Grayanotoxin is found in the nectar of Rhododendron type plants of the Ericaceae family.

  Grayanotoxin containing honey consumption causes mad honey intoxication.

  Binding of Grayanotoxin to sodium channels on the cell membrane results in
- increased permeability of sodium channels.
- inhibition of repolarization.



ECG abnormalities that may be observed in mad honey intoxication

  Sinus bradycardia

  Various types of atrioventricular blocks

  Nodal rhythm

  Atrial fibrillation with slow ventricular response

  Atrial flutter



References

  Anadolu Kardiyol Derg 2012;12:365-366.

  Tex Heart Inst J 2009;36:342-344.

  Clin Toxicol (Phila) 2011;49:438-439.

  Circ J 2008;72:1210-1211.

  J Emerg Med 2010;39:656-658.




ECG 1a. Atrial fibrillation with slow ventricular response after consumption of
mad honey by a 53 years-old man.

The ECG above has been used with the permission of Anatolian Journal of Cardiology and AVES Publishing.



ECG 1b. His ECG next day shows sinus rhythm.

The ECG above has been used with the permission of Anatolian Journal of Cardiology and AVES Publishing.




ECG 2. The ECG above belongs to a 55 years-old woman who developed persistent av block (A) after consumption of
Grayanotoxin-containing mad honey. The ECG on the right (B) was recorded after implantation of a permanent pacemaker.
Coronary angiography showed normal coronary arteries.

Click here for a more detailed ECG

The ECG above has been used with the permission of Anatolian Journal of Cardiology and AVES Publishing.