Search PubMed⌕ Search

Biomedical subjects

Dayimi Kaya

Publications and source records attributed to Dayimi Kaya.

At least 19 recordsLinked to original sources
PubMed2006

Tissue Doppler evaluation of intraventricular asynchrony in isolated left bundle branch block.

BACKGROUND: The aim of this study was to evaluate normal subjects with isolated left bundle branch block (LBBB) using tissue Doppler imaging (TDI) for the presence of intraventricular asynchrony. METHODS AND RESULTS: For this purpose, 23 subjects with isolated LBBB were compared with age-matched asymptomatic healthy subjects without LBBB with respect to global ejection fraction (EF) and isovolumic contraction time (ICTm) in separate left ventricular segments. TDI evaluation revealed prolongation of the ICTm in all of the segments in the LBBB group. Moreover, the ICTm differed significantly in each segment in the LBBB group. The ICTm in the lateral segments were shown to be longer compared to the anteroseptal segments. CONCLUSION: Our results indicate the presence of intraventricular asynchrony in isolated LBBB. This fact may play a role in the decreased global EF and increased cardiac mortality in patients with isolated LBBB.

Bundle-Branch Block↗
PubMed2006

Impaired left ventricular filling in patients with essential hyperhidrosis: an echo-Doppler study.

Essential hyperhidrosis is a well recognized dermatologic and neurologic disorder, characterized by excessive sweating of the eccrine sweat glands. It is also associated with cardiac autonomic dysfunction because sympathetic fibers to eccrine glands of palms of the hand arise from stellate and upper thoracic ganglia, which also innervate the heart. In this study, we investigated cardiac function in patients with essential hyperhidrosis by conventional and tissue Doppler imaging methods. Eighteen subjects with essential hyperhidrosis and eighteen control subjects were included in this study. Pulsed-wave Doppler parameters of the left and right ventricles, which represent diastolic filling abnormalities, were obtained by conventional Doppler and tissue Doppler imaging. Isovolumetric relaxation time, isovolumetric contraction time, ejection time and myocardial performance index were also calculated. Mitral inflow peak early (E(M)) and late (A(M)) velocities and E(M)/A(M) ratio, which represent diastolic filling of left ventricle, were significantly lower in hyperhidrotic subjects than in controls. Also, mitral lateral annulus early and late velocities and early/late velocity ratio, reflecting diastolic filling of left ventricle, were significantly lower in hyperhidrotic subjects than those of controls. However, there were no differences between hyperhidrotic subjects and control subjects with regard to the other echocardiographic indices of left and right ventricle diastolic functions. In conclusion, decreased mitral inflow suggests left ventricle diastolic dysfunction in patients with essential hyperhidrosis. This indicates that hyperactivity of sympathetic nervous system in patient with hyperhidrosis may alter cardiac function in long term.

Adult↗
PubMed2006

Acute smoking-induced alterations in Doppler echocardiographic measurements in chronic smokers.

Acute effects of smoking on left ventricular function have been studied previously. However, effects on right ventricular function have not yet been investigated. In this study, we attempted to investigate, through a combination of conventional and tissue Doppler imaging (TDI), the acute effects of smoking on both left and right ventricular function in chronic smokers. Thirty chronic smokers (with smoking habits of > or =1 pack/day for 74 +/- 1.3 years) underwent a complete transthoracic echocardiographic examination (2-dimensional, pulsed-wave Doppler transmitral and transtricuspid recordings, and TDI recordings of mitral and tricuspid annular velocities) by 3.5-MHz sector transducer. Pulsed-wave Doppler indices of left and right ventricular diastolic function-such as mitral and tricuspid inflows, peak early (E) and late (A) velocities, and E/A ratios-were obtained by conventional Doppler and TDI. Echocardiographic indices of the left and right ventricles--including isovolumetric relaxation time, isovolumetric contraction time, ejection time, and myocardial performance index of right ventricle-were also measured before and 30 minutes after each subject smoked a cigarette. Both mitral and tricuspid inflow measurements changed significantly after smoking a cigarette. Among the TDI measurements, mitral lateral annulus and tricuspid lateral annulus (diastolic, but not systolic) velocities changed after smoking a cigarette. Also, the right ventricular myocardial performance index increased immediately after smoking a cigarette. We found that acute cigarette smoking impaired both left and right ventricular diastolic function in chronic smokers.

