The link between anxiety and palpitation may also explain why many panic attacks involve an impending sense of cardiac arrest. Similarly, physical and mental stress may contribute to the occurrence of palpitation, possibly due to the depletion of certain micronutrients involved in maintaining healthy psychological and physiological function. Gastrointestinal bloating, indigestion and hiccups have also been associated with overstimulation of the vagus nerve causing palpitations, due to branches of the vagus nerve innervating the GI tract, diaphragm, and lungs.Many psychiatric conditions can result in palpitations including depression, generalized anxiety disorder, panic attacks, and somatization. However one study noted that up to 67% of patients diagnosed with a mental health condition had an underlying arrhythmia. There are many metabolic conditions that can result in palpitations including, hyperthyroidism, hypoglycemia, hypocalcemia, hyperkalemia, hypokalemia, hypermagnesemia, hypomagnesemia, and pheochromocytoma. Medication
The medications most likely to result in palpitations include sympathomimetic agents, anticholinergic drugs, vasodilators and withdrawal from beta blockers.Common etiologies also include excess caffeine, or marijuana. Cocaine, amphetamines,  3-4 methylenedioxymethamphetamine (Ecstasy or MDMA) can also cause palpitations. Pathophysiology
The sensation of palpitations can arise from extra-systoles or tachyarrhythmia. It is very rarely noted due to bradycardia. Palpitations can be described in many ways. The most common descriptions include a flip-flopping in the chest, a rapid fluttering in the chest, or pounding in the neck. The description of the symptoms may provide a clue regarding the etiology of the palpitations, and the pathophysiology of each of these descriptions is thought to be different.
Thyroid function tests may demonstrate a hyperthyroid state.Most patients have benign conditions as the etiology for their palpitations. The goal of further evaluation is to identify those patients who are at high risk for an arrhythmia. Recommended laboratory studies include an investigation for anemia, hyperthyroidism and electrolyte abnormalities. Echocardiograms are indicated for patients in whom structural heart disease is a concern.Further diagnostic testing is recommended for those in whom the initial diagnostic evaluation (history, physical examination, and EKG) suggest an arrhythmia, those who are at high risk for an arrhythmia, and those who remain anxious to have a specific explanation of their symptoms. People considered to be at high risk for an arrhythmia include those with organic heart disease or any myocardial abnormality that may lead to serious arrhythmias. These conditions include a scar from myocardial infarction, idiopathic dilated cardiomyopathy, clinically significant valvular regurgitant, or stenotic lesions and hypertrophic cardiomyopathies.An aggressive diagnostic approach is recommended for those at high risk and can include ambulatory monitoring or electrophysiologic studies. There are three types of ambulatory EKG monitoring devices: Holter monitor, continuous-loop event recorder, and an implantable loop recorder.People who are going to have these devices checked should be made aware of the properties of the devices and the accompanying course of the examination for each device. The Holter monitor is a 24-hour monitoring system that is worn by exam takers themselves and records and continuously saves data. Holter monitors are typically worn for a few days.