Biomedical subjects

Aydin Yildirim

Publications and source records attributed to Aydin Yildirim.

14 recordsLinked to original sources

PubMed2007

Cardiac resynchronization improves coronary blood flow.

Asynchronous ventricular activation, induced by left bundle branch block, is known to have deleterious effects on the systolic and diastolic functions of the left ventricle (LV). Cardiac resynchronization therapy (CRT) has been proposed as a complementary method to improve the LV systolic performance by restoring the synchronized contraction patterns in patients with advanced heart failure and left bundle branch block. However, the effect of CRT on myocardial blood flow is not well established. In the present study, we therefore examined the coronary blood flow in 20 patients with idiopathic dilated cardiomyopathy, implanted with a biventricular pacemaker according to the established CRT criteria. Color Doppler settings were adjusted for the optimal coronary flow imaging, and coronary flow velocities were obtained in all patients. Typical diastolic predominant phasic Doppler spectrum of the distal left anterior descending coronary artery (LAD) was recorded. Conventional echocardiographic variables, peak values of the diastolic and systolic LAD velocities, and the velocity time integrals were measured for three or five consecutive beats during CRT with pacemaker on and off. Successful CRT with biventricular pacing increased coronary blood flow velocities of the distal LAD in addition to its well-known benefits on the systolic and diastolic LV performance in patients with significant dyssynchrony. CRT decreased duration of mitral regurgitation and increased diastolic filling time. Peak diastolic velocities and velocity time integral of the distal LAD were increased significantly. In conclusion, successful CRT with biventricular pacing improves coronary blood flow velocities of the distal LAD.

Adult↗

PubMed2006

Left ventricular diastolic function and endothelial function in patients with erectile dysfunction.

The aim of this study was to assess left ventricular diastolic function and forearm endothelial function in patients with erectile dysfunction (ED) without overt cardiovascular disease. Forearm endothelial function and diastolic Doppler parameters, including tissue Doppler imaging, were studied in 32 men with ED and 27 age-matched, healthy, male control subjects. Left ventricular diastolic function in patients with ED and the relation between endothelium-dependent vasodilation and the Doppler parameters of left ventricular diastolic function, including tissue Doppler imaging, were assessed. Endothelium-dependent vasodilation (4.1+/-3.3% vs 9.7+/-4.2%, p<0.001) as well as the mitral inflow E velocity (0.66+/-0.17 vs 0.80+/-0.16 m/s, p=0.01), the E/A ratio (the ratio of mitral inflow E velocity to mitral inflow A velocity; 0.91+/-0.3% vs 1.22+/-0.26%, p<0.001), and the E/Em ratio (the ratio of mitral A-wave velocity to early diastolic velocity in the annulus derived by tissue Doppler imaging; 7.4+/-2.7% vs 6.6+/-1.6%, p=0.03) were smaller in the ED group than in the control group. Deceleration time (228.6+/-61.6 vs 192.9+/-44.6 ms, p=0.03) and isovolumetric relaxation time (112.8+/-18 vs 94+/-15.9 ms, p<0.001) were also prolonged in the ED group compared with the control group. The mitral E-wave velocity (r=0.40, p=0.022), the E/A ratio (r=0.40, p=0.027), and the E/Em ratio (r=-0.52, p= 0.003) were related to endothelium-dependent vasodilation by nivariate analysis. Only the E/Em ratio was correlated with endothelium-dependent vasodilation by multivariate analysis. In conclusion, this study indicates that endothelial function and left ventricular diastolic function are impaired in patients with ED without overt cardiovascular disease.

Blood Flow Velocity↗

PubMed2006

Accessory mitral valve tissue: report of two asymptomatic cases.

Accessory mitral valve tissue is a rare anomaly of embryologic development of the endocardial cushion and may cause substantial and progressive obstruction of the left ventricular outflow tract. Subaortic obstruction resulting from accessory mitral tissue is most likely due to systolic ballooning of the tissue into the outflow tract. The obstruction can occur in the early period of life as a result of mass effect or it can develop gradually due to the continued deposition of fibrous tissues within the left ventricular outflow tract. In patients with accessory mitral valve tissue, surgery is mandatory if there is a significant obstruction in the left ventricular outflow tract. We report two cases with accessory mitral valve tissue causing mild subaortic stenoses which did not require surgery.

Adult↗

PubMed2006

Erectile dysfunction as a generalized vascular dysfunction.

