4 Procedure 1 Interpreting an ECG You will now perform some basic ECG interpreta

ID: 95107 • Letter: 4

Question

4 Procedure 1 Interpreting an ECG You will now perform some basic ECG interpretation. Following are two tracings for which you will calculate the heart rate and determine the duration of key periods of the ECG 1 Identify and label the P wave, QRS complex, T wavc, P.R interval, R.R interval, and Q-T interval on Tracings 1 and 2 in Figure 11.27 Tracing 1 Tracing 2 FIGURE 11.27 ECG tracings Calculate the heart rate for each tracing. Are the values normal or abnormal? Heart Rate Tracing 1: Heart Rate Tracing 2: Determine the R-R interval, QRS duration, P-R interval, and Q-T interval for each tracing, and record the values in 2 3 Table 11.8 TABLE 11.8 Values for ECG Periods Tracing 1 Value R-R interval QRS duration P-R interval Q-T interval Tracing 2

Explanation / Answer

Answer:

Tracing 1

Tracing 2

R-R interval

30mm/beat*0.04 sec/beat=1.20 sec/beat- Abnormal

20mm/beat*0.04 sec/beat=.80 sec/beat- Normal

QRS duration

2 squares*0.04 sec=0.08 sec - Normal

2 squares*0.04 sec=0.08 sec- Normal

P-R interval

5 squares*0.04 sec=0.20 sec- Normal

Q-T interval

11 squares*0.04 sec=0.44 sec- Not normal

10squares*0.04 sec=0.40 sec- Normal

R-R interval- The RR interval is the time between QRS complexes. The instantaneous heart rate can be calculated from the time between any two QRS complexes

QRS duration: time between the beginning and the end of the QRS complex

PR interval: The PR interval is measured from the beginning of the P wave to the beginning of the QRS complex.
QT interval: total duration of the ventricular event, from when the first cell depolarizes to the repolarization of the last cell