Windows might tell you that you can't open it, or in the worst case, you might encounter a SCU file related error message. Before you can open a SCU file, you'll need to figure out what kind of file the SCU file extension refers to. Tip: Incorrect SCU file association errors can be a symptom of other underlying issues within your Windows operating system.
Relevance. Rating Newest Oldest. Best Answer: sinus bradycardia means slow heart rate sinus arrythmia means heart is not beating in the normal rythym but the heart beat is still starting in the right place. Many people live wiht this for their whole lives and never even know they have it. Stress less. Source(s): experience.
Normal sinus rhythm and sinus arrhythmia. 1  Spodick DH. Normal sinus heart rate: sinus tachycardia and sinus bradycardia redefined. Am Heart J 1992; 124:1119. 2  Spodick DH, Raju P, Bishop RL, Rifkin RD. Operational definition of normal sinus heart rate. Am J Cardiol 1992; 69:1245. 3  Mason JW, Ramseth DJ, Chanter DO, et al.