Cihan Cevik

Mayo Clinic - Scottsdale, Scottsdale, AZ, USA

Are you Cihan Cevik?

Claim your profile

Publications (101)208.04 Total impact

  • Source
    Article: Left Ventricular Assist Devices and Gastrointestinal Bleeding: A Narrative Review of Case Reports and Case Series.
    [show abstract] [hide abstract]
    ABSTRACT: BACKGROUND: The use of left ventricular assist devices (LVADs) has become a state-of-the-art therapy for advanced cardiac heart failure; however, multiple reports in the literature describe an increased risk for gastrointestinal (GI) bleeding in these patients. We characterized this association by reviewing recent studies on this topic. HYPOTHESIS: GI bleeding occurs frequently in patients with LVADs, especially with devices with nonpulsatile flow patterns. METHODS: We performed a comprehensive literature review to identify articles that reported GI bleeding in patients with LVADs. Databases used included PubMed, EMBASE, Scopus, Web of Knowledge, and Ovid. Baseline and outcome data were then ed from these reports. RESULTS: We identified 10 case reports and 22 case series with 1543 patients. The mean age was 54.2 years. Most patients had nonpulsatile LVADs (1316, 85.3%). Three hundred and seventeen patients (20.5%) developed GI bleeding; this occurred more frequently in patients with nonpulsatile LVADs. Multiple procedures were performed without complications but often did not identify a definite bleeding site. Suspect lesions occurred throughout the GI tract but were more frequent in the upper GI tract. Many patients had arteriovenous malformations. All patients received medical therapy. None of the patients had their LVAD replaced. The use of anticoagulation did not appear to predispose these patients to more GI bleeding episodes. Conclusions: Patients with LVADs have frequent GI bleeds, especially from arteriovenous malformations, which can occur throughout the GI tract. Most diagnostic and therapeutic interventions can be used safely in these patients. The pathogenesis of the GI bleeding in these patients may involve the use of anticoagulant medications, the formation of arteriovenous malformations, loss of von Willebrand factor activity, and mucosal ischemia. The authors have no funding, financial relationships, or conflicts of interest to disclose.
    Clinical Cardiology 02/2013; · 2.15 Impact Factor
  • Source
    Article: Comparison of Different TEE-Guided Thrombolytic Regimens for Prosthetic Valve Thrombosis: The TROIA Trial.
    [show abstract] [hide abstract]
    ABSTRACT: OBJECTIVES: The aim of this prospective study was to identify the most effective and safest regimen among different thrombolytic treatment strategies. BACKGROUND: The best treatment strategies for prosthetic valve thrombosis have been controversial. METHODS: Transesophageal echocardiography-guided thrombolytic treatment was administered to 182 consecutive patients with prosthetic valve thrombosis in 220 different episodes (156 women; mean age, 43.2 ± 13.06 years) between 1993 and 2009 at a single center. These regimens chronologically included rapid (Group I), slow (Group II) streptokinase, high-dose (100 mg) tissue plasminogen activator (t-PA) (Group III), a half-dose (50 mg) and slow infusion (6 h) of t-PA without bolus (Group IV), and a low dose (25 mg) and slow infusion (6 h) of t-PA without bolus (Group V). The endpoints were thrombolytic success, in-hospital mortality, and nonfatal complication rates. RESULTS: The overall success rate in the whole series was 83.2%; it did not differ significantly among Groups I through V (68.8%, 85.4%, 75%, 81.5%, and 85.5%, respectively; p = 0.46). The overall complication rate in the whole series was 18.6%. Although the overall complication rate was similar among Groups I through IV (37.5%, 24.4 %, 33.3%, and 29.6%, respectively; p > 0.05 for each comparison), it was significantly lower in Group V (10.5%, p < 0.05 for each). The combined rates of mortality and nonfatal major complications were also lower in Group V than in the other groups, with all differences significant except for comparison of Groups IV and V. By multivariate analysis, the predictors of combined mortality plus nonfatal major complications were any thrombolytic therapy regimen other than Group V (odds ratios for Groups I through IV: 8.2, 3.8, 8.1, and 4.1, respectively; p < 0.05 for each) and a history of stroke/transient ischemic attack (odds ratio: 3.5, p = 0.011). In addition, there was no mortality in Group V. CONCLUSIONS: Low-dose slow infusion of t-PA repeated as needed without a bolus provides effective and safe thrombolysis in patients with prosthetic valve thrombosis. (Comparison of Different TRansesophageal Echocardiography Guided thrOmbolytic Regimens for prosthetIc vAlve Thrombosis; NCT01451320).
