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.
Medical tests
On the basis of the above, a number of tests may be ordered:
An electrocardiogram (ECG)
Chest radiograph or chest x rays are frequently performed
Echocardiography can be useful in patients with known cardiac disease or aortic dissection
CT scanning is used in the diagnosis of aortic dissection
V/Q scintigraphy or CT pulmonary angiogram (when a pulmonary embolism is suspected)
Blood tests:
Troponin I or T (to indicate myocardial damage)
Complete blood count
Electrolytes and renal function (creatinine)
Liver enzymes
Creatine kinase (and CK-MB fraction in many hospitals)
D-dimer (when suspicion for pulmonary embolism is present but low)
serum lipase to exclude acute pancreatitis

Management
Management of chest pain varies with the underlying cause of the pain and the stage of care. Prehospital care
Chest pain is a common symptom encountered by emergency medical services. Aspirin increases survival in people with acute coronary syndrome and it is reasonable for EMS dispatchers to recommend it in people with no recent serious bleeding. Supplemental oxygen was used in the past for most people with chest pain but is not needed unless the oxygen saturations are less than 94% or there are signs of respiratory distress. Entonox is frequently used by EMS personnel in the prehospital environment. However, there is little evidence about its effectiveness. Hospital care
Hospital care of chest pain begins with initial survey of a persons vital signs, airway and breathing, and level of consciousness. This may also include attachment of ECG leads, cardiac monitors, intravenous lines and other medical devices depending on initial evaluation.