Holter monitor

As Holter (abbr. LZ ECG ) recording of the electrocardiogram over a prolonged period of 24 hours usually is known in the medicine. According to its inventor, Norman J. Holter, the method is called, especially in the Anglo-Saxon and Holter ECG.

The Holter monitoring is used to assess the extent of cardiac arrhythmias and also track down rare arrhythmia can. Most common is the continuous ECG recording over 24 hours with the help of portable recording devices that can discover and circulatory disorders of the heart. More rarely a discontinuous recording using so-called Event Recorder or Loop Recorder is carried out over longer periods. Implanted event recorder, similar to a cardiac pacemaker, thereby also allow multi-year periods of observation.

Areas of application

The conventional Holter monitoring over 24 hours is mainly used for detection and quantification of arrhythmias in patients with known heart disease or with symptoms that could be caused by arrhythmias. These include tachycardia, palpitations, vertigo, fainting ( syncope ) and temporary paralysis (TIA).

In patients with atrial fibrillation or atrial flutter in the LZ ECG episodes of arrhythmia are often uncovered that were especially at night not noticed by the patient. After a heart attack or myocardial disease undetected life-threatening arrhythmias can be discovered especially in severely impaired pumping force of the heart also, which require special treatment.

If the symptoms mentioned not every day, including the 24 -hour Holter monitoring is often without seminal findings. In these cases, an event recorder can often help to detect cardiac arrhythmia as the cause or rule. Every now and then can be assigned in this way also panic attacks and anxiety disorders as consequences of an arrhythmia.

Basically is possible with considerable expenditure of time and at least three standardized derivatives also include an analysis of the ST segment for the detection of circulatory disorders of the heart muscle. Due to the limited validity of the findings collected in this way and improved other possibilities, this analysis is carried out only in exceptional cases.

Technology

Holter

The 24- LZ- ECG is transmitted over two to six glued to the chest electrodes continuously on a tape or hard memory recorder that is worn on a belt or around the neck. The older analog recording tape cartridge devices resemble a walkman and weigh about 150-220 grams. Modern appliances store digitally on hard drives, compact flash memory cards or similar storage media. They weigh about 100-120 grams and allow a recording time of up to one week. After the end of recording, the data are evaluated with computer assistance, with an average of about 100 thousand cardiac actions need to be analyzed per 24 hours.

Event Recorder

The use of the terms event recorder and loop recorder is not uniform. As an event recorders are often small digital recording device called the size of a mobile phone that is pressed by the patient in response to symptoms such as palpitations or heart stumbles on the skin in the chest area and then record an ECG episode about 30-60 seconds. The event recorder can also function as a mobile phone. The recorded ECG episode is then sent via the GSM network to an emergency call center. Before and after the transfer, the usual voice connection can be used for symptom description and treatment indications, if necessary, the central determine the location of the patient and alert emergency personnel.

Loop recorder, however, draw on the ECG skin electrodes on permanently, but delete it after usually 30 seconds. Only pre-programmed special ECG events and marked by the patient by pressing ECG episodes are permanently stored. A Bluebelt called plastic chest strap with dry electrodes recorded the ECG continuously and alerted upon the occurrence of certain ECG events over a Bluetooth connection and a relay or mobile phone also via GSM network an emergency call center.

Implanted loop recorder can record ECG episodes over one to two years without significant deterioration of the patient, the query of this recorders carried by telemetry. The devices are slightly smaller than pacemakers and implanted under the skin over the heart. Unlike the pacemaker to the heart are not required conducting electrodes. This implantation is quick and easy in the context of an outpatient surgery feasible. These devices are used in people who are not during the episode in a position to apply the loop recorder, for example, a syncope, or if previous tests ( tilt table, ergometry, etc.) have led to no result, and a cardiac etiology must be excluded.