Objective: In this study, we have designed an analog circuit model of the cardiovascular system that is able to simulate normal condition and cardiovascular diseases, such as mitral stenosis, aortic stenosis, and hypertension. Especially we focused on severe aortic stenosis, because it is one of the causes of sudden death in asymptomatic patients. In this study, we aim to investigate the simulation of the cardiovascular system using an electronic circuit model under normal and especially severe aortic valve stenosis conditions. Methods: The Westkessel model including RLC pi-segments is chosen in order to simulate both systemic and pulmonary circulation. The left and right heart is represented by trapezoidal shape stiffnesses. Aortic capacitance and aortic valve characteristics are chosen nonlinear. Severe aortic stenosis is implemented by changing the value of the serial resistance to the aortic valve. MATLAB® software program is used for the model implementation. Results: The results for normal conditions of the given electrical model are similar to the normal cardiovascular physiology. As a result of simulation, a remarkable increase of the left ventricle systolic blood pressure and aortic mean pressure gradient, and decrease of aortic systolic blood pressure are observed in severe aortic valve stenosis. Conclusion: In conclusion, our model is effective and available for simulating normal cardiac conditions and cardiovascular diseases, especially severe aortic stenosis.

Objective: To prospectively evaluate the regional myocardial deformation changes and viability in anterior acute myocardial infarction (AMI) patients before and after primary coronary intervention (PCI) by strain (S)/strain rate (Sr) imaging. Methods: Twenty-one patients presented during the first six hours of an anterior AMI and twenty controls were included in this study. Echocardiographic recordings were obtained from the apical/parasternal images just before PCI, one week and one month after PCI. The S/Sr and velocity (V) were measured from the basal mid and apical segments of the walls supplied by the left anterior descending artery. Myocardial perfusion scintigraphy was performed in the 1st month after PCI. Mann-Whitney U and Wilcoxon tests were used for statistical analysis. Results: Acute myocardial infarction resulted in the reduction of deformation indices (S/Sr/V) in all segments. Deformation indices were increased after successful PCI. The S/Sr values of the normal and ischemic segments after PCI were higher compared to the baseline (ischemic Sr: -1.3±0.3 vs. -1.1±0.3, p=0.04). No difference was noted in the S/Sr values of the necrotic segments during the first week (Sr: -1.1±0.3 vs. -1.0±0.3, p=0.054). For V measurements, no difference was observed between the viability types at the follow-up measurements (p>0.05). Conclusion: The remedial effect of PCI on the deformation values was observed in the first week and continued during the first month. In the early reperfusion period, S/Sr indices have the potential to differentiate necrotic tissue from other viability types. Strain/Strain rate imaging can be used for determination of myocardial deformation changes and parameters of viability. However, V values were insufficient.

Objective: This study was prospectively designed to evaluate the relationship between the mitral A wave acceleration slope (AWA-slope) and the left atrial ejection fraction (LA-EF) after the restoration of sinus rhythm in patients with atrial fibrillation (AF), and also to evaluate the change in the AWA-slope between the sequent second day and first month. Methods: Twenty-nine patients (16 female, mean age 56±13 years) with unknown cause of AF (except for age) converted to sinus rhythm within the first 48 hours were included into the study. A transthoracic echocardiography was performed in all patients on the second day and the first month after restoration of the sinus rhythm. The paired Student’s t test was used in comparisons of the continuous variables. The simple and multiple correlations of the LA-EF were evaluated by the simple and multiple linear regression analyses, respectively. Results: Left atrial ejection fraction (42±17 vs 51±19%, p=0.03) and AWA-slope (950±337 vs 1087±351 cm/sec2, p=0.021) obtained after the first month were greater than on the second day. A significant correlation between LA-EF and AWA-slope was observed both on the second day (r=0.76, p<0.001) and at the end of the first month (r=0.71, p<0.001). In addition, there were the correlations between LA-EF and mitral A wave peak velocity (r=0.42, p=0.025) or mitral E/A ratio (r=-0.39, p=0.040) at the end of the first month. On multiple linear regression analysis, only AWA-slope was found to be related to LA-EF (y=9.35+0.04 (AWA-slope), the overall R2=0.51, beta =0.71; 95% CI 0.02-0.05; p<0.001). Conclusion: Mitral A wave acceleration slope is a simple, reliable and non-invasive method that can be used to evaluate left atrial contractile function. It can also be used in monitoring of atrial stunning period in patients with sinus rhythm converted from AF.

