Browsing by Author "Gunes, Ahmet"

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Comparison of the Effects of Quinapril and Irbesartan on P-Wave Dispersion in Hypertensive Patients
(Springer, 2008) Guntekin, Unal; Gunes, Yilmaz; Tuncer, Mustafa; Simsek, Hakki; Gunes, Ahmet
Introduction: P-wave dispersion (PWD) has been shown to be a non-invasive electrocardiographic predictor for development of atrial fibrillation (AF). Thus, it may be possible to attenuate AF risk through improvement of PWD. In this study, we compared the effects of an angiotensin-converting enzyme (ACE) inhibitor, quinapril, and an angiotensin receptor blocker (ARB), irbesartan, on PWD. Methods: A total of 38 newly diagnosed hypertensive patients were enrolled in the study. The patients were randomly assigned to receive treatment with either irbesartan (150-300 mg) or quinapril (20-40 mg). P-wave durations and PWD were measured at baseline and after 6 and 12 months of treatment. Echocardiographic examinations were performed at baseline and after 12 months of treatment. Results: Both drugs significantly reduced blood pressure to a similar degree (P < 0.001). Deceleration time (both P < 0.001) and isovolumetric relaxation time (both P=0.007) were also significantly reduced, whereas there was no significant change in the early diastolic flow/atrial contraction signal ratio. Both irbesartan and quinapril significantly decreased maximum P-wave duration (Pmax) (P < 0.001 and P=0.002, respectively) and PWD (from 68.0 +/- 22.1 to 41.0 +/- 25.1 msec for irbesartan, and from 70.5 +/- 20.4 to 46.6 +/- 13.3 msec for quinapril; both P < 0.001). Baseline and follow-up blood pressure, heart rate, echocardiographic findings, and P-wave values were not significantly different between the irbesartan and quinapril groups. No patient developed AF during follow-up. There was no significant correlation between PWD and blood pressure or diastolic function parameters. Conclusion: Antihypertensive treatment with either irbesartan or quinapril is associated with significant reductions in Pmax and PWD.
The Effects of Perindopril on Qt Duration and Dispersion in Patients With Coronary Slow Flow
(Springer, 2011) Guntekin, Unal; Gumrukcuoglu, Hasan Ali; Gunes, Yilmaz; Gunes, Ahmet; Simsek, Hakki; Sahin, Musa; Tuncer, Mustafa
Coronary slow flow (CSF) is characterized by delayed opacification of coronary arteries in the absence epicardial occlusive disease. QT duration and dispersion have been reported to be longer in patients with CSF. ACE inhibitors may improve CSF through positive effects on endothelial function. The study included 32 patients having CSF and 25 subjects having normal coronary arteries in coronary angiography. The patients were evaluated with 12-leads electrocardiography and echocardiography before and 3 months after treatment with perindopril. Compared to the control group, maximum corrected QT duration (QTcmax) (432.0 +/- A 28.9 vs. 407.0 +/- A 39.1 ms, p = 0.008) and QT dispersion (QTcD) (64.0 +/- A 16.5 vs. 37.3 +/- A 12.1 ms, p < 0.001), mitral inflow deceleration time (DT) (251.3 +/- A 49.4 vs. 218.8 +/- A 44.5 ms, p = 0.013), and isovolumetric relaxation time (IVRT) (115.8 +/- A 18.4 vs. 107.2 +/- A 22.9 ms, p < 0.001) were significantly longer and E/A ratio 0.85 +/- A 0.2 vs. 1.1 +/- A 0.3, p = 0.004) was lower in patients with CSF. QTcmax (to 407.0 +/- A 28.0 ms, p = 0.001), QTcD (to 44.5 +/- A 11.4 ms, p < 0.001), DT (to 221.6 +/- A 37.7 ms, p < 0.001) and IVRT (to 103.8 +/- A 16.1 ms, p < 0.001) were significantly decreased and E/A ratio (to 0.98 +/- A 0.3, p < 0.001) was significantly increased after treatment with perindopril. Coronary slow may be associated with prolonged QT interval and increased QT dispersion and impaired diastolic filling. Perindopril may be helpful in restoration of these findings.
