Biomedical subjects

Eric Fleury

Publications and source records attributed to Eric Fleury.

3 recordsLinked to original sources

PubMed2007

The use of perfusion scintigraphy to differentiate proximal right coronary artery stenosis from distal right coronary artery stenosis in patients with inferior left ventricular ischaemia.

OBJECTIVE: The identification of patients with a significant proximal right coronary artery (RCA) is of clinical relevance since it may direct diagnostic and therapeutic strategies. This study was performed to determine parameters of (201)Tl RV perfusion SPECT which can be used to discriminate between proximal and distal RCA stenosis in patients with inferior left ventricular (LV) ischaemia. In addition, feasibility and reproducibility of a new semi-quantitative method for the assessment of RV perfusion were evaluated. METHODS: Inferior LV ischaemia was due to a single distal RCA stenosis in 10 (group I) and proximal RCA stenosis in 27 patients (group II). Twenty patients with normal (201)Tl myocardial perfusion scintigraphy and low likelihood of cardiovascular disease were used as a reference (group III). RESULTS: RV (201)Tl stress uptake did not differ between the three groups. However, group II showed a significantly higher (201)Tl rest uptake indicating RV redistribution whereas in group I and III tracer washout was shown. Extent and severity of LV inferior ischaemia was not different between groups I and II. RV redistribution has a sensitivity of 0.74, a specificity of 0.80, and an overall agreement of 0.76 for detecting proximal RCA stenosis. The feasibility of the assessment of RV (201)Tl perfusion was 94%. Inter-observer and intra-observer coefficients of variation for RV (201)Tl perfusion assessment were 1.5 and 2.4%, respectively. CONCLUSION: RV (201)Tl perfusion scintigraphy is feasible and reproducible. RV (201)Tl redistribution can be used to discriminate between proximal and distal RCA stenosis in patients with inferior LV ischaemia.

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PubMed2005

Optimizing sequential biventricular pacing using radionuclide ventriculography.

BACKGROUND: Biventricular pacemakers are usually programmed with the default setting of synchronous biventricular pacing, although the ventricles may be paced sequentially. Whether this parameter is important for optimizing resynchronization therapy is not clear. OBJECTIVES: The purpose of this study was to investigate whether sequential pacing acutely improves left ventricular ejection fraction (LVEF) and dyssynchrony and to assess the feasibility of nuclear ventriculography for device optimization. METHODS: Twenty-seven patients implanted with a biventricular pacemaker or implantable cardioverter-defibrillator for heart failure were studied. LVEF was measured using planar radionuclide ventriculography during simultaneous biventricular pacing and during sequential pacing at four different interventricular intervals ranging from LV-40 (preexciting the left ventricle by 40 ms) to LV+40 (preexciting the right ventricle). Interventricular and intraventricular dyssynchrony were analyzed by phase analysis at each setting. RESULTS: There was great heterogeneity in individual response to VV interval programming. Twenty-four of 27 patients (89%) had significant changes (both favorable and unfavorable) in LVEF at different interventricular delays, with variations of up to 10% in absolute terms. Simultaneous biventricular pacing yielded maximal LVEF in 9 of 27 patients (33%), with a relative increase in LVEF of 18 +/- 14% by optimized sequential pacing in the remaining patients. Interventricular dyssynchrony varied significantly, with least dyssynchrony at the LV-20 setting (P = .024). There were no significant differences in intraventricular dyssynchrony at the different settings. CONCLUSION: Programming VV intervals has considerable impact on LVEF. However, there is a great degree of variation between patients in response to these settings, requiring individual assessment for device optimization.

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PubMedDate not supplied

Normal values and within-subject variability of cardiac I-123 MIBG scintigraphy in healthy individuals: implications for clinical studies.

BACKGROUND: Although several myocardial iodine 123 metaiodobenzylguanidine (MIBG) indices are increasingly used to detect alterations in myocardial sympathetic activity in various forms of cardiac pathology, published measurements of normal values and within-subject variability are lacking. METHODS AND RESULTS: Twenty-five healthy volunteers underwent planar and single photon emission computed tomography (SPECT) imaging. Heart-mediastinum ratio (H/M) and myocardial washout were calculated from planar images comparing three different methods for the assessment of myocardial activity: (1) global region over the myocardium (cavity included), (2) global region over the myocardium (cavity excluded), and (3) fixed small myocardial region. Segmental (relative) uptake and washout were assessed by SPECT. For all MIBG indices, the interindividual variation was the lowest for methods 1 and 2. In SPECT this variation was low for relative segmental uptake compared with washout. In 9 subjects a second MIBG scintigraphy was performed after 3 months. The within-subject variability of H/M and washout assessed by planar methods 1 and 2 was 5%, whereas it was approximately 9% for planar method 3. For relative segmental uptake from SPECT, this variability was 5%. CONCLUSION: MIBG H/M (planar) and relative segmental uptake (SPECT) show a low interindividual and within-subject variability. This enables the detection of small (regional) variations in myocardial sympathetic nervous function, especially to monitor the effect of therapeutic interventions in patients with various cardiac diseases.

3-Iodobenzylguanidine↗