I asked the same question and was given not too long ago. You have to understand the limitations of echocardiography in assessing left atrial size. Although they are telling you that it is dilated and the upper limit of normal is 4 cm, it may actually not be dilated at all. This measurement was most likely obtained on a single 'slice' of the atrium and may not be representatitive of actual left atrial size. For instance if you slice a banana perpendicular to its long axis you may get a small value, but if you cut it at a 45 degreee angle you may get a larger value: simply because you were not perpendicular to its main axis. Often patients, especially patients who may have been heavier in the past do not have the standard orientation in the chest and may be rotated to the left, causing the standard echocardiographic views to be off axis and the consequent inaccuracies in measurements. The most accurate way to measure the left atrial size is to report atrial volumes, but this is difficult to assess in most patients, and in general has very little prognostic value in most patients. The exception are patient with atrial fibrillation whose likelyhood of responding to treatment depends on the left atrial size. Also, left atrium enlargement is usually due to Afib or high blood pressure so you should ask about those when you sepak to you doctor. Heart chambers can remodel themselves, but remember an enlarged atrium is not a disease but a symptom of another condition, once it is resolved in most cases the chambers will get back to a normal size.
Good Luck!
Jon
Yes the above poster is correct. In your case you have not even had an echocardiogram and the diagnosis was made on a 12 lead EKG, which is less accurate then the echocardiogram. The most important point of this is that you quit smoking, as this is a risk factor for cancers and COPD but in the heart for pulmonary hypertension, atrial enlargment and the development of arrhythmias. Left atrial enlargment is a typical substrate into which atrial fibrillation can develop, and this is important because this arrhythmia is a risk factor for death and stroke. Treatment o high blood pressure if present may also decrease the left atrial size and possibly decrease the risk for a fib and other arrhythmias.
I'm sure the doctor will provide you with a better answer, I just wanted you to know what I was told when I asked this same question to my Cardiologist plus what I've read. My Left Atrium was also mildly enlarged at 4.2 cm at the time. Also, I don't think an EKG is nearly as accurate as an echo and your doctor seems to taking the proper precautions.
Good Luck!
Jon
thank you so much for taking the time to respond in such detail...ill just try to relax and wait for the other test results....