Browsing by Author "Guler, N."

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Does Off-Pump Coronary Artery Bypass Surgery Reduce Secretion of Plasminogen Activator Inhibitor-1
(Wiley, 2007) Ozkara, C.; Guler, N.; Batyraliev, T.; Okut, H.; Agirbasli, M.
Prior studies showed that postoperative increase in plasminogen activator inhibitor-1 (PAI-1) levels is associated with an increased risk of graft occlusion after coronary artery bypass surgery (CABG). This prospective study aimed to compare the changes of PAI-1 antigen levels after off-pump and on-pump CABG. Forty-four patients admitted for elective CABG were randomised to on-pump (n = 22) or off-pump (n = 22) surgery. Serum samples were collected for estimation of PAI-1 and tissue plasminogen activator (t-PA) antigen levels preoperatively and 2 h after the operation. The groups were similar in terms of age, weight, gender ratio and extent of coronary disease, left ventricular function and number of grafts per patient. Fibrinogen and t-PA levels increased postoperatively in both the groups when compared with baseline values. After operation, statistical analysis revealed that increase of PAI-1 values was higher in off-pump group (44.1 +/- 9.1 vs. 25.3 +/- 6.9) than on-pump group (37.2 +/- 5.5 vs. 27.3 +/- 7.8, p = 0.002). This study shows that increase in PAI-1 antigen values in patients who undergo off-pump (beating heart) CABG is significantly higher than in those who undergo conventional CABG with cardiopulmonary bypass.
The Effect of Perindopril and Amlodipine on Brachial Artery Pulse Wave Velocities in Patients With Essential Hypertension
(1999) Guler, N.; Bilge, M.; Eryonucu, B.; Ipeksoy, U.
It is known that the brachial artery flow velocity as assessed by duplex Doppler ultrasound is changed in hypertension. The main purpose of this study was to assess the effects of perindopril and amlodipine on the brachial artery pulse wave velocity in essential hypertension. Blood flow profile and velocity of the brachial artery were determined noninvasively by pulsed Doppler ultrasound technique under the guidance of a B-mode ultrasound image. Thirty-two untreated hypertensive patients and 11 control subjects matched for age and sex were included in the study. Hypertensive patients were classified into two groups which were treated either with amlodipine 5 mg or perindopril 4 mg and re-evaluated after 15 days. Patients with essential hypertension had significantly larger peak systolic velocity than those without it (71(18 cm/sec vs. 45(16 cm/sec, P<0.001). After antihypertensive treatment, significant decrease was found in the mean blood pressures of both groups (P<0.001). After treatment with perindopril, peak systolic velocity decreased (73±19 vs 58±14 cm/sec, P<0.05) and duration of systolic flow prolonged (269±18ms vs 291±17ms, P<0.05). Also, after treatment with amlodipine, peak systolic wave decreased (68±15ms vs 55±13ms, P<0.05) and duration of systolic flow prolonged (266±17ms vs 288±18ms, P<0.01). In conclusion, as assessed by duplex Doppler ultrasound, peak systolic wave was increased and systolic flow duration not changed in essential hypertension. Both perindopril and amlodipine treatments decreased peak systolic velocity and prolonged systolic flow duration. Further study is needed to clarify the exact mechanisms of the flow velocity alterations with antihypertensive therapy.
The Effects of Volatile Anaesthetic Agents in Myocardial Repolarization During Induction of Anaesthesia
(1999) Guler, N.; Bilge, M.; Eryonucu, B.; Demirel, C.B.; Kati, I.; Sayarlioglu, M.