The Effects of Perindopril on Qt Duration and Dispersion in Patients With Coronary Slowflow
(Elsevier Ireland Ltd, 2010) Guntekin, Unal; Gunes, Yilmaz; Gunes, Ahmet; Gumrukcuoglu, Hasan Ali; Ceylan, Yemlihan; Simsek, Hakki; Tuncer, Mustafa
Koroner Arter Hastalığında Efor Testi ile Lenfosit Alt Gruplarında Oluşan Değişiklikler
(2000) Gunes, Ahmet; Bilge, Mehmet; Eryonucu, Beyhan; Öner, Ahmet Faik; Güler, Niyazi; Erkoç, Reha
AMAÇ: T lenfositler hücresel bağışıklıktan sorumlu olup, antijen spesifik antikor cevabının oluşmasında esas hücrelerdir. Periferde dolaşan T lenfositlerin %60'ı CD4+ (T-helper), %30'u CD8+ (T-supressor) hücrelerdir. Stres, yorgunluk ve kortikosteroidler bunların aktivitesini olumsuz yönde etkilerken egzersiz ve bazı viral enfeksiyonlar bu hücrelerin aktivitesini artırmaktadır. Perkütan translüminal koroner anjiyoplasti ile oluşturulan iskemi esnasında lenfosit alt gruplarının incelenmesinde CD4 ve CD8 seviyelerinde değişiklik olduğu gösterilmiştir. Bu çalısına, koroner arter hastalığı (KAH) olanlarda, egzersiz ile lenfosit alt gruplarında oluşan değişiklikleri araştırmak amacıyla yapıldı. YÖNTEM: Çalışmaya koroner anjiografilerinde majör koroner arterlerin en az birinde %50 ve üzerinde darlık bulunan ve yaş ortalaması 56±6 yıl olan I4'ü kadın 31 olgu alındı. Kontrol grubunu ise koroner anjiografi endikasyonu olmadığı kanısına varılan, yaş ortalaması 50±9 yıl olan. treadmil testi negatif 5 'i kadın 10 olgu oluşturdu. Lenfosit alt grupları egzersiz öncesi ile hemen sonrasında ve testten 24 saat sonra tespit edildi. BULGULAR: Her iki grupta da lökosit ve lenfosit sayısında egzersiz öncesine göre anlamlı bir yükselme olup 24 saat sonra bu değerlerde bazal değerlere dönüş saptandı. Hasta grubunda, CD4+ T-lenfosit sayısında egzersiz hemen sonrasında istatiksel olarak anlamlı değişiklik olmamakla birlikte 24 saat sonrasında anlamlı artış gözlendi (P<0.05). CD8 T lenfosit düzeyleri kontrol grubunda istatiksel olarak anlamlı düzeyde yükselmezken KAH olanlarda egzersiz hemen sonrasında öncesine göre anlamlı artış (%31±10 'a %39±11. P<0.01) saptandı. SONUÇ: Sonuç olarak, KAH olanlarda fizik egzersiz ile CD8+ T lenfosit alt grubunda artış olmuştur. Bu KAH' lı hastalarda immün fonksiyondaki değişikliğe ve iskemik sendromların immün sistem aracılığıyla oluşan inflamatuar yapısına bağlanabilir. Lenfosit alt grup analizinin egzersiz testindeki yerinin belirlenmesi için daha ileri çalışmalara gereksinim vardır.
Long-Term Follow-Up of P-Wave Duration and Dispersion in Patients With Mitral Stenosis
(Blackwell Publishing, 2008) Guntekin, Unal; Gunes, Yilmaz; Tuncer, Mustafa; Gunes, Ahmet; Sahin, Musa; Simsek, Hakki
Background: Patients with mitral stenosis have prolonged P-wave duration and increased P-wave dispersion (PWD) that have been associated with increased risk for atrial fibrillation. Methods: Thirty mild-to-moderate mitral stenosis patients were followed for 38.4 +/- 10.7 (23-48) months. Baseline and last 12-lead electrocardiographic and transthoracic echocardiographic measurements were evaluated. Maximum and minimum P-wave durations (P-max and P-min) and PWD were calculated. Results: P-max and PWD were significantly higher in patients compared to control group. Left atrial (LA) size, mitral gradient, and pulmonary artery systolic pressure (PASP) were significantly increased and mitral valve area (MVA) was decreased during follow-up. There were significant increases in P-max and PWD and significant decrease in P-min (P-max: 101.0 +/- 12.5 ms vs 105.0 +/- 16.5 ms, P = 0.005; P-min: 59.3 +/- 8.5 ms vs 55.0 +/- 12.3 ms P = 0.004; PWD: 41.7 +/- 5.5 ms vs 50.0 +/- 6.2 ms, P < 0.001). Baseline P-max, P-min, and PWD were significantly correlated with MVA (P-max: r = -0.605, P < 0.001, P-min: r = -0.632, P < 0.001, PWD: r = -0.402, P = 0.0028) and mean mitral gradient (P-max: r = 0.412, P = 0.024, P-min: r = 0.632, P = 0.049, PWD: r = 0.378, P = 0.039). In addition to MVA and mean mitral gradient follow-up P-wave variables were significantly correlated with LA size (P-max: r = 0.573, P = 0.001, P-min: r = 0.636, P = 0.001, PWD: r = 0.265, P = 0.046) and PASP (P-max: r = 0.462, P = 0.011, P-min: r = 0.472, P = 0.008 PWD: r = 0.295, P = 0.047). Conclusions: P-wave duration and PWD increase progressively in accordance with the progression of mitral stenosis. (PACE 2008; 31:1620-1624).
