Final answer:
The statement is true; the heart rate can be determined by measuring the R-R interval on an ECG. The interval between two successive R waves is indicative of the heart's beating rate, and heart rate can be calculated as 60 divided by the R-R interval in seconds. Therefore, the most appropriate correct option is A.
Step-by-step explanation:
The statement that heart rate can be determined by measuring the time between two successive R waves on an electrocardiogram (ECG), known as the R-R interval, is True. The ECG is a record of the voltage created by the wave of depolarization and repolarization in the heart's electrical activity. On an ECG, the R wave is part of the QRS complex, which indicates ventricular depolarization. By measuring the interval between two consecutive R waves, we can determine the rate at which the heart is beating. To calculate the heart rate in beats per minute (bpm), we can use the formula: Heart Rate (bpm) = 60 / R-R interval (in seconds). It is important to assume a constant time between beats when using this method. For example, if the R-R interval is 1 second, the heart rate would be 60 beats per minute.
Understanding the ECG and the R-R interval is important, as arrhythmias can indicate heart rhythm issues. Tachycardia is classified as a heart rate above 100 bpm and bradycardia as a rate below 60 bpm. Proper analysis of ECG can help in diagnosing and treating such conditions.