Holter monitoring vs tilt testing in the investigation of suspected vasovagal syncope.

The aim of this study was to compare the diagnostic yield of 48-hour Holter monitoring with head-up tilt (HUT) test in patients presenting with blackouts suggestive of vasovagal syncope. One hundred and eighteen consecutive patients, 68 women, aged (mean [SD])50 +/- 20 years(range 16-88 years), underwent 48-hour Holter monitoring and 60 degrees HUT test within 3 months. Endpoints were symptom-ECG correlation during Holter monitoring and positive HUT test. Syncope occurred in 3 (3%) patients during Holter monitoring, the rhythm being sinus tachycardia in all. Presyncope was reported in 22 (19%), the rhythm being sinus tachycardia in 6, persistent atrial fibrillation in 2, and normal sinus rhythm in the remainder. Asymptomatic arrhythmias were recorded in 103 (87%) patients. Positive HUT tests occurred in 39 (33%), the pattern being mixed (VASIS type 1) in 14 (36%), cardioinhibitory (VASIS type 2) in 3 (8%), and vasodepressor (VASIS type 3) in 22 (56%). Change in patient management occurred in 3 (3%) patients following Holter monitoring and 39 (33%) patients following HUT test. Holter monitoring produces a low yield of clinically useful information in the investigation of suspected vasovagal syncope. An HUT test should be considered the primary investigation of choice in such patients.