Adult↗
PubMed2005

Heart rate variability in patients with essential hyperhidrosis: dynamic influence of sympathetic and parasympathetic maneuvers.

BACKGROUND: Essential hyperhidrosis has been associated with an increased activity of the sympathetic system. In this study, we investigated cardiac autonomic function in patients with essential hyperhidrosis and healthy controls by time and frequency domain analysis of heart rate variability (HRV). METHOD: In this study, 12 subjects with essential hyperhidrosis and 20 healthy subjects were included. Time and frequency domain parameters of HRV were obtained from all of the participants after a 15-minute resting period in supine position, during controlled respiration (CR) and handgrip exercise (HGE) in sitting position over 5-minute periods in each stage. RESULTS: Baseline values of HRV parameters including RR interval, SDNN and root mean square of successive R-R interval differences, low frequency (LF), high frequency (HF), normalized unit of high frequency (HFnu), normalized unit of low frequency (LFnu), and LF/HF ratio were identical in two groups. During CR, no difference was detected between the two groups with respect to HRV parameters. However, the expected increase in mean heart rate (mean R-R interval) did not occur in hyperhidrotic group, whereas it did occur in the control group (Friedman's P = 0.000). Handgrip exercise induced significant decrease in mean R-R interval in both groups and no difference was detected between the two groups with respect to the other HRV parameters. When repeated measurements were compared with two-way ANOVA, there was statistically significant difference only regarding mean heart rate in two groups (F = 6.5; P = 0.01). CONCLUSION: Our overall findings suggest that essential hyperhidrosis is a complex autonomic dysfunction rather than sympathetic overactivity, and parasympathetic system seems to be involved in pathogenesis of this disorder.

Analysis of Variance↗
PubMed2005

Cigarette smoking and heart rate variability: dynamic influence of parasympathetic and sympathetic maneuvers.

BACKGROUND: Cigarette smoking has been associated with increased activity of the sympathetic nervous system. In this study, we investigated cardiac autonomic function in heavy smokers and nonsmoker controls by analysis of heart rate variability (HRV). METHOD: Twenty-four long-term heavy smokers (men) and twenty-two nonsmoker subjects (hospital staff) were included to study. Time domain [mean R-R interval (RR), the standard deviation of R-R interval index (SDNN), and the root mean square of successive R-R interval differences (RMSSD)] and frequency domain [high frequency (HF) low frequency (LF), and LF/HF ratio] parameters of HRV were obtained from all participants after 15 minutes resting period in supine position (S), during controlled respiration (CR), and handgrip exercise (HGE) over 5-minute periods. RESULTS: Baseline SDNN and RMSSD values were found to be lower in smokers than in nonsmokers. (64+/-10 vs 78+/-22, P<0.05 and 35+/-12 vs 54+/-30 ms, P<0.05). Baseline LF/HF ratio was also found to be higher in smokers than in nonsmokers (1.3+/-0.6 vs 0.9+/-0.5 ms, P<0.05). The other HRV parameters including R-R interval, LF, and HF were not significantly different. During CR, expected increase in RR, SDNN, and RMSSD did not occur in smokers, while it did occur in nonsmokers. Most HRV indices were significantly affected by HGE in both groups. In addition, the duration of smoking was found to be inversely correlated with RMSSD and HF and positively correlated with LF/HF ratio. CONCLUSION: Vagal modulation of the heart is blunted in heavy smokers, particularly during a parasympathetic maneuver. Blunted autonomic control of the heart may partly be associated with adverse event attributed to cigarette smoking.

