Tehran University Medical Journal

---

Background: Percutaneous Transeptal Mitral Commisurotomy (PTMC) has been used in treating mitral stenosis with variable success, its main complication being mitral incompetence. There is a need to define the subgroup of the patients who benefit mostly from the procedure. Methods: We studied 110 patients (age 17 to 60 years mean 33.2) with mitral stenosis. PTMC was performed though femoral vein. All patients underwent echocardiographic evaluation, both before and after the procedure. Clinical, hemodynamic and echocardiographic data were gathered and used to predict the outcome. Results: PTMC was successful in all 110 patients in alleviating the stenosis (mean transmitral gradient before procedure was 17.1 mmHg after procedure 4.4 mmHg). There was no mortality or major complication other than occurrence of mitral regurgitation in 9 cases. In this group only one patient subsequently needed a mitral valve replacement operation. The following parameters were found to have a significant correlation with the success rate of PTMC: lower age, shorter duration of illness, functional class III and IV, larger EF slope, smaller EPSS, smaller amplitude of valve motion, limitation of the posterior leaflet motion and negative history for open commisurotomy. The incidence of mitral regurgitation after procedure was found to be correlated with: atrial fibrillation rhythm before PTMC, lower age, longer duration of illness, more frequent relapse of rheumatic fever, functional class III and IV, less EF slope, limitation of the valve motion, larger left atrium, calcification of posterior leaflet and subvalvular extension. Conclusions: Balloon Mitral Valvuloplasty is an effective and relatively safe procedure in the management of the mitral stenosis. With the proper selection of the patients with the favorable outcome parameters, the rate of complication can be reduced.

---

Background: Atrial and ventricular arrhythmias are among the most common complications after coronary artery bypass graft (CABG) surgery. Previous studies demonstrated that cardiopulmonary bypass itself results in reduced serum magnesium levels. In this study, we evaluated the effect of total blood magnesium level (TMG) on the prevention of perioperative arrhythmias with routine regimens of 2-4 grams supplemental magnesium (SMG). Methods: TMG was measured in patients who were scheduled for CABG on three occasions: just before anesthesia, just after entering the intensive care unit (ICU) after completion of the sugery, and on the first morning after the operation. Patients were evaluated for primary cardiac rhythm and other variables that could have an influence on the magnesium level, including serum creatinine, urine output in the operating room and diuretic therapy. The SMG dosage was also recorded in the operating room and ICU. Patients were then evaluated for the rate and type of arrhythmia for the next three days. Results: The mean TMG levels in 174 cases were 2.2 (0.5), 2.6 (0.6) and 2.4 (0.6) mg/dl for the three occasions, respectively. The mean SMG was 2.5 (1.2) grams. Of 164 patients, 51 (31%) developed the following post-operative arrhythmias: AF (7.3%), non-AF SVA (15.2%) and ventricular (16.5%). The mean serum creatinine level and urine output were 1.2 mg/dl and 1800 ml, respectively. Although there was a significant difference between the TMG levels on the three different occasions (P<0.001), all values were within normal range. When we stratified the TMG levels of the patients based on administered SMG, the Mentel-Haenszel test revealed no significant difference between the first and third TMG (P=0.6). Although the TMG levels were higher in arrhythmic patients compared to those without arrhythmia (2.25 vs. 2.14 mg/dl), both values were within the normal range and there was no significant difference between the two groups. Serum creatinine levels and urine volume were not related to TMG levels. Conclusion: This study indicates that routine magnesium administration has no significant effect on SMG levels. Also, serum creatinine and urine output are not determinant factors for SMG administration. There was no correlation between TMG levels and perioperative arrhythmia. We conclude that the routine regimen of magnesium administration has no effect on the incidence of perioperative arrhythmia, though it is necessary for maintaining normal magnesium levels.

---

Background: Cardiac connective tissue dysplasia syndrome consists of mitral valve prolapse (MVP), anomalously located chordae tendinae of the left ventricle, or a combination of the two. MVP is marked by the displacement of an abnormally thickened mitral valve leaflet into the left atrium during systole. The nonclassic form of MVP carries a low risk of complications. Patients with severe classic MVP can suffer from mitral regurgitation (MR), infective endocarditis, and, infrequently, sudden death from cardiac arrest. Anomalously located left ventricular chordae tendinae are fibrous or fibromuscular bands that stretch across the left ventricle from the septum to the free wall. They have been associated with murmurs and arrhythmias. The purpose of this study is to assess the performance, as measured by the physical working capacity (PWC170) and maximal oxygen consumption (VO2 max), in athletes with cardiac connective tissue dysplasia syndrome.
Methods: Of the 183 male athletes studied, 158 had cardiac connective tissue dysplasia syndrome and 25 were normal, healthy controls. Their mean age was 16.23 (± 5.48) years and mean training time was 5.2 (±- 4.6) years. Athletes with cardiac connective tissue dysplasia syndrome were divided to four groups. Group 1 consisted of those with MVP Group 2 had patients with an additional cord in left ventricle Group 3 was made up of athletes with a combination of MVP and additional cord Group 4 contained athletes with a combination of MVP and MR. All sportsmen were studied by echocardiograph, veloergometer, and those with arrhythmias were studied and recorded using a Holter monitor.
Results: The most common form of this syndrome in our study groups was MVP. The PWC170and VO2 max among the athletes with the combination of MVP+MR (Group 4) was lower than that of athletes in other groups (P<0.05). The most common arrhythmia among the athletes with anomalously located left ventricular chordae, Group 2, was Wolf-Parkinson-White (WPW) syndrome and early repolarization syndrome. The PWC170 and VO2 max in athletes with WPW syndrome, was lower than the other athletes who did not have WPW syndrome (P<0.05).
Conclusion: The lowest PWC170 and VO2 max were in those athletes with a progressive abnormality. However, the PWC170 and VO2 max among athletes with anomalously located left ventricular chordae was normal. Therefore, among athletes with a combination of anomalously located left ventricular chordae and disruption of rhythm, the PWC170 and VO2 max are lower than normal.

---

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.

---

---

---

Background: Systemic Sclerosis (SSc) is an autoimmune disease with multi-organ involvement mostly due to fibrosis and ectopic or excessive collagen fibers production in organs. Myocardial fibrosis is the main finding of cardiac involvement in patients with systemic sclerosis. In recent studies, the presence of Fragmented QRS complexes (FQRS) has been shown in the surface electrocardiogram in relation to fibrosis.
Methods: The present study is a case-control study during March 2019 to February 2020 that was conducted in 148 patients with scleroderma referred to the Rheumatology clinic in Shariati Hospital and 101 non-ischemic individuals in the control group matched by age and sex with the patient group. All the medical records were reviewed and those who were low risk according to 10-year atherosclerotic cardiovascular disease (ASCVD) risk assessment were selected as case groups. Data of ECG were evaluated for availability of FQRS or conductive abnormalities and calculating PR, QRS, QT, QTc and Tp-e intervals.