Prevalence and clinical features of atrial fibrillation in diabetic neuropathy: a cross-sectional, observational study.

OBJECTIVE: This cross-sectional, observational study investigated prevalence and clinical features of atrial fibrillation (AF) in diabetic patient groups with or without autonomic neuropathy. METHODS: One hundred and fourteen consecutive patients with pharmacologically treated type-II diabetes mellitus were enrolled for this study in our institution between January 2010 and December 2010. All patients underwent 12-lead electrocardiography on the day of enrollment for AF detection. All diabetic patients underwent neurologic examination for the presence of diabetic autonomic neuropathy (DAN). Following clinical evaluation, sympathetic skin responses (SSR) and RR interval variability (RRIV) analysis were used for the detection of autonomic neurologic involvement. Patients were divided into two groups according to presence (Group 1) or absence (Group 2) of DAN. Patient groups with or without DAN were compared for AF occurrence. Continuous and categorical data were compared with independent samples t- test and Chi-square statistical tests respectively. RESULTS: Atrial fibrillation prevalence was 24% (n=29) in study population. Diabetic autonomic neuropathy was diagnosed in 47 (39%) patients. Basal characteristics of patients with or without DAN were comparable except glycosylated hemoglobin A (HbA1c) levels. HbA1c levels were found significantly higher in patients with DAN. Atrial fibrillation was diagnosed in 14 patients in Group 1 and in 15 patients in Group 2. Significantly increased AF prevalence (31.9% vs. 20.8%, p=0.014, in groups with and without DAN respectively) was observed in patient group with diabetic autonomic neuropathy. CONCLUSION: The results of this study demonstrated an increased prevalence of AF in patients with diabetic autonomic neuropathy compared with non-neuropathic, diabetic patients. Further investigation of this relation with prospective studies is needed to demonstrate a causal relationship between diabetic autonomic neuropathy and AF.

Central venous obstruction and clinical predictors in patients with permanent pacemaker.

OBJECTIVE: This study investigated the proportion of silent venous obstruction in patients who underwent pacemaker or lead reimplantation for various reasons. We also investigated independent predictors or risk factor of venous obstruction in this patient population. METHODS: Seventy-three patients who underwent pacemaker pulse generator and/or lead reimplantation in our institution between 2007 and 2010 were enrolled for this retrospective case-control study. Prior to procedure, patients underwent ipsilateral venography. Patients' venographies were classified as non-significant obstruction (stenosis ≤70%, including normal venogram), significant obstruction (stenosis >70%) and complete obstruction. Continuous and categorical data were compared with Mann-Whitney U test and Chi-square statistics respectively. Logistic regression analysis was used to identify independent predictors of venous obstruction. RESULTS: Complete or significant silent central venous obstruction (CVO) proportion was detected as 9.5% (n=7). Basal characteristics of patients with or without CVO were comparable. Significantly increased pacemaker pocket erosion incidence (57% vs 0%, p=0.001, in groups with and without CVO respectively) and significantly higher mean pacemaker age (15.3 ± 10.2 years vs 10.4 ± 5.1 years, p=0.047, in groups with and without CVO respectively) were found in group with CVO. Pacemaker pocket erosion (OR 3.00; 95% CI 1.024-9.302; p=0.001), higher pacemaker age (OR 1.33; 95% CI 1.026-1.733; p=0.02) were found as independent CVO predictors in multiple logistic regression analysis. Correlation analysis also revealed a significant correlation between previous or current pacemaker pocket erosion and CVO (r=0.80, p=0.001). CONCLUSION: Ipsilateral venography is a useful procedure prior to pacemaker or lead reimplantation to detect CVO. In addition to the increased pacemaker age, current or past history of erosion and infection at pacemaker pocket are probable clinical conditions related to CVO. These clinical conditions create a predisposition to CVO with unknown mechanisms, according to the results of this preliminary study.

An observational study of the effect of coronary artery disease severity on acute pacing threshold and lead impedance in patients with permanent pacemaker.

