Evidence of cardiomegaly and peripheral edema may indicate heart failure and ischemia or a valvular abnormality.Blood tests, particularly tests of thyroid gland function, are also important baseline investigations (an overactive thyroid gland is a potential cause for palpitations; the treatment, in that case, is to treat the thyroid gland over-activity).The next level of diagnostic testing is usually 24-hour (or longer) ECG monitoring, using a recorder called a Holter monitor, which can record the ECG continuously during a 24-hour or 48-hour period. If symptoms occur during monitoring it is a simple matter to examine the ECG recording and see what the cardiac rhythm was at the time. For this type of monitoring to be helpful, the symptoms must be occurring at least once a day. If they are less frequent, the chances of detecting anything with continuous 24- or even 48-hour monitoring are substantially lowered. More recent technology such as the Zio Patch allows continuous recording for up to 14 days; the patient indicates when symptoms occur by pushing a button on the device and keeps a log of the events.Other forms of monitoring are available, and these can be useful when symptoms are infrequent. A continuous-loop event recorder monitors the ECG continuously, but only saves the data when the wearer activates it. Once activated, it will save the ECG data for a period of time before the activation and for a period of time afterwards – the cardiologist who is investigating the palpitations can program the length of these periods.
Prevalence
Palpitations are a common complaint in the general population, particularly in those affected by structural heart disease. Clinical presentation is divided into four groups: extra-systolic, tachycardic, anxiety-related, and intense. Anxiety-related is the most common. See also
Cardiac dysrhythmia

References
External links

MedlinePlus Medical Encyclopedia, NIH