Right axis deviation

Elizabeth is a 72-year-old woman and is a well-known patient of yours. She has been a smoker for 45 years and has tried to give up many times. She used to smoke a pack a day when younger and she has cut it down to 15 cigarettes a day in the past two years as she has noticed gradually worsening shortness of breath. She is normally slim, slightly flushed, has a chronic productive cough and has a raised respiratory rate with exertion. She comes to you, her GP, today as she ran out of doxycycline two weeks ago. She takes this to reduce her chronic bronchitis. She also takes tiotropium bromide 18 g in the morning and budesomide inhaler 200 mg two puffs twice daily.

You decide to investigate her recent worsening of shortness of breath. A low-dose CT scan shows chronic bronchitis, moderately severe emphysema, hyperinflation and flattening of the diaphragm. Her blood tests are essentially normal apart from a bicarbonate level of 19 mg/L. You organise an ECG (see Figure 1).