Tehran University Medical Journal

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Atrial septal anomalies suggested to play important role in enhancing tendency to induce cerebral embolic events. This study was undertaken to find the frequency of atrial septal anomalies including Patent Foramen Ovale, Atrial Septal Aneurysm and Atrial Septal Defect in patients with etiologically unknown stroke categorized as cryptogenic.
Materials and Methods: 32 patients were studied by transthoracic and transesophageal echocardiography.
Results & Conclusion: The mean age was 50.2 years and standard deviation 10.9 years. 17 patients were male and 15 females, of them 40.6 percent had Patent Foramen Ovale, 15.6 percent had Atrial Septal Aneurysm and 6.3 percent had Atrial Septal Defect. 60 percent of patients who had Atrial Septal Aneurysm had also Patent Foramen Ovale.

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Background: Adenosine receptors play an important role in the treatment of paroxysmal supraventricular tachycardia in cardiovascular system. This effect is through interaction with A1 type of G-protein-coupled adenosine receptors. The effect of N6-cyclopentyladenosine (CPA), an A1-selective adenosine agonist, was studied on ouabain-induced toxicity in spontaneously beating isolated guinea pig atria.

Methods: In the beginning the isolated guinea pig atria were mounted on the organ bath containing modified krebs and contractile responses in the four groups (shame, CPA, ouabain, CPA- ouabain) were measured.

Results: CPA (2-16nM) produced a dose-dependent decrease in the force of contractions (34%-51%) and in the rate of contractions (22%-48%). CPA significantly increased the time of onset of arrhythmia (toxicity) induced by ouabain (1.2µM) when it was administered 10 min before ouabain was added in organ bath. Ouabain (1.2µM) alone produced arrhythmia at 7 min and either asystole or standstill at 22 min. CPA (8nM) increased the time required to produce arrhythmia to 27.5 min and prolonged beating atria to more than 63 min and prevented the occurrence of asystole.

Conclusion: CPA produces direct cardiac action, probably due the inhibition of cardiac Ca²⁺ channel and membrane hyperpolarization of atrium cells in guinea pig atria. Moreover, our results suggest that CPA may reduce the membrane conduction through inhibition of ionic channels, which decrease ouabain- induced toxicity.

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Background: Studies of the association between post operative AF and Plasma level of NT- Pro BNP have reported conflicting findings. The aim of the present study was evaluation of the association between post coronary bypass graft- Atrial Fibrillation (AF) and Plasma level of NT- ProBNP as an independent risk factor of AF development in patients undergoing coronary artery bypass graft.

Methods: In a cohort study, 79 patients with sinus rhythm who admitted in Imam Khomeini Hospital in Tehran, Iran, during February 2009 and February 2010 for CABG are included the study and followed for developing post operative AF rhythm.

Results: Post operative AF was found in 17.7% of patients. The peak time from the operation to the first AF episode was in second post op day in ten patients (71.4%). The serum level of ProBNP in patients with AF was significantly higher (1624± 647 versus 221± 238 pg/ml, p< 0/0001). Increased age, Increased LA size and high plasma level of ProBNP were associated with increased risk for post op AF. After adjustment of risk factors, plasma level of ProBNP was the most important risk factor with odds ratio of 15.34 with CI 95% 1.77-132.95 and then LA diameter with odds ratio of 6.11 with CI 95% 0.99-37.42 was independently correlated with post op AF. Correlation between plasma level of ProBNP with age and LA size was seen too (LA size r = 0.0281, p= 0.012). Between age and ProBNP (r= 0.337, p= 0.002). The best cut off point for plasma ProBNP as a predictor of post op AF was 854 pg/ml.

Conclusion: Increased level of preoperative ProBNP levels could be an independent predictor of post operative Atrial Fibrillation.

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Background: Atrial fibrillation is the most common but benign arrhythmia following cardiac surgery. Although this arrhythmia is often self-limited and vanishes in about 24 hours upon surgery a number of arrhythmias might ensue among which some might be really life-threatening. A multitude of therapeutic modalities have been proposed for the prevention of this arrhythmia and one of them is posterior pericardiotomy. This method has not been fully accepted by the peers yet and more studies are needed to prove its efficacy and benefits to the patients. Methods: In this single-blind randomized clinical trial, done over a 2-year period from February 2009 to January 2011, the effects of posterior pericardiotomy were evaluated in 174 patients (87 the case and 87 the control groups) undergoing elective coronary artery bypass grafting (CABG). The case group underwent CABG with posterior pericardiotomy while the control group underwent CABG-only operation. The postoperative incidence of arrhythmia, especially atrial fibrillation, was assessed for a week using statistical methods. Results: The prevalence of postoperative atrial fibrillations were fewer in the group undergoing CABG with posterior pericardiotomy compared with the CABG-only group (P<0.004). Conclusion: Posterior pericardiotomy seems to reduce the incidence of atrial fibrillation following elective CABG therefore, its application is suggested for elective CABGs

