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Biomedical subjects

Kudret Aytemir

Publications and source records attributed to Kudret Aytemir.

At least 37 records · Page 2Linked to original sources
PubMed2004

The signal-averaged P-wave duration is longer in hypertensive patients with history of paroxysmal atrial fibrillation as compared to those without.

BACKGROUND: Onset of atrial fibrillation in hypertensive patients is usually associated with a high occurrence of cardiovascular complications. Therefore, it is important to assess non-invasively the risk of developing paroxysmal atrial fibrillation (PAF) in hypertensive patients during sinus rhythm. This study was undertaken to determine if hypertensive patients with history of PAF could be identified while in sinus rhythm by measurement of signal-averaged ECG P-wave duration. METHODS: Signal-averaged electrocardiography (SAECG) P-wave recording was performed in 44 hypertensive patients (30 men and 14 women; mean age 60+/-11 years, group A) who had a history of paroxysmal AF and in 50 hypertensive patients without history of AF (33 men and 17 women; mean age 57+/-12, group B). All patients were also evaluated by using echocardiography to measure left ventricular ejection fraction (LVEF) and left atrial diameter (LAD). RESULTS: SAECG P-wave duration was found to be significantly higher in group A than in group B (146+/-14 ms vs. 128+/-11 ms, p<0.001). Left atrial diameter was not significantly different (40.1+/-3.4 mm vs. 39.3+/-3.0 mm, p>0.05), whereas LVEF was significantly lower in group A than group B (63+/-5% vs. 67+/-4%, p=0.03). There was a correlation between SAECG P-wave duration and age (r=0.32, p<0.05). In univariate analysis, SAECG P-wave duration and LVEF were significant predictors of PAF, but only SAECG P-wave duration remained a significant independent predictor of PAF in multivariate analysis. CONCLUSION: The results of this study indicate that hypertensive patients with history of PAF can be detected while in sinus rhythm by signal-averaged ECG P-wave duration.

Adult↗
PubMed2004

Atrioventricular nodal reentrant tachycardia with multiple discontinuities in the atrioventricular node conduction curve: immediate success rates of radiofrequency ablation and long-term clinical follow-up results as compared to patients with single or no AH-jumps.

BACKGROUND: Some patients with atrioventricular nodal reentrant tachycardia (AVNRT) demonstrate multiple discontinuities (AH jump) in their antegrade AV node conduction curves. We evaluated and compared the immediate success rates, procedure-related complications, long-term clinical follow-up results and recurrence rates after slow pathway ablation in patients with multiple versus single or no AH jumps. METHODS: The study group consists of 278 consecutive patients (mean age 36.6 +/- 15.7) who underwent ablation for typical AVNRT, divided into three categories according to the number of AH jumps (>/=50 ms) before ablation: Group-1 consisted of 63 patients (23%) with continuous AV node function curves; Group-2 of 183 patients (66%) with a single jump and Group-3 of 32 (12%) patients showing more than one AH jumps. RESULTS: Age was significantly higher in Group-3 as compared to Group-1 (43 +/- 18 years vs. 34 +/- 16 years, p = 0.020). The electrophysiological features of AVNRT did not differ among groups. Before ablation, the maximum AH interval was significantly longer in Group-3 as compared to Groups-1 and -2 ( p < 0.001 for both). AV node antegrade ERP was significantly shorter in Group-3 than in Group-2, both before and after ablation ( p < 0.050 for both). AV node Wenckebach cycle length (WCL) was shorter in Group-3 as compared to both Groups-1 and -2, before and after ablation ( p < 0.050 for all). AV node WCL was prolonged significantly in all groups after ablation ( p < 0.001 for all). Residual dual pathways were present in 37 of 278 patients (13%) after ablation and were significantly more frequent in Group-3 than Group-2 (31% vs. 15%, p = 0.023). CONCLUSIONS: Patients with multiple AH jumps are older and more often have residual dual atrioventricular nodal pathway physiology after successful ablation but these features do not affect the immediate and long-term success rates of slow pathway ablation as compared to patients with single or no AH jumps.

Adolescent↗
PubMed2004

Maximum P-wave duration and P-wave dispersion predict recurrence of paroxysmal atrial fibrillation in patients with Wolff-Parkinson-White syndrome after successful radiofrequency catheter ablation.

