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Biomedical subjects

A Carpentier

Publications and source records attributed to A Carpentier.

At least 451 records · Page 25Linked to original sources
PubMedDate not supplied

Correlation between clinical and histologic patterns of degenerative mitral valve insufficiency: a histomorphometric study of 130 excised segments.

The objectives of this study were to examine quantitatively the histological changes in incompetent degenerative mitral valves obtained at surgery for mitral valve repair, and to determine whether Barlow's disease (BD) and fibroelastic deficiency (FED) can be distinguished by histology. The billowing mitral leaflet syndrome (or Barlow's disease) and FED can be distinguished on the basis of clinical patterns and gross features, but their histologic patterns have not been described. One hundred thirty patients were studied. Thirty-nine (24 males) had BD; 44 (38 males) FED; 15 (7 males) Marfan's syndrome (MS); and 32 patients (25 males) a non-determined degenerative disease. Histological changes of the resected segment of the valve were quantitatively evaluated using scores of severity. A discriminant analysis was performed. The groups defined by the computer were checked for concordance with groups defined by the surgeon. Collagen alterations were found the most severe in MS patients. BD and MS had the most myxoid infiltration. MS and FED patients had the most elastic fiber alterations. No BD in males and only one in females were misclassified by the discriminant procedure into the FED group. Overall, the percentages of correct matchings were 54% in males and 62% in females. When the age of patients and the size of ring were added to histology to determine whether this additional information provided more discrimination, the percentages of correct matchings reached 90% in males and 100% in females. BD and FED are two fairly distinct entities, which can be distinguished by quantitative histology, whereas only modest differences were found in qualitative histology.

Adolescent↗
PubMedDate not supplied

Assessing human cardiac allograft rejection using MRI with Gd-DOTA.

To explore the potential role of MRI in detecting cardiac allograft rejection in transplant recipients using gadolinium tetraazacyclododecane tetraacetic acid (Gd-DOTA) for contrast enhancement, we examined 7 normal healthy volunteers and 39 patients separated into three groups according to histological findings. Quantitative myocardial enhancement (ME), expressed as the ratio of maximum signal intensity after intravenous Gd-DOTA injection to signal intensity before intravenous injection of Gd-DOTA, was significantly lower for patients without histological rejection (n = 14; regional ME = 83 +/- 41%; mean ME = 53 +/- 24%) when compared with patients with grade 1 histological rejection (n = 18; regional ME = 122 +/- 20%, p = 0.02; mean ME = 70 +/- 14%, p < 0.05) and with patients with grade 2 or 3 rejection (n = 7; regional ME = 135 +/- 44%, p = 0.02; mean ME = 81 +/- 27%, p < 0.05). Myocardial enhancement was not significantly different in patients with grade 1 histological rejection compared with patients with grade 2 or 3 rejection. Because predominant focal areas of ME were observed in all patients, regional ME seemed a better measurement than mean ME to distinguish focal histological changes when the rejection process is beginning. More sophisticated software analysis is necessary to quantify and map high ME to establish the exact relationship between the extent of edema and the severity of rejection.

Adolescent↗
PubMedDate not supplied

Propafenone in the conscious dog with chronic atrioventricular block: mechanisms of chronotropic cardiac effects and plasma concentration-response relationships.

The chronotropic effects of propafenone were studied in the conscious dog with chronic atrioventricular block. Propafenone at 0.5-4 mg/kg, i.e., at plasma levels within the assumed therapeutic range, dose relatedly raises atrial rate. This effect falls off and bradycardia is even observed at 0.5 and 1 mg/kg once plasma levels have dropped below 330 +/- 31 ng/ml. After atropine, propafenone (2 mg/kg) lowers atrial rate, after propranolol it raises it, and after pindolol it does not modify it. Propafenone dose relatedly raises ventricular rate, although again this effect subsequently reverses at 4 mg/kg. After atropine, propranolol, and pindolol, propafenone (2 mg/kg) instead of initially raising ventricular rate lowers it lastingly. It initially lowers mean blood pressure according to dose. At 2 mg/kg neither this effect nor the plasma levels are modified by the antagonists. The beta-blocking potency is 1/40th that of propranolol as determined against isoproterenol-induced cardioacceleration. These results show that the atrial cardioacceleration due to propafenone results from direct and reflex vagolytic action and that the bradycardia at low plasma levels (buffered by the vagolytic effect at high levels) seems due to its membrane-stabilizing action. They also show that the initial ventricular cardioacceleration is a reflex response to its hypotensive effect, whereas the ventricular bradycardia at high doses is attributable to its membrane-stabilizing action and its albeit weak beta-blocking action.

