Sinus Rhythm

This page provides an overview of our free sinus rhythm training materials, practice drills and reference guide.

What is sinus rhythm?

Sinus rhythm means a normal heart beat, both with respect to the heart rate and rhythm. Heart rate will fall between 60 and 100 beats per minute. The shape of the electrocardiogram (EKG) tracing will exhibit certain key attributes to be considered normal, as discussed below.

Sinus Rhythm EKG (ECG) Tracing

EKG tracings are printed on grid paper or displayed on a patient monitor. These tracings, the EKG waveform, have key features which indicate sinus rhythm or abnormalities (arrhythmias).

sinus rhythm waveform

There are six wave components which are commonly analyzed in determining if the EKG is a sinus rhythm. These wave components provide clues regarding the underlying condition of the heart:

  • P Wave
  • PR Interval
  • PR Segment
  • QRS Complex
  • QT Interval
  • ST Segment

The P wave is the first bump and is normally an upward bump. The p wave measures atrial depolarization. The P wave is followed by the QRS complex. It typically starts with a negative deflection, Q; then a large positive movement, R; and next a negative movement, the S wave. The QRS complex indicates ventricular depolarization and contraction. Following the QRS complex, T wave is normally a modest upwards waveform, indicating repolarization of the ventricles. The PR interval, PR segment, QT interval and ST segment are also evaluated using the EKG analysis in order to determine if the EKG tracing represents a sinus rhythm.

Overview of EKG Training

A good starting point for learning abnormal heart rhythms vs a sinus rhythm is our EKG Basics training course. The course provides training on the key features of an EKG tracing. These features include observing P-wave forms, measurement of EKG intervals and segments, assessment of rhythm, calculating heart rate, and the evaluation of other relevant wave segments. The EKG practice drills allow students to build skills interactively.

Basics of Cardiac Rhythm Training

Heart Rhythm Practice Drills

The heart rhythm practice drills provide an EKG tracing and users are asked to identify the type of arrhythmia or normal sinus rhythm. Each answer is immediately evaluated and the correct classification of the EKG tracing is provided, along with a detailed explanation. A directory of arrhythmias is also provided.

Heart Rhythm Practice Drills

Heart Rhythm Quiz

The quiz is presented like a classroom exam with 20 tracings to be evaluated. After all tracing questions are answered, your quiz is immediately graded. The graded report provides a score as well as the correct answer to each question. Top scores and mean scores are also provided. This quiz draws its questions from a library of over 300 abnormal EKGs as well as normal sinus rhythm strips, allowing users to take the quiz multiple times.

ECG Quiz

ECG Monitor Challenge (beta version)

Try the beta version of our ECG monitor challenge. This quiz uses a simulated patient monitor with moving waveform instead of a paper tracing. As with the quiz described above, twenty questions are presented, then a graded report is available.

ECG Monitor Challenge

External References

Medical Dictionary