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A new and dynamic syndrome occurring in individuals with Idiopathic Ventricular Fibrillation or tachycardia due to genetic mutations affecting Phase 1 (Early Repolarization) of the action potential has been identified by Michel Haïssaguerre and his colleagues.
Numerous cellular physiologists and researchers have contributed to our understanding of this syndrome. Recognition of this syndrome may help to prevent some of the sudden cardiac deaths in athletes and other individuals.
Before then, it has to overcome "growing pains" of being mis-named and the failure of Electrocardiographers to deal with R wave downslope phenomena (J waves, notches and slurs) prior to this time. When R wave downslope phenomena are present, we have to clarify the J-point definition as well as specify where end of the QRS complex and beginning of the ST segment occur.
Prior to 2009, ECG waveform definitions and measurement were based on inclusion of the R wave downslope phenomena in the QRS complex per the CSE Measurement Statement but recent studies have not done so.


These stable 12 lead ECG measurment issues have to be resolved if appropriate population studies can be performed to demonstrate that R wave downslope phenomena (Haïssaguerre ECG patterns) can be used to predict individuals at risk of sudden cardiac death due to this genetic mutation.
==Early Repolarization==
Characterization of standard 12 lead ECG abnormalities can be facilitated by considering the portion of the cardiac ventricular myocytes action potential which influences them. This is only helpful for action potential phenomena originating with the initial wave of activation. Their temporal timing is influenced mainly by transmural dispersion from endo to epicardium. This contrasts with late potentials which are due to phase 0 of the action potentials (depolarization) originating from myocardium isolated by fatty tissue (epsilon waves of ARVD) or by fibrosis (cardiomyopathy) experiencing major delays. These can be arrhythmogenic because they compete with the normal pacemakers.  
Characterization of standard 12 lead ECG abnormalities can be facilitated by considering the portion of the cardiac ventricular myocytes action potential which influences them. This is only helpful for action potential phenomena originating with the initial wave of activation. Their temporal timing is influenced mainly by transmural dispersion from endo to epicardium. This contrasts with late potentials which are due to phase 0 of the action potentials (depolarization) originating from myocardium isolated by fatty tissue (epsilon waves of ARVD) or by fibrosis (cardiomyopathy) experiencing major delays. These can be arrhythmogenic because they compete with the normal pacemakers.  


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Before the prognostic significance of the Haïssaguerre Pattern can be demonstrated, there must be agreement on what measurments should be made. It appears that for stable ECG patterns with a QRS duration (including an end QRS slur J wave/slur) less than 120 msec, we should follow the CSE Measurement statement (1985)and consider the J point (also known as QRS end, J-junction, ST0[zero msec] or ST beginning) to occur after the R wave downslope notch/slur/or J wave as determined across all 12 leads. And that the measurement baseline be set in an interval immediately preceding QRS onset as per the CSE Measurement statement. Some of the bizarre and dynamic ECGs may require other rules for measurments but for now the CSE statement should be followed.
Before the prognostic significance of the Haïssaguerre Pattern can be demonstrated, there must be agreement on what measurments should be made. It appears that for stable ECG patterns with a QRS duration (including an end QRS slur J wave/slur) less than 120 msec, we should follow the CSE Measurement statement (1985)and consider the J point (also known as QRS end, J-junction, ST0[zero msec] or ST beginning) to occur after the R wave downslope notch/slur/or J wave as determined across all 12 leads. And that the measurement baseline be set in an interval immediately preceding QRS onset as per the CSE Measurement statement. Some of the bizarre and dynamic ECGs may require other rules for measurments but for now the CSE statement should be followed.


==Summary==
A new and dynamic syndrome occurring in individuals with Idiopathic Ventricular Fibrillation or tachycardia due to genetic mutations affecting Phase 1 (Early Repolarization) of the action potential has been identified by Michel Haïssaguerre and his colleagues.
Numerous cellular physiologists and researchers have contributed to our understanding of this syndrome. Recognition of this syndrome may help to prevent some of the sudden cardiac deaths in athletes and other individuals.
Before then, it has to overcome "growing pains" of being mis-named and the failure of Electrocardiographers to deal with R wave downslope phenomena (J waves, notches and slurs) prior to this time. When R wave downslope phenomena are present, we have to clarify the J-point definition as well as specify where end of the QRS complex and beginning of the ST segment occur.
Prior to 2009, ECG waveform definitions and measurement were based on inclusion of the R wave downslope phenomena in the QRS complex per the CSE Measurement Statement but recent studies have not done so.


These stable 12 lead ECG measurment issues have to be resolved if appropriate population studies can be performed to demonstrate that R wave downslope phenomena (Haïssaguerre ECG patterns) can be used to predict individuals at risk of sudden cardiac death due to this genetic mutation.
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==References==
==References==
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