OBJECTIVE: We hypothesize that generalized vascular dysfunction may be the underlying cause in patients with erectile dysfunction (ED) without atherosclerosis and its major risk factors. METHODS: In all, 30 outpatients with ED and 25 healthy volunteers as a control group were enrolled for this study. Aortic stiffness was calculated from data obtained by echocardiographic examination, which was performed using commercially available equipment with a 2.5- to 3.5-MHz transducer. Endothelium-dependent flow-mediated dilation (FMD) of the brachial artery was assessed using a high-resolution ultrasound system with a 10-MHz linear-array vascular transducer. Shear stress and nitroglycerin was used as a stimulus for assessing endothelium-dependent FMD and nonendothelium-dependent dilation of the brachial artery. RESULTS: FMD was significantly decreased in the ED group compared with control group (4.1 +/- 3.1% vs 9.7 +/- 3.5%, P < .001). Nonendothelium-dependent dilation was statistically insignificant in patients with ED compared with control subjects (13 +/- 3.9% vs 15.4 +/- 3.8%, P = .55). The relationship between ED and FMD was significant (r = -0.66, P < .001), whereas no relationship was found between ED and nonendothelium-dependent dilation (r = -0.23, P > .05). Aortic strain (3.7 +/- 2.7% vs 9.5 +/- 3.2%, P < .001) and distensibility (1.5 +/- 1.0 vs 4.7 +/- 2.9 cm2.dyne(-1).10(-3), P < .001) were found significantly lower in the ED group than in the control group. The relationship between ED and aortic stiffness was also significant (for aortic strain; r = -0.62, P < .001 and for aortic distensibility; r = -0.60, P < .001). CONCLUSION: Aortic and brachial artery functions are impaired in men with ED without cardiovascular disease or its major risk factors, indicating a more generalized vascular disease.

Aorta↗

PubMed2006

Heart rate variability in patients with systemic sarcoidosis.

PURPOSE: The identification of subjects with systemic sarcoidosis at higher risk for sudden death is an unresolved issue. An influence of the autonomic activity on the genesis of ventricular arrhythmias was postulated. Heart rate variability (HRV) analysis provides a useful method to measure autonomic activity, and is a predictor of increased risk of death in various conditions. Therefore, the aim of the study was to evaluate HRV in patients with systemic sarcoidosis. METHODS: The study included 35 patients with biopsy proven systemic sarcoidosis who were not taking antiarrhythmic medications. Thallium scintigraphy was performed to all patients with systemic sarcoidosis. The cardiac sarcoidosis was accepted in 16 patients as abnormal thallium scintigraphy and normal coronary arteriography. The time-domain analysis of HRV was expressed as the standard deviation of all normal to normal NN intervals (SDNN) detected during 24-hour Holter monitoring. Twenty-four healthy subjects represented a control group for HRV analysis. RESULTS: There were no differences in age (44 +/- 13 years for cardiac sarcoidosis, 42 +/- 15 years for noncardiac sarcoidosis, and 40 +/- 10 years for control group; P = NS), sex (the ratio of female; 63%, 68%, and 55%, respectively; P = NS), and echocardiographic ejection fraction (63 +/- 10%, 67 +/- 8%, and 69 +/- 6%, respectively; P = NS) among study groups. The mean SDNN value of the group with cardiac sarcoidosis was significantly lower than both the group with noncardiac sarcoidosis and the control group (72 +/- 32 ms vs 110 +/- 46 ms and 152 +/- 36 ms; P < 0.05, respectively). CONCLUSION: HRV is decreased in patients with systemic sarcoidosis compared to the control group. This decreasing is more obvious in patients with cardiac sarcoidosis.

Adult↗

PubMed2005

Comparison of coronary flow velocities between patients with obstructive and nonobstructive type hypertrophic cardiomyopathy: noninvasive assessment by transthoracic Doppler echocardiography.

BACKGROUND: We aimed to compare coronary flow velocity (CFV) measurements of patients with nonobstructive (NHCM) and obstructive hypertrophic cardiomyopathy (HOCM) by using transthoracic Doppler echocardiography (TTDE). METHODS AND RESULTS: In 11 patients with NHCM and 26 with HOCM, CFV in the distal left anterior descending (LAD) coronary was measured by TTDE (3.5 MHz) under the guidance of color Doppler flow mapping in addition to standard 2D and Doppler echocardiography. The results were compared with 24 normal participants who had no evidence of cardiac disease. Peak diastolic velocity of LAD was also higher in NHCM and HOCM than controls (52 +/- 14 cm/sec and 54 +/- 20 cm/sec vs 41 +/- 11 cm/sec, respectively, P < 0.01). The analysis of systolic velocities revealed abnormal flow patterns in 16 (61%) patients with HOCM (12 systolic-reversal flow and 4 no systolic flow) and 6 (54%) (5 reversal flow and 1 zero flow) patients with NHCM (-11 +/- 30 cm/sec and -13 +/- 38 cm/sec, vs 24 +/- 9 cm/sec, respectively, P < 0.001). Linear regression analysis demonstrated no correlation between intraventricular pressure gradient and coronary flow velocities in HOCM patients. However, there were significant positive and negative correlations between septal thickness and diastolic and systolic velocities, respectively (r = 0.50, P < 0.002, and r =-0.43, P < 0.005). CONCLUSION: We conclude that the coronary flow velocity abnormalities are independent from the type of hypertrophic cardiomyopathy.

