[Sensitization of tilt-table testing for syncope of unknown etiology: which drug to use?].
OBJECTIVE
The sensitivity of tilt-table testing in the diagnosis of vasovagal syncope is between 30% and 50% only. The most common method currently used to improve the sensitivity of the test is the administration of isoproterenol i.v. However, this method is difficult to perform and time consuming. The objective of our study was to compare sublingual trinitrin administration to i.v. isoproterenol during tilt-table testing.


METHODS
We analyzed the results of 257 consecutive patients referred for tilt testing. Patients who had a negative test received either a ten minutes infusion of i.v. isoproterenol at the dose of 4 mcg/kg/min, or 0.4 mg of trinitrin given sublingually.


RESULTS
Two hundred (and) fifty-seven patients underwent tilt-table testing. In the first group (isoproterenol group), 42 patients (39%) had a spontaneous positive tilt test, compared to 45 patients (31%) in the trinitrin group (P = NS). After sensitization, 24 additional patients (22%) had a positive test in the isoproterenol group vs 55 patients (37%) in the trinitrin group (P = NS). The total number of positive tests was 66 (61%) in the isoproterenol group compared to 100 (68%) in the trinitrin group (P = NS).


CONCLUSIONS
Sublingual trinitrin is at least as good as IV isoproterenol during tilt-table testing. Because trinitrin is simpler to use and because its administration is much faster than isoproterenol, it should be recommended as the drug of choice to improve the sensitivity of tilt-table testing.
Salamé
E
E
Service de cardiologie, hôpital Hôtel-Dieu-de-France, rue Alfred-Naccache, Beyrouth, Liban. etsalame@hotmail.com
Neemtallah
R
R
Azar
R
R
Antonios
S
S
Jazra
C
C
Kassab
R
R
D000286:Administration, Sublingual; D000293:Adolescent; D000328:Adult; D000368:Aged; D001794:Blood Pressure / Q000502:physiology; D002316:Cardiotonic Agents / Q000008:administration & dosage / Q000627:therapeutic use; D002317:Cardiovascular Agents / Q000627:therapeutic use*; D004562:Electrocardiography; D005260:Female; D006339:Heart Rate / Q000502:physiology; D006801:Humans; D007262:Infusions, Intravenous; D007545:Isoproterenol / Q000008:administration & dosage / Q000627:therapeutic use; D008297:Male; D008875:Middle Aged; D005996:Nitroglycerin / Q000008:administration & dosage / Q000627:therapeutic use; D011237:Predictive Value of Tests; D012680:Sensitivity and Specificity; D019462:Syncope, Vasovagal / Q000175:diagnosis* / Q000209:etiology; D018667:Tilt-Table Test / Q000379:methods* / Q000706:statistics & numerical data; D014665:Vasodilator Agents / Q000008:administration & dosage / Q000627:therapeutic use
D002316:Cardiotonic Agents; D002317:Cardiovascular Agents; D014665:Vasodilator Agents; D005996:Nitroglycerin; D007545:Isoproterenol