Definition

  The terminal part of S wave where it meets the onset of ST segment is called J point.

  Elevation of the J point results in the appearance of a new wave at the end of the QRS complex

      which is called
J wave (Osborn wave).


Causes of elevated J point (J wave)

  Early Repolarization (ER)

  Brugada Syndrome

  Hypothermia

  Hypervagotonia

  Acute myocardial ischemia

  Hypercalcemia

  Subarachnoid hemorrhage

  Spinal cord injuries resulting in sympathetic denervation.



In J Wave Syndromes, the appearance of J wave is dynamic.

  Increased vagal tone, bradycardia and hypothermia eases the appearance of J wave.

  Adrenergic stimulation (exercise) may diminish the J wave.

  Most prominent J waves appear before the onset of VT or VF attack.



J Wave Syndromes

  Early Repolarization (ER)

  Brugada Syndrome



Common aspects of ER and Brugada Syndrome

  More frequently observed in males.

  ST elevation and J wave are observed.

  Arrhythmic events

                  o       frequently occur in ages of 35-45 years.

                  o       frequently occur during bradycardia.

                  o       decrease by Quinidine or Isoproterenol.



For
Early Repolarization click here


For
Brugada Syndrome click here



References

  J Am Coll Cardiol 2003;42:401-409.

  Heart Rhythm 2012;9:249-255.

  Europace 2011;13:283.

  Pacing Clin Electrophysiol 2007;30:817-819.

  Singapore Med J 2008;49:160-163.

  Jpn Heart J 2003;44:1033-1037.

  Journal of Electrocardiology 2011;44:656-661.

  J Electrocardiol 2001;34:345-349.

  Cir Cir 2004;72:125-129.

  J Emerg Med 1994;12:199-205.

  J Spinal Cord Med 2002;25:33-38.

  Anadolu Kardiyol Derg 2012 Dec;12:699-700.





ECG 1. ER in an apparently healthy 39 years-old man. ER is more frequently observed in midprecordial leads (C3 and C4).
In ER, two aspects of ST elevation differentiate it from the ST elevation of myocardial infarction: In ER,
J point is elevated and
the ST segment is upwardly concave
.

The observation of ER
in MID PRECORDIAL leads (V2, V3, V4) is generally regarded as having a benign prognosis.

J point : The point where S wave meets the ST segment.


Click here for a more detailed ECG





ECG 2a. The Holter tracing above show how labile the J wave is.
At 00:06
when heart rate increases up to 80s , J wave almost disappears .
At 02:34,
when heart rate decreses down to 50s , J wave becomes more clear .

Click here for a more detailed Holter tracing



ECG 2b. The same patient's Holter tracing, 2-3 minutes later.
When heart rate decreses down to 50s , the J wave becomes
obvious
. When heart rate increases up to 80s , the J wave almost disappears .

Click here for a more detailed Holter tracing





ECG 3a. The ECG above was recorded from a 21 years-old man whose body temperature was 30.1 Celsius degrees.
Giant J waves (Osborn waves) are seen.


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ECG 3b. J waves disappeared after treatment of hypothermia.


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The ECGs above have been used with the permission of Anatolian Journal of Cardiology and AVES Publishing.

Click here to read the relevant article by Dr. Murat Yalcin et al.





ECG 4a. The ECG above belongs to a 45 years-old man. His coronary arteries are normal.
Leads V2 to V5 show J point elevation at a heart rate of 110/minute.
It was recorded just before the treadmill exercise test.

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ECG 4b. The ECG above was recorded at the peak exercise of his treadmill test (heart rate is 164/minute).
J point elevation has disappeared with adrenergic stimulus.

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ECG 4c. The above ECG was recorded 3 minutes after termination of the treadmill exercise test (recovery period).
Now the heart rate is 132/minute. J point elevation started to reemerge at lead V2.

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ECG 4d. His resting ECG next day shows J point elevation (leads V3 to V6) at a heart rate of 97/minute.

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