Intravenous Nitrates for Pharmacological Stimulation During Head-up Tilt Testing in Patients with Suspected Vasovagal Syncope and Healthy Controls
| Autor: | Gunnar Strobel, Paul Dendale, Pierre Block, Cathy Daniels, Leonard Kaufman, Paul Meyvisch, Arnaud J. J. Aerts |
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| Přispěvatelé: | Biomedical Statistics and Informatics, Vrije Universiteit Brussel |
| Jazyk: | angličtina |
| Rok vydání: | 1999 |
| Předmět: |
Adult
Male Supine position Vasodilator Agents Blood Pressure Isosorbide Dinitrate Sensitivity and Specificity Drug Administration Schedule Heart Rate Tilt-Table Test Syncope Vasovagal medicine Humans In patient Vasovagal syncope Presyncope Dose-Response Relationship Drug biology Receiver operating characteristic business.industry Pharmacological stimulation Syncope (genus) Head up tilt General Medicine Middle Aged biology.organism_classification medicine.disease ROC Curve Anesthesia Female Cardiology and Cardiovascular Medicine business |
| Popis: | Nitrates may be used for pharmacological stimulation during tilt testing for the diagnosis of vasovagal syncope. In this study we assessed the diagnostic value of intravenous nitrates during tilt testing in patients with a typical history of vasovagal syncope. Twenty patients and 23 controls were tilted at 700 for a maximum duration of 30 minutes. After a 10-minute baseline supine phase, the test started with a continuous nitrate infusion at 1 microg/kg/min and increased every 5 minutes by 1 microg/kg/min, to a maximum of 6 microg/kg/min at the end of the test. The test was ended if the subjects developed a positive response (syncope or presyncope). Nineteen patients (95%) and 17 (74%) of the controls had a positive response. At test end sensitivity was 95%, but specificity was 26% and accuracy was 58%. Receiver operator characteristics (ROC) analysis revealed a maximum accuracy of 79% at 18 minutes, with a sensitivity of 80% and a specificity of 78%. Intravenous nitrates during tilt testing in patients with typical clinical criteria of vasovagal syncope is highly effective in provoking vasovagal syncope. Based on the ROC analysis, a maximum accuracy of 79% was attained at 18 minutes (at a dose of 4 microg/kg/min), suggesting a good diagnostic performance when tilt duration is limited to this point. A positive result requiring more than 18 minutes of stimulated tilting should be interpreted with caution, due to the accompanying considerable decrease of specificity. |
| Databáze: | OpenAIRE |
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