Key Points Definition and measurement: The P wave is atrial depolarization. Measure duration from initial deflection to return to baseline and amplitude from baseline to peak. Normal values: Duration <120…
Key Points Definition: Sinus pause/arrest is failure of the sinus node to generate an impulse, producing a transient absence of P waves. On ECG the pause does not equal an…
Key Points Fewer P waves than QRS complexes: This means impulses are originating from below the atria (junctional, ventricular, or paced), or from ectopy interrupting sinus rhythm. Clinical relevance: In…
Key Points Absence of Sinus Rhythm: The lack of clear P waves before the QRS complexes suggests loss or dysfunction of sinus activity. Potential Causes: This pattern can result from…
Key Points Non-conducted P waves (too many P waves) occur when atrial impulses fail to conduct to the ventricles. Automated ECG interpretations are unreliable in irregular rhythms and with non-conducted…
Key Points Definition: Sinus tachycardia is a regular rhythm originating from the sinoatrial (SA) node, defined by a heart rate >100 bpm in adults or above age-adjusted norms in children….
Key Points Definition: Sinus bradycardia is a rhythm originating from the sinoatrial (SA) node with a rate < 60 bpm. Physiological Occurrence: Common in young, healthy adults, athletes, and during…
Key Points Definition: Right atrial enlargement (RAE) is an increase in the size of the right atrium, typically resulting from chronic pressure or volume overload, commonly related to cardiac or…
Key Points Normal Sinus Rhythm: In a normal rhythm, the sinus node initiates atrial depolarization, resulting in a P wave with a normal axis: upright in lead II, inverted in…