Animals↗
PubMedDate not supplied

Selective cardiac hypothermia versus coronary perfusion. A study of ischemic complications in two series of 100 consecutive valvular patients.

Myocardial protection, in two parallel series of 100 consecutive valvular patients operated upon between June 1972 and July 1973 in Broussais Hospital, was afforded in two different ways: one withh hypothermic ischemia (H.I.) as it was advocated by N. Shumway, the other with coronary perfusion (C.P.) of a beating heart with consecutive ischemic periods limited to 20 minutes. Three parameters were used to evaluate the quality of protection: death with primary cardiogenic shock, post-operative myocardial infarction and acute cardiac insufficiency making it necessary to use post-operative inotropic support. Death was 1% (H.I.) and 5% (C.P.). Infarctions were 5% (H.I.) and 8% (C.P.). Acute cardiac insufficiency was: with cardiogenic shock 0% (H.I.) and 4% (C.P.), without cardiogenic shock 8% (H.I.) and 2% (C.P.). Peculiar aspects of myocardial infarction in each series are analyzed, and apparent absence of correlation between aortic cross-clamp time and ischemic complications is discussed. A "myocardial intrinsic factor" seems to be part of each valvular group and appears also to be an important factor in producing ischemic complications.

Adolescent↗
PubMedDate not supplied

[Circulatory assistance through cardiomyoplasty and aortomyoplasty. Experience and first clinical results].

The finding that skeletal muscles can be made resistant to fatigue by progressive electrical stimulation has been used as a means of providing circulatory support in cardiac surgery. The first application of this discovery was dynamic cardiomyoplasty, performed for the first time in man in 1985 at the Broussais Hospital, Paris. The latissimus dorsi muscle is transposed into the thorax, then attached around the heart and finally stimulated synchronously with the ventricular systole. So far, more than 200 patients in the whole world (including 57 at the Broussais Hospital) have undergone this operation with results that are increasingly encouraging. In these cases the muscle is used to reinforce or replace the left or right ventricle, but other applications are being studied, such as double cardiomyoplasty (left latissimus dorsi and right pectoralis major muscles), cardiomyoplasty of the right atrium and aortomyoplasty which produces aortic counterpulsation. The development of these techniques underlines the ever growing interest raised by this type of autologous circulatory support.

Assisted Circulation↗
PubMedDate not supplied

[Changes in the vascular wall induced by surgical glues. Experimental study].

The effects on vascular tissues of two different types of surgical glue, gelatin-resorcinol-formaldehyde (GRF) and fibrin (Tissucol) were tested on the rat abdominal aorta. The GRF glue induced destruction of the vascular wall: multiple inclusions of the glue were noted in the media. Conversely, the fibrin glue preserved the normal architecture of the three arterial layers. The use of GRF glue therefore should be avoided on particularly fragile tissues (e.g. coronary arteries), and it seems preferable in such cases to use the fibrin glue.

Animals↗
PubMedDate not supplied

Cardioprotective effect of trimetazidine during coronary artery graft surgery.

Reperfusion injury remains the most uncontrolled phenomenon during cardiac surgery. Potential myocardial protection by trimetazidine was tested in a double blind placebo controlled study on 19 patients undergoing aorto-coronary bypass surgery. The trimetazidine group was composed of 10 patients and the placebo group of 9 patients. Pretreatment was started three weeks before surgery with 1 tablet (trimetazidine 20 mg) t.i.d. and the same drug was added to the cardioplegic solutions (trimetazidine: 10(-6) M). The cross clamping time was 41.1 +/- 3.8 minutes in the trimetazidine group and 39.8 +/- 2.3 minutes in the placebo group. Metabolic measurements showed that the increase of malondialdehyde measured in the coronary sinus 20 minutes after reperfusion was significantly (p = 0.014) less in the trimetazidine group (from 1.60 +/- 0.11 to 1.79 +/- 0.2 mumol/L-1) than in the placebo group (from 1.17 +/- 0.11 to 2.84 +/- 0.58 mumol/L-1). Myosin was present 4 hours after surgery in all patients in the placebo group and in 5 of the 10 of the trimetazidine group (p = 0.036). Haemodynamic measurements showed that patients pretreated with trimetazidine had a better ventricular function, as assessed by the stroke work index (SWI) significantly (p = 0.01) higher in the trimetazidine group (0.0391 +/- 0.0029 g/min/m2/beta) than in the placebo group (0.0282 +/- 0.0026 g/min/m2/beat), the evolution of SWI during surgery was not significantly different between the two groups. Thus trimetazidine seems to reduce ischaemia-reperfusion damage during cardiac surgery; moreover pretreatment with trimetazidine allows the patient to face the operation with better ventricular function.

