Biomedical subjects

Mehmet Eren

Publications and source records attributed to Mehmet Eren.

39 records · Page 3Linked to original sources

PubMed2002

Relationship between resting parameters of the mitral valve and exercise capacity in patients with mitral stenosis: can the diastolic filling period predict exercise capacity?

BACKGROUND AND AIMS OF THE STUDY: In order to provide patients with better exercise capacity, interventional therapy to the mitral valve is often carried out in mitral stenosis (MS). Hence, it is crucial to determine exercise capacity before deciding on the time of intervention. The study aim was to demonstrate whether resting parameters of the mitral valve, notably left ventricular diastolic filling period (LVDFP) and mitral valve resistance (MVR), relate to restricted exercise capacity. METHODS: Forty-six patients (30 females, 16 males; mean age 44+/-11 years; range: 33-55 years) with rheumatic MS were enrolled. Exercise capacities of patients were grouped according to NYHA classification and maximal exercise tolerance values obtained using exercise testing. Exercise capacity in male patients was quantified. Relationships between patient variables and exercise capacity were evaluated using simple linear regression analysis. In order to identify determinants of exercise capacity, a discriminate multivariate analysis was performed with variables, which were found to correlate significantly in the univariate analysis. RESULTS: There were no correlations between echo score, MVR, planimetric mitral valve area (MVA), MVA obtained by the pressure half-time method or calculated by the continuity equation, and transmitral mean gradient and exercise capacity classes as defined by both NYHA and exercise testing. The only predictor of exercise capacity class determined by discriminate multivariate analysis using the significant parameters in the linear regression analysis was LVDFP. The quantified exercise capacity in male patients correlated only with LVDFP (r = 0.64, p = 0.008). CONCLUSION: Exercise capacity cannot be predicted using routine resting parameters of the mitral valve (including MVR) in patients with MS. In this respect, the LVDFP may be of value.

Adult↗

PubMed2002

Determination of vena contracta and its value in evaluating severity of aortic regurgitation.

BACKGROUND AND AIMS OF THE STUDY: Recent studies evaluating the severity of valvular insufficiencies have focused on the effective regurgitant orifice area (EROA), which corresponds hydrodynamically to the cross-sectional area of the vena contracta (VC). The study aim was to quantify aortic regurgitation (AR) by using color Doppler imaging of the VC. METHODS: Fifty-five patients with chronic AR were enrolled into the study. VC was visualized by transthoracic echocardiography from the apical echocardiographic window. The quantitative Doppler (QD) method, depending on mitral and aortic stroke volumes, was taken as a reference method. EROA, regurgitant volume (RV) and regurgitant fraction (RF) were calculated using both VC and QD simultaneously in all patients, and the results obtained with each method were compared. RESULTS: EROA(QD) (r = 0.96), RFQD (r = 0.84), RVQD (r = 0.82), and AR grade 3+ or 4+ (r = 0.74) were statistically significantly correlated with VC (4.8+/-1.2 mm). In the multivariate analysis, VC was related only to EROA(QD). The EROA (r = 0.96, p <0.001; mean difference 0+/-0.03 cm2, SEE = 0.004 and p >0.05), RV (r = 0.97, p <0.001; mean difference =1.3+/-4.8 cm3, SEE = 0.65 cm3 and p >0.05) and RF (r = 0.93, p <0.001; mean difference = 1.46+/-4.9%, SEE = 0.66% and p >0.05) obtained by both methods agreed well with each other. VC had a sensitivity of 80%, a specificity of 86%, and an accuracy of 84% in determining severe AR for VC > or =5.5 mm. CONCLUSION: The vena contracta can be visualized using a transthoracic approach from the apical window. The severity of AR can be evaluated using the VC width itself, and also in combination with Doppler data.

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↗