Shortened head-up tilt testing potentiated with sublingual nitroglycerin in patients with unexplained syncope

Teste de inclinação (Tilt-test): do necessário ao imprescindível

“…After administration of 300 mg of sublingual nitroglycerin, a positive response was observed in more than 26% of the patients and in 6% of the control group, resulting in a specificity of 94%. Similar data were presented by other authors in subsequent years 9,15,18 (Table 1). …”

“…Many authors consider that it is enough to stop the HUTT when the doctor believes that the loss of consciousness is imminent -phase called presyncope -, and there is no reason to subject the patient to the huge discomfort resulting from hypotension or bradycardia, which will allow defining the vasovagal response 1,26,27 . More recent studies have considered that the positivity criterion is the induction of syncope or presyncope, when associated with bradycardia or hypotension 11,13,14,18,26,28 .…”

“…Likewise, when one analyzes more recent studies, it is possible to notice a significant decrease in specificity when, in sensitized protocols, the duration of the passive phase is equal to or more than 30 minutes. Protocols with shorter passive phases, or even without a passive phase, followed by sensitization with nitrate or isoproterenol, are linked with specificities that range from 84 to 97% 18,28,38 , whereas, in studies that used a more prolonged passive phase, there was a decrease in specificities (48 to 70%) 9,11,15 . Therefore, limiting the total duration of the examination seems to guarantee good specificity.…”

Guidelines on management (diagnosis and treatment) of syncope

“…Pooled data from three studies [110][111][112] using this protocol, in a total of 304 patients, showed a positive response rate of 69% which was similar to the positive rate of 62% observed in 163 patients from three other studies [109,112,113] using a passive phase duration of 45 min and 400 g nitroglycerin spray administration. With this protocol, specificity remained high, being 94% in 97 controls [110][111][112] . Thus a 20 min passive phase before nitroglycerin administration appears to be an alternative to the more prolonged 45 min passive phase.…”

Ordinary Autonomic Unbalance Can Reflect Diagnosis of Neurally Mediated Reflex Syncope

“…If no syncope or presyncope occurred within 30 min, the HUT test was performed again 15 min after drug administration. For drug loading, patients were administered ATP 0.1-0.2 mg / kg , isoproterenol 0.01 g / kg per min [16][17][18][19][20] , or isosorbide dinitrate 5 mg 21,22 . If no syncope or presyncope was induced during the HUT test after administration of these drugs, the patients were deemed to have a negative result on the HUT test.…”