Adult↗

PubMed2004

Determinants of coronary flow abnormalities in obstructive type hypertrophic cardiomyopathy: noninvasive assessment by transthoracic Doppler echocardiography.

We aimed to visualize the coronary flow velocities (CFV) of patients with hypertrophic obstructive cardiomyopathy by using transthoracic Doppler echocardiography, and to determine the relationship between abnormal CFV patterns and conventional echocardiography indices. Guided by 2-dimensional echocardiography and Doppler color flow mapping, CFV in the distal left anterior descending coronary artery were measured in 21 patients with hypertrophic obstructive cardiomyopathy using a 3.5-MHz transducer. The results were compared with those of 18 control subjects. Abnormal systolic flow patterns were observed in 15 (71%) patients (11 systolic-reversal flow and 4 no systolic flow). For patients and control subjects, peak diastolic velocity and velocity-time integral obtained from distal left anterior descending coronary artery were higher (63 +/- 21 cm/s and 18.5 +/- 4 cm vs 41 +/- 11 cm/s and 14.2 +/- 5 cm, respectively; P <.01 for both) whereas peak systolic velocity and velocity-time integral were significantly lower (-17 +/- 10 cm/s and 4.5 +/- 6 cm vs 24 +/- 9 cm/s and 9.5 +/- 4 cm, respectively; P <.001 for both). Significant positive and negative correlations between diastolic CFV and septal thickness index (r = 0.79, P <.0001), and between systolic CFV and septal thickness index (r = -0.65, P <.005), have been observed. CFV abnormalities that could easily be recorded by a standard Doppler echocardiographic study seem to be related to septal thickness rather than the degree of obstruction in hypertrophic obstructive cardiomyopathy.

Adult↗

PubMed2004

Median nerve excursion during endoscopic carpal tunnel release.

OBJECTIVE: Restriction of the excursion of the nerve has been accepted as a pathogenetic element in carpal tunnel syndrome. The goal of this article was to evaluate the median nerve excursion in the carpal tunnel measured as a function of wrist position before and after endoscopic carpal tunnel release (ECTR) on 28 hands of 22 patients. METHODS: The position of cylindrical stainless steel markers embedded within the median nerve was measured by a direct radiographic technique. Each upper extremity was examined in three wrist positions. Then, endoscopic release with Menon's technique was performed, and the measurements were repeated. RESULTS: In this prospective clinical study, most (93%) of the patients experienced resolution of their symptoms. Before and after ECTR, median nerve excursion was linear and was affected by wrist position. Before ECTR, when the wrist was moved from the end of dorsiflexion to the end of palmar flexion, the median nerve underwent a mean total excursion of 28.8 mm at the wrist. A comparison of the before and after ECTR excursion showed no statistical differences in the amount of motion. CONCLUSION: The single-portal ECTR does not seem to influence the median nerve excursion for the wrist positions studied in patients with carpal tunnel syndrome. The results from this in vivo study showed longitudinal gliding of the median nerve twice as great as in in vitro studies.

Adult↗

PubMed2004

Effect of patient age at surgical intervention on long-term right ventricular performance in atrial septal defect.