Adult↗
PubMed2005

Peripheral vascular endothelial function in essential hyperhidrosis.

BACKGROUND: Essential hyperhidrosis, a disorder of the eccrine sweat glands, is associated with sympathetic overactivity and the aim of the present study was to determine endothelium-dependent vasodilator function in patients with this condition. METHODS AND RESULTS: Using high-resolution ultrasound, the diameter of the brachial artery at rest and during reactive hyperemia (flow-mediated dilatation, %FMD endothelial-dependent stimulus to vasodilatation), as well as after sublingual administration of nitroglycerin (%NTG endothelium-independent vasodilatation) was measured in 18 subjects (mean age 27+/-5 years) with essential hyperhidrosis and 24 healthy control subjects (mean age 29+/-5 years). Baseline brachial artery diameter and FMD were comparable in both groups (BAD: 4.1+/-0.7 mm vs 4.3+/-0.5 mm (control), p = 0.8; FMD: 5.6+/-1.9% vs 6.7+/-2.2%, p=0.1). The time-averaged flow velocity during peak reactive hyperemia was similar in the 2 groups (75+/-11 cm/s vs 72+/-10 cm/s, p = 0.5), nor did NTG-induced dilatation in the patients with essential hyperhidrosis differ significantly from that in healthy control subjects (12.8+/-2.7% vs 14.0+/-3.6%, p = 0.3). CONCLUSION: These findings suggest that endothelium-dependent dilatation of large conduit arteries is preserved in essential hyperhidrosis and it seems to be a localized disorder of the eccrine sweat glands rather than a generalized disorder involving vascular endothelium.

Adult↗
PubMed2005

Comparison of the predictors for atrial rhythm disturbances between trained athletes and control subjects.

Atrial rhythm disturbances, particularly atrial fibrillation (AF), are frequently encountered in trained athletes. P wave dispersion (PWD) is a recent electrocardiographic (ECG) marker that reflects velocity of atrial impulse propagation. However, it remains unknown whether the P wave duration and PWD are different between athletes and sedentary controls. In this study we therefore determined the P wave duration and PWD, markers for conduction abnormalities, in trained athletes and controls. Fifty athletes and sex and age-matched 40 healthy sedentary controls were included in the study. All of the athletes were the members of a local athletic college and they were regularly maintaining their sportive activities; the duration of athletic competition was 7.7 +/- 3.3 years and the average athletic time was 10.1 +/- 1.6 hours/week. The 12-lead surface ECG was obtained from each subject in the supine position. The P wave duration was measured, and the difference between the maximum and minimum P wave duration was defined as the PWD. Distribution of sex, age, body mass index, blood pressure was similar in athletic groups and controls. Heart rate was significantly lower in the athletes than in the controls (66 +/- 7 vs 73 +/- 9 beats/min, p < 0.05). Maximum and minimum P wave durations were not statistically different in athletic group and controls (115 +/- 6 vs 114 +/- 4 ms and 74 +/- 8 vs 74 +/- 7 ms, respectively). In addition, PWD did not differ significantly in both groups (41 +/- 6 vs 40 +/- 7 ms, respectively). Thus, athlete's heart is not associated with prolonged P wave duration and increased PWD, indicating that P wave duration or PWD could not be used as a predictor for AF developed in trained athletes.

Adult↗
PubMed2004

Comparison of the effects of ipratropium bromide and salbutamol on autonomic heart rate control.