BACKGROUND: Identification of patients at risk for PAF recurrence after AP ablation is important because of the necessity for additional therapies. OBJECTIVES: To determine whether Maximum P-wave duration (Pmax) and P-wave dispersion (Pd ) detected on surface ECG after successful accessory pathway (AP) ablation can predict the recurrence of paroxysmal atrial fibrillation (PAF). METHODS: Seventy-eight patients with Wolff-Parkinson-White (WPW) syndrome who had at least one documented PAF episode and underwent catheter ablation were enrolled. Pmax, minimum P-wave duration (Pmin) and Pd were determined on a surface ECG recorded on a high resolution computer screen on day 2 after ablation of the AP. RESULTS: There was no significant difference in terms of basic clinical data and electrophysiological findings between patients with (Group-1, n = 19) and without (Group-2, n = 59) recurrence of PAF during follow-up of 21 +/- 10 months. Pmax and Pd were significantly higher in Group-1 than Group-2 (120 +/- 15 vs. 96 +/- 10 ms and 47 +/- 12 vs. 25 +/- 7 ms, respectively; p < 0.001 for both). Pmin didn't differ significantly. A Pmax value of > or = 103 ms separated Group-1 from Group-2 with a sensitivity of 84.2%, specificity of 72.9%, positive predictive value of 50%, and negative predictive value of 93.5%. A Pd value of > or = 32.5 ms separated Group-1 from Group-2 with a sensitivity of 89.5%, specificity of 84.7%, positive predictive value of 65.4%, and negative predictive value of 96.2%. Pmax (p < 0.010) and Pd (p < 0.001) were found to be significant univariate predictors of PAF, whereas only Pd remained significant in multivariate analysis (p = 0.037). CONCLUSION: Pd > or = 32.5 ms and Pmax > or = 103.0 ms predict the recurrence of PAF after ablation with acceptable positive and negative predictive values. Pd > or = 32.5 ms is an independent predictor of recurrence of PAF after catheter ablation in patients with WPW syndrome.

Adolescent↗
PubMed2004

Left ventricular long-axis function is reduced in patients with rheumatic mitral stenosis.

Left ventricular long-axis function evaluated by M-mode or tissue Doppler echocardiography has been shown to be useful indexes of left ventricular systolic function; however it has not been evaluated in patients with mitral stenosis. We examined the left ventricular long-axis function of the patients with pure mitral stenosis and normal global systolic function as assessed by fractional shortening of the left ventricle (LV). Fifty-two patients with pure mitral stenosis and twenty-two healthy controls were evaluated by echocardiography. Although there was no statistically significant difference in global systolic function, M-mode derived systolic motion of the septal side and (12 +/- 3 vs 14.4 +/- 1.5 mm, P = 0.016) the lateral side of mitral annulus (13.2 +/- 3 vs 16.8 +/- 2 mm, P = 0.001) were both significantly lower in the patients with mitral stenosis than control subjects. Similarly tissue Doppler systolic velocity of the septal annulus (7.6 +/- 1.1 vs 10.4 +/- 3.2 cm/s, P = 0.03) and lateral mitral annulus (7.6 +/- 1.1 vs 10.4 +/- 3.2 cm/s, P = 0.003) were also significantly lower in patients with mitral stenosis than in controls. There was a statistically significant correlation between septal annular motion and annular velocity (r = 0.643, P = 0.002). Septal annular motion and annular velocity were also correlated with left atrial ejection fraction (r = 0.338, P = 0.005 and r = 0.676, P = 0.001, respectively). Thus, patients with mitral stenosis had significantly impaired long-axis function evaluated by M-mode or tissue Doppler echocardiography despite normal global systolic function.

Adult↗
PubMed2004

Increased P wave dispersion and maximum P wave duration after hemodialysis.

BACKGROUND: Atrial fibrillation is a frequent arrhythmia in patients undergoing hemodialysis. The consequences of hemodialysis on P wave durations and P wave dispersion have not been fully understood. The objective of this study was to study the effect of dialysis on P wave maximum (Pmax), P wave minimum (Pmin), and P wave dispersion (Pd). METHODS: We studied Pmax, Pmin, and Pd in 32 patients (17 men and 15 women, mean age 54 +/- 18 years) with chronic renal failure undergoing hemodialysis. The difference between maximum and minimum P wave duration was calculated and defined as P wave dispersion (Pd= Pmax- Pmin). RESULTS: There was a significant increase in Pmax at the end of dialysis compared to the beginning (98 +/- 13 ms vs. 125 +/- 12 ms, P < 0.001). Pmin did not show any significant change (71 +/- 11 ms vs. 73 +/- 10 ms, P = 0.42). Pd was significantly increased at the end of dialysis (27 +/- 9 ms vs. 52 +/- 11 ms, P < 0.001). There was a negative correlation between serum potassium, magnesium, phosphate, blood urea nitrogen, and creatinin at the end of dialysis and Pmax and Pd, respectively (P < 0.05). A weak positive correlation was found between serum calcium, bicarbonate at the end of dialysis and Pmax and Pd (P < 0.05). CONCLUSION: Hemodialysis ends with significant increase in P wave maximum duration and P wave dispersion, which might be responsible for the increased occurrence of atrial fibrillation in these groups of patients.

