Question

a) Why would exercise influence the R-R interval? Would a change in R-R interval following a short period of exercise be the same for all people, why/why not?

b) Each component of the ECG waveform is associated with a particular activity during the cardiac cycle. Based on your knowledge of the actions of the heart associated with the P, Q, R, S, and T waves in the ECG, and what actions in the heart generate the lub-dub sounds, when would you expect to hear the lub and dub sounds in relation to the different components of the ECG waveform?

Answer 1

a. Yes, exercise influence the R-R interval it's because of exercise increses heart rate. Normal R-R interval is 0.6-1.2 seconds but during exercise, it becomes shorter.

Changes in the R - R interval is for a short period of time and it's different for all people, it totally depends on the intensity of exercise(High intensity, High HR and Low R-R interval), the strength(High strength, Slightly increases in HR and Slightly decreases in R -R interval), age of the person(Incrsees age, High HR, Low R R interval), the condition of the heart(Weaken Heart, Very high HR, Very low R R Interval).

b.

P Wave - Depolarization of Atrium

QRS complex - Depolarisation of Ventricles

T wave - Repolarisation of Ventricles

The heart sound Lub, and Dub

Lub (S1) - It is due to the turbulence of blood in heart caused by the closure of Atrioventricular valves (Mitral and Right AV valve).

You can hear the Lub sound with the QRS complex.

Dub (S2) - It is due to the closure of the Aortic valve and Pulmonary valve.

You can hear the Dub sound at the beginning of T wave.