AIMS: B2-agonists and anticholinergic drugs may alter cardiac autonomic modulation. The aim of this study was to investigate the effects of inhaled salbutamol and ipratropium bromide on heart rate variability (HRV). METHODS AND RESULTS: A randomized, double-blind, crossover design study was conducted on 13 healthy volunteers. Salbutamol, ipratropium or placebo was administered in three different testing sessions. Time domain parameters; mean R-R interval (mean-RR), the standard deviation of R-R interval (SDNN) and the root mean square of successive R-R interval differences (RMSSD) and power spectral analysis of HRV were assessed in the supine position and during handgrip exercise before and after taking each drug. In time domain analyses, ipratropium administration resulted in a reduced mean-RR, SDNN and RMSSD during handgrip exercise compared with baseline values (775 +/- 30 ms vs. 748 +/- 21 ms, P < 0.05; 57 +/- 5 ms vs. 50 +/- 5 ms, P < 0.05; 30 +/- 2 ms vs. 26 +/- 2 ms, P < 0.01, respectively). This effect was not detected with salbutamol or placebo administration. In frequency domain analyses, salbutamol but not ipratropium and placebo inhalation increased high frequency power/total power during handgrip exercise compared with baseline (0.09 +/- 0.02 vs. 0.12 +/- 0.02, P < 0.05). CONCLUSION: Ipratropium inhalation may alter autonomic control of the heart rate in therapeutic doses during mild sympathetic stimulation in healthy subjects, while salbutamol does not show these effects.

Adrenergic beta-Agonists↗
PubMed2004

Sildenafil citrate does not alter ventricular repolarization properties: novel evidence from dynamic QT analysis.

BACKGROUND: Sildenafil citrate may have direct cardiac electrophysiological effects, and is possibly responsible for some cardiac events. The aim of our study was to investigate the effects of sildenafil citrate on QT dynamicity properties with a new QT analysis program showing even small changes in ventricular repolarization. METHODS: Twenty-four-hour Holter electrocardiographic recordings were used to obtain the data in the predrug phase (1-hour rest position before drug administration), and in the postdrug phase (1-hour rest position, which began 60 minutes after 50 mg oral sildenafil citrate administration). With the special QT analysis program (Verda, Reynolds Medical Ltd., UK); mean values of RR, QT, QTo (corrected QT), J (the exponent of correction formula) and S (QT/RR plots slope) parameters together with QT variability indexes (QTVI) were calculated for study phases. RESULTS: Mean +/- SEM values for RR and QT were higher in postdrug phase than in predrug phase (RR: 845 +/- 42 ms vs 816 +/- 46 ms, P < 0.05; QT: 371 +/- 8 ms vs 361 +/- 9 ms, P < 0.05). However, sildenafil did not induce any significant change in mean +/- SEM values for QT(o), J, and S in postdrug phase compared with predrug phase (408 +/- 10 ms vs 406 +/- 8 ms, 0.474 +/- 0.030 vs 0.433 +/- 0.025, 0221 +/- 0.020 vs 0.198 +/- 0.017, respectively; P > 0.05). QTVIs were also not different in each phase (predrug: -0.874 +/- 0.071 vs postdrug: -0.997 +/- 0.067, P = 0.109). CONCLUSIONS: Fifty milligrams sildenafil does not affect QT dynamicity properties. The cardiac events associated with sildenafil could not be explained with ventricular arrhythmias.

Administration, Oral↗
PubMed2004

Effect of smoking on endothelial function and wall thickness of brachial artery.

BACKGROUND: Impaired flow mediated dilatation (FMD) and increased wall thickness (WT) of the brachial artery have been associated with atherosclerosis and its risk factors. In this study we sought to determine brachial artery wall thickness in chronic smokers and the instantaneous effect of smoking on brachial artery endothelium dependent vasodilator function in smokers and non-smokers. METHOD AND RESULTS: Using a high-resolution ultrasound, WT of posterior brachial artery wall, the diameter of brachial artery at rest and during reactive hyperemia (FMD %), as well as after sublingual administration of nitroglycerine (nitroglycerine mediated dilatation (NMD) %) was measured in 20 smokers and 20 non-smokers. Wall thickness (WT) of the posterior brachial artery wall and the wall index (WI) were greater in smokers than non-smokers. The baseline brachial artery diameter was comparable in smokers and non-smokers. Flow mediated dilation (FMD) was found to be less in smokers than non-smokers. The NMD in smokers also did not differ significantly from that in non-smokers. Flow mediated dilation significantly reduced after smoking compared to baseline in both groups. However, NMD remained unchanged after smoking in both groups. CONCLUSIONS: Increased WT and impaired endothelium-dependent dilatation of brachial artery suggests that cigarette smoking disrupts vessel wall morphology long before atherosclerosis is manifest.

