# Presentation: 840443

## Digital Holter in Drug Studies The ISHNE Holter Standard Output File Format

**Wojciech Zareba, MD, PhD**
**Director of ECG Core Lab**
**Associate Professor of Medicine (Cardiology) **** Heart Research, Cardiology Unit, University of Rochester**
**Rochester, NY**

**HEARTWZ@HEART.ROCHESTER.EDU**

## Benefits of Digital Holter in Drug Studies

**Analysis of adaptation of QT to wide spectrum of changing****     heart rate (not available when using resting ECGs).**
**Analysis of dynamic features of repolarization including****	****-   QT – RR relationship (regression analysis, slope)****	****-   QT or repolarization morphology variability****	****-   T wave alternans****	****-    access to night data.**
**Application of novel algorithms for repolarization analyses****     including automatic area based approach. **

**Benefits of Digital Holter in Drug Studies**

## Example of Holter-based Repolarization Analysis (RT_offset) of a Drug (in blue) vs. Placebo (in black)

**Example of Holter-based Repolarization Analysis (RT_offset) ****of a Drug (in blue) vs. Placebo (in black)**

**Absolute RT_offset**

**Fridericia corrected RT_offset**

## RTm and RR in Holter Monitoring in Healthy Subject and LQTS Patient

**RTm and RR in Holter Monitoring ****in Healthy Subject and LQTS Patient**

## Repolarization Correlation Index for Consecutive 128 Beats in Healthy Subject (upper panel) and in Dilated Cardiomyopathy Patient (lower panel)  

**Repolarization Correlation Index for Consecutive 128 Beats in Healthy Subject (upper panel) and in Dilated Cardiomyopathy Patient (lower panel)  **

**Burattini L and Zareba W. J Electrocardiol 1999;32(suppl): 166-172**

## T Wave Area 

**T Wave Area **

**Merri M et al. Circulation 1989;80:1301-8****1.      ****Zareba Wetal. J Electrocardiol 1997; 30(suppl):191-195.**

## Why Standard Output Format for Holter ? 

**  ****Holter ECG recordings are increasingly used in clinical trials****     and drug testing studies.**
**  ****Tapes served as universal medium, but are replaced by digital****     technology.**
**  ****Lack of compatibility between digital recordings from various****     manufacturers.  **
**  ****Need for universal standard output format that could be****     exported from and imported to commercial and custom-made****     computer systems used for data analysis.**

## ISHNE Holter Standard Output Task Force (1998)

***Academia:*****Wojciech Zareba (Chairman; USA), **_**Fabio Badilini (Italy), **_**Pierre Maison-Blanche (France), Jean-Philippe Couderc (USA), Emanuela Locati (Italy), Edward Berbari (USA)*****Industry participation:*****Biosensor; Braemar; Burdick; Del Mar Avionics; ELA Medical; Fukuda Denshi; Marquette; Medicomp; Mortara Instruments; Nihon Kohden; Oxford Medical; Quinton; Reynolds; Spacelab; Zymed  **

**Annals of Noninvasive Electrocardiology 1998;3:261-266 http://www.ishne.org/HTML/S2.htm**

## ISHNE Holter Standard Output File Format

**1. Magic Number**
**2. Checksum**
**3. Header**
**4. ECG Data**
**ECG annotation is the subject of ongoing update of the output format   **
** **

## ISHNE Holter Standard Output File Format

**	****Header**
**	****	****- ECG Block size****	****	****- Lead Specification****	****	****- Lead Quality****	****	****- Amplitude Resolution****	****	****- Dynamic range****	****	****- Pacemaker**

## ISHNE Holter Standard Output File Format

**Code ****	****     Lead **
**0 ****	****	****     Unknown**
**1****	****	****     Generic bipolar ****	**
**2****	**** ****	****     X bipolar **
**3 ****	****	****     Y bipolar**
**4****	****	****     Z bipolar**
**5 to 10 ****	****     I to aVF (limb leads)**
**11 to 16      V1 to V6 (precordial leads)     **

