Integrated whole-heart computational workflow for inverse potential mapping and personalized simulations.

BACKGROUND: Integration of whole-heart activation simulations and inverse potential mapping (IPM) could benefit the guidance and planning of electrophysiological procedures. Routine clinical application requires a fast and adaptable workflow. These requirements limit clinical translation of existing simulation models. This study proposes a comprehensive finite element model (FEM) based whole-heart computational workflow suitable for IPM and simulations. METHODS: Three volunteers and eight patients with premature ventricular contractions underwent body surface potential (BSP) acquisition followed by a cardiac MRI (CMR) scan. The cardiac volumes were segmented from the CMR images using custom written software. The feasibility to integrate tissue-characteristics was assessed by generating meshes with virtual edema and scar. Isochronal activation maps were constructed by identifying the fastest route through the cardiac volume using the Möller-Trumbore and Floyd-Warshall algorithms. IPM's were reconstructed from the BSP's. RESULTS: Whole-heart computational meshes were generated within seconds. The first point of atrial activation on IPM was located near the crista terminalis of the superior vena cave into the right atrium. The IPM demonstrated the ventricular epicardial breakthrough at the attachment of the moderator band with the right ventricular free wall. Simulations of sinus rhythm were successfully performed. The conduction through the virtual edema and scar meshes demonstrated delayed activation or a complete conductional block respectively. CONCLUSION: The proposed FEM based whole-heart computational workflow offers an integrated platform for cardiac electrical assessment using simulations and IPM. This workflow can incorporate patient-specific electrical parameters, perform whole-heart cardiac activation simulations and accurately reconstruct cardiac activation sequences from BSP's.

A long-term, multicenter, open-label study of risperidone in elderly patients with psychosis. On behalf of the Risperidone Working Group.

RATIONALE: Studies have shown that risperidone is safe and efficacious in young and middle-aged adults with chronic schizophrenia, but considerably fewer data are available on the treatment of elderly patients with schizophrenia or other psychotic disorders, particularly long-term outcomes. OBJECTIVE: A 12-month, open-label study was conducted to assess the effects of risperidone in elderly, chronically ill, psychotic patients. METHODS: This study enrolled 180 elderly, chronically ill, psychotic patients (median age, 72 years [range 54-89]), 97 of whom completed the 12-month study. At endpoint, the mean dose of risperidone was 3.7 mg/day. RESULTS: Clinical improvement (> or =20% reduction in Positive and Negative Syndrome Score [PANSS] total score) was achieved by 54% of patients at endpoint. There were significant reductions in PANSS total, subscale (positive, negative, and general psychopathology), and cognition cluster scores at endpoint (p<0.001). Clinical Global Impressions severity of illness scores showed continued improvement through month 12 (p<0.001). In contrast, PANSS data from a historical comparable control group of patients receiving conventional antipsychotic agents showed no symptom improvement over a 12-month treatment period. The severity of preexisting extrapyramidal symptoms (EPS) in patients treated with risperidone decreased significantly from baseline to endpoint (p<0.001), and the use of antiparkinsonian medication decreased from 41.1% of patients before the trial to 25.6% during the trial. There were no spontaneous reports of tardive dyskinesia (TD) and the incidence of assessed TD was 4.3% in contrast to the expected 26% reported in middle-aged and elderly patients receiving conventional antipsychotic agents for 1 year. CONCLUSIONS: Long-term treatment with risperidone was associated with continued symptom improvement, a decrease in the severity of preexising EPS, and a low incidence of TD in elderly psychotic patients.

[Antidepressive agents in the elderly]. / Antidepressiva bij bejaarden.

Depressive disorders are the most common psychiatric illness in the elderly. All tricyclic antidepressants show comparable therapeutic efficacy, thus the choice of drug is based on their side effects profiles rather than on degree of therapeutic efficacy. The secondary amines nortriptyline and desipramine are drugs of choice for the elderly depressive patient because of their relatively mild side effects profile. New-generation antidepressants remain second choice. Patients suffering from a psychotic depression often require a combination of an antidepressant drug with an antipsychotic drug. Addition of lithium to a cyclic antidepressant can produce a rapid and lasting remission in patients with a major depressive disorder who do not respond to a cyclic antidepressant alone. Treatment with MAO-inhibitors or electroconvulsive therapy can also be considered in refractory cases.

Assessment of myocardial damage in patients with acute myocardial infarction by serial measurement of serum alpha-hydroxybutyrate dehydrogenase levels.

A method is presented for routine estimation of ultimate infarct size in patients with acute myocardial infarction (AMI). This method implies the calculation of the total quantity of alpha-hydroxybutyrate dehydrogenase (HBDH) released by the heart per liter of plasma, with the use of five to seven plasma samples per patient during the first 4 days after onset of infarction. The choice of HBDH for this purpose was motivated by a relatively small error in estimated enzyme release for slowly eliminated enzymes. The practicality of this method was studied in the coronary care unit at Leiden University Hospital where, in 1979, 146 patients with AMI were included in the study. In 100 patients (68%) HBDH-infarct size could be calculated precisely, and in 12 other patients (8%) the assessment of HBDH-infarct size was less accurate. In 34 patients (23%), HBDH-infarct size was unobtainable because of early death (eight cases), infarctions too small in size to assess or nonexistent (six cases), too much time elapsed since infarction (six cases), and incomplete plasma sampling (14 cases). Analysis of data shows that the larger HBDH-infarct sizes were found to be associated significantly with signs of heart failure, low stroke index and low ejection fraction, presence of tachycardias and interventricular conduction disturbances, high score of left ventricular wall motion abnormalities, large myocardial perfusion defect measured with thallium-201, in-hospital death, and death in the first year after infarction. A low but significant correlation was observed between HBDH-infarct size and the severity of coronary arterial lesions.