PR interval: time interval from onset of
atrial depolarization to onset of
• QT interval: duration of ventricular
depolarization and repolarization
• RR interval: duration of ventricular
• PP interval: duration of atrial cycle. As a positive wave
within the heart
moves toward a
there is a upward
Heart rate is calculated as the number of times the heart beats
per minute. It usually measures ventricular rate (the number of
QRS complexes) but can refer to atrial rate (the number of P
waves). The method chosen to calculate HR varies according to
rate and regularity on the ECG tracing.
Left Atrial Abnormality & 1st degree AV Block-KH Frank G.Yanowitz, M.D.
The P-wave is notched, wider than 0.12s, and has a prominent negative (posterior) component in V1 - all criter for left atrial abnormality or enlargement (LAE). The PR interval 0.20s. Minor ST-T wave abnormalities are also present.