    JACC. Cardiovascular imaging 02/2013; 6(2):206-216. · 14.29 Impact Factor
  • Article: No Harmful Effect of Dialysis-Induced Hypotension on the Myocardium in Patients Who Have Normal Ejection Fraction and a Negative Exercise Test.
    [show abstract] [hide abstract]
    ABSTRACT: Background: We investigated the effects of dialysis-induced hypotension (DIH) on the myocardium of patients who have a normal ejection fraction and normal treadmill stress tests. Methods: This study included 26 end-stage renal disease (ESRD) patients with DIH, 30 ESRD patients without DIH (non-DIH), and 30 control subjects. Mitral-myocardial systolic velocity (MSV), the mitral E'/A' ratio, the left ventricle filling pressure index (E/E' ratio), tricuspid-MSV, and the tricuspid E'/A' ratio were calculated. Results: Biventricular systolic and diastolic functions were impaired in dialysis patients. The mitral and tricuspid MSV were similar between DIH and non-DIH patients (8.03 ± 0.90 cm/s vs. 8.31 ± 1.68 cm/s, p = 0.896, and 13.27 ± 2.97 cm/s vs. 13.15 ± 2.37 cm/s, p = 0.980). Mitral and tricuspid E'/A' were similar between DIH and non-DIH patients. (1.30 ± 0.53 vs. 1.16 ± 0.56, p = 0.695, and 0.70 ± 0.24 vs. 0.68 ± 0.33, p = 0.976). Likewise, the E/E' ratio was similar between DIH and non-DIH patients (8.20 ± 2.83 vs. 8.28 ± 2.53, p = 0.990). Conclusion: Although biventricular systolic and diastolic function is impaired in dialysis patients compared to controls, DIH episodes did not have an adverse effect on the myocardial functions.
    Kidney and Blood Pressure Research 10/2012; 35(6):671-677. · 1.46 Impact Factor
  • Article: Medical literature searches: a comparison of PubMed and Google Scholar.
    [show abstract] [hide abstract]
    ABSTRACT: Medical literature searches provide critical information for clinicians. However, the best strategy for identifying relevant high-quality literature is unknown. We compared search results using PubMed and Google Scholar on four clinical questions and analysed these results with respect to article relevance and quality. Abstracts from the first 20 citations for each search were classified into three relevance categories. We used the weighted kappa statistic to analyse reviewer agreement and nonparametric rank tests to compare the number of citations for each article and the corresponding journals' impact factors. Reviewers ranked 67.6% of PubMed articles and 80% of Google Scholar articles as at least possibly relevant (P = 0.116) with high agreement (all kappa P-values < 0.01). Google Scholar articles had a higher median number of citations (34 vs. 1.5, P < 0.0001) and came from higher impact factor journals (5.17 vs. 3.55, P = 0.036). PubMed searches and Google Scholar searches often identify different articles. In this study, Google Scholar articles were more likely to be classified as relevant, had higher numbers of citations and were published in higher impact factor journals. The identification of frequently cited articles using Google Scholar for searches probably has value for initial literature searches.
    Health Information & Libraries Journal 09/2012; 29(3):214-22. · 0.89 Impact Factor
  • Article: The role of hypervirulent Staphylococcus aureus infections in the development of deep vein thrombosis.
    Eric Martin, Cihan Cevik, Kenneth Nugent
    [show abstract] [hide abstract]
    ABSTRACT: Patients with sepsis frequently have activated coagulation pathways triggered by tissue factor, reduced levels of anticoagulation factors, reduced fibrinolysis, activated endothelial surfaces, and activated platelets. These processes result in disseminated intravascular coagulation and microthrombus formation and contribute to multi-organ system failure. S aureus surface proteins and exotoxins can contribute to thrombus formation through effects on the coagulation pathway and on anticoagulation factors. In addition, S aureus can activate endothelial surfaces and platelets. Some exotoxins such as the Panton-Valentine leukocidin can cause leukocyte lysis and additional injury to endothelial surfaces. These events can cause microthrombosis and deep venous thrombosis. Several case series have described an association between acute hematogenous osteomyelitis secondary to S aureus and the development of deep venous thrombosis in extremities. In addition, a recent clinical case review of staphylococcal community-acquired pneumonia demonstrated that patients who died secondary to these infections frequently had deep venous thrombosis. These observations support the idea that S aureus can contribute to thrombus formation. We recently cared for a patient who developed splanchnic vein thrombosis during an episode of staphylococcal cellulitis associated with bacteremia and multi-organ system failure. The pathogenesis of splenic vein thrombosis differs from the pathogenesis of deep venous thrombosis in the extremities in some, but not all, respects. Clearly the presence of circulating staphylococci and associated proteins could contribute to the formation of thrombi in the splanchnic circulation. Patients with hypervirulent staphylococcal infections require evaluation for deep venous thrombosis in extremities and in unusual sites. The development of these clots has a potentially significant impact on management and outcome. This review considers the pathogenesis of deep vein thrombosis in patients with sepsis, the potential contributions of Staphylococcus aureus in this process, and clot formation in unusual locations which greatly increases the complexity of patient care.