Administration, Sublingual↗
PubMed2004

Acute cigarette smoking-induced hemodynamic alterations in the common carotid artery--a transcranial Doppler study--.

BACKGROUND: Cigarette smoking has been shown to temporarily alter cerebral flow velocity and vasomotor reactivity, so the aim of this study was to assess the acute effects of smoking a single cigarette on the common carotid artery (CCA) hemodynamics in healthy nonsmokers. METHOD AND RESULTS: Using a 7.0 MHz linear transducer of a computed sonography system, the CCA hemodynamics, including the diameter of the left and right CCA, peak systolic velocity, maximum end-diastolic velocity, time-averaged maximum velocity pulsatility index, resistivity index, flow volume, diameter and area of the CCAs, were measured in 16 healthy nonsmokers before and immediately after smoking a cigarette. Compared with the baseline, heart rate and blood pressure significantly increased, the diameter, flow volume and area of each CCA were unchanged, and the pulsatility index and resistivity index were significantly altered after smoking. In addition, the peak systolic velocity, maximum end-diastolic velocity and time-averaged maximum velocity were significantly altered after smoking. CONCLUSIONS: Cigarette smoking significantly altered the CCA hemodynamics in nonsmokers, probably as a consequence of enhanced adrenergic activity.

Adult↗
PubMed2004

[The effects of rilmenidine on cardiac autonomic function in healthy volunteers].

INTRODUCTION AND OBJECTIVES: Rilmenidine is an antihypertensive drug whose antihypertensive effect occurs via a sympatholytic action on the central nervous system. However, the effects of rilmenidine on autonomic cardiovascular function are not clear. The aim of this study was to evaluate the acute effect of rilmenidine on autonomic cardiac function by measuring heart rate variability. SUBJECTS AND METHOD: A total of 20 healthy men (mean age, 263 years) were included in the study; 1 mg of rilmenidine or placebo was given to participants on different days in a double-blind crossover randomized study protocol. After drug administration, time domain and frequency domain parameters of heart rate variability were determined before and after 2 h with the patient in supine decubitus and during the handgrip exercise with 5-min electrocardiographic recordings. RESULTS: Rilmenidine caused an increase in mean RR values after administration when compared to pre-drug administration recordings with the patient in supine decubitus (929 ms vs 860 ms, P<.05), but this effect was not found in the placebo group. However, there were no differences in other time domain parameters or in any of the frequency domain parameters (normalized low frequency unit, normalized high frequency unit and low frequency/high frequency ratio) with the participant in supine position in either group. In addition, neither rilmenidine nor placebo modified heart rate variability parameters during the handgrip exercise. CONCLUSION: Administration of a single dose of rilmenidine increased vagal tone without affecting vagal modulation in the supine position. The absence of vagal tone increase during the handgrip exercise suggests that this effect of rilmenidine is minimal.

Adult↗
PubMed2003

The effect of dopamine type-2 receptor blockade on autonomic modulation.

