ECG Rhythms Practice Quiz

An electrocardiogram (ECG) records the electrical activity of the heart. This information is critical in diagnosing various cardiac conditions and assessing heart function.

The P wave reflects the electrical depolarization of the atria. Recognizing this wave is essential for understanding atrial activity in an ECG tracing.

The QRS complex signifies the depolarization of the ventricles. Its duration and morphology help assess the electrical conduction through the ventricular tissue.

The T wave represents the repolarization of the ventricles. It is a key indicator in evaluating the recovery phase of the ventricular muscle after contraction.

The R-R interval measures the time between successive R waves and is used to calculate the heart rate. A consistent R-R interval typically indicates a regular heart rhythm.

Atrial fibrillation is known for its irregularly irregular rhythm and absence of clear P waves. This disorganized atrial activity makes it distinct from other arrhythmias.

Atrial flutter is typically identified by a sawtooth pattern in the ECG. This pattern results from rapid, regular atrial contractions and is key to its diagnosis.

A prolonged QT interval is associated with a heightened risk of torsades de pointes, a potentially life-threatening ventricular arrhythmia. This finding requires careful clinical attention and management.

ST-segment elevation is a hallmark finding in myocardial infarction, indicating acute injury to the heart muscle. Recognizing this pattern is vital for timely intervention and management.

Tachycardia is generally defined as a heart rate exceeding 100 beats per minute. Identifying this condition on an ECG is crucial for diagnosing underlying cardiac issues.

The PR interval represents the time required for an electrical impulse to travel from the atria to the ventricles. This interval is a key indicator of AV nodal conduction efficiency.

A bundle branch block is generally identified by a widened QRS complex due to delayed ventricular conduction. This abnormality can signal issues with the heart's electrical pathways.

The ST segment reflects the plateau phase between ventricular depolarization and repolarization. It is critical in evaluating conditions like myocardial ischemia.

A prominent U wave is most often associated with hypokalemia. This abnormal wave appears due to delayed repolarization, serving as an important diagnostic clue for electrolyte imbalances.

A normal sinus rhythm is characterized by regular R-R intervals and the consistent presence of a P wave before each QRS complex. This pattern indicates healthy, coordinated cardiac conduction.

A heart rate below 60 bpm indicates bradycardia, and a prolonged PR interval suggests a first-degree AV block. Together, these findings point to sinus bradycardia with first-degree AV block.

Ventricular tachycardia is generally characterized by a wide QRS complex and often displays AV dissociation. These features help differentiate it from supraventricular tachycardia, even when aberrant conduction occurs.

Pathological Q waves are typically indicative of myocardial infarction, reflecting areas of dead cardiac tissue. Their presence is crucial for diagnosing previous or ongoing myocardial injury.

Delta waves, seen as a slurred upstroke at the start of the QRS complex, are characteristic of Wolff-Parkinson-White syndrome. This finding indicates the presence of an accessory pathway causing pre-excitation of the ventricles.

Electrical alternans is characterized by beat-to-beat variations in the amplitude of the QRS complex. It is an important finding because it is often linked to a significant pericardial effusion, which may require urgent intervention.