Holter Recording

Indications for AECG• Patients with unexplained syncope, near syncope or

episodic dizziness in whom the cause is not obvious

• Patients with unexplained recurrent palpitation

• To assess antiarrhythmic drug response

• Pacemaker and ICD function

• Patients with suspected variant angina

• Evaluation of possible or documented long QT

syndromes

AECG equipmentIn 1957, Dr. Norman Holter introduces portable

devices to record the ECG

Current AECG equipment provides the detection and analysis of arrhythmias,ST-segment deviation, R-R intervals, QRS-T morphology

Two categories of AECG recorders

• Continuous recorders

• Intermittent recorders

AECG equipment…Continuous recorders• Used for 24 to 48 hours, which investigate

symptoms or ECG events that are likely to occur within that time frame

Intermittent recorders • Used for long periods of time (weeks to months)

to provide briefer, intermittent recordings to investigate events that occur infrequently

Intermittent recorders…

External insertable loop recorder

Recording from external ILR

Intermittent recorders Loop recorder• It should be worn continuously

• Particularly useful if symptoms are quite brief or if symptoms include only very brief incapacitation of the patient

• Family members can activate the recorder if the patient actually loses consciousness

• Newer loop recorders can be implanted under the

skin for long-term recordings

Intermittent recorders…Event recorder• It should be attached by the patient and activated

after the onset of symptoms

• It is not useful for arrhythmias that cause serious symptoms such as loss of consciousness or near loss of consciousness because these devices take time to find, apply, and activate

• They are more useful for infrequent, less serious but sustained symptoms that are not incapacitating

Continuous recorders

Conventional AECG recorders typically are small, lightweight devices

They contain a quartz digital clock and a separate recording track to keep time

A patient-activated event marker is conveniently placed on the device for the patient to indicate the presence of symptoms or to note an event

Continuous recorders...

Limitations• Expense

• Limited storage capacity of digital data

Continuous recorders...

Storage methodologies1.Flash memory card

2.Portable hard drive

Continuous recorders...Flash cards• Very small, compact storage devices, size of a credit card

• Storage capacity --- 20 to 40MB

• Removed from the recording device once the recording is completed

• Inserted into a separate device where the data can be played back and analyzed

Continuous recorders...

Portable hard drive• Utilize the same technology used in laptop computers

• Storage capacity --- >100MB

• It cannot be removed from the recorder

• Data to be downloaded to another storage device or

electronically transferred

Methods of electrode preparation

The skin over the electrode area should be

• Shaved

• Gently abraded

• Cleansed with an alcohol swab

Methods of analysisArrhythmia Analysis• Each beat is classified as normal,VPC,APC,paced,

others or unknown

• Summary data describing the frequency of atrial and ventricular arrhythmias are displayed typically in both tabular and graphical formats

Methods of analysis…Conditions not suitable for interpretation

• LVH

• Preexcitation

• LBBB

• Marked baseline ST-segment distortion

ASSESSMENT OF SYMPTOMS THAT MAY BERELATED TO DISTURBANCES OF HEART

RHYTHM

Determination of the relation between patient’s transient symptoms to cardiac arrhythmias

Commonly caused by transient arrhythmias

1.Syncope

2.Near syncope

3.Dizziness

4. Palpitation

Less commonly caused by transient arrhythmias

1.Shortness of breath

2.Chest discomfort

3.Weakness

4.Diaphoresis

5.Transient ischemic attack

6.Vertigo

After Myocardial Infarction

The 1-year risk of developing a malignant arrhythmia in an MI survivor after hospital discharge is 5% or less

The goal in risk-stratifying ---To identify at high risk patients Reduce arrhythmic events with an intervention

After Myocardial Infarction…

The goal in risk-stratifying…

PVCs associated with a higher mortality

• Frequent PVCs (10 per hour)

• High-grade ventricular ectopy (repetitive PVCs, multi-form PVCs,VT)

After Myocardial Infarction…

AECG is not needed in• Asymptomatic post-MI patients EF >

40% ---malignant arrhythmias are rare

Thank you