologists are called on to follow up cardiac transplant patients. Cardiological follow-up requires a knowledge of the electrocardiographic and electrophysiological features of the transplanted heart after surgery and the suppression of autonomic innervation. The transplanted heart ECG is characterised by the presence of 2 P waves of different morphology and frequency (from the native and transplanted atria), an acceleration of the sinus rhythm, clockwise rotation of the longitudinal axis, right bundle branch block and ST-T segment changes. The increase in heart rate during exercise is catecholamine-dependent, more progressive and less important than in normal subjects, as is the deceleration of the cardiac rhythm when exercise is stopped. The observation of early sinus node dysfunction is not rare (6.6%) and though usually asymptomatic and transient, implantation of a pacemaker is commonly proposed with different modes of stimulation (VVI, VVIR, AAIR, AAT). The authors have observed changes in the electrophysiological properties of experimental transplanted hearts during acute rejection. The most important of these were in the conduction of the activation within the atrium and in the atrioventricular node, and a reduction in the amplitude of the ventricular potential. The recording of these changes in humans by a non-invasive method could help early diagnosis of acute rejection and limit the number of endomyocardial biopsies. Of the non-invasive techniques under assessment, signal-averaged electrocardiography (temporal and/or frequency analysis) seems to be the most promising.

Anatomic and radiologic bases of surgery of the thoracic aorta

Lesions of the thoracic aorta create problems related to their site and relations with the main aortic branches. The aim of surgery must be to treat the lesion while ensuring perfusion of the tissues excluded by clamping during the operation. Anatomic study of the aortic lesions is based on imaging. Angiography is still often the basic examination though it shows only the lumen and course of the aorta. However, CT and MRI visualise the aortic wall and especially the relations of the aorta to the mediastinal structures. A comparison of anatomic and imaging studies was made on 10 fresh subjects coming from the anatomy department of the Saints-Pères and from the school of surgery of Fer à Moulin. Sections were made every 3 to 5 mm in 3 planes (sagittal, coronal and axial) after CT localisation of the plane of section. This anatomic study was correlated with CT and MR images made on healthy volunteers. The choice of surgical management of a lesion of the thoracic aorta is based on preoperative anatomic assessment by imaging applied not only to the aorta but also to its branches and the territory supplied.

The thoracic esophagus: sectional anatomy and radiosurgical applications

The relationships of a tumor of the thoracic esophagus to the adjacent mediastinal structures are currently studied by means of computed tomography (CT), magnetic resonance imaging (MRI) and, more recently, by echoendoscopy. However, the assessment of axial mediastinal CT and of MRI in the coronal and sagittal planes calls for some degree of experience. To further this training a sectional anatomy is proposed in correlation with imaging of the thoracic esophagus and the posterior mediastinum. Ten fresh subjects whose vascular networks had been previously injected with colored resin were sectioned along the three planes of space after positioning under CT monitoring. The axial sections were compared with the CT images made with a GE 9800 Quick scanner. Three frontal and sagittal sections were compared with the MRI images made with a GE Signa apparatus using a high magnetic field. The relations of the esophagus were studied at three levels: the supra-azygo-aortic segment, where it is related to the left subclavian artery; the inter-azygo-aortic segment, where access to the esophagus is barred on the left by the aortic arch and on the right by the arch of the azygos vein, section of which provides ample access; and the sub-azygo-aortic segment, where the esophagus passes behind the left main bronchus and to the right of the descending aorta, two organs whose invasion contraindicates excision of a tumor of the esophagus but is difficult to assess by current thoracic imaging techniques. The esophagus then descends behind the left atrium; the investigation of the kinetics of the heart cavities by transesophageal echocardiography is an application of this anatomic relationship.(ABSTRACT TRUNCATED AT 250 WORDS)

[Value of the association of blood cardioplegia and energetic warm reperfusion in cardiac transplantation]

Blood cardioplegia at 8 degrees C results in cardiac standstill whilst maintaining minimal metabolic functions of the cardiac cell. Reinjection every 20 minutes allows cellular reoxygenation, the delivery of essential elements (Tham, CPD), and the elimination of products of myocardial degradation accumulated during ischemia. Before declamping the aorta, a reperfusion with warm blood (34 degrees C) containing glutamate and GTN enables restocking of the energy reserves (Krebs' cycle) and a lowering of coronary and systemic resistances. This technique used systematically if even more effective when the ischemic time is prolonged as is the case in cardiac transplantation. The 50 transplants performed since January 1989 with this form of myocardial protection were compared with 50 procedures performed in 1988 with crystalloid cardioplegia. There was no significant difference in the duration of ischemia or of cardiopulmonary bypass between the two groups. Patients benefitting from blood cardioplegia defibrillated spontaneously more frequently, required lower doses of Dopamine for shorter periods and were extubated earlier.

Prognostic indices of survival in patients supported with temporary devices (TAH, VAD)

In an attempt to identify current indications and patient selection criteria for the use of mechanical circulatory support, we reviewed our experience in 83 patients who received a total artificial heart (TAH; n = 43), ventricular assist device (VAD) (n = 13), centrifugal pump (n = 17) or extracorporeal membrane oxigenation (ECMO) (n = 8) as a bridge to transplantation (Group I, n = 50) or for recovery from heart failure (Group II, n = 33). Comparing patients successfully transplanted (n = 20) or weaned (n = 9) who survived initial hospitalization, and those who died on mechanical support, there were no differences in preoperative renal, hepatic or pulmonary functions. Postoperative urinary output and bilirubin levels were the earliest variables affecting survival, and urinary output 24 hours after implant was discriminative in patients who survived (p less than 0.01). Age (above or below 40 years) and modality of terminal heart failure (acute versus chronic) were the most important factors affecting survival in the bridge to transplant group: 82% of young patients with acute decompensation were transplanted and 63% are long-term survivors while all patients over 40 years with chronic heart failure died on mechanical support (MS). In postcardiotomy patients, duration of cardiopulmonary by-pass (CPB) was significantly different comparing survivors with those who died in either bridge or recovery groups and all patients who had a CPB greater than 4 hours died on MS or after transplantation or weaning. In conclusion, preoperative indices indicating reversibility of multiple organ dysfunction remain to be identified.(ABSTRACT TRUNCATED AT 250 WORDS)

[Infected false aneurysm at the level of an aortotomy cicatrix 5 years after mechanical replacement of the aortic valve]

The authors report the case of Streptococcus Bovis Infection of a pseudoaneurysm which developed in the aortotomy suture line five years after aortic valve replacement with a Bjork-Shiley prosthesis. This was an isolated lesion without involvement of the prosthesis or aortic ring and was an operative finding.