I find it very unsettling that the last two doctors I saw were willing to diagnose me for a lung problem without either an x-ray or a culture (I told both of them that I work in conditions where there is potential for mold/dust/dirt). Most distressing was the second doctor who gave me not one but two asthma medications that have a possible side effect of irregular heartbeat. Then the doc (mentions nothing of these possible side effects) recommends that I see a cardiologist because of a slow pulse rate saying "you might be developing an irregular heartbeat".
I am sorry to have got focused on the negative issues about NAET. Your description of sudden onset asthma, plus what sounds like a very normal pulmonary function test suggests an irritant or allergic air way disease. So it could be fine everywhere else, except during such location (work) or season (wet/damp if mold, summer if grass, etc.).
I would still recommend a very simple panel of tests - the intradermal skin test - performed in an allergist's office. This involves the application of minute amount of allergens - usually airborne - under the skin on a grid on your back - 20 or more allergens - it is read 20 minutes later.
http://www.nlm.nih.gov/medlineplus/ency/article/003519.htm It might be formulated (the number and type of allergens ) depending on your geographic location or occupation. Once you identified the allergen - you can avoid it, or simply using asthma medicine during the season where the allergen is present. If it is dust mite - environmental control - avoiding carpets, HEPA filters, etc... might be suggested. I am not a "real" physician, so I can't tell if your irregular heart beat is the cause, or effect of your lung problem. Some lung problems can lead to heart problems, and some heart problems lead to lung problems. If you can tell us the exact ekg rhythm, perhaps TSM can give you more insight.
I believe that most bronchodilators (asthma medications) are adrenergic products, more specifically for the lung, and less for the heart. Used 3 to 4 times a day, they don't affect the heart much. But used repeatedly, they will accelerate the heart - like drinking too much coffee or pop. So we have to warn you, but not to scare you. Asthma is a potentially deadly disease, so a physician must prescribe a rescue inhaler. The other medicine used in asthma are the inhaled steroids. From a holistic standpoint, this scares the c**p out of me to be puffing daily. But apparently, doctors prescribe it for daily use all the time. The third type seems safer to me, is the cromolyn (intal) type, which has no steroid, and does not affect the heart. I am sure there are other classes since I graduated from med school years ago. My son and I are both allergic to cats - and the only time I get wheezy is if my cat vomits.... or if I am cleaning up vomits. And it is funny, as I've always owned a cat for the last 20 years!
Individuals develop allergies spontanously throughout life. I no longer use chapsticks, as I developed an allergy to an ingredient about 4 years ago. That SB'er who developed milk allergy out of the blue, for instance. If you have an identifiable allergen - you might want to look into it and avoid it. Seek alternative medicine if you like, but please also look into seeing a good allergist for your asthma care. It is very holistic, in my opinion, to identify an allergen.... Then simply actively seeking to avoid it. Beware of the REAL docs who depends on a simple blood test and tell you what to avoid, and what not to eat. That test has no value in most cases of allergy.... but will identify what you are NOT allergic to well.