OBJECTIVEto study the characteristics of arrhythmia after a positive head-up tilt table test (HUTT).

METHODShead-up tilt table test (BHUT) or sublingual nitroglycerin-provocation head-up tilt table test (SNHUT) were performed in 1374 patients at the Second Xiangya Hospital of Central South University from March of 2001 to August of 2009. Arrhythmias were recorded in 169 patients after a positive HUTT [57 male, age 6 - 65 years, 86 children < 18 years, mean age (23.1 ± 14.8) years].

RESULTSarrhythmias developed in 75 patients (44.38%) post a positive BHUT and in 94 patients (55.62%) post a positive SNHUT. Major types of arrhythmias were sinus bradycardia (143/169, 84.62%), junctional escape rhythm (55/169, 32.54%) and sinus arrest (26/169, 15.38%). Sinus bradycardia was more common in adult (P < 0.01). Occurrence of junctional escape rhythm and sinus arrest was not affected by age, gender and test mode. Arrhythmia and the manifestation of syncope or pre-syncope occurred simultaneously in 77 (45.56%) patients and mainly in BHUT, while arrhythmia appeared later than the syncope manifestation in 92 (54.44%) patients and mainly in SNHUT (P < 0.05). Arrhythmia and blood pressure reduction occurred simultaneously in 84 (53.50%) cases and mainly in BHUT, while arrhythmia appeared later than reduction of blood pressure in 73 (46.50%) cases and mainly in SNHUT (P < 0.01).

CONCLUSIONS(1) the common types of arrhythmia were sinus bradycardia, junctional escape rhythm and sinus arrest after a positive HUTT. Occurrence of sinus arrest was not affected by age, gender and test mode. (2) In BHUT, arrhythmia occurred mostly simultaneously with the manifestation of syncope or pre-syncope and blood pressure reduction, while arrhythmia appeared later in SNHUT.