The Effect of Paroxetine on Ouabain-Induced Toxicity in Isolated Guinea Pig Atria

It has been reported that selective serotonin reuptake inhibitors (SSRIs) possess some cardiac effects. In the present study we have investigated the effect of paroxetine (PX), a potent SSRI agent, on spontaneously as well as ouabain-induced arrhythmia beating isolated guinea-pig atria. The Guinea-pig heart was rapidly removed; the auricles were dissected out in oxygenated modified Krebs solution. The rate and force of spontaneous contractions were recorded isometrically with a photosensitive transducer. PX (1-16 µg/ml) caused a dose-dependent decrease in the rate of contractions (14-70%) and contractile force (8-16%). Ouabain alone (1.2 µg/ml) produced arrhythmia at 7.2 ± 1.5 min and asystole at 20.1 ± 3.1 min. Pretreatment with PX (4 µg/ml) significantly increased the time of arrhythmia onset to 19.8 min. In addition, PX prolonged the duration of action beating from 20.1 ± 3.1 min to 43.1± 2.6 and delayed the occurrence of asystole. The pattern of contractile force by PX + ouabain treatment was more regular than that observed after administration of ouabain alone. The above findings may the probably be due to the inhibition of cardiac Na+ and Ca2+ channels or autonomic nervous system. Results also suggest that PX may reduce the membrane conductance through inhibition of ionic channels to prevent ouabain-induced arrhythmia

Knowledge Management in Cardiac Surgery: The Second Tehran Heart Center Adult Cardiac Surgery Database Report

Background: The Adult Cardiac Surgery Databank (ACSD) of Tehran Heart Center was established in 2002 with a view to providing clinical prediction rules for outcomes of cardiac procedures, developing risk score systems, and devising clinical guidelines. This is a general analysis of the collected data. Methods: All the patients referred to Tehran Heart Center for any kind of heart surgery between 2002 and 2008 were included, and their demographic, medical, clinical, operative, and postoperative data were gathered. This report presents general information as well as in-hospital mortality rates regarding all the cardiac procedures performed in the above time period. Results: There were 24959 procedures performed: 19663 (78.8%) isolated coronary artery bypass grafting surgeries (CABGs); 1492 (6.0%) isolated valve surgeries; 1437 (5.8%) CABGs concomitant with other procedures; 832 (3.3%) CABGs combined with valve surgeries; 722 (2.9%) valve surgeries concomitant with other procedures; 545 (2.2%) surgeries other than CABG or valve surgery; and 267 (1.1%) CABGs concomitant with valve and other types of surgery. The overall mortality was 205 (1.04%), with the lowest mortality rate (0.47%) in the isolated CABGs and the highest (4.49%) in the CABGs concomitant with valve surgeries and other types of surgery. Meanwhile, the overall mortality rate was higher in the female patients than in the males (1.90% vs. 0.74%, respectively). Conclusion: Isolated CABG was the most prevalent procedure at our center with the lowest mortality rate. However, the overall mortality was more prevalent in our female patients. This database can serve as a platform for the participation of the other countries in the region in the creation of a regional ACSD

Evaluating the Potential Effect of Melatonin on the post-Cardiac Surgery Sleep Disorder

Background: Postoperative neurological injuries, including cognitive dysfunction, sleep disorder, delirium, and anxiety, are the important consequences of coronary artery bypass graft surgery (CABG). Evidence has shown that postoperative sleep disturbance is partly due to disturbed melatonin secretion in the perioperative period. The aim of this study was to evaluate the effect of melatonin on postoperative sleep disorder in patients undergoing CABG. Method: One hundred forty-five elective CABG patients participated in a randomized double-blind study during the preoperative period. The patients were randomized to receive either 3 mg of melatonin or 10 mg of Oxazepam one hour before sleep time. Each group received the medication from 3 days before surgery until the time of discharge. Sleep quality was evaluated using the Groningen Sleep Quality Score (GSQS), and the incidence of delirium was evaluated by nursing records. Sleep quality and anxiety scores were compared before and after surgery through the Wilcoxon signed-rank test. The analysis of covariance (ANCOVA) and independent t-test were used to compare the sleep and anxiety scores between the groups. P values ≤ 0.05 were considered statistically significant. Results: Totally, 137 patients at a mean age of 60 years completed the study (76% male). The analysis of the data showed that sleep was significantly disturbed after surgery in both groups. The patients in the Oxazepam group demonstrated significantly higher disturbance in their mean postoperative GSQS score than did their counterparts in the melatonin group (p value < 0.001). A smaller proportion of the participants experienced delirium in the melatonin group (0.06%) than in the Oxazepam group (0.12%); however, this difference was not statistically significant. Conclusion: The result of the present study revealed that melatonin improved sleep in post-cardiac surgery patients more than what was observed with Oxazepam. Therefore, melatonin may be considered an effective alternative for Benzodiazepines in the management of postoperative sleep disorder