    Thrombosis Research 07/2012; 130(3):302-8. · 2.44 Impact Factor
  • Article: Percutaneous ventricular assist device in hypertrophic obstructive cardiomyopathy with cardiogenic shock: bridge to myectomy.
    [show abstract] [hide abstract]
    ABSTRACT: We present the case of a 69-year-old woman with end-stage hypertrophic obstructive cardiomyopathy who developed cardiogenic shock. She underwent emergent placement of a percutaneous left ventricular assist device (TandemHeart) in the catheterization lab as a bridge support device until a septal myectomy could be performed as definitive treatment. This case suggests a novel and promising use of the TandemHeart as a bridge to myectomy.
    The Annals of thoracic surgery 03/2012; 93(3):978-80. · 3.74 Impact Factor
  • Article: Telmisartan decreases atrial electromechanical delay in patients with newly diagnosed essential hypertension.
    [show abstract] [hide abstract]
    ABSTRACT: Atrial electromechanical delay (EMD) parameters predict the development of atrial fibrillation. We investigated the effect of telmisartan treatment on atrial EMD parameters in patients with newly diagnosed essential hypertension. Thirty-six patients with essential hypertension were treated with telmisartan (80 mg/day) for 6 months. Baseline electrocardiographic P-wave measurements and echocardiographic atrial EMD parameters were compared with the 6-month follow-up. Pmax and Pd were significantly decreased (108.4 ± 6.1 vs 93.9 ± 6.2 milliseconds, 33.4 ± 8.6 vs 19.5 ± 7.0 milliseconds, respectively, P = .0001 for each) after 6-month telmisartan therapy. The atrial EMD parameters were decreased from baseline (mitral EMD, 68.9 ± 4.9 vs 53.8 ± 4.9 milliseconds; septum EMD, 51.6 ± 7.1 vs 42.6 ± 7. milliseconds1; tricuspid EMD, 48 ± 6.9 vs 39 ± 6.9 milliseconds; interatrial EMD, 20.9 ± 5.5 vs 14.8 ± 5.7 milliseconds; P = .0001 for each parameter). The reduction of interatrial EMD was correlated with the reduction in systolic BP nighttime and the increase in mitral E wave velocity/mitral A wave velocity ratio. Telmisartan decreased the atrial EMD parameters in patients with newly diagnosed essential hypertension.
    Journal of electrocardiology 03/2012; 45(2):123-8. · 1.08 Impact Factor
  • Article: Conductive energy devices: a review of use and deaths in the United States.
    [show abstract] [hide abstract]
    ABSTRACT: Conductive energy devices (CEDs) have been temporally associated with morbidity and mortality in police work, but the frequency of use and of complications is not certain. This is a literature review using PubMed and Google Scholar searches to identify population-based CED studies, studies reporting morbidity and mortality with CEDs, and studies in healthy volunteers. Recent studies indicate that CEDs are used approximately 83 to 338 times per million population per year in the United States. The subjects have a typical profile, including young men with belligerent or bizarre behavior who often have a psychiatric disorder or are intoxicated with drugs. The mortality estimates range from 0.0% to 1.4% of subjects controlled with CEDs. Limited information from autopsy studies indicates that death is frequently associated with confounding factors, especially intoxication with illicit drugs. Conductive energy devices are used frequently during police work and are associated with a low but definite mortality rate. The use of CEDs and the management of at-risk subjects need more study.
