Dear Abby: May I respond to your column regarding excessive waits in doctors' offices (Sept. 1)?

I am a board-certified interventional cardiologist who has been practicing for 30 years. I work 85 to 90 hours each week. As hard as we try, our office schedule often falls behind. Despite recommendations that acute problems go to the emergency room, unscheduled patients come to the office with chest pains, and they must be attended to. Even scheduled patients can develop complex medical issues that require extra, unplanned time to evaluate and treat.

Our patients with a history of heart disease do not mind waiting when the office runs behind because they receive the same specialized extra-care treatment when they need it. Delays that result from spending extra time evaluating and treating sick patients with complicated problems is not "unprofessional" behavior as "Larry W." implied. On the contrary, it relates to the art of medicine and caring for the well-being of each patient above all else.

And for the architect, I wonder when he last worked a 90-hour week, took seven or eight phone calls from his clients after midnight, and got up at 3 a.m. to do an emergency two-hour procedure before returning to his office at 8 in the morning bright-eyed, bushy-tailed and running on schedule the rest of the day? — Dr. Ron in Las Vegas

Dear Dr. Ron: I felt it was only fair to print your response to my follow-up column on "Sick of Waiting in Denver." That column elicited a mountain of letters, all of them offering reasonable explanations for the delays in medical offices. Read on:

Dear Abby: Many factors cause doctors to run behind. Routine physicals can reveal life-threatening conditions that must be dealt with immediately.

Also, people do not reveal the true reason for their visit when they call, so they are not given the appropriate amount of time for the appointment. A teenager brought in for vomiting could have the stomach flu, onset diabetes or even be pregnant.

A colleague once had a woman complaining of abdominal pain who gave birth in the exam room. That definitely took more than 15 minutes! — M.D. in Woodstock, Ill.