Objective: This prospective observational study investigated predictive power of interatrial conduction time (IACT) and P wave dispersion (PWD), in addition to other atrial fibrillation (AF) predictors, in patients undergoing coronary artery bypass surgery (CABG). Methods: Eighty-one patients undergoing CABG were enrolled. Before surgery, IACT and PWD were measured. Time interval from electrocardiographic P wave to echocardiographic transmitral a wave was defined as IACT. Rhythm monitorization was used for AF detection. Continuous and categorical data were compared with independent samples t test and Chi-square statistics. Multiple logistic regression analysis was used to identify independent AF predictors. Results: During a follow-up period of 6.4±2.1 days, AF developed in 14 patients (17%). There were no significant differences between patients with or without AF according to age, gender, number of bypass grafts, cross-clamp duration, systolic function, and left atrial diameter. Significantly increased PWD and IACT were found in AF group (PWD: 37±9 ms vs 24±8 ms, p=0.005 and IACT: 129±11 ms vs 117±11 ms, p=0.01) as compared to group without AF. Increased PWD (OR 1.17; 95% CI 1.04–1.31; p=0.02), absence of beta-blocker treatment (OR 8.88; 95% CI 1.62–48.45; p=0.01), diabetes (DM) and hypertension (HT) combination (OR 1.45; 95% CI 1.15-4.22; p=0.01) were independent AF predictors. However, IACT predictive power had borderline significance (OR 1.03; 95% CI 0.95-1.12; p=0.06). Conclusion: Increased PWD, absence of beta-blocker therapy, HT-DM combination were independent AF predictors following CABG. There was significant difference between groups according to IACT, however predictive value of IACT was nonsignificant. Other studies are needed to establish predictive power of IACT.

Objective: High sensitivity C-reactive protein (hsCRP) and neopterin are associated with atherosclerosis. We aimed to evaluate the association between hsCRP and neopterin, and myocardial ischemia during exercise stress test (EST) in patients with stable angina pectoris (SAP) and to assess the predictive value of these mediators in obstructive coronary artery disease. Methods: Forty-five patients with SAP were included in this prospective observational study. EST- positive group included 23 patients (15 males, mean age 54±10 years) and EST-negative group-22 patients (14 males, mean age 52±9 years). In each patient, blood samples were obtained 1 hour before and 30 minutes after EST. In EST-positive group, coronary angiography was performed to determine the presence and severity of coronary artery lesions as assessed by Gensini score. Statistical analysis was performed using Chi-square, unpaired t, Mann-Whitney U and Wilcoxon rank tests. Logistic regression analysis was used to establish the predictive value of tests. Results: Before EST, hsCRP and neopterin levels were similar between the two groups, however, hsCRP levels were higher in EST-positive group after EST (p=0.03). There was no significant difference between the two groups with respect to neopterin levels after EST (p=0.4). In EST-positive group, EST resulted in significant increases in both hsCRP and neopterin levels (from 3.8±2.8 mg/L to 4.3±3.1 mg/L, p=0.001; from 8.7±4.0 nmol/L to 13.1±10.0 nmol/L, p=0.001, respectively). In EST-negative group only neopterin levels significantly increased after EST (from 6.9±1.8 nmol/L to 9.0±3.9 nmol/L, p=0.001). No relation was observed between the obstructive coronary lesions and the levels of hsCRP or neopterin at any point. Conclusion: In SAP patients, independent with the existence of obstructive coronary lesion, elevated levels of hsCRP after EST might be an indicator of immune activation caused by myocardial ischemia.

Objective: Fibrinolytic therapy remains a legitimate option for many patients presenting with acute ST-segment elevation myocardial infarction (STEMI). Shorter time- to- treatment for patients with STEMI administered fibrinolytic therapy has repeatedly been shown to reduce mortality. A well-organized collaborative team approach was implemented in April 2007. The purpose of this study was to examine the effect of implementing a well-organized collaborative team approach on the outcome in patients with acute STEMI treated with fibrinolysis. Methods: Sociodemographic, clinical, laboratory, and time interval data were prospectively collected on 109 consecutive patients (the study group) and 155 patients from the years 2005–2007 (the control group) retrospectively. A single-phone call was made to discuss case. Emergency department evaluation was bypassed for definitive case. An electrocardiogram was faxed to the on-call cardiologist for suspected case. Door-to-needle times were calculated as medians. Mortality was assessed by reviewing records of all patients visiting outpatient clinic. For the rest, information was obtained over the phone. Median door-to-needle times were compared using Mann-Whitney U test. The Fisher’s exact test was used to compare 6-month mortalities. Results: Improvements were seen in door-to- needle times in the study group regardless of time of presentation (reduced from 59 minutes to 29 minutes during off hours) (reduced from 35 minutes to 18 minutes during regular hours) (p<0.0001). Mortality was significantly reduced in the study group (2 deaths, 1.8%) compared with the control group (12 deaths, 7.7%, p=0.048). Conclusion: The mortality of patients presenting with acute STEMI treated with fibrinolytic therapy was significantly reduced after optimal hospital organization.