Atrial Fibrillation↗
PubMed2004

The significance of P wave duration and P wave dispersion for risk assessment of atrial tachyarrhythmias in patients with corrected tetralogy of Fallot.

BACKGROUND: The aim of the present study was to determine the potential role of P wave duration and P wave dispersion for risk assessment of atrial tachyarrhythmias in patients with corrected tetralogy of Fallot (ToF). METHODS: The maximum P wave duration, minimum P wave duration, and the P wave dispersion from the 12-lead surface electrocardiogram of the patients and controls were measured. Electrophysiological study was performed only in the patient group. RESULTS: The study group consisted of 25 patients with corrected ToF with a mean age of 16.4 +/- 4.25 years and 25 age-matched healthy control subjects. Patients underwent repair at a mean age of 4.6 +/- 3.41 years (range: 1-19), and the mean duration of follow-up of 11.8 +/- 1.7 years (range: 9-15) after surgery. On electrophysiological study sinus node dysfunction was detected in 3 patients (12%), atrial tachyarrythmias-atrial flutter or fibrillation-in 5 patients (20%), both sinus node dysfunction and atrial flutter in 1 patient (4%), and AV conduction delay in 1 patient (4%). P wave dispersion is significantly higher in patients with atrial tachyarrhythmia inducible by electrophysiological study than in other patients (P < 0.05). A P wave dispersion value of >35 ms has a high predictive accuracy (sensitivity = 83% and specificity = 89%) for inducible atrial tachyarrhythmia in patients with corrected tetralogy of Fallot. CONCLUSION: P wave dispersion is an easily measured electrocardiographic marker with a good sensitivity and specificity for predicting atrial arrhythmias in patients after correction of ToF.

Adolescent↗
PubMed2004

Is carotid atherosclerosis more important in patients with mitral annular calcification than in those without?

It has been suggested that mitral annular calcification (MAC) may be a manifestation of generalized atherosclerosis. However, how the incidence and extent of coronary artery disease (CAD) are affected by the coexistence of carotid atherosclerosis (CAS) in patients with versus without MAC have not yet been studied. We studied 101 patients with echocardiographic MAC and 52 controls without MAC to investigate the clinical impact of CAS on the frequency and severity (defined as the number of obstructed vessels) of CAD in patients with MAC. Carotid Doppler ultrasonographic examination was performed on all patients before coronary angiography. In patients with both MAC and CAS, the incidences of CAD and multivessel disease (> or = 2 vessel or left main coronary artery disease) were significantly higher than in the control group with CAS alone (91% versus 68%, P = 0.008 and 76% versus 44%, P = 0.004, respectively). On the other hand, among study and control patients without CAS, although the frequencies of CAD and multivessel disease were higher in patients with MAC, interestingly, the differences were not statistically significant (37% versus 58% and 15% versus 26%, respectively, P > 0.05 for both). Stepwise multiple logistic regression analysis revealed that CAS (P < 0.001), MAC (P < 0.01) and, to a limited extent hypertension (P = 0.054), were independent predictors for the presence of CAD. In conclusion, the coexistence of CAS is more important in patients with MAC than in those without as it provides valuable information about the incidence and severity of underlying CAD. In cases with MAC but without CAS, MAC could be caused by factors other than atherosclerosis.

Aged↗
PubMed2003

Detection of patients with hypertrophic cardiomyopathy at risk for paroxysmal atrial fibrillation during sinus rhythm by P-wave dispersion.

