Short head-up tilt test. Evaluation of time to syncope in nitroglycerine potentiated

The aim of the present study was to evaluate the time to syncope in Nitroglycerine potentiated short Head-up tilt test. This was a descriptive cross sectional study conducted in Armed Forces Institute of cardiology from May 2006 to May, 2007. A total number of 90 patients with orthostatic intolerance both male and female were studied. Head-up tilt test protocol consisted of a Stabilization phase which lasted for five minutes Passive tilt phase: Patients were tilted at 70 [degree sign] for orthostatic stress for 15 minutes. In case of no symptoms the test continued with the drug provocation phase which lasted for 15 minutes. The patients were administered 400 micro g of nitroglycerine sublingually in aerosol preparation. Development of symptoms were noted at 5, 10 and 15 minutes. A total number of 90 patients were examined during the study period. The tilt table test was classified as positive in 58.9% of patients and was negative in 41.1%. The test was positive in five patients without the drug provocation [9.4%]. The responses were classified as positive vasodepressor in 35.8%, 15.09% as mixed and cardioinhibitory 15.09% in patients of neurally mediated syncope. The total time to display of symptoms to positivity in HUTT was 17.89 +/- 6.99. The mean time to syncope after the administration of nitroglycerine was 5.61 +/- 4.17 minutes. Our study concludes that the drug administered phase can be reduced to 12 +/- 3 minutes

Short duration head-up tilt test: a comparison with conventional long protocol in patients of orthostatic intolerance

Orthostatic intolerance is development of symptoms during upright standing relieved by recumbency. An individual's predisposition to orthostatic intolerance [development of symptoms during upright posture] can be identified by Head-up Tilt Test [HUT]. The aim of the present study was to compare the diagnostic yield [Percentage of patients tested positive] of short duration with conventional HUT. The study was conducted in Islamic International Medical College, Rawalpindi in collaboration with Armed Forces Institute of Cardiology/National Institute of Heart Diseases. A total number of 100 patients with orthostatic intolerance were studied. The conventional and short duration HUT protocols were compared. Conventional protocol had a passive tilt phase of 30 minutes and drug provocation phase of 20 minutes while the short duration protocol had both phases of 15 minutes, thereby reducing the test duration by 20 minutes. All patients underwent short duration HUT and patients with positive test were considered positive for conventional HUT as well. Patients having negative short duration HUT underwent conventional HUT after one week. Comparison was done using Chi-square statistics and p<0.05 was considered significant. Diagnostic yield of short duration and conventional HUT was 53% and 63% respectively with no statistically significant difference between the two protocols [p=0.15]. Head-up tilt test [HUT] is an effective investigative tool for orthostatic intolerance with satisfactory diagnostic yield. Short duration HUT may be substituted for conventional HUT to save time and to accommodate more patients