QT dispersion may serve as a measure of variability in ventricular repolarization time and may be a means of identifying patients at risk of arrhythmias and sudden death after different clinical settings. The acute responses of QTc dispersion were assessed in 47 American Society of Anesthesiology (ASA) class 1 or 2 patients receiving volatile anaesthetic agents. Anaesthesia was induced with sevoflurane (n=16), halothane (n=17), or isoflurane (n=14), and the inspired concentration increased to reach an end- tidal concentration of 1% to 6%. Recordings of ECG, heart rate, blood pressures were obtained at the following times: prior to induction of anaesthesia, 1 min and 3 min after stable end-tidal concentration, 1 min and 3 min later vecuronium administration, and 1 min and 3 min after tracheal intubation. All the patients studied had normal values of QTc interval and QTc dispersion at rest. All anaesthetic agents significantly increased QTc dispersion compared with baseline values. Both isoflurane and sevoflurane increased QTc interval compared with baseline in contrast to halothane which did not change it significantly. Thus, anaesthetic agents cause myocardial repolarization abnormalities in man in terms of increased QTc dispersion. This may be relevant in the aetiology of arrhythmias in patients receiving anaesthesia without cardiovascular disease.
Leucocyte-Depleted Blood Cardioplegia
(Sage Publications Ltd, 2007) Ozkara, C.; Guler, N.; Kutay, V.; Guducuoglu, H.; Kitmaz, A.; Ozcan, S.
The effect of the depletion of leucocytes from cardioplegic and initial myocardial reperfusion blood on the inflammatory response and myocardial protection in patients with unstable angina undergoing cardiopulmonary bypass (CPB) was studied. Patients were allocated randomly to a leucocyte-depleted (LD) group or a control group. The LD group received continuous retrograde LD isothermic blood cardioplegia and the control group received isothermic blood cardioplegia. Blood samples were collected at seven time-points before, during and after the procedure. Total leucocyte counts of cardioplegia blood in the LD group were significantly lower than in the control group, but systemic leucocyte and neutrophil counts after CPB did not differ between the groups. The levels of adhesion molecules, cytokines, elastase and malondialdehyde were significantly increased after CPB in both groups and reached peak values 2 - 6 h after surgery; no other significant differences were found. LD cardioplegia and myocardial reperfusion did not attenuate the endothelial and neutrophilmediated components of the CPB-induced inflammatory response, which may lead to myocardial reperfusion injury.
P Wave Dispersion in Hypertensive Urgency
(Russian Heart Failure Soc, 2008) Tuncer, M.; Fettser, D.; Gunes, Y.; Batyraliev, T.; Guntekin, U.; Gumrukcuoglu, H. A.; Guler, N.
Background and purpose: P wave dispersion (PWD) has been accepted as a predictor for atrial fibrillation (AF) in hypertension and some other cardiac diseases. The aim of this study was to compare the P wave parameters between patients with mild-moderate hypertension and those with hypertensive crises. Methods: A total of 48 patients, 24 of who presented to the emergency department with hypertensive urgency and 24 patients who were followed in the cardiology clinic with mild-moderate essential hypertension were included in this study. P wave durations were measured manually by two investigators blinded to data of patients. Results: The maximal duration of P wave (P-max) and the PWD were found to be significantly different between groups, being longer in patients with hypertensive urgency (p=0,05 and 0,02; respectively). Conclusions: PWD increases in hypertensive urgency states. Clinical implication of this finding should be addressed with further, prospective studies conducted on larger samples.
Recovery of Left Ventricular Systolic Function After Left Anterior Descending Coronary Artery Stenting
(2005) Agirbasli, M.; Guler, N.
Our objective was to determine the factors affecting recovery of left ventricular (LV) contractility and myocardial perfusion after percutaneous coronary intervention (PCI). We selected 60 consecutive patients who underwent successful left anterior descending coronary artery (LAD) stenting. The mean stent diameter and length were 3.37 ± 0.47 mm and 17.4 ± 6 mm, respectively. Supporting a functional impact of successful PCI, myocardial perfusion and LV ejection fraction (LVEF) improved at 6 ± 3 months after the procedure (48.8 ± 11.6% vs 52.5 ± 11.5%, P = 0.05). Patient related factors such as diabetes mellitus, presentation with acute coronary syndrome, and age did not seem to affect LVEF change after the procedure. On univariate analysis, the change in LVEF after PCI was only related to the stent diameter. The increase in LVEF was higher in patients who received a stent >3 mm in diameter (P = 0.041). There was a weak but statistically positive correlation between the stent diameter and the LVEF change after the procedure (R = 0.267, P = 0.049). Other procedure related factors such as multivessel PCI or stent length did not affect the percent ejection fraction change after stenting.