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Background: In recent years, consumption of whole-blood for the treatment of patients has decreased but use of biological plasma-derived medicines such as albumin, immunoglobulin and coagulation factors have increased instead. Paying attention to albumin molecular structure is important for its isolation from human plasma. Albumin is a single-chain protein consisting of about 585 amino acids and a molecular weight of 66500 Daltons. Albumin is a stable molecule and it is spherical in shape. There are different methods for human albumin preparation. Considering the large consumption of this biological drug in clinical settings, methods with fewer steps in production line are of big advantage in saving time and manufacturing more products.

Methods: In this project, we prepared human albumin using hollow fiber cartridges in order to omit the rework on fraction V+VI. Human albumin is usually produced by the application of cold ethanol method, where albumin is obtained from fraction V by doing a rework on fraction V+VI to separate fraction V.

Results: In the current work, human albumin was prepared from fraction V+VI by the help of hollow fiber cartridges. With a concentration of 20%, the obtained albumin had 96.5% of monomer and 3.5% of polymer and polymer aggregate.

Conclusion: Comparing the obtained human albumin with a number of commercial human albumin samples by the use of SDS-page, the results were satisfactory regarding the 3.5 percent polymer and aggregate rate for the prepared albumin.

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Background: Nowadays, the treatment of choice for anatomical correction of transposition of great arteries is arterial switch but some children are not good candidates for this operation. In these cases atrial switch or Senning procedure is an accepted method, thus outcome of this procedure needs to be better delineated.

Methods: This prospective study included 65 patients that underwent Senning operation in Shahid Rajaee Hospital in Tehran, Iran from 2002 to 2009 and were followed-up for one year.

Results: The early and late mortality rates were 16.9% and 1.5%, respectively. 51.8% of early deaths were due to simple Senning procedure, 38.9% due to a Senning with the closure of ventricular septal defect, with or without the repair of pulmonary artery stenosis, 9.3% related to palliative Senning and one late death due to simple Senning. The most common arrhythmia was accelerated junctional rhythm (18.5%). 15% of cases had Senning pathway obstruction and 1.7% had baffle leaks. Regardless of the mortalities, three patients (5.7%) had significant tricuspid regurgitation. Right ventricular systolic dysfunction was found in 13.3% of the cases, primarily in Senning with ventricular septal defect closure (37.5%). One case (1.9%) had visible cyanosis and three (5.7%) had exertional dyspnea but 94.3% of cases remained in functional class I.

Conclusion: Since the majority of deaths following Senning procedure occur during the first month, especially on the second day post-operatively, assiduity during early post-operative period is crucial. Tricuspid regurgitation or right ventricular systolic dysfunction was not detected in most patients, suggesting optimistic prognosis for these patients.

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Background: It is generally accepted that the selective adenosine triphosphate-dependent potassium channel openers (KATP openers) have a dramatic role in the treatment of some cardiovascular disorders. The aim of this study was to investigate the effects of diazoxide, a potent ATP-related potassium channel opener, on spontaneously beating isolated rat atria to achieve more accurate approaches to treat cardiovascular diseases, such as atrial related disorders including atrial arrhythmias.
Methods: After induction of anesthesia, we exsected the heart and isolated the atria of 48 male Wistar rats. Later, we recorded the beating and contractile force of the atria by a physiograph. Subsequently, we studied the effects of diazoxide (2 to 100 µg/mL) on beating and contractile force of the isolated atria 5, 10, 15 and 20 minutes after applying the drug onto the atria.
Results: Diazoxide administration (2 to 100 µg/mL) showed a significant decrease (7% to 49% depending on concentration) in atrial beatings (P≤0.001) and in contractile force (1.5% to 67% depending on concentration), (P≤0.001). The effects began several minutes after applying the drug onto the tissues.
Conclusion: This study revealed that diazoxide has a direct concentration-dependent effect on cardiac performance and leads to reduction in beating rates and contractile force of the heart. This effect seems to be related to the activation of mitochondrial or sarcolemmal KATP channels. Since the inhibitory action of diazoxide on the heart was very remarkable and prompt, this agent may also exhibit antiarrhythmic properties.

