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F Alajmo

Publications and source records attributed to F Alajmo.

10 recordsLinked to original sources
PubMed1998

Effect of 5-HT4 receptor stimulation on the pacemaker current I(f) in human isolated atrial myocytes.

OBJECTIVE: 5-HT4 receptors are present in human atrial cells and their stimulation has been implicated in the genesis of atrial arrhythmias including atrial fibrillation. An I(f)-like current has been recorded in human atrial myocytes, where it is modulated by beta-adrenergic stimulation. In the present study, we investigated the effect of serotonin (5-hydroxytryptamine, 5-HT) on I(f) electrophysiological properties, in order to get an insight into the possible contribution of I(f) to the arrhythmogenic action of 5-HT in human atria. METHODS: Human atrial myocytes were isolated by enzymatic digestion from samples of atrial appendage of patients undergoing coeffective cardiac surgery. Patch-clamped cells were superfused with a modified Tyrode's solution in order to amplify I(f) and reduce overlapping currents. RESULTS AND CONCLUSIONS: A time-dependent, cesium-sensitive increasing inward current, that we had previously described having the electrophysiological properties of the pacemaker current I(f), was elicited by negative steps (-60 to -130 mV) from a holding potential of -40 mV. Boltzmann fit of control activation curves gave a midpoint (V1/2) of -88.9 +/- 2.6 mV (n = 14). 5-HT (1 microM) consistently caused a positive shift of V1/2 of 11.0 +/- 2.0 mV (n = 8, p < 0.001) of the activation curve toward less negative potentials, thus increasing the amount of current activated by clamp steps near the physiological maximum diastolic potential of these cells. The effect was dose-dependent, the EC50 being 0.14 microM. Maximum current amplitude was not changed by 5-HT. 5-HT did not increase I(f) amplitude when the current was maximally activated by cAMP perfused into the cell. The selective 5-HT4 antagonists, DAU 6285 (10 microM) and GR 125487 (1 microM), completely prevented the effect of 5-HT on I(f). The shift of V1/2 caused by 1 microM 5-HT in the presence of DAU 6285 or GR 125487 was 0.3 +/- 1 mV (n = 6) and 1.0 +/- 0.6 mV (n = 5), respectively (p < 0.01 versus 5-HT alone). The effect of 5-HT4 receptor blockade was specific, since neither DAU 6285 nor GR 125487 prevented the effect of 1 microM isoprenaline on I(f). Thus, 5-HT4 stimulation increases I(f) in human atrial myocytes; this effect may contribute to the arrhythmogenic action of 5-HT in human atrium.

Action Potentials↗
PubMed1990

[Mitral valve replacement with the Björk-Shiley monostrut prosthesis: a 4-year clinical experience].

Mitral valve replacement with Björk-Shiley monostrut prostheses was performed in 142 patients, aged 18 to 73 (mean age: 53.8). A group of 101 patients underwent isolated mitral replacement (group A), while both mitral and aortic (in one case tricuspid) valves were replaced in 41 (group B). In 19 of group A patients and in 9 of group B patients a tricuspid annuloplasty was added. Hospital mortality was one case in each group (group A: 1%; group B:2.4%). The cause of death was low output in both cases (i.e. not valve-related). Late mortality occurred in 4 cases (4%) in group A, and in 3 cases (7.3%) in group B (follow-up: 6 to 58 months; mean follow-up: 24 months). Actuarial survival was 93.79% in group A and 89.94% in group B one year after surgery; it was 93.79% in group A and 81.76% in group B after 3 years. All deaths from undetermined causes, as well as any new unexplained neurological deficit or peripheral emboli, were considered to be valve-related: 84.18% of group A patients, as well as 67.90% of group B, were event free after 3 year (actuarial). most valve-related events occurred in the first year after surgery. We observed thromboembolism in 3 cases for each group: one patient in group B had pannus formation over the prosthetic annulus; prosthetic valve endocarditis in 1 case of group A and 2 of group B; significant hemorrhage due to anticoagulant therapy in 1 (group A); one patient in each group died suddenly, 4 and 7 months postoperatively. One group A patient and 2 group B patients were reoperated: a new valve prosthesis was implanted in two patients. Mean transvalvular gradient, as determined by echocardiography, was 3.8 +/- 2.3 (SD) mmHg in the case of isolated mitral replacement. In conclusion, we believe these results are highly encouraging, especially in the isolated mitral replacement group. Björk-Shiley monostrut prosthesis has been demonstrated to be a reliable valve substitute, with an acceptable incidence of complications. No Björk-Shiley monostrut prosthesis structural deterioration was seen, and its hemodynamic behaviour may be considered satisfactory.