OBJECTIVE: This study investigated the effect of coronary artery disease (CAD) severity, distribution and left ventricular ejection fraction (LVEF) on acute ventricular pacing threshold and lead impedance at the time of pacemaker implantation. METHODS: One hundred and thirty-two patients who received a ventricular pacemaker or internal cardioverter-defibrilator (ICD) lead in our institution between 2007-2010 were included in this observational study. Patients were divided into ICD and anti-bradycardic pacemaker (PM) groups. Groups were compared for ventricular stimulation threshold, lead impedance and LVEF. Later, groups were sub-grouped according to the severity and distribution of CAD and subgroups were compared in both groups for ventricular stimulation threshold, lead impedance. Quantitative data of groups were compared by means of independent samples t-test. RESULTS: Ventricular pacing thresholds were found significantly higher ICD group compared with PM group (p<0.05). Impedance and LVEF values were significantly lower in ICD group (p<0.05). Impedance and ventricular pacing thresholds were comparable in subgroups of ICD and PM groups. Our study does not confirm any relationship between pacing parameters and severity-distribution of CAD and LVEF. CONCLUSION: Patients with ventricular ICD lead had higher pacing thresholds but lower pacing impedance values comparing with PM group. This study did not find any significant relationship between pacing parameters at implantation and LVEF, severity and distribution of CAD.

Limited bedside echocardiography by emergency physicians for diagnosis of diastolic heart failure.

INTRODUCTION: The identification of diastolic heart failure (DHF) is important for determining the prognosis of congestive heart failure patients. This study attempted to determine the accuracy of emergency physicians who performed bedside echocardiography (BECH) in patients with diastolic dysfunction. METHODS: Three attending emergency physicians underwent 3 h of didactic and 3 h of hands-on training taught by a cardiology specialist for the echocardiographic diagnostic criteria of DHF. Between February and April 2010, the emergency physicians performed BECH for patients presenting with dyspnoea, and echocardiographic views were recorded. Our gold standard for the diagnosis of diastolic dysfunction was the cardiologists' echocardiography report. Results were compared with χ(2) testing. RESULTS: Of the 69 enrolled patients, 51 were diagnosed as having diastolic dysfunction by emergency physicians. The sensitivity of BECH was 89% (77-95) and specificity was 80% (51-95) with 95% CI. The accuracy of the emergency physicians' echocardiographic diagnosis was 87%. CONCLUSION: BECH performed by emergency physicians may serve as an objective, rapid, non-invasive tool in the assessment of patients presenting with dyspnoea in ED.

The role of nebivolol in the prevention of contrast-induced nephropathy in patients with renal dysfunction.

OBJECTIVE: This prospective study was designed to evaluate the potential protective effect of nebivolol compared with metoprolol on the development of contrast-induced nephropathy (CIN) following coronary angiography in patients with renal dysfunction. METHODS: Ninety patients with stable coronary angina pectoris with renal insufficiency (creatinine value ≥1.2 mg/dl) were included for this prospective study. Patients were divided into two groups. Patients in group 1 (n=55) received oral administration of nebivolol 5 mg/daily for coronary artery disease and/or hypertension. Group 2 consisted of 35 patients who received metoprolol 50 mg/daily for the same indications. All patients were hydrated with 0.9% NaCl at a rate of 1 mL/kg/hr for 12 hours before and 24 hours after the procedure. Patients were also given N-acetylcysteine (NAC) 600 mg twice a day, beginning 24 hours before and continuing 48 hours after the procedure. All patients underwent routine coronary angiography. Serum creatinine was assessed just before, immediately after and 48 hours after the procedure. CIN was defined as an increase in serum creatinine concentration of ≥25% within 48 hours after the procedure compared to the patient's baseline value. Tests for significance between groups were conducted using the independent sample t-test for continuous variables and Chi-square test for categorical variables. RESULTS: Baseline serum creatinine levels were statistically comparable in two groups. Following angiography, serum creatinine levels increased in both groups. Post-angiographic creatinine levels were not statistically different in the nebivolol and the metoprolol groups. Contrast induced nephropathy developed in 13 patients (24%) of the nebivolol group and in 12 patients (33%) of the metoprolol group. The incidence of CIN was statistically significantly lower in the nebivolol group comparing with the metoprolol group (p=0.03). CONCLUSION: The use of oral nebivolol for one week at a dose of 5 mg per day may decrease the incidence of contrast-induced nephropathy in patients who underwent coronary angiography with renal dysfunction. The small numbers of this study do not allow to draw final conclusion on the use of nebivolol in the prevention of CIN. Therefore, larger studies may be necessary to address the definite role of nebivolol in this setting.

Tricuspid annular motion in right coronary artery-related acute inferior myocardial infarction with or without right ventricular involvement.

