What is sinus tachycardia?

Q: My husband, as defence officer, had to undergo his annual medicals last week in which his ECG is abnormal. Investigations are on but we do not have any reports on the tests done as these are not given out. But his blood/lipid profile are all within normal range and BP is 126/80-134/80. He has something called sinus tachycardia, his aortic flow is 246, and doctors at the defence hospital have admitted him for the past 7 days for further investigations. My husband has passed all fitness tests and is a physically active person. He is 38 years old, ht. 5ft 5 1/2in, weight 66 kgs. Now they have asked for thyroid tests and he took an echocardiograph and will also take a stress echo. His chest X-ray is normal. It is only the heart rate that the doctors are concerned about. Please advise on the diagnosis and whether it is curable?. What does sinus tachycardia imply?

A:Sinus tachycardia means his resting heart rate is more than 100 beats/min. This can happen in many situations like fever, thyrotoxicosis, lack of exercise leading to physical deconditioning etc. He will need thyroid investigations to rule out thyrotoxicosis. Correction of the cause will correct this condition.