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I can understand your worries. It is not common in general population. It occurs mostly in those who have heart attack, angina, have high blood pressure or some valvular disease, especially aortic valve.
Other cause is fibrotic degeneration of conduction channels, but it occurs usually in old age as age-related degeneration. It may progress slowly and lead to trifascicular block or complete heart block.
Treatment is not advised if heart rate is normal. If in future heart rate decreases or block progresses than cardiac pacemaker may be necessary to implant. Risk of this condition is that if it is due to fibrosis, then it may spontaneously progress which may take years. Other risk is that if anytime in future you have angina or heart attack, then there are more chances of further progression of block as compared to those who do not have this block.
I advise you to repeat ECG, have an echocardiography done to see valvular disease, if present, monitor blood pressure.