    Journal of Investigative Medicine 12/2011; 59(8):1203-10. · 1.96 Impact Factor
  • Article: Hyperthyroidism and pulmonary hypertension: an important association.
    [show abstract] [hide abstract]
    ABSTRACT: Pulmonary hypertension is a complex disorder with multiple etiologies. The World Health Organization Group 5 (unclear multifactorial mechanisms) includes patients with thyroid disorders. The authors reviewed the literature on the association between hyperthyroidism and pulmonary hypertension and identified 20 publications reporting 164 patients with treatment outcomes. The systolic pulmonary artery (PA) pressures in these patients ranged from 28 to 78 mm Hg. They were treated with antithyroid medications, radioactive iodine and surgery. The mean pretherapy PA systolic pressure was 39 mm Hg; the mean posttreatment pressure was 30 mm Hg. Pulmonary hypertension should be considered in hyperthyroid patients with dyspnea. All patients with pulmonary hypertension should be screened for hyperthyroidism, because the treatment of hyperthyroidism can reduce PA pressures, potentially avoid the side-effects and costs with current therapies for pulmonary hypertension and limit the consequences of untreated hyperthyroidism. However, the long-term outcome in these patients is uncertain, and this issue needs more study. Changes in the pulmonary circulation and molecular regulators of vascular remodeling likely explain this association.
    The American Journal of the Medical Sciences 12/2011; 342(6):507-12. · 1.39 Impact Factor
  • Article: Epicardial fat thickness is associated with non-dipper blood pressure pattern in patients with essential hypertension.
    [show abstract] [hide abstract]
    ABSTRACT: Epicardial fat tissue reflects visceral adiposity and is a suggested cardiometabolic risk factor. Patients with abdominal obesity have an increased prevalence of the non-dipper blood pressure (BP) pattern, but it is unclear whether the same is true of patients with increased epicardial fat thickness (EFT). The association between EFT and circadian BP changes in patients with recently diagnosed essential hypertension was examined. Sixty hypertensive patients underwent echocardiography, treadmill stress testing, and 24 hours of ambulatory BP monitoring. Epicardial fat thickness and left ventricular mass (LVM) index were measured by using transthoracic echocardiography. The patients were categorized into two groups according to their BP pattern (group 1, non-dippers; group 2, dippers). The mean EFT and LVM of patients in group 1 (n = 24) (EFT, 7.6 ± 2.1 mm; LVM, 130 ± 31.2 g/m(2)) were significantly greater than those of group 2 (n = 36) (EFT, 5.5 ± 1.2 mm, P = .0001; LVM, 107 ± 23.7 g/m(2), P = .002). The average systolic BP over 24 hours (BP(s) 24) and average diastolic BP over 24 hours (BP(d) 24) of group 1 (BP(s) 24, 151.1 ± 17.6 mm Hg; BP(d) 24, 94.1 ± 16.5 mm Hg) were significantly higher than those of group 2 (BP(s) 24, 136.7 ± 11.9 mm Hg, P = .0001; BP(d) 24, 84.6 ± 10.6 mm Hg; P = .008). Multivariate backward logistic regression analysis demonstrated that the non-dipper BP pattern was associated with EFT (standardized β coefficient = 0.87, P = .005) and LVM (standardized β coefficient = 0.43, P = .016). An EFT ≥ 7 mm was associated with the non-dipper BP pattern with 44% sensitivity and 94% specificity (receiver operating characteristic area under curve of 0.72, 95% CI [0.59-0.83], P = .0007). Epicardial fat thickness was above average in newly diagnosed, untreated hypertensive patients with non-dipper BP pattern. The echocardiographic measurement of EFT may be used to indicate increased risk of hypertension-related adverse cardiovascular events.
    Clinical and Experimental Hypertension 10/2011; 34(3):165-70. · 1.07 Impact Factor
  • Article: Concurrent acute coronary syndrome and ischemic stroke following multiple bee stings.
    International journal of cardiology 09/2011; 151(2):e47-52. · 7.08 Impact Factor
  • Article: Echocardiographic epicardial fat thickness is associated with carotid intima-media thickness in patients with metabolic syndrome.
