The responses of the carotid baroreflex and of the peripheral sympathetic system to stimulations induced by either lower body negative pressure (LBNP -40 mmHg) or cold pressor test were investigated ...in eight volunteers before and after 48 h in the -6 degrees head-down tilt (HDT).
Geometry (diastolic diameter and pulsatile distention) and dynamics (cross-sectional compliance and tangential tension) of the bulb and the common carotid artery were investigated using ultrasonic devices, echotracking and aplanation tonometry. The activity of the sympathetic system was evaluated through measurements of plasma concentrations of catecholamines (CAs) and 3,4-dihydroxyphenyl glycol (DHPG).
During LBNP -40 mmHg, the pulsed tangential tension was decreased and the pressure amplification, induced by the reflexion of the pressure wave, was increased with no difference between before and after HDT. Since cross-sectional compliance and distensibility coefficient remained unchanged and the carotid contour of the waveform unaltered, it is concluded that the carotid reflexogenic area reads the same message during LBNP whether the cardiovascular system was deconditioned or not. Nonetheless, during LBNP after 48 h HDT, the heart rate accelerated faster and CAs and DHPG concentrations increased out of proportion, suggesting that the peripheral sympathetic activity was more reactive after HDT than before. Finally, forearm vascular resistances were measured in response to cold pressor test; they increased in the same proportion after HDT when compared with before.
Results indicate that the carotid baroreflex and the peripheral sympathetic system were not deficient after 48 h HDT.
Percutaneous mitral valvuloplasty Vahanian, A; Michel, P L; Trabelsi, S ...
Annales de médecine interne,
1987, Letnik:
138, Številka:
8
Journal Article
Recenzirano
Thirty six adults with severe mitral stenosis underwent attempted percutaneous mitral commissurotomy. The valvuloplasty could not be performed in 6 cases; post-transseptal haemopericardium (1 case), ...inability to cross the mitral valve or the septum (5 cases). Therefore percutaneous commissurotomy was performed in 30 cases; the average age was 43 +/- 17 years (range 20-79 years). Eight patients had undergone previous valve surgery; 24 patients were very symptomatic (NYHA Classes III or IV). The valvuloplasty was performed with a single balloon in 22 cases and by simultaneous inflation of two balloons in 8 cases. Moderate mitral regurgitation present before the procedure was significantly aggravated in 2 cases leading to secondary surgery. In the other patients percutaneous commissurotomy led to a clear-cut haemodynamic improvement; the transvalvular pressure gradient fell from 15 +/- 4 to 6 +/- 2 mm Hg, p less than 0.01 and mitral valve surface area increased from 1.1 +/- 0.2 to 2.2 +/- 0.4 cm2, p less than .001. The best results were obtained with the double balloon technique in patients with little valve destruction. Percutaneous mitral valvuloplasty is therefore a tempting alternative to closed heart mitral commissurotomy in pure mitral stenosis with pliable valves. Larger series with a longer follow-up are needed to assess the morbidity and long-term results of this technique.
To assess the feasibility of percutaneous mitral commissurotomy, we undertook dilatation of mitral stenosis in 26 adults. The procedure was unsuccessful in six patients (hemopericardium in one, and ...five failures). In 20 patients (mean age: 41 +/- 13 years) the procedure was successful. We used a single balloon (Trefoil 3 X 12 mm) in eight patients and two balloons in 12 (Trefoil 3 X 10 mm + 19 mm). After valvuloplasty, valve function was improved: the mean transvalvular gradient decreased from 14 +/- 4 mm Hg to 7 +/- 2 mm Hg (P less than 0.001) and valve area increased from 1.1 +/- 0.2 cm2 to 2.2 +/- 0.4 cm2 (P less than 0.01). In a patient with severe valvular and subvalvular disease, mitral regurgitation increased from grade I to grade III. From this preliminary series, we conclude firstly that percutaneous valvuloplasty is feasible in adults with mitral stenosis, and secondly, that it results in a significant improvement in valve function with a low incidence of complications.
The cross-reactivity of the PGI
3 metabolite, Δ17-6-keto-PGF
1α, with antibodies against 6-keto-PGF
1α for radioimmunoassays (RIA) has been investigated. Δ17-6-keto-PGF
1α was obtained either from ...commercial sources or after its purification from endothelial cells. In the latter case, primary cultured bovine aortic endothelial cells were incubated for 20 min at 37°C with 10 μM eicosapentaenoic acid (EPA) in the presence of 2 μM 13-hydroperoxy-octadecadienoic acid, an activator of the EPA cyclooxygenation, and the 6-keto-PGF
1α and Δ17-6keto-PGF
1α produced were separated by RP-HPLC. Then, cross-reactivities of the commercial and purified Δ17-6-keto-PGF
1α with 6-keto-PGF
1α antibodies were determined and found not to exceed 10%. In addition, the amounts of prostacyclin-related compounds detected by direct measurements in media of cells loaded with EPA were compared with those obtained after purification of 6-keto-PGF
1α. In accordance with the cross-reactivity data, we found that RIA in media mainly measured 6-keto-PGF
1α, the Δ17-6-keto-PGF
1α formed being undetected at 90%. It is concluded that 6-keto-PGF
1α antibodies generally used for RIA of 6-keto-PGF
1α are highly specific since they can discriminate a metabolite bearing an additional double bond such as the PGI
3 metabolite Δ17-6-keto-PGF
1α.
