Biomedical subjects

F Ertaş

Publications and source records attributed to F Ertaş.

6 recordsLinked to original sources

PubMed2000

Left atrial appendage function in patients with different pacing modes.

Many studies suggest that patients who receive a ventricular pacemaker have a higher incidence of systemic thromboembolism compared to patients receiving a physiological pacemaker. However, the exact mechanism regarding the etiology of thromboembolism remains unclear. We evaluated the left atrial appendage (LAA) functions, using multiplane transesophageal echocardiography (TEE), in patients with different pacing modes. In order to evaluate the ejection fraction (EF), peak emptying (V(E)) and filling (V(F)) flow velocities of the LAA by TEE, we studied 31 patients (mean age 63+/-18.5 years) who had been paced for 5.0+/-2.9 years. Patients with atrial fibrillation, left ventricular dysfunction and mitral valve disease were excluded. The pacing indications were complete atrioventricular block (AVB) in 19 patients (9 VVI, 10 VDD or DDD) and sick sinus syndrome (SSS) in 12 patients (5 VVI, 7 DDD). Mean EF, V(E) and V(F) of the LAA were significantly lower in all patients with ventricular pacing (25.5+/-15.6%, 30.4+/-15.6 cm/s and 29. 1+/-19.2 cm/s, respectively) compared to those with physiologic pacing (48.5+/-16.9%, 59.6+/-16.3 cm/s, 57.9+/-18.5 cm/s, respectively) (P<0.01 in all). When patients were further classified with respect to underlying heart disease whether they had SSS or AVB, all measurements of the LAA (EF, V(E) and V(F)) in both subgroup of patients with SSS and AVB were found significantly lower in those with ventricular pacing than in those with physiologic pacing (Tables 3 and 4). This decrease, especially in LAA flow, was much greater in those with SSS (Mean V(E) and V(F) <20 cm/s). In a patient paced with VVI for SSS, a thrombus was detected within the LAA cavity. In conclusion, these results suggest that the pacing modality appeared to influence the LAA functions in paced patients. Patients with asynchronous ventricular pacing modes had a significantly higher incidence of depressed LAA functions than did patients with physiological pacing, especially more marked in patients with sick sinus syndrome. This may be a factor responsible for increased risk of thrombus formation and thromboembolic events in this patient population.

Adult↗

PubMed2000

Atrial sensing performance of a single-lead VDD pacing system during physical activities.

This study was undertaken to evaluate the atrial sensing performance of a single-lead atrial synchronous-ventricular pacing system during various physical activities on late follow-up. Fourteen patients (mean age 55 +/- 17 years) with a third-degree or high-degree atrioventricular block and normal sinus node function were treated with the single-lead Thera VDD (Medtronic, Inc, Minneapolis, MN) pacemaker system. Mean P-wave amplitude at implantation was 3.2 +/- 1.3 mV. To assess the VDD system performance, P-wave amplitudes during various physical maneuvers (supine, sitting, deep breathing, standing, and exercise; respectively) were measured and atrial sensing was evaluated at a mean follow-up of 11 +/- 4 months. During deep breathing, minimum and maximum P-wave amplitudes (0.8 +/- 0.7, 1.2 +/- 1.0 mV, respectively) were found to be significantly lower than the standing position (minimum, 1.1 +/- 0.9, maximum, 1.4 +/- 1.1 mV P = .02 in both). No significant difference was found during other physical maneuvers. During the testing maneuvers, atrial undersensing was observed in 8 patients (57%) at the nominal atrial sensitivity of 0.5 mV. After increasing the atrial sensitivity (0.25 mV), no sensing failure was observed in these patients. It has been concluded that Medtronic Thera VDD system is a safe and reliable device with an easy implantation technique providing effective atrioventricular synchronization. The sensing problems, which may occur on late follow-up, can be corrected successfully by reprogramming. To achieve an optimal atrial sensing function in patients with a single-lead VDD pacing, we recommend that the atrial sensing capability should be examined in various physical maneuvers.

Adult↗

PubMed1999

Echocardiographic evaluation of left ventricular diastolic function in chronic cor pulmonale.

In this study we hoped to understand the abnormalities of left ventricular filling dynamics in chronic cor pulmonale. Our findings showed a severe left ventricular diastolic impairment, directly related to a progressive increase in pulmonary hypertension itself, as expressed by correlation analysis between systolic pulmonary artery pressure and the following parameters: transmitral flow velocity in early/late diastole ratio (r = -0.69, p <0.001), isovolumic relaxation time (r = 0.54, p = 0.001), and transmitral flow velocity in early diastole (r = -0.59, p <0.01).

Adult↗

PubMed1999

Value of ST-segment depression during paroxysmal supraventricular tachycardia in the diagnosis of coronary artery disease.