Dopamine2 (D2)-like receptor antagonists are widely used for the treatment of gastroparesis and vomiting. Metoclopramide (MCP), a peripheral and central D2-like receptor antagonist, stimulates the sympathetic nervous system and may alter autonomic modulation, but the net effect of MCP to the heart is not known. The aim of our study was to investigate the effects of MCP on cardiac autonomic modulation, using power spectral analysis of heart rate variability. We evaluated the effect of MCP on cardiac autonomic modulation during prolonged supine and standing positions in 9 healthy men. We intravenously administered 10 mg MCP and placebo in a double blind and crossover manner to all participants during continuous electrocardiography recording. Placebo or MCP was administered after 15 minutes in supine position (REST phase), where participants remained for an additional 50 minutes (PSUP phase) and then stood up for 10 minutes (STA phase). Five-minute intervals were selected for power spectral analysis, and average values were calculated for low frequency (LF), normalized unit of LF (LFnu), high frequency (HF), normalized unit of HF (HFnu) components of the power spectrum, and for LF/HF ratio.Heart rate alterations were statistically significant during placebo administration (Friedman's p < 0.0001). These changes were related to the decrease in PSUP phase and increase in STA phase in post hoc analyses. There was a trend toward lower LFnu in PSUP phase (Friedman's p = 0.050), but LF/HF ratio changes did not reach a statistically significant level during placebo administration. MCP administration prevented the decrease in heart rate and LFnu component was seen with placebo in PSUP phase. Heart rate alterations also reached a significant level during MCP administration (Friedman's p = 0.002), and post hoc analyses showed that these changes were mainly related to the increase in STA phase. In contrast to placebo, MCP administration resulted in significant alterations in LFnu and LF/HF ratio (Friedman's p = 0.004 and p = 0.003, respectively). Two-way ANOVA model for LF/HF ratio changes showed that MCP induced a significant upward shift in LF/HF ratio than placebo during each phase of the study (F = 5.570; p = 0.031). We concluded that the net effect of MCP on sympathovagal balance is an increased sympathetic drive to the heart. MCP prevented the decrease in sympathetic drive to the heart during prolonged supine position and augmented sympathetic drive to the heart during mild sympathetic stimulation such as induced by standing up.

Adult↗
PubMed2003

Single dose nasal 17beta-estradiol administration reduces sympathovagal balance to the heart in postmenopausal women.

AIM: Long-term estrogen replacement therapy has favorable results on autonomic cardiovascular functions in postmenopausal women. Although acute estrogen administration has beneficial modulations on autonomic tone in animal studies, there are still controversies about the effects of acute estrogen on autonomic modulation to the heart in humans. The aim of this double-blind study was to investigate the acute effects of intranasal 17beta-estradiol administration on autonomic control of heart rate. METHODS: Nineteen postmenopausal women with typical hormone profiles were crossover randomized to 300 micro g nasal 17beta-estradiol (Aerodiol, Servier, Chambray-les-Tours, France) or an identical placebo at least 5 days apart. Both time domain and frequency domain heart rate variability (HRV) parameters were obtained during controlled respiration (CR) and handgrip exercise (HGE), before and 45 min after 17beta-estradiol or placebo administration. RESULTS: Baseline HRV parameters were similar for each occasion. Time domain indices obtained after 17beta-estradiol administration were not significantly different from results obtained with the placebo. In frequency domain parameters, 17beta-estradiol administration resulted in a reduced low frequency to high frequency ratio (LF/HF ratio) when compared with the placebo during CR (0.72 +/- 0.09 vs 1.00 +/- 0.15, P < 0.05) but not during HGE (3.03 +/- 0.37 vs 2.86 +/- 0.30, P > 0.05). CONCLUSION: A single intranasal 17beta-estradiol administration acutely reduced sympathovagal balance to the heart during the course of parasympathetic maneuver in healthy postmenopausal women.

Administration, Intranasal↗
PubMed2003

Lacrimo-auriculo-dento-digital syndrome with QT prolongation.

We present a case of a young boy in whom lacrimo-auriculo-dental-digital (LADD) syndrome with QT prolongation was detected. According to Bazett's formula, corrected QT was 504 ms. There were no published data about LADD syndrome with QT prolongation. This is the first case concerning LADD syndrome associated with QT prolongation. It is known that deafness and QT prolongation occur in potassium channel dysfunction. QT prolongation and deafness may be associated with potassium channel dysfunction in patients with LADD syndrome. As a result QT prolongation may be a new component of the LADD syndrome.

Abnormalities, Multiple↗