    [show abstract] [hide abstract]
    ABSTRACT: Carotid intima-media thickness (CIMT) is a potential indicator of subclinical atherosclerosis in patients with metabolic syndrome (MetS). Epicardial fat thickness (EFT) is suggested as a new cardiometabolic risk factor. We investigated the association between EFT and CIMT in patients with MetS. Forty patients with MetS were compared with 40 age- and sex-matched subjects without MetS in terms of echocardiographic EFT, CIMT, anthropometric measurements, and metabolic profile in this cross-sectional study. The waist circumference, total and LDL-cholesterol, fasting glucose, triglycerides, systolics and diastolic blood pressure levels, hs-CRP, and homeostasis model assessment index for insulin resistance (HOMA-IR) were significantly increased in patients with MetS. The EFT and CIMT were also increased significantly in patients with MetS compared to controls (7.2 ± 2 mm vs. 5.7 ± 1.9 mm; P = 0.001, 0.74 ± 0.1 mm vs. 0.59 ± 0.1 mm; P < 0.01, respectively). Echocardiographic EFT was the only independent predictor of CIMT in the multivariate analysis (standardized β coefficient = 0.74, P < 0.001). EFT is associated with increased CIMT in patients with MetS.
    Echocardiography 08/2011; 28(8):853-8. · 1.24 Impact Factor
  • Article: Assessment of atrial conduction time in patients with coronary artery ectasia.
    [show abstract] [hide abstract]
    ABSTRACT: Coronary artery ectasia (CAE) is associated with increased sympathetic activity, plasma levels of inflammatory markers, and oxidative stress. These factors can also cause arrhythmias such as atrial fibrillation. Atrial conduction abnormalities in patients with CAE have not been investigated in terms of atrial electromechanical delay obtained by tissue Doppler echocardiography. Ninety patients with pure CAE (n = 30), nonobstructive coronary artery disease (NO-CAD) (n = 30), and angiographically normal coronary arteries "controls" (n = 30) were compared in terms of electrocardiographic P-wave measurements, echocardiographic atrial electromechanical coupling (AEC) parameters, and interatrial conduction delay. The mean left atrium diameter in the CAE group was similar to the NO-CAD group but significantly greater than the control group (3.62 ± 0.28 vs 3.46 ± 0.32 vs 3.41 ± 0.31 cm, P = 0.021). P maximum and P-wave dispersion were significantly increased in the CAE group compared to the NOCAD group and the control group (108.6 ± 6.6 vs 97.9 ± 6.6 vs 93.5 ± 6.2, P = 0.0001; 34.4 ± 7.6 vs 23.2 ± 7.8 vs 19.4 ± 7.7 ms, P < 0.0001). Mitral AEC, septal AEC, and tricuspid AEC were significantly higher in the CAE group than the NO-CAD group and the control group (68 ± 4.5 vs 57 ± 4.5 vs 53 ± 4.6 ms, P < 0.0001; 50.7 ± 7 vs 42.7 ± 7 vs 41.7 ± 7.2 ms, P = 0.0001; 47 ± 6.7 vs 39.1 ± 6.7 vs 38.1 ± 6.6 ms, P < 0.0001). Interatrial conduction delay was significantly increased in the CAE group compared to the NO-CAD group and the control group (21 ± 5.5 vs 17.8 ± 5.6 vs 15 ± 5.6 ms, P < 0.0001).The correlation analysis demonstrated that the interatrial conduction delay and P-wave dispersion (Pd) were positively correlated with number of ectatic segments (ESN) (r = 0.41, P = 0.024 vs r = 0.49, P = 0.006). Stepwise multiple linear regression analysis revealed that the ESN was the only independent determinants of interatrial conduction delay (P = 0.024). Pd and interatrial conduction delay are prolonged in patients with CAE compared to NO-CAD patients and the healthy controls.
    Pacing and Clinical Electrophysiology 07/2011; 34(11):1468-74. · 1.35 Impact Factor
  • Article: The prevalence of echocardiographic accretions on the leads of patients with permanent pacemakers.