Metoprolol ve Diltiazemin Mitral Darlıklı Olgularda P Dalga Dispersiyonuna Etkisi
(2003) Eryonucu, Beyhan; Gunes, Ahmet; Güler, Niyazi; Demirbag, Recep; Sinci, Ayhan
Atriyum büyümesi ve kalp debisinin azalmasına bağlı artmış sempatik aktivite sonucu mitral darlığında P dispersiyonu (P dis) artmaktadır. P diş artması ile atriyal jibrilasyon gelişimi arasında yakın bir ilişki olduğu bilinmektedir. Bu çalışmada ise mitral darlıklı olgularda P dis maksimum P dalga süresi (P max) ve minimum P dalga süresi (P min) üzerine metoprolol ve diltiazemin etkisi araştırıldı. Metoıl: Mitral darlıklı 84 olgu metoprolol grubu 44 hasta (36 sı kadın, yaş ortalaması 38+12 yıl) ve diltiazem grubu 40 lias ta (35 kadın, yaş ortalaması 40±9 yıl) olarak iki gruba randomize edildi. Tedavi öncesi ve sonrası transtorasik ekokardiyorafik inceleme ile sol atriyum boyutu, sol ventrikül çapları, mitral kapağa ait zirve ve ortalama gradiyentler mitral kapak alanı ve sol ventrikül ejeksiyon fraksiyonları hesaplandı. Elektrokardiyografilerde tedavi öncesi ve sonrasında P dalga süreleri büyüteç yardımıyla ölçüldü. Bulgular: Her iki grubun başlangıç ekokardiyografik değerleri ile P max. P min ve P dis değerleri arasında anlamlı fark yoktu (p>0.05). Bir aylık metoprolol tedavisi ile P max. Pmin ve P dis ile transmitral ortalama gradiyentte (TMOG) belirgin azalma gözlendi (p<0.01). Diltiazem grubunda ise P max. P dis ve TMOG değerlerinde anlamlı azalma görülürken P min değerinde anlamlı fark saptanmadı (p>0.05). İki grup karşılaştırıldığında ise metoprolol grubunda P max ve P dis ile TMOG de anlamlı derecede azalma saptandı (p
Noninvasive Assessment of Atherosclerosis in Patients With Isolated Hypertension
(Wiley, 2010) Guntekin, Unal; Gunes, Yilmaz; Gunes, Ahmet; Ceylan, Yemlihan; Gumrukcuoglu, Hasan Ali; Yucel, Yavuz; Tuncer, Mustafa
Background: Endothelial dysfunction is considered the first stage in the development of atherosclerosis. Brachial artery flow-mediated dilatation (FMD) has been used to assess endothelial dysfunction. An impaired FMD response may reflect a vascular phenotype prone to atherosclerosis. The thickness of the common carotid intima-media (CIMT) as measured by ultrasound represents a marker of structural atherosclerosis. Recently, it has been shown that color M-mode propagation velocity measured along the origin of descending thoracic aorta (AVP) may reflect atherosclerosis. In this study, the effects of isolated hypertension on these atherosclerosis markers are investigated. Methods: Fifty patients with newly diagnosed hypertension and forty healthy people were enrolled. Patients were evaluated with transthoracic echocardiography. Diastolic functions were evaluated by transmitral filling parameters of deceleration time (DT), E/A ratio, and isovolumetric relaxation time (IVRT). Carotid intima-media thickness, FMD, and AVP were measured. Results: Age, gender, and BMI of both groups were similar. Compared to control group CIMT, DT and IVRT values were significantly higher, and FMD and AVP values were significantly lower in hypertensive patients. There were significant correlations between AVP and CIMT (r = -0.699, P < 0.001), AVP and FMD (r = 0.400, P < 0.001), and FMD and CIMT (r = -0.600, P < 0.001). Carotid intima-media thickness, AVP, and FMD were significantly correlated with systolic and diastolic blood pressures and DT and IVRT. Conclusions: In patients with isolated hypertension, AVP and FMD decrease and CIMT increases. In addition, CIMT is inversely correlated with AVP and FMD, and AVP is directly correlated with FMD. (ECHOCARDIOGRAPHY 2010;27:155-160).
