First of all I want to congratulate on your decision of choosing a healthy lifestyle and embarking on this journey will require a strong will power.
Coming to details you provided, cigarette have nicotine, which by it's nature increases the heart rate but given your chronic history of smoking it would be best to rule out any cardiac issues
Next Steps
consult a cardiologist and a pulmonologist for detail evaluation of your heart and lungs condition and necessary steps to proceed with
Health Tips
avoid smoking and vigorous exercise which may be detrimental to condition further