**	****Lead Quality**
**Code****	****Lead Quality**
**0****	****unknown (unrated) **
**1****	****good quality permanently **
**2              intermittent noise <10% ****	****of total length **
**3              frequent noise (> 10%) **
**4****	****lead disconnection (<10%) **
**5****	****lead disconnection ( >10 %) **
** **

**ISHNE Holter Standard Output File Format**

## ISHNE Holter Standard Output File Format

** **
** **
** ****Size (in bytes) of variable length block ****	****	****long int ****	****	****4**
** **
** ****Size (in samples) of ECG ****	****	****	****	****long int ****	****	****4**
** **
** ****Offset of variable length block (in bytes from **
** **
**        ****beginning of file, i.e. 8 +2 + 512 = 522) ****	****	****long int ****	****	****4**
** **
** ****Offset of ECG block ****	****	****	****	****long int ****	****	****4**
** **
**Version of the file ****	****	****	****	****	****short int ****	****	****2**
** **
**Subject First Name ****	****	****	****	****char[40] ****	****	****40 **
** **
**Subject Last Name ****	****	****	****	****char[40] ****	****	****40 **
** **
**Subject ID ****	****	****	****	****	****char[20] ****	****	****20 **
**                **

**ISHNE Holter Standard Output File Format**

## Description 					data-type 	# of bytes

** **
**Subject Sex (0: unknown, 1: male, 2:female) ****	****	****short int ****	****	****2**
** **
** **
**Date of recording (European) ****	****	****	****3 short int ****	****6**
** **
**Date of creation of Output file (European) ****	****	****3 short int ****	****6**
** **
**Start Time (European: hour [0-23], min, sec) ****	****	****3 short int ****	****6 **
** **
**Number of stored Leads ****	****	****	****	****short int ****	****	****2**
** **
**Lead specification (see included Table) ****	****	****12 short int ****	****24**
** **
**Lead quality (see included Table) ****	****	****	****12 short int ****	****24**
** **
**Amplitude resolution in integer # of nV ****	****	****12 short int ****	****24**
** **
**Pacemaker code (see text for description) ****	****	****short int ****	****	****2**
** **
**Type of recorder (either analog or digital) ****	****	****char[40] ****	****	****40**
** **
**Sampling rate (in Hertz) ****	****	****	****	****short int ****	****	****2**
** **
**Proprietary of ECG (if any) ****	****	****	****char[80] ****	****	****80**
** **
**Copyright & restriction of diffusion (if any) ****	****	****char[80] ****	****	****80**
** **
**Reserved ****	****	****	****	****	****char[90] ****	****	****90**

## The ECG block will follow the header block with samples stored multiplexed, as follows:

** **
**                ****| ch1, 1st sample | 2 bytes**
** **
**                ****| ch2, 1st sample |**
** **
**                ****| ch3, 1st sample |**
** **
**                ****| ......... |**
** **
**                ****| chn, 1st sample |**
** **
**                ****| ch1, 2nd sample |**
** **
**                ****| ch2, 2nd sample | **
** **
**                ****| ch3, 2nd sample |**
** **
**                ****| .................... |**
** **
**                ****| chn, 2nd sample |**

## Magic Number			8CRC				2

**Fixed-size block****	****	****512**
**Variable-size block****	****	****var**
**ECG data****	****	****	****var**

**CRC Domain -Header**

**Sequential Structure of the ISHNE Standard Output File Format  **

## ISHNE Holter Standard Output File Format

**Application that permit conversion between MIT ECG files ****(format 16 and 212) and ISHNE ECG files. ****(This application has been kindly and freely provided by GE Medical Systems and can be obtained upon request from ISHNE representatives).**
**Ongoing work on the format of annotation segment for the data. **

**ISHNE Holter Standard Output File Format**

## Conclusions

** ****There are numerous benefits of Holter-derived analyses of dynamic features of repolarization.**
**ISHNE Standard Output File Format provides common platform for uniform collection, analysis and retrospective evaluation of ECG data acquired using digital recorders from different manufacturers. ****	**
**Further adoption of this standard together with implementation of standard annotation file for Holter recordings will improve both clinical and research operation.  **

**Conclusions**