Qtc Dispersion in Hyperthyroidism and Its Association With Pulmonary Hypertension
(Wiley, 2009) Guntekin, Unal; Gunes, Yilmaz; Tuncer, Mustafa; Simsek, Hakki; Gumrukcuoglu, Hasan Ali; Arslan, Sevket; Gunes, Ahmet
Background: Several studies have reported that hyperthyroidism is associated with prolonged QT interval corrected by the heart rate (QTc) and pulmonary hypertension (PHT). Methods: Forty-seven patients with newly diagnosed overt hyperthyroidism and 20 healthy people were enrolled in the study. Transthoracic echocardiography, 12-lead surface electrocardiogram, and thyroid hormone levels were studied at the time of enrollment and after achievement of euthyroid state with propylthiouracil treatment. Results: Baseline clinical characteristics were similar. However, heart rate (90.5 +/- 19.6 vs 79.2 +/- 13.7 bpm, P = 0.024), pulmonary artery systolic pressure (PASP) (26.0 +/- 12.0 vs 10.6 +/- 4.0 mmHg, P < 0.001), E deceleration time (DT) (191.8 +/- 25.6 vs 177.0 +/- 10.7 ms, P = 0.016), isovolumetric relaxation time (IVRT) (91.38 +/- 12.3 vs 79.6 +/- 10.5 ms, P < 0.001), and QTc dispersion (QTcD) (50.3 +/- 17.2 vs 38.9 +/- 11.6 ms, P = 0.009) were significantly higher in hyperthyroid patients compared to control group. Heart rate (to 74.1 +/- 13.8, P < 0.001), QTcD (to 37.3 +/- 10.1 ms, P < 0.001), DT (to 185.3 +/- 19.7 ms, P = 0.008), IVRT (to 88.6 +/- 10.3 ms, P = 0.056), and PASP (23.1 +/- 10.1 mmHg P < 0.001) were significantly decreased after achievement of euthyroid state. Although PHT was present in 16 patients before treatment only six patients still had PHT during euyhyroid state. Compared to patients with normal PASP, QTcD was significantly longer in patients with PHT (56.5 +/- 15.8 vs 37.9 +/- 12.8 mmHg P < 0.001). There were also significant correlations between QTcD and presence of PHT (r = 0.516, P < 0.001) and PASP (r = 0.401, P = 0.009). Conclusions: Hyperthyroidism is a reversible cause of PHT and diastolic dysfunction. Increased QTcD observed in hyperthyroidism may be associated with PHT and diastolic dysfunction. These abnormal findings in hyperthyroidism often normalize with the achievement of euthyroid state. (PACE 2009; 32: 494 499)
Synthesis of New Axially Coumarin Disubstituted Silicon(IV) Phthalocyanines, Investigation of Their Dna-Binding Properties and Inhibitory Activities on Ache and Buche
(Bentham Science Publ Ltd, 2025) Gunes, Ahmet; Meletli, Furkan; Danis, Ozkan; Agirtas, Mehmet Salih; Yalcin, Bahattin
Introduction In this study, we report on the synthesis and characterization of new silicon (IV) phthalocyanine compounds (SiPcs) axially substituted with coumarin-linked derivatives, designed for potential application in photodynamic therapy (PDT) due to their photophysical properties.Methods Characterization was carried out using FT-IR, UV-Vis, MALDI-TOF-MS, and 1H NMR spectroscopy. In dimethyl sulfoxide (DMSO), the SiPcs produced singlet oxygen with quantum yields of 0.17 to 0.19, assessed by the DPBF quenching method. DNA binding studies via UV-Vis spectroscopy and molecular docking suggested high binding affinities (Delta G0 values between -9.90 to -10.4 kcal/mol) and stable interactions with calf thymus DNA (ct-DNA).Results The compounds showed promising inhibitory activity against acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE), with IC50 values indicating higher potency and selectivity compared to galantamine, a known cholinesterase inhibitor.Conclusion The combined singlet oxygen generation, DNA binding, and enzyme inhibition data underscore the potential of these SiPc-coumarin derivatives as multifunctional agents for PDT and neuroprotective applications such as Alzheimer's disease (AD).