Controversy exists about the influence of patient age on the benefit of surgery in atrial septal defect (ASD). Tissue Doppler echocardiography (TDE) when applied to atrioventricular annuli provides variables reliably reflecting the performance of the corresponding ventricle. We sought to investigate the effect of timing of surgery on biventricular functions by comparing the conventional echocardiography variables and TDE profiles of right and left atrioventricular annuli in patients treated at various ages. Conventional echocardiography and TDE analysis of mitral and tricuspid annuli were performed in 20 controls and 61 patients who underwent surgical ASD closure 2.8 +/- 2.5 years before the study. Standard parameters included were right and left-sided dimensions, estimated pulmonary artery pressure, ejection fraction, and tricuspid annular motion amplitude. TDE variables were systolic, early and late diastolic peak velocities at tricuspid lateral-and mitral-annulus at lateral and septal corners. Two subsets of patients who underwent surgery before (group 1, n = 20) and after 25 years (group 2, n = 41) formed our subgroups. Peak systolic TDE velocity and tricuspid annular motion amplitude had the lowest value in group 2 (P < 0.01 and <0.02, respectively). Late diastolic TDE velocity was significantly lower in group 2 compared to group 1 (P < 0.05). Increased right ventricular and atrial dimensions (P < 0.001 for both) and the estimated pulmonary artery pressure (P < 0.03) were the conventional measurements discriminating group 2 from group 1. The TDE profile of the mitral annulus was similar between the groups. These results suggest that delayed ASD closure is a relatively less effective procedure to restore secondary right ventricular dysfunction, as demonstrated by significantly different TDE measurements reflecting right ventricular longitudinal contraction and relaxation.

Adult↗

PubMed2003

Assessment of the effects of various maneuvers on both atrial pressure changes.

The aim of the present study was to determine which maneuver causes the greatest pressure difference between both atria by measuring right and left atrial pressures simultaneously after certain maneuvers. Thirty-two coronary care unit patients, whom a Swan-Ganz catheter was inserted because of acute left ventricular dysfunction, hypotension, sinus tachycardia with unknown cause, were included in this study. The basal values of peak right atrium (RA) pressure and corresponding pulmonary capillary wedge pressure (PCWP) were measured via two separated transducers. Patients were tutored with several trials to perform breath holding, successive three strong coughs, Valsalva maneuver, 20 degrees head down, respectively. In the end of these maneuvers, the peak RA pressure and corresponding PCWP were measured simultaneously. All maneuvers caused an increase in RA pressure. The highest peak RA pressure was obtained by means of the Valsalva maneuver (7.6 +/- 5 versus 20.4 +/- 7.6 mmHg before and after Valsalva, respectively; P<0.001). PCWP (18.8 +/- 5.9 mmHg) increased only with coughing (21.2 +/- 6.7 mmHg, P<0.01) and 20 degrees head down maneuver (20 +/- 5.7 mmHg, P<0.05). The highest increase in pressure gradient between peak RA pressure and corresponding PCWP was observed during Valsalva maneuver (-11 +/- 6.6 vs. 2.3 +/- 5.9 mmHg, P<0.001). The lowest increase was obtained in 20 degrees head down maneuver (-11 +/- 6.6 vs. -8.5 +/- 5.8 mmHg, P<0.001). When measuring the pressure of both atria invasively and simultaneously, Valsalva maneuver was the most effective maneuver consistent with pressure difference in favour of RA among all the other maneuvers.

Atrial Function, Left↗

PubMed2003

Aortic stiffness in patients with cardiac syndrome X.

AIM: Recently, the close relationship between aortic stiffness and cardiovascular mortality has aroused the interest of investigators in carrying out studies related to aortic stiffness. This study aims to investigate the aortic stiffness parameters in patients with cardiac syndrome X, a disorder that is believed to be a generalized disturbance of the vasodilator function of small arteries. MATERIAL AND METHODS: 18 patients with typical chest pain and angiographically normal coronary arteries associated with a positive exercise test were included in the study. The control group consisted of 27 patients with angiographically normal coronary arteries and no ischaemia on exercise testing. Antianginal medication was withheld 4 weeks before the study and transthoracic echocardiography was performed using a Hewlett-Packard Sonos 1500 instrument with a 2.5 MHz phased array transducer. Ascending aorta diameters were measured on the M-mode tracing at a level 3 cm above the aortic valve. Diameter change, pulse pressure, aortic strain and distensibility were measured as aortic stiffness parameters. RESULTS: The aortic diameter change was less in the syndrome X group than in the control group (0.15 +/- 0.04 cm/m2 vs. 0.28 +/- 0.12 cm/m2, p < 0.001). Likewise, aortic strain (9 +/- 3% vs. 18 +/- 8%, p < 0.001) and distensibility (4.01 +/- 1.71 cm2 x dyn(-1) x 10(-3) vs. 9.95 +/- 5.08 cm2 x dyn(-1) x 10(-3), p < 0.001) was significantly lower in the syndrome X group than in the control group. CONCLUSION: The deterioration in aortic elasticity properties in patients with cardiac syndrome X suggests that this disease may be a more generalized disturbance of the vasculature.

Adult↗

PubMed2003

A new echocardiographic approach in assessing pulmonary vascular bed in patients with congenital heart disease: pulmonary artery stiffness.