    [show abstract] [hide abstract]
    ABSTRACT: The aim of this study was to investigate the prevalence and clinical significance of echocardiographic "accretions" on intracardiac leads in patients with permanent pacemakers. Two hundred eleven patients with permanent cardiac pacemakers implanted between 1988 and 2005 were called by telephone to participate in this study. The cohort was identified retrospectively and followed prospectively after recruitment. Seventy-five patients who agreed to participate in the study were examined by using transthoracic and transesophageal echocardiography for the detection of pacemaker lead accretions. Blood samples were also obtained for aerobic and anaerobic cultures, high-sensitivity C-reactive protein, erythrocyte sedimentation rate, and complete blood count. The medical records of the patients were analyzed carefully, and patients were called by telephone to investigate mortality and clinical events after 5 years of follow-up. The initial study group included 28 women and 47 men (mean age, 60 ± 15 years). At least one echocardiographic accretion on the pacemaker leads was identified in 16 subjects (21%) by transthoracic echocardiography and in 21 subjects (28%) by transesophageal echocardiography. All accretions were in the right atrial portion of the leads, whereas the ventricular segments of the leads were free of accretions. Patients with pacemaker lead accretions were significantly younger than those without accretions (P = .03). At 5-year follow-up, information could be obtained from 60 of the 75 patients. Among these 60 patients, 28 (46%) had died. There was no difference in mortality between patients who did and did not have lead accretions (P = .96). Patients who died during follow-up were older (P < .001), had shorter time intervals from pacemaker implantation to study enrollment (P = .002), had increased left atrial (P = .007) and right atrial (P = .04) sizes, and had higher pulmonary artery systolic pressures (P = .012) than those who were alive at 5 years. Logistic regression analysis revealed that age and pulmonary artery systolic pressure were independent predictors of mortality. Accretions on permanent pacemaker leads can be detected by both transthoracic and transesophageal echocardiography. Follow-up data did not demonstrate any effect of these accretions on 5-year survival.
    Journal of the American Society of Echocardiography: official publication of the American Society of Echocardiography 07/2011; 24(7):803-7. · 2.98 Impact Factor
  • Article: Heyde's syndrome: A critical review of the literature.
    [show abstract] [hide abstract]
    ABSTRACT: Heyde's syndrome is an uncommon association between aortic stenosis and gastrointestinal bleeding. Although initially described during the late 1950s, with subsequent reports of a possible link between these disorders, controversy persists regarding the incidence, pathogenesis, and treatment of this syndrome. The main disagreements center on the actual association of aortic stenosis and angiodysplasia, though other controversies include the pathogenesis of Heyde's syndrome, ranging from von Willebrand factor deficiency and age-related degeneration to mucosal ischemia and cholesterol embolization. A variety of treatment modalities of the syndrome has been applied, including medical management, endoscopic therapy, embolization, and aortic valve replacement. Here, the controversies surrounding Heyde's syndrome, which focus on pathogenesis and treatment, are reviewed with the aim of providing a clearer understanding of the syndrome and the implications for patient care.
    The Journal of heart valve disease 07/2011; 20(4):366-75. · 0.81 Impact Factor
  • Article: Attenuated cardiovascular response to sympathetic system activation during exercise in patients with dialysis-induced hypotension.
    [show abstract] [hide abstract]
    ABSTRACT: We wished to investigate potential causes of dialysis-induced hypotension (DIH), including the attenuated cardiovascular response to sympathetic system activation during exercise and myocardial dysfunction. This study included 26 end-stage renal disease (ESRD) patients with DIH, 30 ESRD patients without DIH (Non-DIH), and 30 control subjects. Each patient was evaluated with echocardiography and a symptom-limited treadmill stress test. The chronotropic index (CRI), heart rate recovery (HRR), systolic blood pressure response to exercise (SBP response), and tissue Doppler systolic myocardial velocities were calculated. The HRR and velocities were reduced in dialysis patients compared to controls; however, they were similar in patients with and without DIH. Patients with DIH had the lowest CRI compared to the Non-DIH group (0.62 ± 0.15 vs. 0.73 ± 0.17, p = 0.020) and controls (0.62 ± 0.15 vs. 0.86 ± 0.11, p < 0.001). Similarly, patients with DIH had the lowest SBP response values compared to the Non-DIH (34.88 ± 15.01 vs. 55.67 ± 25.42, p = 0.002) and controls (34.88 ± 15.01 vs. 59.70 ± 23.04, p < 0.001). Patients with DIH have inadequate sympathetic activity of the cardiovascular system during exercise and impaired left ventricular systolic function. Both factors could contribute to the development of hypotension during hemodialysis.
    American Journal of Nephrology 05/2011; 33(6):491-8. · 2.54 Impact Factor
  • Article: Intraventricular and papillary muscle dyssynchrony is related to the diastolic phase of functional mitral regurgitation in patients with non-ischemic dilated cardiomyopathy.