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Background: The 3-hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) reductase inhi-bitors (statins) have revolutionized the treatment of hypercholesterolemia. Some evide-nce indicated the role of nodal refractoriness and concealed conduction in anticipating the ventricular rate during atrial fibrillation. Recent evidence has indicated that statins can reduce the incidence of both supraventricular and ventricular arrhythmias. The aim of the present study is to investigate adenosine A1 receptor role on simvastatin protecti-ve effects on atrioventricular nodal properties in isolated atrial fibrillation model of rabbit heart.
Methods: The present study was performed in cardiovascular research center of Golestan University of Medical Sciences in 2012. Recovery and atrial fibrillation protoc-ols were used to study electrophysiological properties of atrioventricular node in 5 groups of male Newsland rabbits (n=40). Extracellular recording was carried out from transitional cells of posterior and anterior extension of AV-node and upper part of atrium and its bundle. All stimuli protocols repeated in the presence of adenosine A1 receptor agonist and antagonist (dipridamole and CPX) alone or with simvastatin on isolated perfused atrio-nodal preparation. Extracellular field potential recording was sampled during specific stimulation protocols.
Results: Significant inhibition was observed in basic node properties such as wencke-bach prolongation, functional refractory period, effective refractory period and atriove-ntricular node conduction time with simvastatin (P<0.05). Simvastatin prolonged His-His interval and increased number of concealed beat in atrial fibrillation protocol (P<0.05). The simvastatin protective effects on atrioventricular nodal properties were intensified by dipridamole as an adenosine A1 receptor agonist (P<0.05), but CPX as an adenosine A1 receptor antagonist could only dampen them (P>0.05).
Conclusion: Our results showed that the use of adenosine agonist increased simvastatin effects on electrophysiological properties of atrioventricular node, but its antagonist could not prevent these effects. This may indicate simvastatin protective mechanism on atrioventricular node electrophysiological properties without adenosine direct involve-ment.

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Background: Atrial fibrillation is the most common arrhythmia after cardiac surgery. Vitamin C as an antioxidant has an important role in reducing the incidence of postop-erative atrial fibrillation. The present study aimed at administrating vitamin C as a way to reduce the incidence of post-CABG atrial fibrillation. Methods: In this double-blind, parallel clinical trial, 170 patients with coronary artery disease who underwent CABG surgery, by using a table of random numbers are di-vided into intervention and control groups to receive placebo or vitamin C. The clinical and surgical characteristics of the patients in the two groups were similar. The interven-tion group received 2 mg of vitamin C intravenously, the night before surgery. This drug followed by 500 mg, twice a day for five days after surgery. On the other hand patients in the control group received placebo (normal saline intravenously). After operation two groups were compared regarding Important outcomes such as postoperative arrhythmia, ICU stay and hospital stay. Results: One hundred eighteen men and fifty two women with a mean age of 59.1±9.8 years were enrolled in the study in two vitamin C and placebo groups (each consisting of 85 patients). The incidence of postoperative atrial fibrillation was 12.9% in the vita-min C group and 29.4% in the control group (P=0.009). ICU stay in the vitamin C group were 2.5±1.4 days versus 3.0±1.6 days in controls (P=0.035) and hospital stay in the vitamin C group were 6.6±1.5 days versus 8.2±2.3 days in controls (P<0.001). Conclusion: Vitamin C is relatively safe, inexpensive, well tolerated and has a low complication. According to the 44% reduction in the incidence of atrial fibrillation in vitamin C patients undergoing coronary artery bypass grafting surgery, this drug can be prescribed as a prophylaxis for prevention of post-CABG atrial fibrillation.

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Background: The occurrence of Atrial Fibrillation (AF) is linked to an increased inflam-matory response after cardiac surgery that is significantly decreased by anti-inflammatory treatments. The present study aimed at administrating Colchicine as a way to reduce the incidence of post- Coronary Artery Bypass Graft (CABG) atrial fibrillation. Methods: In this double-blind, parallel clinical trial, 216 patients with coronary artery disease who underwent CABG surgery, by using a table of random numbers are divided into intervention and control groups to receive placebo or Colchicine. The clinical and surgical characteristics of the patients in two groups were similar. The intervention group received 1.0 mg of Colchicine tab, the night before surgery and on the morning of surgery. This drug followed by 0.5 mg twice a day for five days after surgery. On the other hand patients in the control group received only placebo (ineffective pill with similar size to Colchicine). After operation two groups were compared regarding important outcomes such as postoperative arrhythmia, ICU stay and hospital stay. The data were assessed using SPSS software (version 17) and t-test and 2 statistical tests. Results: One hundred fifty six men and sixty women with a mean age of 59.9±9.3 years were enrolled in the study in two Colchicine and placebo groups (each consisting of 108 patients). The incidence of postoperative atrial fibrillation was 14.8% in the Col-chicine group and 30.6% in the control group (P= 0.006). ICU stay in the Colchicine group were 2.4±1.3 days versus 3.1±1.5 days in controls (P< 0.001) and hospital stay in the Colchicine group were 6.6±1.5 days versus 8.1±2.0 days in controls (P< 0.001). Conclusion: Colchicine is an anti-inflammatory medication and has very few side effects at low doses. According to the 48% reduction in the incidence of atrial fibrillation in Colchicine patients undergoing coronary artery bypass grafting surgery, this drug can be prescribed as a prophylaxis for prevention of post-CABG atrial fibrillation.

