An electrocardiogram does not provide information about

Stroke volume of the heart cannot be estimated from an ECG. ECG is a graphical representation of the electrical activity of the heart during a cardiac cycle.

The heart rate of an individual can be determined by counting the number of QRS complexes on ECG that occur in a given time period.

Arrhythmia refers to an abnormal heart rhythm. During an arrhythmia, the heart can beat too fast (tachycardia), too slowly (bradycardia), or with an irregular rhythm. ECG is the most common test used to diagnose an arrhythmia.