Brief Answer: You should exclude modifiable causes of sinusal tachycardia, by further laboratory examinations. The alternatives of treatment, may be to increase the dosage of Tropolol, or to use another drug such as Verapamil (Calaptin). You should discus it before with your treating doctor. Detailed Answer: Hello, Thank you for using HCM. There are different causes of sinusal tachycardia such as: Damage to heart tissues from heart disease, abnormal electrical pathways in the heart present at birth (congenital),or disease or congenital abnormality of the heart. In case of the above etiologic causes, the only thing to do is to do a better rate control (heart rate less than 90/min in rest). You may increase the Tropolol dosage at weekly, or longer, intervals, up to 400 mg orally once a day, or you can try Verapamil 40 mg orally 3 times a day , with upward titration based on therapeutic efficacy, assessed at the end of the dosing interval till a daily dosages of 360 mg. Before using it, you should discus with your treating doctor, as he is aware of your medical background. On the other hand, sinus tachycardia may be caused by other medical conditions such as: anemia, high blood pressure, medication side effects, imbalance of electrolytes, overactive thyroid (hyperthyroidism). In these cases sinusal tachycardia can be treated by treating the causing factor. So, you should do a full blood count, thyroid hormones level(TSH, fT3, fT4), electrolyte levels in blood(Na, K, Cl, Ca). In case of alterations of the above mentioned exams results, then you should deal with them. Meanwhile, avoid consume of alcohol, caffeinated beverages. Try not to get stressed and don t smoke, as they may rise up the heart rate. Hope this is helpful. Let me know if you need more clarifications. Otherwise please close and rate the answer. Kind Regards, Dr. Juarda