Incidence, diagnostic yield and safety of the implantable loop-recorder to detect the mechanism of syncope in patients with and without structural heart disease.
OBJECTIVE
To evaluate the incidence, diagnostic yield and safety of implantable loop recorders (ILRs) in patients with or without structural heart disease (SHD).


RESULTS
Two-hospitals, observational, prospective study in consecutive patients with unexplained syncope who underwent an ILR implantation. Between November 1997 and December 2002, a total of 2052 patients with syncope were evaluated (referral population of 590000 inhabitants). The diagnosis remained unexplained in 371 (18%). Of these, 103 patients (5% of total, 28% of unexplained syncope) received an ILR. SHD was present in 38 (37%), and absent in 65 (63%). During a median follow-up of 13 months, syncope was recorded in 52 patients. While patients with and without SHD had similar incidence of syncope recurrence, its mechanism was different. Patients with SHD more frequently had paroxysmal AV block and tachyarrhythmias and patients without SHD more frequently had sinus bradycardia/sinus arrest or no arrhythmia. More patients with SHD finally received an ILR-guided therapy. Sudden death occurred in one patient with SHD. Five syncope-related injuries were noted in 3 patients.


CONCLUSIONS
The mechanism of syncope is different in patients with and without SHD; diagnostic yield and safety are similar in both groups. About 28% of patients with unexplained syncope have an indication to ILR implantation. The need for ILR implantation in the general population is 34 implants/million inhabitants/year.
Solano
Alberto
A
Arrhythmologic Centre, Department of Cardiology, Ospedali del Tigullio, Via don Bobbio 25, 16033 Lavagna, Italy. aritmo@asl4.liguria..it
Menozzi
Carlo
C
Maggi
Roberto
R
Donateo
Paolo
P
Bottoni
Nicola
N
Lolli
Gino
G
Tomasi
Corrado
C
Croci
Francesco
F
Oddone
Daniele
D
Puggioni
Enrico
E
Brignole
Michele
M
D000368:Aged; D002037:Bundle-Branch Block / Q000150:complications / Q000175:diagnosis; D002311:Cardiomyopathy, Dilated / Q000150:complications / Q000175:diagnosis; D015716:Electrocardiography, Ambulatory / Q000295:instrumentation; D004567:Electrodes, Implanted; D005260:Female; D006331:Heart Diseases / Q000150:complications / Q000175:diagnosis* / Q000628:therapy; D006349:Heart Valve Diseases / Q000150:complications / Q000175:diagnosis; D006801:Humans; D008297:Male; D018670:Monitoring, Ambulatory / Q000295:instrumentation; D009203:Myocardial Infarction / Q000150:complications / Q000175:diagnosis; D010138:Pacemaker, Artificial; D011446:Prospective Studies; D012008:Recurrence; D013575:Syncope / Q000175:diagnosis* / Q000209:etiology