Hi friend Welcome to Health Care Magic You should go to ER A thorough physical examination is the first step - Routine 12-lead Electrocardiogram (ECG) is part of clinical examination. What you are describing is ECTOPIC beat. A beat comes earlier than normal – this itself is not usually felt. The next beat is a bit delayed - longer time to recover form early extra beat – so heart fills more and the beat appears forcible – thud / lubb - - dubb - - lubb - - dubb - lubb - - - DUBB / If a routine ECG does not show, 24 to 48 hour ambulatory monitoring (Holter) is done to analyse and plan for further management ECHOcardiogram is necessary to see the heart valves (Mitral Valve Prolapse) / heart muscle (Cardiomyopathy) and heart function (Ejection fraction, wall motion abnormality) – Have you done it? Your drugs are less likely to be causing this – but you need to check you BP and electrolytes, as you are on Cymbalta Other medicines may be responsible - like phenylephrine or pseudo-ephedrine used for de-congestion of sinuses may be responsible. Anxiety / Alcohol / Tobacco (smoking, chewing) / Caffeine (too much coffee, cola) are common causes. Rarely, there are abnormal nerve paths (pass tracts) in the heart. Though they may be normal in many, it is advisable to investigate. Often, no treatment may be necessary. Some times a beta blocker is initiated – the doctor seeing you will give appropriate advice, based on his assessment. Take care Wishing you speedy recovery God bless Good luck