OBJECTIVE: Tricuspid annular movement and velocities before and after thrombolytic therapy were investigated for the detection of right ventricular (RV) involvement in RCA (right coronary artery)-related acute inferior myocardial infarction (IMI). METHODS: Patients with RCA-related acute IMI were evaluated for this pilot prospective cohort study. Annular movement was measured by TAPSE (tricuspid annular plane systolic excursion), and annular velocities were measured by tissue Doppler echocardiography. Data collected before and after thrombolysis and angiography. Diagnosis of RV myocardial infarction (RVMI) was defined by co-presence of electrocardiographic and angiographic criteria. Chi-square and Student's t-tests were used in statistical analysis. RESULTS: Thirty-one patients were included. Before thrombolysis, annular velocities and TAPSE were found significantly higher in patients without RVMI than in patients with RVMI. Comparison of tricuspid systolic velocity (Sa) and movement before and after thrombolytic therapy in patients without RVMI revealed no significant difference (21.6±2.1 mm vs. 21.8±2.0 mm p>0.05 and 136.1±8.8 mm/s vs. 137.5±9.0 mm/s p>0.05, for TAPSE and Sa respectively). Contrarily, in patients with RVMI, TAPSE and systolic velocity increased significantly after thrombolysis compared with pre-thrombolysis (16.2±2.0 mm vs. 17.6±1.8 mm p=0.001 and 110.0±12.6 mm/s vs. 113.08±12.7 mm/s p=0.027 for TAPSE and Sa respectively). Diastolic velocities did not change significantly after thrombolysis in patients with RVMI. CONCLUSION: Tricuspid annular movement and velocity measurement by echocardiography may contribute to echocardiographic diagnosis of RV involvement in RCA-related IMI. Patients without RVMI have significantly higher annular velocities and TAPSE than in patients with RVMI before thrombolysis. Only in IMI patients with RVMI, significant increases in TAPSE and Sa were observed after thrombolysis.

[Value of interatrial conduction time and P wave dispersion in the prediction of atrial fibrillation following coronary bypass surgery]. / Koroner baypas cerrahisi sonrasi atriyal fibrilasyonu öngörmede interatriyal ileti süresi ve P dalga dispersiyonunun degeri.

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.

An important role for VCAM-1, but not for ICAM-1 in restenosis following coronary stent implantation.

OBJECTIVE: In this study, we evaluated the possibility that, levels of circulating adhesion molecules following direct stent implantation may be a marker of restenosis. METHODS: This prospective, observational study investigated levels of circulating intercellular (ICAM-1), and vascular cell (VCAM-1) adhesion molecules in 15 patients with stable angina pectoris before and after coronary stent implantation for single vessel-single lesion disease in proximal left anterior descending artery. All patients received bare-metal stents. Patients underwent repeat coronary angiography for detection of restenosis at 6 month. Continuous data between patients with and without restenosis were compared using Mann-Whitney U test. Repeated measurements were compared using Wilcoxon T test. Categorical data were compared using Chi-square statistics. RESULTS: Baseline ICAM-1 and VCAM-1 concentrations before percutaneous coronary intervention (PCI) were 4.89±2.28 and 46.35±22.96 ng/ml respectively. Levels of ICAM and VCAM increased nonsignificantly 24 hours after PCI (5.01±2.35 ng/ml and 52.57±19.40 ng/ml, respectively). Six patients (40%) developed restenosis within 6 months. Mean stent length, mean stent diameter, and mean dilatation pressure were comparable in patient groups with and without restenosis. Levels of plasma VCAM-1 measured before and after PCI did not change significantly in patients without restenosis. However, these levels increased significantly in the group of restenosis. At 6 months, patients who developed restenosis, had higher VCAM-1 levels, as compared to baseline values (from 45.1±21.0 to 57.2±14.3 ng/ml, p=0.05). Plasma levels of pre and post PCI ICAM-1 did not differ significantly between groups with and without restenosis. CONCLUSION: These results suggest a more dominant role for VCAM-1, but not for ICAM-1 in development of restenosis following coronary stent implantation.

[The effect of atrial pacing on left ventricular diastolic function and BNP levels in patients with DDD pacemaker]. / DDD tipi kalici kalp pilli olgularda atriyumun elektriksel uyarilmasinin sol ventrikül diyastolik fonksiyonu ve BNP seviyeleri üzerine etkisi.