Between February, 1986 and October, 1987 percutaneous aortic valvuloplasty was attempted in 78 patients: 25 men (32 p. 100) and 53 women aged from 61 to 89 years (mean 79.5 years). All patients were ...symptomatic; 9 were in class II, 49 in class III and 20 in class IV of the NYHA classification. The decision to try percutaneous valvuloplasty was determined by the high surgical risk associated with age (over 75 in 87 p. 100 of the patients), poor physiological condition or concurrent pathology, or by refusal of surgery. 70 dilatations could actually be made (90 p. 100) either by the brachial route (n = 39) or the femoral route (n = 18) or the transseptal route (n = 7) or by a combined brachial and femoral route which enabled the double balloon technique to be used (n = 6). The procedure comprised 5.6 +/- 3 inflations and lasted for 58 +/- 29 min. The diameter of the largest balloon utilized was greater than 20 mm in 75 p. 100 of the cases. Dilatation reduced the aortic gradient from 62 to 28 mmHg (p less than 0.001) without altering the cardiac index (2.36 to 2.32 l/min/m2) and significantly increased the aortic valve area from 0.49 to 0.76 cm2 (p less than 0.001). At the end of the procedure the aortic valve area was greater than 0.7 cm2 in 63 p. 100 and greater than 1 cm2 in 14 p. 100 of the patients. Five patients had to be operated upon within the month following dilatation (3 after technical failure, 2 for poor functional results).
The results of percutaneous mitral valvuloplasty in 5 adult patients with mitral stenosis are presented. The average age was 55 years (37-72 years); 4 patients were in functional Class III and 1 in ...Class IV. The three oldest patients were in atrial fibrillation, and 2 of them had severe valvular and subvalvular lesions. Valvuloplasty was carried out with a "Trefoil" balloon (3 X 12 mm; effective cross sectional area at maximal inflation: 3.8 cm2). The procedure was successful in 4 patients. In the other patient, it was not possible to position the balloon across the stenotic valve. After valvuloplasty, the mean mitral gradient decreased (14 +/- 5 to 6 +/- 2 mmHg, p less than 0.05) without a significant change in cardiac index (2.9 +/- 0.5 vs 2.7 +/- 0.4 l/mn/m2; NS): this indicated an increased mitral valve surface area (1.1 +/- 0.2 to 1.8 +/- 0.05 cm2, p less than 0.05). In parallel, echocardiographic measurements of mitral valve surface area increased from 0.9 +/- 0.2 to 1.8 +/- 0.3 cm2, p less than 0.05, and Doppler pressure halt time fell from 220 +/- 50 to 116 +/- 13 ms, p less than 0.05. There were no operative complications and, in particular, no resulting angiographic mitral regurgitation. These preliminary results suggest that percutaneous mitral valvuloplasty may be a valuable alternative therapeutic procedure to surgery in selected patients.
In order to evaluate the effectiveness and risks of percutaneous mitral commissurotomy (PMC), we tried this procedure in 130 patients. Nine attempts were unsuccessful due to pre-PMC complications ...(haemopericardium 2, air embolism 1) or to technical failure (6 cases, 5 of which occurred in the first 15 attempts). PMC could be performed in 121 patients: 88 women and 33 men aged from 13 to 79 years (mean 42 + 15 years); 22 patients had previously been operated upon, 5 had a history of embolism, 99 were in functional stage III or IV. Echocardiography divided these patients into 3 groups: 29 had calcified leaflets (group 1), 42 had flexible leaflets and little alteration of the subvalvar system (group 2), and 49 had flexible leaflets with alteration of the subvalvar system (group 3). Mitral regurgitation grade 1/4 was present in 32 cases. PMC was performed with one balloon (Trefoil 3 x 12 mm) in 14 patients and therafter with two balloons (Trefoil 3 x 10 mm plus conventional 15 or 19 mm balloon) in 107 patients. PMC resulted in significant improvement in haemodynamic values: the mean capillary pressure fell from 20 +/- 7 to 11 +/- 5 mmHg (p less than 0.0001) and the mean mitral gradient from 16 +/- 6 to 6 +/- 2 mmHg (p less than 0.0001), while the cardiac index rose from 2.7 +/- 0.6 to 3.1 +/- 0.7 l/mn/m2 (p less than 0.001) and the mitral valve area (MVA) from 1.1 +/- 0.2 to 2.2 +/- 0.5 cm2 (p less than 0.0001).
163 patients aged from 27 to 70 years (mean 52 +/- 10 years), including 152 men and 11 women, received a thrombolytic treatment within the first 6 hours (mean 192 +/- 73 mn) of a myocardial ...infarction. 61 patients received streptokinase (SK) intravenously (group 1), 64 patients, single-chain rt-PA (group 2), 11 patients, two-chain rt-PA (group 3), 11 patients, rt-PA followed by intracoronary streptokinase (group 4), and 16 patients, acyl enzyme (group 5). In addition, all patients had heparin and 86 (53%) had aspirin. Immediately after thrombolysis, coronary arteriography was performed in 95 patients (58%), and this was followed by transluminal angioplasty in 49 of them (30%). The infarction was either anterior (n = 81) or inferior (n = 78) or lateral (n = 4). No fatal or neurological bleeding occurred. 17 haemorrhagic complications were observed; 5 of these (3%) were severe, requiring blood transfusion and, in 1 case, surgery; 12 were significant (7.4%) and produced changes in haematocrit. Nine of the 17 haemorrhages were associated with catheterization and localized to the site of arterial puncture. Severe bleeding occurred in patients treated with intravenous SK (3/61) or with rt-PA followed by intracoronary SK (2/11). There was a significant difference in the incidence of spontaneous bleeding between the SK group (4/61) and the single-chain rt-PA group (0/64; p less than 0.05). In the latter group, the minimum fibrinogen level was lower in patients who had a haemorrhagic complication.