    [show abstract] [hide abstract]
    ABSTRACT: Functional mitral regurgitation (FMR) is commonly encountered in patients with heart failure, and is associated with an adverse prognosis. It is hypothesized that left ventricular (LV) and papillary muscle systolic dyssynchrony causes diastolic mitral regurgitation (DMR) in non-ischemic dilated cardiomyopathy (DC) patients. A total of 77 patients with non-ischemic DC was enrolled, of whom 25 were without DMR (group I) and 52 with DMR (group II). Mitral valve apparatus measurements were calculated using two-dimensional echocardiography, while LV/papillary muscle (Pap-index) systolic dyssynchrony parameters were calculated using tissue Doppler echocardiography. The FMR volumes were similar between the two groups (19.4 +/- 10.6 and 22.4 +/- 11.1 ml/beat in groups I and II, respectively). Both groups had similar mitral valves, as assessed by the geometry of the mitral valve apparatus parameters, including tent area, mitral annulus diameter, and tethering distance. However, the maximal intraventricular mechanical delay (MIMD; p < 0.001), peak (+/- SD) myocardial sustained systolic velocity (Ts-SD; p < 0.001) and Pap-index (p < 0.001) were each significantly increased in group II. Strong correlations were apparent between DMR and dyssynchrony parameters [(Ts-SD; r = 0.74, p < 0.001), MIMD (r = 0.78, p < 0.001) and Pap-index (r = 0.78, p < 0.001)]. Linear regression analysis revealed the MIMD (OR 2.94, 95% CI 2.7-6.6, p < 0.001), Ts-SD (OR 3.6, 95% CI 1.2-3.5, p < 0.001) and Pap-index (OR 2.2, 95% CI 1.27-1.35, p = 0.001) to be independent predictors of DMR. In patients with non-ischemic DC, DMR may serve as a useful indicator of mechanical LV/papillary muscle dyssynchrony, especially when used in combination with the other echocardiographic parameters.
    The Journal of heart valve disease 03/2011; 20(2):136-45. · 0.81 Impact Factor
  • Article: Fragmented QRS complexes are associated with cardiac fibrosis and significant intraventricular systolic dyssynchrony in nonischemic dilated cardiomyopathy patients with a narrow QRS interval.
    [show abstract] [hide abstract]
    ABSTRACT: Myocardial scar causes heterogeneous ventricular activation, which results in fragmentation of QRS complexes on ECG. Myocardial fibrosis in patients with nonischemic cardiomyopathy (NDCM) can be identified as late gadolinium enhancement (LGE) areas on cardiac magnetic resonance (CMR) studies. We investigated the association of fragmented QRS (fQRS) complexes with systolic dyssynchrony and myocardial fibrosis in patients with NDCM. Twenty patients with NDCM and sinus rhythm who had fQRS complexes were evaluated with CMR. The association of fQRS complexes with LGE and systolic dyssynchrony was investigated. Nineteen patients had significant systolic dyssynchrony with echocardiography. Among 19 patients with significant dyssynchrony, 14 (74%) patients had fQRS complexes in the most delayed contracting segment or one of the dyssynchronous segments, whereas five patients (26%) had fQRS complexes in a lead which is discordant with the dyssynchronous segment on echocardiography. Seventeen patients had LGE in their CMR. Among the 17 patients with LGE; 13 patients (76%) had fQRS complexes concordant with LGE present segments. Fragmentation of QRS complexes on ECG is associated with intraventricular systolic dyssynchrony and subendocardial fibrosis in NDCM patients with a narrow QRS interval and sinus rhythm.
    Echocardiography 01/2011; 28(1):62-8. · 1.24 Impact Factor
  • Source
    Article: The role of isovolumic acceleration in predicting subclinical right and left ventricular systolic dysfunction in hypertensive obese patients.
