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Biomedical subjects

Michael Schlegl

Publications and source records attributed to Michael Schlegl.

5 recordsLinked to original sources
PubMed2006

Time course of left ventricular volumes in severe congestive heart failure patients treated by optimized AV sequential left ventricular pacing alone--a 3-dimensional echocardiographic study.

BACKGROUND: This study evaluates the acute and chronic resynchronizing effects of AV sequential left ventricular (LV) pacing on LV function in patients with impaired cardiac function and conduction disorders by 3-dimensional transesophageal echocardiography. METHODS AND RESULTS: Twenty-nine patients with congestive heart failure, with LV ejection fraction (LVEF) < or = 30%, QRS duration > or = 120 milliseconds, and New York Heart Association Class II to IV, were implanted with a cardiac resynchronization device using an LV lead only, according to the invasively determined hemodynamic optimal pacing site and AV delay. Patients underwent 3-dimensional transesophageal echocardiography before randomization to treatment (baseline) and at 12-month follow-up (resynchronization--12 months). Three-dimensional volumes were acquired on resynchronization and during intermittent switch-off at intrinsic depolarization. The values of stroke volume were 43.2 +/- 13.3 (intrinsic-baseline), 51.7 +/- 17.4 (intrinsic--12 months), 57.2 +/- 15.6 (resynchronization-baseline), and 64.6 +/- 18.9 (resynchronization--12 months). Analysis of variance demonstrated a significant effect of resynchronization at different periods (P < .001) and a significant time effect (P < .05) for stroke volume. Similar results were observed with ejection fraction (LVEF). No effect was observed with LV end-diastolic volume, whereas a therapy effect with no time effect was observed with LV end-systolic volume. CONCLUSIONS: A significant acute increase of LV stroke volume and LVEF was found by resynchronization by LV pacing alone. A continuous improvement of LV stroke volume and LVEF occurred with time of follow-up (reverse remodeling). The initial therapeutic effect persisted during 12-month follow-up independently of time of follow-up and QRS width. No significant decrease of LV end-diastolic size during chronic resynchronization was detected in contrast to previous studies with resynchronization by biventricular pacing.

Cardiac Pacing, Artificial↗
PubMed2004

Panic disorders and agoraphobia: side effects of treatment with an implantable cardioverter/defibrillator.

BACKGROUND: Implantable cardioverter/defibrillator (ICD) treatment has reduced the mortality of patients with a high risk of sudden cardiac death. However, ICD discharges may cause anxiety with respect to new discharges and lead to preventive, for example, phobic, behavior. This study evaluated the frequency of panic disorders and agoraphobia in patients with ICD and assessed the risk factors in their development. HYPOTHESIS: Treatment with ICD represents a risk factor in the development of anxiety disorders. METHODS: Ninety patients with ICD were examined using a standardized lifetime Diagnostic Interview of Psychiatric Syndromes (DIPS). This interview makes it possible to estimate the incidence of panic disorders and agoraphobia. The impact of the severity of the underlying cardiac disease, the number of ICD discharges, and the subjective appraisal of the shock experience on the development of panic disorders and agoraphobia was assessed. RESULTS: Fifteen patients (16.7%) developed anxiety disorders after ICD implantation. The incidence was 21% in patients with and 6.9% in patients without ICD discharge. In patients with two or more ICD discharges annually, the incidence of panic disorders and agoraphobia was higher than that in patients with a single ICD discharge annually (62 vs. 10%, p<0.01). The intensity of self-observation of their body was significantly related to the development of anxiety disorders (p<0.001). CONCLUSION: Panic disorders and agoraphobia are frequent side effects of ICD treatment. Risk factors in the development of these disorders are two or more ICD discharges annually and a negative cognitive appraisal of ICD discharges. Therapeutic efforts should aim at reducing the number of ICD discharges and provide early psychological treatment.

Adaptation, Psychological↗
PubMed2004

Cardiac resynchronization therapy optimization by finger plethysmography.

OBJECTIVES: We tested a simple noninvasive method for cardiac resynchronization therapy (CRT) optimization using standard finger photoplethysmography (FPPG). BACKGROUND: CRT can increase left ventricular cardiac output in patients with heart failure and ventricular conduction delay. Optimal therapy delivery depends on an appropriate AV delay. Multiple invasive and noninvasive methods have been attempted to identify patients and the best AV delay for CRT, but all suffer from a combination of high patient risk, cost, complexity, and low reproducibility. METHODS: FPPG and invasive aortic pressure data were simultaneously collected from 57 heart failure patients during intrinsic rhythm alternating with very brief periods of pacing at 4 to 5 AV delays. After correcting data for artifacts, the median percentage responses for each AV delay were classified as positive, negative, or neutral compared to baseline (Wilcoxon rank test). RESULTS: FPPG correctly identified positive aortic pulse pressure responses with 71% sensitivity (95% CI: 60-80%) and 90% specificity (95% CI: 84-94%) and negative aortic pulse pressure responses with 57% sensitivity (95% CI: 44-69%) and 96% specificity (95% CI: 91-98%). The magnitude of FPPG changes were strongly correlated with positive aortic pulse pressure changes (R(2) = 0.73, P < .0001) but less well correlated with negative aortic pulse pressure changes (R(2) = 0.43, P < .0001). FPPG selected 78% of the patients having positive aortic pulse pressure changes to CRT and identified the AV delay giving maximum aortic pulse pressure change in all selected patients. CONCLUSIONS: FPPG can provide a simple noninvasive method for identifying significant changes in aortic pulse pressure with high specificity, including identifying patients in whom aortic pulse pressure increases with CRT and the AV delay giving the maximum aortic pulse pressure.

Aorta↗