BACKGROUND: Paroxysmal atrial fibrillation (PAF) in hypertrophic cardiomyopathy (HCM) is associated with poor prognosis. Previous studies have shown good correlation between P-wave dispersion (Pd) and occurrence of PAF. However, Pd in patients with HCM for predicting PAF has not been studied. HYPOTHESIS: The aim of the study was to determine whether Pd could identify patients with HCM who are likely to suffer from PAF. METHODS: Twenty-two patients with HCM with a history of PAF (Group 1) and 26 patients with HCM without a history of PAF (Group 2) were studied. Maximum (Pmax) and minimum (Pmin) P-wave durations, as well as P-wave dispersion (Pd = Pmax - Pmin) were calculated from 12-lead surface electrocardiograms (ECG). RESULTS: P-wave dispersion was significantly different between the groups (Group 1: 55 +/- 6 ms vs. Group 2: 37 +/- 8 ms; p<0.001), while Pmax (Group 1: 134 +/- 11 ms vs. Group 2: 128 +/- 13 ms; p = 0.06) and Pmin (Group 1: 78 +/- 9 ms vs. Group 2: 81 +/- 7 ms; p = 0.07) was not significantly different. Patients with a history of PAF had higher left atrial diameter than the patients without PAF (Group 1: 52 +/- 8 mm vs. Group 2: 48 +/- 10 mm; p = 0.02). A cut-off value of 46 ms for Pd had a sensitivity of 76% and a specificity of 82% in discriminating between patients with and without PAF. CONCLUSION: This study suggests that P-wave dispersion could identify patients with HCM who are likely to develop PAF.

Adult↗
PubMed2003

Assessment of heart rate turbulence in the acute phase of myocardial infarction for long-term prognosis.

This study is designed to assess the value of heart rate turbulence (HRT) in the acute phase of MI for prediction of long-term mortality risk. The study included 128 consecutive acute MI patients with 24-hour Holter recordings to evaluate HRT (turbulence onset and slope), SDNN, mean RR interval, and ventricular premature beat frequency. LVEF was evaluated by two-dimensional echocardiography. Data from 117 patients (mean age 58 +/- 11 years) were available for further analysis. Twelve patients died during follow-up (mean 312 +/- 78 days). Although SDNN < 70 ms was the most powerful predictor of mortality among all presumed risk factors (hazard ratio 20 [95% CI 2.6-158]; P = 0.004) in univariate Cox regression analysis, in multivariate analysis LVEF < or = 0.40 and turbulence slope < or = 2.5 ms/RR interval were the only independent predictors of mortality (hazard ratio 6.9 [95% CI 1.8-26]; P = 0.006, hazard ratio 7.3 [95% CI 1.4-37]; P = 0.016, respectively). Addition of HRT parameters for LVEF increased remarkably the positive predictive value (60%) without any decrease in the negative predictive value (92%). Blunted HRT reaction within the first 24 hours of acute MI is an independent predictor of long-term mortality. Furthermore, its predictive power is comparable and also additive to that of LVEF.

Case-Control Studies↗
PubMed2003

Relationship between noninvasive reperfusion criteria and pulsed-wave tissue Doppler parameters in patients with acute myocardial infarction receiving thrombolytic therapy.

Several studies have proven that noninvasive reperfusion criteria (NRC) have prognostic significance in patients receiving thrombolytic therapy (TT) after acute myocardial infarction (acute MI). In this study, we investigated the relationship between NRC and pulsed tissue Doppler (PTD) parameters in patients receiving TT after acute MI, and the role of PTD in the management and follow-up of patients with acute MI. The study group(n= 41)was divided into four subgroups defined as: anterior and posterior MI, with or without NRC. In the first PTD measurements (2-3 days after acute MI), all acute MI patients had significantly smaller peak systolic (S-wave) velocity in all evaluated segments and longer Q-Speak durations (time elapsed from the inscription of the Q-wave on the surface ECG to the peak of the S-wave in PTD) as compared with control patients(n= 22; P < 0.001 for both). Among the diastolic parameters, the E/A ratio was significantly smaller in the study group compared with the control group(P < 0.001). Among the patients who had received TT in the first 2 hours, those patients who had NRC displayed significantly higher peak S-wave values in all evaluated segments than those without NRC(P < 0.05). The second PTD study (4-5 weeks after acute MI), revealed that the difference between the systolic PTD parameters of the noninfarcted regions of the study and control groups disappeared. Infarct-related segments, however, displayed significant improvement only in patients having NRC. There was a significant positive correlation between the mean mitral annular S-wave velocity and left ventricular ejection fraction(r = 0.59, P < 0.001). In conclusion, a significant relationship was observed between the PTD parameters and the NRC, which are known to have prognostic significance.

Case-Control Studies↗
PubMed2003

Seasonal variability of QT dispersion in healthy young males.