    [show abstract] [hide abstract]
    ABSTRACT: Isovolumic acceleration assessed by tissue Doppler imaging has been proposed as a preload-independent indicator of left ventricular contractility. We investigated the utility of isovolumic acceleration in the prediction of preclinical right and left ventricular systolic dysfunction in hypertensive and obese subjects. Seventy-eight obese subjects (BMI >30 kg/m2; 57 women, 21 men; mean age 51±8 years) were prospectively enrolled. Fifty patients (64.1%) had hypertension and 33 patients (42.3%) had diabetes mellitus. All the subjects were assessed by conventional and tissue Doppler echocardiography. Myocardial velocities of the left ventricular septal and lateral mitral annulus and lateral tricuspid annulus were determined. Isovolumic contraction wave was defined as the preceding wave of the systolic wave that began before the peak of the R wave on the electrocardiogram. Myocardial isovolumic acceleration was measured by dividing the peak velocity by the time passed from the onset of the wave (zero-crossing) during isovolumic contraction to the peak velocity of the wave. Waist circumference was in positive correlation with left ventricular end-systolic (r=0.22, p=0.047) and end-diastolic (r=0.384, p=0.001) diameters, and in negative correlation with the peak systolic velocity of the tricuspid annulus (r=-0.311, p=0.006). Although hypertensive and normotensive (n=28) obese subjects had similar myocardial velocities, lateral tricuspid annular isovolumic acceleration (p=0.027), septal isovolumic acceleration (p=0.026), and septal isovolumic contraction myocardial velocity (p=0.018) were significantly lower in hypertensive patients. Isovolumic acceleration and isovolumic contraction myocardial velocity analysis may be useful in the diagnosis of subclinical left and right ventricular dysfunction in hypertensive obese patients.
    Turk Kardiyoloji Dernegi arsivi: Turk Kardiyoloji Derneginin yayin organidir 01/2011; 39(1):9-15.
  • Article: Rosuvastatin therapy does not affect serum MMP-13 or TIMP-1 levels in hypercholesterolemic patients.
    [show abstract] [hide abstract]
    ABSTRACT: Matrix metalloproteinases degrade the collagen content of atherosclerotic plaque and reduce plaque stability. In tissue sections of atherosclerotic plaque, the expression of matrix metalloproteinases is increased. 3-Hydroxy-3-methylglutaryl coenzyme A reductase inhibitors (statins) decrease the tissue expression of matrix metalloproteinases-1, -2, -3, and -9 in atheromatous plaque by attenuating the inflammatory process that leads to increased expression. However, it is not known whether statins decrease levels of matrix metalloproteinase-13--an enzyme crucial to the initiation of collagen degradation-as part of their plaque-stabilizing effect.We prospectively examined the effect of statin therapy on serum levels of matrix metalloproteinase-13, tissue inhibitor of metalloproteinase-1, and low-density-lipoprotein cholesterol in 14 patients with hypercholesterolemia. All were at low risk for adverse cardiovascular events and were given 20 mg/d of rosuvastatin for 4 weeks. Post-therapy levels of matrix metalloproteinase-13 and tissue inhibitor of metalloproteinase-1 were compared with baseline levels. Although low-density-lipoprotein cholesterol levels were significantly decreased in the 14 patients (mean baseline level, 152 ± 21 mg/dL vs mean post-therapy level, 73 ± 45 mg/dL; P < 0.001), matrix metalloproteinase-13 and tissue inhibitor of metalloproteinase-1 levels were unchanged (matrix metalloproteinase-13, 0.295 ± 0.06 ng/mL vs 0.323 ± 0.11 ng/mL, P = 0.12; and tissue inhibitor of metalloproteinase-1, 400.8 ± 43.4 ng/mL vs 395.3 ± 47.5 ng/mL, P = 0.26). We conclude that even though there was a decrease in low-density-lipoprotein cholesterol, short-term, high-dose rosuvastatin therapy has no effect on matrix metalloproteinase-13 and tissue inhibitor of metalloproteinase-1 levels in hypercholesterolemic patients. However, further investigation is warranted.
    Texas Heart Institute journal / from the Texas Heart Institute of St. Luke's Episcopal Hospital, Texas Children's Hospital 01/2011; 38(3):229-33. · 0.65 Impact Factor

Institutions

  • 2013
    • Mayo Clinic - Scottsdale
      Scottsdale, AZ, USA
  • 2012
    • Universal Çamlıca Hospital
      İstanbul, Istanbul, Turkey
    • Baylor College of Medicine
      Houston, TX, USA
  • 2011–2012
    • Medical Park Hospitals
      İstanbul, Istanbul, Turkey
    • St. Luke's Episcopal Health System
      Houston, TX, USA
  • 2008–2012
    • Texas Tech University Health Sciences Center
      • Department of Internal Medicine
      Lubbock, TX, USA
  • 2003–2011
    • Koşuyolu Kalp ve Araştırma Hastanesi
      İstanbul, Istanbul, Turkey
  • 2010
    • Kasimpasa Military Hospital
      İstanbul, Istanbul, Turkey
  • 2009–2010
    • Gaziosmanpasa Hospital
      İstanbul, Istanbul, Turkey