OBJECTIVE: We aimed to investigate the effect of atrial pacing on left ventricular diastolic function and brain natriuretic peptide (BNP) levels in patients with DDD pacemaker. METHODS: Thirty patients with complete atrio-ventricular (AV) block and DDD pacemaker were included. All patients had normal left ventricular systolic function. Echocardiographic diastolic function parameters (transmitral and tissue Doppler velocities during early (E and E') and late (A and A') filling) and NT-pro-BNP levels were evaluated prospectively during atrial sensing and pacing periods. Echocardiographic data were compared with paired sample t test and NT-pro-BNP levels were compared with Wilcoxon test. RESULTS: Echocardiographic E/A, E'/A', E/E' ratios were calculated as 0.72+/-0.34, 0.61+/-0.21 and 8.76+/-2.58 during atrial sensing period. Same parameters were found as 0.71+/-0.23, 0.64+/-0.16 and 8.93+/-3.16 respectively during atrial pacing period. Echocardiographic left ventricular diastolic function parameters were not significantly different during atrial pacing and atrial sensing periods. Median plasma NT-pro-BNP levels were measured as 142 pg/ml (min-max 47-563 pg/ml) and 147 pg/ml (min-max 33-1035 pg/ml) during atrial sensing and pacing periods respectively. These levels were not significantly different (p=0.86). CONCLUSION: The result of this study has shown that, atrial pacing has not any additional detrimental effect on left ventricular diastolic function parameters in paced patients with normal left ventricular systolic function.

[Retrospective analysis of 1650 permanent pacemaker implantations experience over two different consecutive time periods in a single cardiology clinic]. / Bir kardiyoloji kliniginde ardisik 2 ayri dönemde takilan 1650 kalici kalp pilinin retrospektif karsilastirmali incelemesi.

OBJECTIVE: Indications for pacing, pacing modes, and demographics of patients who underwent pacemaker implantation between two different time periods were compared in this study. METHODS: Pacemaker registry of our cardiology department was used to evaluate these changes from 1986 to 2007 (First period: 1986-1996, second period: 1997-2007) retrospectively. RESULTS: Registry revealed 776 implantations in the first and 874 implantations in the second period. The percentages of first implantation were 89% and 70.1% respectively. Nearly 50% of the patients in both periods were female. Main indications for pacing were atrioventricular (AV) block, sick sinus syndrome (SSS) and slow ventricular rate during atrial fibrillation in both periods. Implantation of VVI-AAI pacemakers have decreased (77.8%/1.5% to 51%/0.3%, p=0.05) and implantation of DDD-VDD pacemakers have increased (19.3%/1.3% to 42.3%/6.3%, p=0.05) during the second period compared to the first period. Permanent pacemaker implantation for SSS has decreased significantly from 31.1% in the first period to 12.0% (p=0.05) in the second period. Implantation for AV block has increased significantly from 63.3% to 79.7% (p=0.05) in the second period. CONCLUSION: Our data revealed temporal changes in pacemaker implantation practice during last twenty years in the cardiology department of a teaching hospital. Implantation of VVI-AAI pacemakers have decreased significantly during the second period. Permanent pacemaker implantation for AV block has also decreased during the last period.

Progression of conduction system disease in a paced patient with Kearns-Sayre syndrome.

The Kearns-Sayre syndrome is a rare condition characterized by external ophthalmoplegia, retinal pigmentary degeneration and progressive impairment of cardiac conduction. We report a patient with the permanent pacemaker. The spontaneous cardiac impulse formation disappeared during long-term follow-up in this patient with Kearns-Sayre Syndrome.

Evaluation of insulin resistance in normoglycemic patients with coronary artery disease.

