Differential Diagnosis of rSr' Pattern in Leads V1-V2. Comprehensive Review and Proposed Algorithm

One of the more frequent dilemmas in ECG interpretation is the differential diagnosis of an rSr' pattern in leads V-1-V-2. We often face this finding in asymptomatic and otherwise healthy individuals and the causes may vary from benign nonpathological variants to severe or life-threatening heart diseases, such as Brugada syndrome or arrhythmogenic right ventricular dysplasia. In other cases, a normal variant of rSr' pattern can be misinterpreted as pathological after the occurrence of certain clinical events such as cardiac arrest or syncope of unknown cause. In this review we analyze in detail all the possible conditions, both benign and pathological that may explain the presence of this electrocardiographic pattern. We also propose a simple electrocardiographic algorithm for differential diagnosis.