Hi friend, Welcome to Health Care Magic You need investigations – You have not stated your personal habits, family history, or co-morbidities, even age or gender...which could influence the diagnosis and outcome... Anaemia / Anxiety / Alcohol / Tobacco (smoking) / Caffeine (too much tea, coffee, cola) / Fever / Infection / Pain / Stress / Thyroid / Vitamin D, calcium, magnesium / Medicines like Phenylephrine used for ‘cold’; Salbutamol used for asthma and so on - may be responsible.... / Illicit ‘drugs’ like Amphetamine are notorious to cause abnormal beats / At times, abnormal nerve paths in the heart (bypass tracts) or disease of the conduction system may be responsible! ECHOcardiogram is necessary to see the heart valves (Mitral Valve Prolapse) / heart muscle (Cardiomyopathy) and heart function (Ejection fraction, wall motion abnormality) / clots... TMT – Treadmill exercise ECG; may be with thallium isotope – is necessary to evaluate ischemia (reduced blood flow / Coronary Artery Disease) If there are no clues and if the problem is still bothering to the extent of interfering with life style, you may need Electro Physiological Studies (EPS) it resembles angio – a catheter is put inside the heart / electrical activity recorded / stimulation and suppression tests are carried out / suitable medicine tested and so on. Though the test is the gold standard, it is INVASIVE and is not generally done unless there are compelling indications. This super-speciality expert is called ELECTRO-PHYSIOLOGIST. The treating doctor may suggest them depending on need, based on his assessment of the situation. / There are other advanced treatment modalities - like ablation (thermal or radio-frequency), which could be done during EPS. Take care Wishing speedy recovery God bless Good luck