Objective: We aimed to evaluate coronary blood flow by means of the TIMI (Thrombolysis in Myocardial Infarction) frame count in patients with idiopathic dilated cardiomyopathy who had angiographically proven normal coronary arteries and compare the results with those of healthy subjects. Methods: This retrospective study included 62 patients with idiopathic dilated cardiomyopathy (34 men, 28 women; mean age 59.7±10.6 years) and 62 control subjects without dilated cardiomyopathy (28 men, 34 women; mean age 56.6±9.8 years). All patients and control subjects had angiographically proven normal coronary arteries. Dilated cardiomyopathy patients had a left ventricular ejection fraction <45%. The TIMI frame count was determined for each major coronary artery in each patient. Statistical analysis was performed using Student’s t test, Chi-square test and Pearson correlation analysis. Results: The TIMI frame counts for each major epicardial coronary artery were found to be significantly higher in patients with idiopathic dilated cardiomyopathy compared to control subjects (corrected TIMI frame count for left anterior descending coronary artery: 37.0±12.5 vs 28.7±11.6, respectively, p<0.001; left circumflex coronary artery: 37.7±12.1 vs 31.0±12.5, respectively, p=0.003; right coronary artery: 37.4±12.6 vs 30.7±11.6, respectively, p=0.003). Mean TIMI frame count had significant although weak positive correlation with left ventricular end-diastolic diameter (r=0.350, p<0.001) and left ventricular end-systolic diameter (r=0.358, p<0.001). Conclusion: We have shown that patients with idiopathic dilated cardiomyopathy and angiographically normal coronary arteries have higher TIMI frame counts for all three coronary vessels, indicating impaired coronary blood flow, compared to control subjects without dilated cardiomyopathy.

Objective: Autonomic dysfunction is an important marker of prognosis in congestive heart failure (CHF) and may determine the symptoms and progression of CHF. The aim of our study was to investigate whether preserved autonomic function assessed by heart rate variability (HRV) analyses is related to absence of CHF symptoms despite prominently reduced systolic function. Methods: The study had a cross-sectional observational design. Fifty patients with left ventricular ejection fraction (EF) below 40% were enrolled. The patients were divided into two groups according to their CHF symptomatic status as Group 1 (NYHA functional class I, asymptomatic group) and Group 2 (NYHA functional class≥ II, symptomatic group). Plasma C-reactive protein (CRP), N-terminal proB-type natriuretic peptide (NT-proBNP) levels, echocardiographic parameters and HRV indices were measured while the patients were clinically stable in each group. Possible factors associated with the development of CHF symptoms were assessed by using multiple regression analysis. Results: Baseline clinical characteristics and left ventricular EF were similar in the two groups. Serum CRP (15±21 vs 7±18 mg/L, p=0.011) and NT-proBNP levels (1935±1088 vs 1249±1083 pg/mL, p=0.020) were significantly higher in symptomatic group. The HRV parameters (SDNN: 78±57 vs 122±42 ms, p=0.001; SDANN: 65±55 vs 84±38 ms, p=0.024; SDNNi: 36±41 vs 70±46 ms, p<0.001; triangular index [Ti]: 17±12 vs 32±14, p<0.001) were also significantly depressed in symptomatic group. When multiple regression analysis was performed, only HRV indices of autonomic function were significantly associated with the asymptomatic status (SDNN, OR: 1.016, 95%CI: 1.002-1.031, p=0.028; SDNNi, OR: 1.030, 95%CI: 1.008-1.052, p=0.006; TI, OR: 1.088, 95%CI: 1.019-1.161, p=0.011). Conclusion: Preserved autonomic functions were shown to be associated with absence of CHF symptoms independently of angiotensin converting enzyme inhibitor/angiotensin receptor blocker’s treatment and BNP levels and may be protective against the development of CHF symptoms despite advanced left ventricular systolic dysfunction.

