Statistics from Altmetric.com
Editor,—A 70 year old Chinese women was admitted with symptoms of paraesthesia on her limbs, hypertension, dizziness, extreme bradycardia, and a positive Trousseau's sign. She was on atenolol for hypertension, but she did not recover from the bradycardia even after stopping her antihypertensive. She subsequently developed proximal myopathy and Chvostek's sign.
Results of routine blood tests, including corrected calcium, phosphate, and magnesium concentrations, were within normal limits. Other investigations ruled out the possibility of porphyrias and antibody related diseases.
Electromyography revealed features of “acquired neuromyotonia”, but on specific testing the antibody to voltage gated potassium channel was not detected. No other cause could be established for this rare neurological syndrome.
Twenty four hour Holter monitoring revealed sinoatrial block with more than 900 pauses of >2 sec, but subsequent investigations failed to establish any evidence of coronary artery disease. The patient later had a dual chamber pacemaker inserted for this.
Neuromyotonia is a membrane disorder and antibody to voltage gated potassium channel has been shown to be one its features. There is no literature describing the association between it and any kind of heart block.
I would be interested to know if there is any relationship between sinoatrial block and neuromyotonia.