An Accessible Algorithm for the Quick and Precise Interpretation of Atrioventricular Blocks in Electrocardiograms

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  FIGURE 1. Algorithm for detecting AV blocks without grouped beating. (a) This algorithm is used for ECGs without grouped beating. It follows a stepwise assessment of QRS regularity, P–P interval regularity, and the number of P waves between QRS complexes to identify underlying rhythms and potential atrioventricular (AV) blocks. (b) This panel shows the continuation of the algorithm when one P wave is present per QRS complex without grouped beating. PR intervals are categorized by duration to differentiate normal sinus rhythm, pre‐excitation syndromes, first‐degree AV block, and possible AV dissociation or ventricular tachycardia in cases of variable PR intervals. (c) This panel shows the continuation of the algorithm when two or more P waves are present between QRS complexes without grouped beating. Based on PR interval behavior and QRS width, the algorithm helps distinguish 2:1 AV block, high‐grade AV block, and complete AV block and provides guidance for further subtyping using lead V1. Note: The algorithm is specifically designed for abnormal or complex ECGs rather than general ECG screening. HR, heart rate; LGL, Lown–Ganong–Levine syndrome; WPW, Wolff–Parkinson–White syndrome.

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  FIGURE 2. Algorithm for determining rhythms with grouped beating. This algorithm illustrates the diagnostic approach for ECGs with grouped beating, in which QRS complexes occur in repeating patterns followed by pauses. It includes assessment of the number of QRS complexes per group, R–R interval regularity, P–P interval patterns, and PR interval behavior to help diagnose Mobitz type I AV block, Mobitz type II AV block, and other underlying atrial conduction abnormalities. Note: The algorithm is specifically designed for abnormal or complex ECGs rather than general ECG screening.