What does the QRS complex look like?

As the name suggests, the QRS complex includes the Q wave, R wave, and S wave. These three waves occur in rapid succession. The QRS complex represents the electrical impulse as it spreads through the ventricles and indicates ventricular depolarization.

What is represented by QRS complex?

A combination of the Q wave, R wave and S wave, the “QRS complex” represents ventricular depolarization. This term can be confusing, as not all ECG leads contain all three of these waves; yet a “QRS complex” is said to be present regardless.

What is ECG morphology?

While electrocardiographic morphology deals with interpretation of the shape (amplitude, width and contour) of the electrocardiographic signals, arrhyth- mology is devoted to the study of the rhythm (sequence and frequency) of the heart.

Are QRS complexes narrow?

Narrow QRS complex tachycardias are fast cardiac rhythms (generally more than 100 beats/min) with a QRS duration of 100 ms or less. Differential diagnosis of tachycardia with narrow QRS complex (shorter than 0.12 second). Although rarely life-threatening, these arrhythmias are a common source of morbidity.

What causes a QRS complex?

Abnormal QRS complexes are produced by abnormal depolarization of the ventricles. Duration of an abnormal QRS complex is greater than 0.12 seconds. Shape of an abnormal QRS complex varies from almost normal to wide and bizarre and/or slurred and notched.

What happens after the QRS complex?

Atrial and ventricular depolarization and repolarization are represented on the ECG as a series of waves: the P wave followed by the QRS complex and the T wave. The first deflection is the P wave associated with right and left atrial depolarization. Wave of atrial repolarization is invisible because of low amplitude.

What does it mean when QRS complex is inverted?

• Usually the QRS complex consists of positive. (upright) deflections called R waves and. negative (inverted) deflections called Q and S. waves. • If there is no R wave, the complex is called a QS.

What are the normal values of ECG?

Normal ECG values for waves and intervals are as follows: RR interval: 0.6-1.2 seconds. P wave: 80 milliseconds. PR interval: 120-200 milliseconds.

What is abnormal ECG report?

An abnormal ECG can mean many things. Sometimes an ECG abnormality is a normal variation of a heart’s rhythm, which does not affect your health. Other times, an abnormal ECG can signal a medical emergency, such as a myocardial infarction /heart attack or a dangerous arrhythmia.

What is normal ECG level?

Normal intervals Normal range 120 – 200 ms (3 – 5 small squares on ECG paper). QRS duration (measured from first deflection of QRS complex to end of QRS complex at isoelectric line). Normal range up to 120 ms (3 small squares on ECG paper).

What does a narrow QRS complex indicate?

Narrow (normal) QRS complexes indicate that the ventricles are depolarized normally; this can only be the case if the impulse (which depolarizes the ventricles) passes through the bundle of His, and hence it originates in the atria. In other words: tachycardias with narrow QRS complexes originate in the atria.

How do you treat a wide QRS complex?

Treatment / Management

1. SVT will typically be managed with adenosine, Afib with WPWS will be treated with amiodarone, and Afib with aberrancy with either diltiazem or a beta-blocker.
2. Typically, amiodarone will be the first-line drug of choice for all ventricular arrhythmias (VT, polymorphic VT, Vfib, etc.)

What are the morphologies of the QRS complex?

On a normal electrocardiogram, it can be seen in leads V5 and V6. RS: tall R wave followed by a deep S wave, with similar amplitude (biphasic QRS). It is the characteristic morphology in lead sV3. rS: small R wave followed by a deep S wave.

Which is the characteristic morphology of a QRS wave?

qRs: Small initial non-pathological Q wave, followed by a tall R wave and a small S wave. On a normal Electrocardiogram, it can be seen in leads V5-V6. RS: Tall R wave followed by a deep S wave, with similar amplitude (biphasic QRS). It is the characteristic morphology in V3.

What are the alternating QRS morphologies and PR intervals?

This is followed by a P-wave that conducts with a PR interval of 190 ms with RBBB and normal axis, indicating intact conduction through the left anterior fascicle (dashed arrow). The alternating pattern of incomplete LBBB with prolonged PR interval followed by RBBB and LAFB with shorter PR interval then resumes.

How are narrow QRS complexes related to atrial flutter?

Narrow (supraventricular) complexes arise from three main places: AV node / junction (= either no P wave or an abnormal P wave with a PR interval < 120 ms) Sinus rhythm: Each narrow complex is preceded by a normal P wave. Atrial flutter: Narrow QRS complexes are associated with regular flutter waves.