OBJECTIVE: The state of pulmonary vascular bed in congenital heart disease is the predictor of the patients clinical condition, prognosis and outcome of surgical intervention. This study aims to investigate the condition of pulmonary vascular bed analyzing pulmonary artery stiffness by means of Doppler echocardiography. METHODS: Thirty-three patients (16 females, mean age 26+/-15 years) with various congenital heart diseases such as atrial septal defect (20 patients), ventricular septal defect (10 patients), patent ductus arteriosus (2 patients), atrioventricular septal defect (1 patient) were enrolled in this study. Systemic flow (Qs), pulmonary flow (Qp), systemic vascular resistance, pulmonary vascular resistance were calculated according to Fick method by using data obtained during left and right heart catheterization. Echocardiographically, pulmonary artery stiffness (PAS) was calculated by using maximal frequency shift (MFS) and acceleration time (AcT) of the pulmonary artery flow trace. PAS (kHz/sec)= MFS/AcT. RESULTS: Invasively, the average Qp/Qs, mean pulmonary artery pressure, and pulmonary vascular resistance were found as 2.58+/-1.25, 25+/-20 mmHg, and 135+/-217 dyn.sec.cm-5, respectively. Echocardiographically, PAS was found to be 33+/-17 kHz/sec. Pulmonary artery stiffness was correlated with mean pulmonary artery pressure (r=0.63; p<0.001) and pulmonary vascular resistance (r=0.55, p<0.001), while no relation was found with Qp/Qs. CONCLUSION: Estimation of pulmonary artery stiffness by using pulmonary flow maximal frequency shift and acceleration time obtained by means of Doppler echocardiography may give us an idea about the state of pulmonary vascular bed.

Adult↗

PubMed2002

Left atrial maximum volume is a recurrence predictor in lone atrial fibrillation: an acoustic quantification study.

Predictors of recurrence in lone atrial fibrillation have not been clearly identified. Acoustic quantification (AQ) is a promising method in the assessment of left atrial (LA) volumes. The purpose of the present study was to investigate the potential of LA volumes obtained by standard manual tracing and AQ methods in predicting AF-recurrence after restoring the sinus rhythm in patients with lone AF, and to test the agreement between the two approaches. Standard echocardiography combined with AQ was performed in 28 patients with lone AF one hour after the sinus rhythm was regained, and in 10 controls. LA volumes were determined by conventional manual tracing and AQ methods. AQ waveforms of LA were obtained by drawing a region of interest around the LA border. The agreement of the two methods was tested by Bland-Altman analysis. Patients were followed up for 6 months for the occurrence of AF recurrence. A good correlation was observed between AQ and manual tracing methods in determining both minimal (r=0.59) and maximal (r=0.88) LA volumes. Patients with AF recurrence had a significantly larger maximum LA volume as assessed with both methods (P<0.05 for both). M-mode derived LA dimension and isovolumic relaxation time were additional predictors of recurrence in patients with lone AF. In lone AF, patients prone to recurrence could be predicted by determining LA maximum volume assessed either by AQ or manual tracing methods. AQ provides on-line, accurate estimation of LA volumes.

Adult↗

PubMedDate not supplied

Prediction of infarct-related coronary artery of patients with acute inferior myocardial infarction by a predischarge exercise test index.

The predictive accuracy of electrocardiographic markers in identifying the infarct-related artery of myocardial infarctions has been a subject of extensive investigation. The present study was designed to test whether the index L II/L III ratio adapted to exercise electrocardiograms could be utilized as a marker to distinguish right coronary and left circumflex arteries as culprit coronaries in acute inferior myocardial infarctions. For this purpose, 82 patients with a positive-symptom-limited and/or submaximal treadmill exercise test with modified Bruce protocol after an acute inferior myocardial infarction were studied. Those patients with ST segment elevation during the stress test were included in the study. ST segment index was defined as the ratio of exercise-induced ST elevation amplitude in L II/L III. Patients were classified as having an index > 1 (n=24) and < 1 (n=58), and the findings were compared with the findings on coronary angiography. The groups were comparable with respect to age, gender, peak exercise level, and double products achieved. Circumflex artery was the infarct-related one in the majority (21/24; 88%) of patients with an index > 1, whereas most (51/58; 88%) patients with an index < 1 had the culprit lesion in their right coronary artery (p<0.001). The ratio of exercise-induced ST elevations in leads L II and L III has a significantly high ability to discriminate the infarct-related coronary artery in patients with uncomplicated inferior myocardial infarction. Considering the prognostic importance of the type of coronary involvement, this index could be a part of predischarge evaluation in this patient group.

Coronary Angiography↗