One of two conditions could be occurring. The first is paroxysmal supraventricular tachycardia
where the heart suddenly starts beating too fast. It may be a primary condition or a secondary condition to chronic anxiety. The second may be panic attacks from anxiety causing a startle reflex in which the sympathetic nervous system
temporarily ramps up the heart rate. If the first one is the case, primary cardiac disease can cause this, but other electrolyte, endocrine, or metabolic abnormalities can also affect heart rate and rhythm. Your doctor may recommend certain tests based on the physical exam, such as an ECG, bloodwork, a 24-hour holter monitor
or event monitor to 'catch and record' the episode. More critical conditions may require and echocardiogram
. Searching the net and knowing the possible differentials will prepare you for your physician appointment, but will not replace it. However, there is nothing wrong with empowering yourself with some additional knowledge that will help convince you to see your doctor. I wish you good health.