We evaluated 39 patients >45 years old with paroxysmal supraventricular tachycardia (SVT), 21 of whom had ST-segment depression during SVT. Treadmill exercise testing, including thallium stress scintigraphy, was performed in all patients and coronary angiography in 21 patients with ST-segment depression. Based on the presence of abnormal findings on exercise electrocardiogram and/or thallium in 7 of 21 patients (33%) with ST-segment depression, with additional corroboration by angiographic data, we conclude that myocardial ischemia and coronary artery disease is one, but not the only, mechanism involved in the genesis of ST-segment depression during paroxysmal SVT.

Aged↗

PubMed1998

Exercise performance in patients with dilated cardiomyopathy: relationship to resting left ventricular function.

Relationship between maximal exercise tolerance and resting indexes of left ventricular systolic and diastolic function were evaluated in 35 men, aged 55.1 +/- 10.4 years, with dilated cardiomyopathy. Clinical diagnosis of dilated cardiomyopathy was confirmed with M-mode echocardiography (M-mode echocardiographic end-diastolic dimension >55 mm, fractional shortening <25%, increased E point septal separation). Coronary angiography was considered mandatory for exclusion of patients with coronary artery disease. Patients with mitral regurgitation (> or =grade 2) and rhythm other than sinus were excluded. According to the functional classification of New York Heart Association 6 patients were in class I, 11 in class II, 12 in class III and 6 in class IV. Left ventricular ejection fraction (LVEF), stroke volume (SV) and left ventricular end-diastolic pressure (LVEDP) were measured with contrast angiography. Peak early (VE) and late (VA) transmitral filling velocities and their ratio (E/A), isovolumetric relaxation time (IRT) and deceleration time (DT) were computed from pulsed wave Doppler echocardiograms. On completion of all resting measurements, patients underwent symptom limited upright treadmill exercise testing using a modified Naughton protocol and maximal exercise performance metabolic equivalent work load (NETS) was calculated from the speed, incline and length of time at the stage using standard tables to make interpatient comparisons. Significant correlation has been found between NYHA class and METS (r= -0.77, P<0.001). However NYHA class II and NYHA class III patients were found to have similar METS (P=0.317). Patients were further divided into two groups on the basis of exercise data. Group I consisted of 22 patients with relatively preserved exercise tolerance (> or =4 METS) and Group II included 13 patients with impaired exercise tolerance (> or =4 METS). This arbitrary classification was based upon previously described survival differences in these two groups. There were no differences between two groups in terms of age, gender distribution (all were male), heart rate and arterial blood pressure. LVEF, LVEDP, stroke volume, VE, VA, E/A, IRT and DT were also similar between two groups. Strong positive correlation was observed between LVEDP and VE (r=0.74) while IRT and VA negatively correlated with LVEDP (r= -0.77 and r= -0.81 respectively) but neither of resting indexes of left ventricular systolic and diastolic function showed significant correlation with METS and exercise duration.

Cardiomyopathy, Dilated↗

PubMed1997

Left ventricular filling and ejection fraction after successful percutaneous balloon mitral valvuloplasty.

The effect of percutaneous balloon mitral valvuloplasty (PBMV) on left ventricular (LV) filling and ejection fraction (EF) still remains controversial. We evaluated LV filling and EF in 23 patients (19 women and four men, mean age 35.6+/-9.6, range 17-56 years) with mitral stenosis (MS) and sinus rhythm immediately before and after successful PBMV not complicated with significant mitral regurgitation and arrhythmia during left ventriculography. After PBMV mean mitral valve area increased from 1.4+/-0.2 to 2.2+/-0.3 cm2 (P<0.01), mean mitral valve gradient (MVG) decreased from 18.6+/-5.7 to 6.9+/-3.2 mmHg (P<0.01) and mean left atrial pressure (LAP) decreased from 26.0+/-8.2 to 12.3+/-5.2 mmHg (P<0.01). We did not determine any change in EF (before PBMV 61.8+/-9.3% and after PBMV 61.8+/-7.6% (P>0.05)). Heart rate did not change significantly before and after valvuloplasty (P>0.05). Despite the decrease in LAP and MVG, the early diastolic filling fraction of left ventricle did not change (before PBMV 59.5+/-7.5%, after PBMV 57.8+/-8.9% (P>0.05)). Also, we did not determine any increase in LV end diastolic volume index (before PBMV 89.9+/-27.7 cm3/m2 and after PBMV 84.6+/-20.9 cm3/m2 (P>0.05)). However, LV end diastolic pressure increased significantly after PBMV (from 6.6+/-3.0 to 11.3+/-4.9 mmHg (P<0.01)). We conclude that in patients with MS, LV diastolic performance is impaired and LV EF does not change acutely after PBMV.

Adolescent↗