3.3.1Diagnostic Test: Holter monitoring 24-hour

StudyParticipantDiagnostic tests
Aronow 1993
case series; study held in USA.
Setting: geriatrics; chronic care facility.

Funding: not stated
TLoC population: unclear/not stated. Prior tests: All patients had at least 1 prior test.
elderly patients with unexplained syncope; vasodepressor, drug-induced, carotid sinus, neurological syncope, orthostatic hypotension, valvular heart disease, HCM, acute MI, PE, hypoglycaemia excluded
Definition of TLoC: sudden transient loss of consciousness with inability to maintain postural tone; not seizure, vertigo, dizziness, coma, shock or other altered consciousness.
Inclusion criteria: elderly patients with unexplained syncope.
Exclusion criteria: vasodepressor, drug-induced, carotid sinus, neurological syncope, orthostatic hypotension, valvular heart disease, hypertrophic cardiomyopathy, acute MI, pacemaker malfunction, pulmonary embolus, hypoglycaemia.
Patient characteristics: age: mean age 82 (range 62 to 97) years; sex: 68% female; some patients with existing heart disease (48% had coronary artery disease); TLoC history: not stated
Comorbidities: not stated. Other details: elderly patients
Other study comments: case series no comparator; additional data added in from Aronow 1992 (same patients) number 823.
Index test: 24 hour ambulatory ECG (Avionics model 445); time: 24 hours (n=148)
for Target Condition/Outcome: symptom/rhythm correlation: pauses >3s; sustained VT; AF with ventricular rate >190 beats pre minute; nonsustained VT; other complex ventricular arrhythmias
Comolli 1993
case series; study held in Italy.
Setting: Division of Internal Medicine.
Funding: not stated
TLoC population: patients with a history of recurrent syncope but 12-lead ECG normal. Prior tests: All patients had at least 1 prior test.
negative clinical examination, routine haematological tests, chest x-ray, ECG
Definition of TLoC: syncopal episodes.
Inclusion criteria: negative clinical examination, routine haematological tests, chest x-ray, ECG.
Exclusion criteria: none stated.
Patient characteristics: age: mean 67 years (range 19 to 86 years); sex: 54% female; Unclear/not stated with existing heart disease (not stated);
TLoC history: not stated
Comorbidities: not stated. Other details: little info
Other study comments: case series no comparator; test appeared to be used as triage to inform whether patients should be admitted or not. Test carried out “in case syncope might be linked to abnormalities of rhythm or cardiac conduction”
Index test: Holter monitor (Kontron tape); time: 24 hours (n=287)
for Target Condition/Outcome: abnormalities of rhythm whether associated with TLOC or not: major abnormalities defined as VT; pauses over 2 seconds; bradycardia below 30 bpm; high grade AV block; minor: ventricular ectopy; supraventricular ectopy; paroxysmal SVT; paroxysmal AF
Lacroix 1981
case series; study held in Canada.
Setting: Department of Medicine.
Funding: none stated
TLoC population: patients with a history of recurrent syncope but 12-lead ECG normal. Prior tests: All patients had at least 1 prior test.
syncope of unknown aetiology (some patients had had exercise tests & echo)
Definition of TLoC: not defined.
Inclusion criteria: syncope of unknown aetiology.
Exclusion criteria: documented arrhythmia at presentation; Wolff-Parkinson-White syndrome.
Patient characteristics: age: mean age 61 (14) years; sex: 58% male; some patients with existing heart disease (46% had coronary heart disease and 19% had other heart disease); TLoC history: mean 4 episodes per patient; 1st episode mean of 16 months before referral
Comorbidities: not stated. Other study comments: case series
Index test: Holter two-lead monitor in 94 patients and bedside 24-hour monitoring in 6 patients; time: 24 hours (n=100)
for Target Condition/Outcome: symptom/rhythm correlation: not prespecified; rhythms found were VTAF; wide complex tachy; SVT; atrial flutter; ventricular pause over 3sAV blcok (Mobitz type I or II)
Sarasin 2001
case series; study held in Switzerland.

Setting: Emergency Department. ED.
Funding: not stated
TLoC population: unclear/not stated. Prior tests: All patients had at least 1 prior test.
patients presenting to ED with syncope; had had ECG, BP, carotid massage and syncope still unexplained

Definition of TLoC: sudden transient loss of consciousness with inability to maintain postural tone and spontaneous recovery.
Inclusion criteria: patients aged 18 years or older presenting to ED with syncope.
Exclusion criteria: symptoms compatible with seizure vertigo, dizziness, coma or shock.
Patient characteristics: age: mean age 60 (23) years in whole group (range 18–93 years); sex: 52% female; some patients with existing heart disease (unclear how many had heart disease in Holter group); TLoC history: not stated
Comorbidities: unclear. Other details: see below
Other study comments: case series; some of these patients went on to have external loop (see section b number 841) and tilt test (see section c number 842)
Index test: Holter; time: 24 hours (n=122)
for Target Condition/Outcome: prespecified: sinus pause 3s or more/symptom+ pause 2s or more; sinus brady 35bpm or less/symptomatic brady 40bpm or less; AF+slow ventricular response (RR 3s/more); SVT 30s or more, 180bpm or more, or systolic BP 90mmHg/less; 2nd deg (Mob 2)/complete AV block; VT

From: Appendix D1, Included studies characteristics

Cover of Transient Loss of Consciousness (‘Blackouts’) Management in Adults and Young People
Transient Loss of Consciousness (‘Blackouts’) Management in Adults and Young People [Internet].
NICE Clinical Guidelines, No. 109.
National Clinical Guideline Centre for Acute and Chronic Conditions (UK).
Copyright © National Clinical Guideline Centre for Acute and Chronic Conditions, 2010.

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