Nocturnal pauses in Holter monitoring : How significant is it ?

Holter monitoring is the Initial test for all those with documented  syncope (or Pre syncope ) with suspected cardiac arrhythmia .It is a 24 hour ambulatory  ECG monitoring , expected to pick up any electrical abnormality and its correlation with the resultant symptom if any. Though the test looks  attractive , the diagnostic yield is far less. (About 10%) .The reason being the episodes can be rare  to be  missed by 24hr sample time. We have extended Holter (48hr) , Event monitors , Loop recorders and implantable devices that can record ECG for extended periods.(18 Months ,Reveal Plus Medtronic)  that improve the yield  up to 45%. One common issue that often confuse us  while reporting  Holter is, the  pauses that occur during day / night . What is the significance of these pauses * ?  Nocturnal vs Daytime Pauses are obviously significant when the patient is awake . It is generally accepted pauses more than 3 seconds during day time  (ie Heart rate of < 20/mt ) is significant . This is logical , as pauses more than that,  is expected to cause syncope ( or atleast pre-syncope ).The problem comes when you document pauses more than 3 seconds without any symptoms . Then this  difficult  question comes up ,At what degree of pause syncope occurs ? How is that some persons mange  even prolonged pauses with just giddiness.(Good overall vascular integrity and tone ! ) We know such pauses are  especially  common during sleep. How does the brain react when pauses o...
Source: Dr.S.Venkatesan MD - Category: Cardiology Authors: Tags: Uncategorized Source Type: blogs