Before the onset of cardiac arrest during sleep, patients often exhibit symptoms of coronary heart disease such as chest tightness, shortness of breath, and palpitations. Often, these individuals do not pay enough attention to the symptoms, do not undergo timely medical examinations at a hospital, and consequently, there is a delay in the treatment of the condition. It is very unfortunate that sudden deaths occur during sleep, possibly due to fatigue, poor rest, and underlying heart disease, which then leads to cardiac arrest. The precursors of such events can vary from person to person; symptoms may include chest tightness and palpitations, among others. Therefore, it is important that we pay attention to these signs.