Name four questions related to heart function that you could answer by examining an ECG and one abnormal condition that may be indicated by each function. Solution 1). Electrocardiograph is an instrument used to record the electrical activities of the heart. The graph obtained by the electrocardiograph is called as electrocardiogram (ECG). The electrical events are denoted with the letters P, Q, R, S and T; these are called electrical waves. The “P wave (also called as atrial complex)” is the first and positive wave in ECG. It is produced due to the atrial depolarization that lasts for 0.1 sec. Atrial repolarization merges with “QRS complex.” QRS complex is also known as initial ventricular complex, which is produced due to the ventricular depolarization. The “Q wave” is a negative wave that continues as a positive “R wave (tallest wave).” The R wave is followed by “S wave,” which is a negative wave. “T wave” is the last positive wave that represents final ventricular complex; it is produced due to the ventricular repolarization. The four questions that can be answered from ECG are, 1). Heart rate determination 2). Cardiac arrhythmias identification 3). Electrical disorders of auricles and ventricles 4). What is the indication of heart block? Heart Block: It is a condition in which electrical signals through the cardiac conduction system is not travelled normally. This occurs due to the disease and degeneration of the fibres of the conduction system. Due to the disease of the one or both the Atrioventricular branches, a bundle branch block will occur. Total heart block will occur due to disease of AV node. In case of total heart block signals produced in the SA node will not reach the ventricles as the AV node is diseased. In ECG complex atrial depolarization is represented by P-wave. Depolarization of the ventricles is represented by QRS-complex. In case of total heart block depolarization of the ventricles is not present due to signals are not travelled to the ventricles as the AV node is diseased. Only atrial depolarization is present in total heart block. Due to this only P-waves are present and QRS complexes are absent in total heart block..

1. Name four questions related to heart function that you could answer by examining an ECG and
one abnormal condition that may be indicated by each function.
Solution
1).
Electrocardiograph is an instrument used to record the electrical activities of the heart. The graph
obtained by the electrocardiograph is called as electrocardiogram (ECG). The electrical events
are denoted with the letters P, Q, R, S and T; these are called electrical waves.
The “P wave (also called as atrial complex)” is the first and positive wave in ECG. It is produced
due to the atrial depolarization that lasts for 0.1 sec.
Atrial repolarization merges with “QRS complex.” QRS complex is also known as initial
ventricular complex, which is produced due to the ventricular depolarization.
The “Q wave” is a negative wave that continues as a positive “R wave (tallest wave).” The R
wave is followed by “S wave,” which is a negative wave. “T wave” is the last positive wave that
represents final ventricular complex; it is produced due to the ventricular repolarization.
The four questions that can be answered from ECG are,
1). Heart rate determination
2). Cardiac arrhythmias identification
3). Electrical disorders of auricles and ventricles
4). What is the indication of heart block?
Heart Block: It is a condition in which electrical signals through the cardiac conduction system is
not travelled normally. This occurs due to the disease and degeneration of the fibres of the
conduction system.
Due to the disease of the one or both the Atrioventricular branches, a bundle branch block will
occur. Total heart block will occur due to disease of AV node. In case of total heart block signals
produced in the SA node will not reach the ventricles as the AV node is diseased.
In ECG complex atrial depolarization is represented by P-wave. Depolarization of the ventricles
is represented by QRS-complex.
In case of total heart block depolarization of the ventricles is not present due to signals are not
travelled to the ventricles as the AV node is diseased. Only atrial depolarization is present in
total heart block. Due to this only P-waves are present and QRS complexes are absent in total
heart block.