My sister was diagnosed with Sinus Tachycardia during her pregnancy, with her pulse rate varying between 110-135. Her resting pulse was around 100-110. After delivery, when her vitals were checked, everything was normal, including her pulse rate. But again, she is facing the same issue, her pulse rate is ranging between 100-130. Even while doing normal household chores, it rises upto 140. Though her resting pulse (while sleeping) is less than 100. She got both ecg and Echo done. Her ecg says sinus tachycardia while her echo is perfectly normal. Her thyroid profile is normal too and her hemoglobin (after delivery) is 11.5 She is worried about having a heart attack in future. Is that possible?