The QRST complex is a part of the electrocardiogram (ECG) that represents the electrical activity of the ventricles during one heartbeat. It begins with the QRS complex, which indicates ventricular depolarization and the contraction of the ventricles. The Q wave is the initial negative deflection, followed by the R wave (a positive deflection) and the S wave (a negative deflection). After this, the T wave appears, representing ventricular repolarization or recovery. The duration and shape of the QRST complex are clinically important for detecting heart abnormalities such as arrhythmias, conduction defects, and myocardial infarction. Overall, it reflects the complete cycle of ventricular contraction and relaxation.

1. Project :PQRST Complex

2. Introduction
Electrocardiograph (ECG)
ECG is defined as recording of electrical activity of heart on a
graph paper ,
Or
Graphical representation of electrical activity of heart.
Significance
1. ECG gives information about rate and rhythm of the heart.
2. It is a diagnostic tool for various heart conditions like
hypertrophies, ischemia , infraction, arrhythmia ,conduction
problem and pace maker activity .
3. ECG does not provide information about mechanical activity.

3. P wave
This is the fiorst small , rounded upward deflection .
Atrial depolarization , initiated by the SA node , causes the p wave .
With atrial depolarization complete , the impulses delayed at the AV node .
Duration – 0.08 – 0.1 sec

4. QRS Complex
It consist of three sub components the Q wave , R wave
, S wave
Ventricular depolarization begins at apex , causing the
QRS complex .
This is a sharp prominent group of wave .
Atrial repolarization occurs .

5. T wave
Ventricular repolarization begins at apex , causing the T
wave .
Ventricular repolarization is completed .
here ventricles reset electrically after contraction.

6. ECG
uses
electrocardiogram Is useful in determining and diagnosing the following
• heart rate
• heart rhythm
• abnormal electrical conduction
• poor blood flow to heart muscle
• heart attack
• coronary artery disease
• hypertrophy of heart chambers

7. By Aradhna Meshram
B.Pharm 3rd year , SRTM University Nanded