Specificity and total positive rate of head-up, tilt testing potentiated with sublingual nitroglycerin in older patients with unexplained syncope

The aim of this study was to assess the specificity and total positive rate of head-up tilt testing (HUTT) potentiated with sublingual nitroglycerin i n detecting the vasovagal origin of unexplained syncope in the elderly, sin ce the diagnostic value of this non-invasive test has not yet been proven i n this age group. In a period of 3 years, 128 elderly patients (mean age 71 .6 +/-5.1 years, 50% males) with syncope of unknown origin, and 101 control subjects matched for age and gender were tilted upright to 60 degrees for 45 minutes. If syncope did not occur, sublingual nitroglycerin (0.4 mg) was administered, and observation Was continued for 20 minutes. The positive r esponse was defined as the reproduction of syncope or pre-syncope according to VASIS definition. During the unmedicated phase, syncope occurred in 26 patients (20.3%) and in no members of the control group. After nitroglyceri n, 53 patients (41.4%) and 2 control subjects (2%) displayed syncope. The t otal positive rate of the test Was 61.8% With a specificity of 98.0%. In co nclusion, HUTT potentiated with sublingual nitroglycerin provides an adequa te specificity and total positive rate in old patients with unexplained syn cope; therefore it can be proposed as a useful diagnostic tool to detect th e vasovagal origin of syncope not only in middle but also in advanced age. (C) 2001, Editrice Kurtis.