Objective: Any disease specific Health Related Quality of Life Instrument for Chronic Heart Failure (CHF) is lacking in Turkey. The aim of this study is to adapt the Chronic Heart Failure Questionnaire (CHQ) into Turkish and probe the reliability and validity of this questionnaire. Methods: There are four dimensions of this 20 items scale. These dimensions are: dyspnea (5 items), fatigue (4 items), emotional status (7 items) and mastery (4 items). Response options were evaluated using a 7 -point Likert type scale. Quality of life (QOL) improves as the score increases. A total of 205 CHF patients hospitalized in the Department of Cardiology of Ege University hospital were enrolled in this study. The CHQ was applied to the patients twice with a wash-out period of 15 days. Confirmatory approach was used during the reliability and validity analysis. Cronbach alpha test was used for the reliability analysis. Confirmatory factor analysis (CFA) was used for the construct validity testing. NYHA classification for testing the criterion validity; SF-36 and WHOQOL-100 General Health and QOL facet for convergent validity testing of the Turkish version of the CHQ were used. Responsiveness to change was evaluated by Effect Size analysis by using test-retest data. Results: The range of Cronbach alpha values is 0.72-0.94. A considerable ceiling and floor effects were observed for the dyspnea dimension of the scale but no problematic items were observed for the entire scale. The CFA results supported the original four factors scale structure. Criterion and construct validity rebuts were satisfactory. Effect sizes obtained among dimensions of the CHQ were between 0.13 and 0.56. Conclusion: Overall results revealed that Turkish version of the CHQ is a reliable and valid instrument to be used for the evaluation of CHF patients.

Objective: The prone position is commonly utilized to reduce false positive perfusion defects because this position overcomes the diaphragmatic inferior wall attenuation in single-photon emission computerized tomography (SPECT) studies. We investigated whether the prone position had an important advantage over the supine position in determining the severity and extent of infarct in patients with acute inferior myocardial infarction (MI). Methods: Twenty-nine male patients (mean age 61±10 years) with acute inferior MI were enrolled in the cross-sectional study. After injection of thallium-201 (201Tl) under resting conditions, redistribution SPECT imaging was twicely performed in each subject, in both the supine and prone positions, consecutively. The extent and severity scores of the perfusion defects were calculated from the sum of individual segment scores. Myocardial infarction size was also evaluated using peak cardiac troponin T (cTnT) levels. Wilcoxon rank and Spearman’s rank correlation tests were used for statistical analyses of data. Results: For the supine vs. prone positions, the median defect severity scores were 8 (4-13) vs. 5 (0.5-8.5) and the defect extent scores were 4 (3-5.5) vs. 3 (0.5-4.5), respectively. Both perfusion defect scores in the prone position were significantly lower than those in the supine position (p<0.001). The mean peak cTnT level during hospitalization was 7.2±3.9 μg/l. Peak cTnT levels were correlated with all SPECT parameters. However, the correlation was greater in the prone position (defect severity: r=0.712, p<0.001) (defect extent: r=0.790, p<0.001) than in the supine position (defect severity: r=0.495, p<0.01) (defect extent: r=0.481, p<0.01). Conclusion: In patients with inferior MI, the SPECT results revealed a significant difference between the supine and prone images. The perfusion extent and severity scores of SPECT in the inferior wall with prone imaging correlates better with the peak troponin compared to the supine position. Comparative studies that use advanced imaging tools are needed to verify our present findings.

Objective: In patients with tetralogy of Fallot, infants less than 12 months old and children between one and four years old were compared after total repair surgery for determination of outcome of surgery, risk factors influencing mortality and morbidity. Methods: Fifty- two patients with tetralogy of Fallot between five months and four years of ages were included into the study. The patients were divided into two groups depending on their ages; Group 1; one year old and younger (n=21) whereas, group 2; one and four years old (n=31). Statistical analysis was performed using Mann-Whitney U, Chi-square or where appropriate Fisher’s exact tests and logistic regression analysis was applied for determination of predictors of mortality. Results: The parameters that were different between two groups include; age (Group 1; 10.00±1.67 months and Group 2; 2.39±0.77 years, p<0.001), weight (Group 1; 9.74±2.23 kg, Group 2; 11.97±1.78 kg, p<0.001), McGoon ratio (Group 1; 1.94±0.29, Group 2; 2.19±0.27, p=0.001). Mortality is found in 3 patients in group 1 (14.2%) whereas, in five patients in group 2 (16%) and the difference was not statistically significant. In group 2 in only one patient (0.03%) had complete atrioventricular block and required permanent pacemaker implantation. When patients were compared according to groups with and without mortality, the significant differences were found in following variables: peritoneal dialysis (p=0.001), pleural effusion (p=0.02), right ventricular pressure (p=0.001) and right ventricle/aorta pressures ratio (p=0.001). However, none of these risk factors had significant value in prediction of mortality. Conclusion: Depending on these results, in patients under one year of age with symptomatic tetralogy of Fallot, if there are no other pathologies that have potential to increase risk of mortality, the complete repair surgery can be performed with same amount of risks and similar morbidity and mortality ratios.