Blood Transfusion, Autologous↗
PubMedDate not supplied

Traumatic ventricular septal defects. Report of 3 cases with tricuspid valve rupture in 2 cases.

Traumatic ventricular septal defects (TVSD) are rare complications of cardiac trauma. This report describes 3 cases of TVSD secondary to penetrating trauma in 2 patients and to blunt trauma in one case. Echocardiography confirmed the diagnosis in all cases. Surgical correction was performed in the 3 cases. In 2 patients associated tricuspid trauma was present requiring tricuspid valve repair.

Adolescent↗
PubMedDate not supplied

MR tissue characterization of a right atrial mass: diagnosis of a lipoma.

A case of histologically confirmed benign lipoma of the right atrium is presented. Magnetic resonance imaging was successfully used to visualize and characterize the tumor previously detected by echocardiography. T1-weighted MR was superior to echocardiography and was in surgical agreement with examination in identifying the relationship of the lipoma to the right atrial wall, the coronary sinus, and the interatrial septum. Comparison of measurements of the tumor's signal intensities on T1- and T2-weighted images and T2 relaxation time with those of surrounding myocardium and mediastinal fat allowed a preoperative diagnosis of lipoma. Magnetic resonance may obviate surgical intervention in selected asymptomatic cases where the diagnosis of benign lipoma appears likely.

Aged↗
PubMedDate not supplied

[Circulatory assistance by aorto-ventricular shunt. A new implantation technique].

This technique is original in that it involves a single site (the ascending aorta) easily accessible to cannulation. Following lateral clamping of the ascending aorta, a bifurcate Dacron prosthesis is anastomosed. The draining cannula is introduced through one of the branches of the prosthesis and manually guided through the aortic sigmoid leaflets down to the left ventricular ejection outlet. The perfusion cannula is introduced through the outer branch of the prosthesis. The end of this cannula is positioned at the origin of the prosthesis to avoid a possible bend in the fork. This technique is a simple and effective means of providing left ventricular support.

Anastomosis, Surgical↗
PubMedDate not supplied

[Arterial hypertension in heart transplant recipients].

Arterial hypertension is frequent after cardiac transplantation. Since cyclosporin was introduced its incidence has risen up to 40 to 100 per cent of the patients. Its date of onset and severity are variable. Arterial hypertension acts on the heart by increasing left ventricular hypertrophy and transplant dysfunction and on the kidney by aggravating the cyclosporin-induced renal impairment which is often present. Several mechanisms have been suggested to account for the occurrence of hypertension in these patients, including poor neurological control of blood pressure, a hypothetical haemodynamic effect and the influence of corticosteroids and cyclosporin. Cyclosporin seems to play the main role. The treatment of this iatrogenic arterial hypertension remains to be precisely determined.

Adrenal Cortex Hormones↗
PubMedDate not supplied

[Ascending aortic ectasia. New reinforcement technique].

Enlargement of the ascending aorta associated with dystrophic aortic incompetence frequently progresses to aneurysm and its complications. This potential course can be prevented by using a simple technique including insertion of a Mersuture net covering the entire ascending aorta, associated with local application of gelatin-resorcin-formalin glue.

Adhesives↗
PubMedDate not supplied

[Surgical treatment of Prinzmetal's syndrome. Report of sixty operated cases (author's transl)].

The results of the surgical treatment of Prinzmetal's angina are reported in this study of 60 patients. The operative mortality is 3,3 percent and the incidence of post-operative infarction is 20 percent. 53 patients were followed over an average period of 2,7 years. The global survival rate is 91 percent at 5 years, the infarction rate is 24 percent. 76 percent of the sublims are asymptomac. The patients can be classified in three group : isolated lesions, multiple lesions and spasms.

Angina Pectoris↗
PubMedDate not supplied

Dynamic cardiomyoplasty: a new approach to assist chronic myocardial failure.

The concept of 'reconstructive cardiac surgery' using a stimulated autologous skeletal muscle has been investigated in this research. Our approach has been to investigate the substitution or reinforcement of a ventricular wall by a contractile tissue. The experiments have demonstrated the feasibility of this technique and the long-term adaptability and adequate electrophysiological properties of the Latissimus Dorsi flap transferred to a heterotopic position over the heart. Long-term biocompatible fatigue resistant muscle stimulation has become possible in experimental and clinical cases as a result of the development of specially designed electrodes and the use of a progressive sequential stimulation protocol to adapt the skeletal muscle to a cardiac support function. Autologous pericardium treated with glutaraldehyde was found to be a suitable material to close the ventricular cavity. Cardiomyoplasty with autologous skeletal muscle to restore ventricular contractility seems to be a valid alternative in addition to current methods of treatment for irreversible myocardial failure.

Animals↗