BACKGROUND: Insulin resistance is clearly associated with coronary artery disease (CAD) in diabetics. Insulin resistance may also be present in normoglycemic individuals, and some of these patients can be diagnosed as having metabolic syndrome (MS) according to various definitions. However, the relationship between hyperinsulinemia and CAD is obscure in normoglycemic individuals, especially in patients who do not meet the criteria for MS. HYPOTHESIS: This study evaluated insulin resistance in normoglycemic patients with CAD, and investigated the association of insulin resistance with inflammation and lipid levels. METHODS: Fifty-six CAD patients, and 57 age- and sex-matched controls with normal coronary arteries confirmed by conventional coronary arteries angiography were included in the study. Participants were considered for the diagnosis of MS according to criteria of the National Cholesterol Education Program (NCEPATP III) and the International Diabetes Federation (IDF). Fasting plasma glucose, insulin, lipids, and c-reactive protein (CRP) levels were studied. The homeostasis model assessment insulin resistance index (HOMA IR) was calculated. RESULTS: The ratio of subjects with MS was similar in the 2 groups. Insulin, CRP, low-density lipoprotein (LDL) cholesterol, and HOMA IR were higher in the study group than in the controls. The HOMA IR, LDL cholesterol, and serum CRP levels were determined as predictors of CAD. CONCLUSION: Our data revealed that insulin resistance and subclinical inflammation are present in normoglycemic patients with CAD. As the proportion of patients with MS was similar in the 2 groups, we suggest that HOMA IR values may provide more sensitive information than MS definitions about the association between insulin resistance and CAD in normoglycemic patients.

Should we revascularize before implanting a pacemaker?

BACKGROUND: The effect of coronary revascularization on disappearance of the severe conduction disturbances is still unclear. HYPOTHESIS: We sought to determine whether revascularization may induce recovery of sinus rhythm in patients with significant coronary artery disease and complete atrioventricular block (AVB). METHODS: Fifty-three patients who had third-degree AVB and significant coronary artery disease were enrolled. Patients with acute coronary syndromes were excluded. Thirty-three (62%) patients were men and the mean age was 65 +/- 10 y. All patients received a permanent dual-mode, dual-pacing, dual-sensing (DDD) pacemaker. Coronary disease was treated medically in 16 (30%) patients due to patient preference or ineligibility. Thirty-seven (70%) patients underwent a revascularization procedure (coronary artery bypass grafting [CABG]: 16, percutaneous coronary intervention [PCI]: 21 pts). Mean follow-up was 36 +/- 6 mo and patients were evaluated every 3 mo according to their resting electrocardiograms (ECGs) at each visit. RESULTS: In the medically treated group, 13 (81%) patients still had third-degree AVBs at the end of the follow-up period, while 3 (19%) patients returned to normal sinus rhythm. On the other hand, 27 out of 37 patients (73%) who were revascularized were still in complete AVB, and 10 patients from this group (27%) had returned to normal sinus rhythm. There was no statistically significant difference between the revascularized and medically treated groups in terms of need for a pacemaker. CONCLUSIONS: Patients who have concomitant severe conduction disturbances and significant coronary disease may well receive a pacemaker before a revascularization procedure. Our data shows that coronary revascularization has little, if any, impact on returning to normal AV conduction.

Locations of coronary artery lesions in patients with severe conduction disturbance.

The relation between conduction disturbances and coronary pathology is often uncertain. The aim of this study was to examine the location of coronary lesions in patients who have an indication for a permanent pacemaker. Between 2001 and 2006, 203 consecutive patients (121 men (59%), mean age, 65 +/- 10) who had severe conduction disturbance underwent coronary angiography before pacemaker implantation. Third degree AV block was present in 172 (84%), sick sinus syndrome in 21 (11%), and Mobitz II, second degree AV block in 10 (5%). The coronary angiographic study included stenosis severity and classification of pathological anatomy. Sixty-two age-matched subjects with coronary artery lesions > 50% but without conduction disturbance made up the control group. The locations of coronary lesions were classified as follows: Type I: Lesions not related to septal branches or AV node (AVN) artery; Type II: Lesions involving the septal perforators of LAD but not RCA; Type III: Lesions compromising blood supply to SAN or AVN (No LAD septal involvement); and Type IV: Combination of Type II and Type III. Of 203 patients, insignificant coronary pathology was found in 141 (70%- group X). Sixty-two patients (30%) had coronary stenoses > 50% (group I) and Type II coronary anatomy was the most prevalent (n = 24, 38.7%), followed by Type IV (n = 22, 35%). Type III was found in 10 (16%) and Type I in 6 (9.6%). This distribution of CAD was significantly different from the control group in whom the most prevalent lesion locations were Type III and I (39% and 31%, respectively) (P < 0.05). Patients with severe conduction disturbances tend to have a specific coronary lesion distribution that involves either proximal LAD branches or a combination of this with significant RCA disease, compromising supply to sinoatrial or AV nodes.