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Background: Atrial fibrillation (AF) is the most common arrhythmia after cardiac surgery. AF leads to longer duration of hospitalization, thromboembolism, and impaired hemodynamics after heart surgery. One of the most important causes of postoperative AF, inflammation, and oxidative stress status. For this reason, it is useful to control the dysrhythmia. Coenzyme Q10 (CoQ10) as an antioxidant that has an important role in reducing the incidence of postoperative AF. The present study aimed at administering CoQ10 as a way to reduce the incidence of post-CABG atrial fibrillation. Methods: In this double-blind randomized controlled trial study, 80 patients with coronary artery disease who underwent coronary artery bypass graft surgery (CABG) in Rajaie Cardiovascular, Medical and Research Center from April to November 2014, randomized are divided into intervention and control groups to receive placebo or CoQ10 The surgical characteristics of the patients in two groups were similar. The intervention group will receive the oral CoQ10 supplement 150 mg/d for 7 days before surgery. After operation two groups were compared regarding important outcomes such as postoperative arrhythmia, intensive care unite (ICU) stay and hospital stay. Atrial arrhythmias are considered significant If more than 10 minutes duration atrial and with a shorter duration of arrhythmia, but with recurrence again. Results: Thirty-eight women and forty-two men with a mean age of 58.37±7.98 years were enrolled in the study in two CoQ10 and placebo groups (each consisting of 40 patients). The incidence of postoperative AF was 45% in the control group to 20% in the intervention group decreased after supplementation (P=0.030). ICU stay and length of in-hospital stay did not significant. The incidence of arrhythmias ventricular tachycardia (VT) and VF in this period was not significant (P=0.865). Conclusion: Q10 supplements have low side effects. Due to the reduction in the incidence of AF in patients after, CABG, these supplements can be recommended for the prevention of AF.

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Background: Recently, the role of inflammation and oxidative stress in the pathophysiology of atrial fibrillation (AF) after cardiac surgery has been emphasized. Vitamin C as an antioxidant important role in reducing the incidence of postoperative atrial fibrillation. This study aimed to investigate, administration of vitamin C, as a way to reduce the incidence of atrial fibrillation after coronary bypass surgery.

Methods: In this double-blind clinical study, 290 patients in Rajaee Heart Center, from March 2013 to December 2014 who underwent coronary artery bypass surgery were randomly divided into intervention and control groups to receive vitamin C and placebo. The intervention group before the surgery in the operating room received 2 grams of vitamin C intravenously then one gram per day for four days prior to surgery. After the operation, the two groups were compared in terms of the following: Atrial and ventricular arrhythmias after surgery, ICU stay and hospital stay and duration of intubation.

Results: 113 cases and 177 controls (191 men and 99 women) with a mean age of 55.40±14.40 years in both groups (vitamin C and placebo) were enrolled. The incidence of postoperative atrial fibrillation was 55% in the placebo group to 35% in the vitamin C group decreased (P= 0.001). Duration of intubation in the intervention group 11.8 and the control group was 14.14 hours (P= 0.004). The amount of drainage was lower in vitamin C group (P= 0.003). Vitamin C had no effect on the rates of hospital and ICU stay (P= 0.075). There was no significant reduction in threatening arrhythmia (VT) and VF in this period (P= 0.159).

Conclusion: Vitamin C supplements may reduce atrial fibrillation after coronary artery bypass surgery also can improve conditions such as reducing the duration of intubation. With regard to the safety, these supplements can be recommended for the prevention of atrial fibrillation before coronary artery bypass surgery.

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Background: Wolff-Parkinson-White syndrome is a rare but well-known disease that predisposes a person to cardiac arrhythmias. But sometimes this syndrome is accompanied by heart failure in the affected person. Several causes have been proposed for this complication including recurrent or incessant tachyarrhythmias that are frequently found in symptomatic (especially children) Wolf-Parkinson-White syndrome patients causing heart dysfunction and dilation and dilated cardiomyopathy, and also pre-excitation-related dyssynchrony leading to progressive ventricular remodeling and dilation. In this report, a patient is introduced who has improved his heart failure by radio-frequency ablation of free wall type of this syndrome.