Actuarial Analysis↗
PubMed1989

High-dose aprotinin: hemostatic effects in open heart operations.

Two groups of patients were prospectively studied to evaluate the hemostatic effects of high-dose aprotinin in open heart operations. Group A patients (n = 22) received aprotinin during the entire surgical procedure. Group B patients (n = 12) served as controls. The groups were homogeneous for base variables and for cardiopulmonary bypass duration. Postoperative bleeding was lower in group A (mean, 486 mL) than in group B (830 mL) (p less than 0.01). The need for banked blood decreased by approximately half in the aprotinin patients (mean: group A, 213 mL; group B, 409 mL). Hemoglobin levels were similar in the two groups (postoperative day 7: group A, 11.29 g/100 mL; group B, 11.26 g/100 mL; NS). Platelet count decreased at the end of operation in both groups (99,000 and 95,000/mL, respectively; NS) and then increased beyond baseline levels before discharge. No complications were observed that could be attributed to aprotinin. In conclusion, we believe that the use of high-dose aprotinin is safe and effective. It decreases blood loss and reduces the need for banked blood in cardiac operations, particularly in select groups of patients (eg, those undergoing reoperation, Jehovah's Witnesses, those with renal failure).

Adult↗
PubMed1988

[Compliance problems in the oral anticoagulant treatment of patients wearing heart valve prostheses].

The need for and the efficacy of oral anticoagulation in patients who have undergone prosthetic valve replacement is widely demonstrated. The aim of this study is to assess how dicumarolic treatment is understood and actually accomplished by patients. A 30-question form was sent to 292 patients discharged following valve replacement, 5 to 45 months (mean: 19 months) after surgery. All of the 220 patients who submitted their answers, were effectively on oral anticoagulants. More than 95% of them knew exactly the suggested optimal prothrombin activity range. About one fifth of the patients has laboratory tests performed weekly, and nearly one half does so every 10-15 days. One fourth of the patients does not consult a physician for decision making about drug dosage. Difficulties in maintaining anticoagulation in the desired range, occurring at least once every month, are reported by 18.6% of patients. Haemorrhage was never experienced by 83.18%; in one single case thromboembolism was apparent. A few patients (2.27%) think of oral anticoagulation as a "difficult" treatment. We conclude that complete information is needed, about the aim, the modality, and the potential hazard of oral anticoagulation, so that a better understanding of the treatment and an improved cooperation between physicians and patients can result in benefits, in terms of the safety and efficacy of life-long antithrombotic therapy.

Administration, Oral↗
PubMed1980

[Epicardial pacing: clinica evaluation and comparison with transvenous pacing (author's transl)].

Clinical experience with permanent epicardial pacing during a five year-period in our centre is presented. The report is based on 37 epicardial and 656 transvenous pacemaker implantations. Intraoperative and early postoperative mortality were absent in the epicardial pacing group. Late hospital mortality, morbidity and electro-mechanical complications were less than with transvenous pacing. Among the complications peculiar to the epicardial pacing technique, we observed 3 cases of breakage of a lead, at the level of its epicardial connection. We conclude that the use of epicardial leads represents a safe and effective technique of cardiac pacing.

Adult↗
PubMedDate not supplied

A rare complication of mitral valve replacement. Intraoperative fracture of the right fibrous trigone following a superior approach to the left atrium. Case report.

A rare complication of mitral valve replacement is reported. Following a superior approach, through the roof of the left atrium the mitral valve was replaced with a Björk-Shiley prosthesis in a 52-year-old female, who had undergone previous closed commissurotomy. Fracture of the right fibrous trigone occurred at surgery, following the completion of mitral valve replacement. The lesion was successfully repaired on cardiopulmonary bypass under cardioplegic arrest, placing sutures, after an oblique aortotomy, from below the noncoronary aortic cusp. The postoperative course was uneventful, without occurrence of a-v block. We believe that a superior approach to the left atrium may be a valid alternative for mitral valve surgery in some selected cases.

Female↗
PubMedDate not supplied

Partial anomalous pulmonary venous return of an uncommon type.

We report a rare case of complete anomalous venous return from the right lung to the supradiaphragmatic part of the inferior vena cava, associated with sinus venosus atrial septal defect. The defect was corrected with direct reimplantation of the anomalous venous trunk into the left atrium and direct suture of the ASD. A good operative result was obtained. As a great variety of associative patterns between partial APVR and ASD exists in literature, we outline the necessity of an accurate pre- and intra-operative diagnosis, in order to achieve the most satisfactory surgical result.

Child, Preschool↗