Electrocardiogram (ECG) Basics

Front

What is an electrocardiogram (ECG)?

Back

An ECG is an exam that records the heart's electrical activity over time, allowing analysis of electrical impulse conduction through different cardiac structures.

Front

What is expected in a physiological ECG?

Back

In healthy individuals, a specific pattern of waves, intervals, and segments with durations and amplitudes within established ranges is expected.

Front

What is the normal resting heart rate range?

Back

The normal resting heart rate varies from 60 to 100 beats per minute (bpm).

Front

What are bradycardic and tachycardic rhythms?

Back

Bradycardic rhythms are below 60 bpm, while tachycardic rhythms are above 100 bpm.

Front

Where does the normal electrical activation pattern originate?

Back

The normal electrical activation pattern, or sinus rhythm, originates in the sinoatrial node.

Front

How is the sinus rhythm identified?

Back

It is identified by the presence of positive P waves in leads D1, D2, and aVF, with stable morphology and PR interval.

Front

What does the P wave represent?

Back

The P wave represents atrial depolarization.

Front

What are the normal duration and amplitude of the P wave in lead D2?

Back

The P wave should have a duration of less than 120 ms and an amplitude of less than 2.5 mm in lead D2.

Front

What does the PR interval reflect?

Back

The PR interval reflects the time between the start of atrial and ventricular depolarization.

Front

What is the normal duration of the PR interval?

Back

The PR interval should last between 120 and 200 ms.