BACKGROUND: There are few data related to the seasonal influences on the QT dispersion. METHODS: We analyzed the effects of seasons on QT dispersion in a large group of healthy young males. We studied the seasonal variability of QT dispersion in 523 healthy male subjects aged 22 +/- 4 years (ranging from 20 to 26). Four seasonal 12-lead resting electrocardiograms (ECGs) recorded at double amplitude were performed at 25 mm/s at intervals of 3 months. Subsequent ECGs were recorded within 1 hour of the reference winter recording. QT dispersion was defined as the difference between the longest and the shortest mean QT intervals. RESULTS: There was a significant seasonal variation in QT dispersion (P = 0.001), with the largest QT dispersion in winter (71 +/- 18 ms) and the smallest one in spring (43 +/- 19). CONCLUSION: There exists a significant seasonal variation in QT dispersion of healthy subjects and such variability should be taken into consideration in the evaluation process of QT dispersion.

Adult↗
PubMed2003

Decreased protein Z concentrations complicating the hypercoagulable state of Behçet's disease.

Protein Z is a vitamin-K-dependent plasma protein that serves as a cofactor for the inhibition of factor Xa. Although the precise physiologic function of protein Z is still unknown, abnormal plasma protein Z concentrations have been associated with a number of thrombotic disease states. There is the evidence of universal activation of the hemostatic system in Behçet's disease (BD), which represents a hypercoagulable/prothrombotic state. Circulating protein Z levels in patients with BD were evaluated. Plasma protein Z concentrations were assayed in 24 patients with BD (male/female: 13/11, mean age 35.4 years) and in 24 healthy controls (males/females: 14/10, mean age 59.8 years). The disease duration was 10.6 years (range, 1-30 years). None of the subjects in either group had received anticoagulants within 3 weeks before the study, and none of them had liver dysfunction. Patients complicated with vascular disease were also excluded from the study. Mean plasma concentrations of protein Z were 141 ng/mL (range, 56.8-257) in healthy controls and 107.8 ng/mL (range, 21.2-202) in BD patients (p<0.05). There was a positive correlation between the disease duration and protein Z levels in the study group (p<0.05, r=0.448). Alterations of protein Z concentrations could complicate the pathobiology of the prothrombotic state of BD. Furthermore, the tendency of increment in the protein Z with the passage of time may reflect the diminution of the disease activity.

Adolescent↗
PubMed2002

Physiological mechanisms influencing cardiac repolarization and QT interval.

Cardiac repolarization primarily results from activation of outward currents carried by potassium ions which are heterogeneously distributed throughout the myocardial layers which can lead to changes in various phases of cardiac cycle. QT interval is a reflector of cardiac repolarization and can be influenced by heart rate, autonomic nervous system, gender and time of the day. T wave alternans (TWA), specifically the discordant pattern is a feature of abnormal cardiac repolarization that can be used as a predictor of ventricular arrhythmias.

Arrhythmias, Cardiac↗
PubMed2002

Seasonal variation of P-wave dispersion in healthy subjects.

We studied the seasonal variability of P dispersion in 523 healthy male patients, aged 22 +/- 4 years (range, 20-26). Four seasonal 12-lead resting electrocardiograms were recorded at 2 mV/cm standardization and at 50 mm/s paper speed at intervals of three months. Electrocardiograms were recorded between the hours 10 to 12 AM. The difference between the maximum P-wave duration and minimum P-wave duration was calculated and defined as "P dispersion." There was a significant seasonal variation in the maximum P-wave duration (P = .001) and P dispersion (P = .001), with the longest maximum P-wave duration (121 +/- 16 ms) and P dispersion (41 +/- 7 ms) observed in winter and the shortest maximum P-wave duration (106 +/- 15 ms) and P dispersion (24 +/- 8 ms) observed in summer. The minimum P-wave duration did not show any significant seasonal variation. In conclusion, there exists a significant seasonal variation in the maximum P-wave duration and P dispersion in healthy patients. Seasonal variation of P dispersion resulted from the significant variation of maximum P-wave duration.

Adult↗
PubMed2002

Cardiac tuberculosis with multiple intracardiac masses: a case report.

In this report, clinical, echocardiographic, and pathologic findings of a patient with multiple masses caused by tuberculosis both in the left and right side of the heart are presented. After antituberculosis treatment some of the masses disappeared and some became smaller. Although an intracardiac mass caused by tuberculosis is very rare, it should be considered in the list of masses detected by echocardiography.

Adult↗