Heart block (atrioventricular block)

For a lay person:

Heart block is a problem with the heart's electrical system, in which the signal from the upper chambers to the lower chambers is delayed or blocked. Mild forms often cause no symptoms, but complete heart block can make the heart beat very slowly. It is more common in older people, after heart attacks and with some medicines.

For a trained medical person:

Atrioventricular conduction is delayed (first degree) or intermittently or completely interrupted (second-degree Mobitz I or II, third degree), from fibrosis of the conduction system, ischaemia, drugs (beta-blockers, calcium channel blockers, digoxin), myocarditis, Lyme disease or infiltrative disease. Diagnosis is by ECG and ambulatory monitoring. Management is removal of reversible causes, with permanent pacing for symptomatic or high-grade block; temporary pacing or atropine may be needed acutely.

In Chinese medicine:

Liu and Tseng's textbook differentiates this condition into these patterns: Qi and Yin Deficiency; Heart and Kidney Yang Deficiency; Yang Deficiency About to Collapse. Treatment follows the pattern a patient presents with, not the Western diagnosis alone.

When to get help: Get emergency care for fainting, chest pain, severe breathlessness or a very slow pulse with dizziness. Herbs containing cardiac glycosides or aconite can worsen heart block and are dangerous here.