Fluctuating heartbeat during exercise (among other concerns)

[soo_defeated]

I have recently started going to the gym, doing cardio for 60-90 minutes per day.  I try to keep my heart rate below 150 since I have just started working out again.  I am 18 years old, I'm not over weight (145lbs, 5'6").  I do smoke, but only about 3-10 cigarettes per day, and I have recently quit drinking (not completely, I still have a single drink maybe once or twice a month).

I notice that my heart rate continuously fluctuates.  It will go back and forth between 140 and 151 in a matter of seconds.  I have noticed that almost everybody elses heart rate stays about the same (give or take 1 or 2 beats).  I am wondering if this is a major problem.

Also, since I have started working out I have noticed that my resting heart rate is actually faster than usual.  100-110 instead of 80-96.  It has even gotten to the point where it will wake me from my sleep.

I have an appointment with a cardiologist in a month due to an episode where my pulse was 120+ that I had on new year's day (although my doctor said it was most likely a panic attack). I'm worried.   Should I look for a sooner appointment?  Is this serious?

[soo_defeated]

It was never much lower, if anything it was higher.  I haven't been very active for the past 6 years.

[Jerry_NJ]

It is good you have an appointment.  

I recommend if your stomach will take it that you take an aspirin every day, with a meal to make it softer on your stomach.  

Any irregularity in HR can be a cause for clot formation, that's why I recommend a aspirin, it will give you some protection and you don't need a prescription.

Your HR is a bit high, even at 80-96 when at rest, but anything under 100 is considered acceptable.  Was your HR lower in the past?

You already knolw the answer about smoking, don't.  As for a (one) drink on occasion, that shouldn't be a problem.  There is a lot of evidence that one drink can be a plus, not a negative.  I'm not suggesting take an alcohol dring every day.