Tachycardia is not necessarily caused by dyspnea. There are many causes of tachycardia, including physiologic tachycardia and pathologic tachycardia. In physiological factors, tachycardia is usually caused by excessive nervousness, anxiety, fatigue, stress, or drinking a lot of alcohol, espresso, strong tea, which can lead to tachycardia and palpitations. For pathological factors causing fast heartbeat, there are common cardiac diseases, such as coronary heart disease unstable angina, acute myocarditis, malignant arrhythmia, severe heart failure, there will be tachycardia. For respiratory disorders, such as severe dyspnea, a series of conditions such as tachycardia, rapid heartbeat, palpitations, chest tightness, and shortness of breath can be triggered. For other factors leading to dyspnea, such as patients with acute respiratory distress syndrome, there will also be a rapid heartbeat. Therefore, usually dyspnea will trigger a rapid heartbeat, but the factors leading to a rapid heartbeat are not exclusively caused by dyspnea.