Palpitations

Palpitations are the perceived abnormality of the heartbeat characterized by awareness of cardiac muscle contractions in the chest, which is further characterized by the hard, fast and/or irregular beatings of the heart. It is both a symptom reported by the patient and a medical diagnosis. Palpitations are the perceived abnormality of the heartbeat characterized by awareness of cardiac muscle contractions in the chest, which is further characterized by the hard, fast and/or irregular beatings of the heart. It is both a symptom reported by the patient and a medical diagnosis. Symptoms include a rapid pulsation, an abnormally rapid or irregular beating of the heart. Palpitations are a sensory symptom and are often described as a skipped beat, rapid fluttering in the chest, pounding sensation in the chest or neck, or a flip-flopping in the chest. Palpitation can be associated with anxiety and does not necessarily indicate a structural or functional abnormality of the heart, but it can be a symptom arising from an objectively rapid or irregular heartbeat. Palpitation can be intermittent and of variable frequency and duration, or continuous. Associated symptoms include dizziness, shortness of breath, sweating, headaches and chest pain. Palpitation may be associated with coronary heart disease, hyperthyroidism, diseases affecting cardiac muscle such as hypertrophic cardiomyopathy, diseases causing low blood oxygen such as asthma and emphysema; previous chest surgery; kidney disease; blood loss and pain; drugs such as antidepressants, statins, alcohol, nicotine, caffeine, cocaine and amphetamines; electrolyte imbalances of magnesium, potassium and calcium; and deficiencies of nutrients such as taurine, arginine and iron. Three common descriptions of palpitation are 'flip-flopping' (or 'stop and start'), often caused by premature contraction of the atrium or ventricle, with the perceived 'stop' from the pause following the contraction, and the 'start' from the subsequent forceful contraction; rapid 'fluttering in the chest', with regular 'fluttering' suggesting supraventricular or ventricular arrhythmias (including sinus tachycardia) and irregular 'fluttering' suggesting atrial fibrillation, atrial flutter, or tachycardia with variable block; and 'pounding in the neck' or neck pulsations, often due to cannon A waves in the jugular venous, pulsations that occur when the right atrium contracts against a closed tricuspid valve. Palpitation associated with chest pain suggests coronary artery disease, or if the chest pain is relieved by leaning forward, pericardial disease is suspected. Palpitation associated with light-headedness, fainting or near fainting suggest low blood pressure and may signify a life-threatening abnormal heart rhythm. Palpitation that occurs regularly with exertion suggests a rate-dependent bypass tract or hypertrophic cardiomyopathy. If a benign cause for these concerning symptoms cannot be found at the initial visit, then ambulatory monitoring or prolonged heart monitoring in the hospital might be warranted. Noncardiac symptoms should also be elicited since the palpitations may be caused by a normal heart responding to a metabolic or inflammatory condition. Weight loss suggests hyperthyroidism. Palpitation can be precipitated by vomiting or diarrhea that leads to electrolyte disorders and hypovolemia. Hyperventilation, hand tingling, and nervousness are common when anxiety or panic disorder is the cause of the palpitations. The current knowledge of the neural pathways responsible for the perception of the heartbeat is not clearly elucidated. It has been hypothesized that these pathways include different structures located both at the intra-cardiac and extra-cardiac level. Palpitations are a widely diffused complaint and particularly in subjects affected by structural heart disease. The list of etiologies of palpitations is long, and in some cases, the etiology is unable to be determined. In one study reporting the etiology of palpitations, 43% were found to be of cardiac etiology, 31% of psychiatric etiology and approximately 10% were classified as miscellaneous (medication induced, thyrotoxicosis, caffeine, cocaine, anemia, amphetamine, mastocytosis). The cardiac etiologies of palpitations are the most life-threatening and include ventricular sources (premature ventricular contractions, ventricular tachycardia and ventricular fibrillation), atrial sources (atrial fibrillation, atrial flutter) high output states (anemia, AV fistula, Paget's disease of bone or pregnancy), structural abnormalities (congenital heart disease, cardiomegaly, aortic aneurysm, or acute left ventricular failure), and miscellaneous sources (postural orthostatic tachycardia syndrome abbreivated as POTS, Brugada syndrome, and sinus tachycardia).