Atrial flutter with 1:1 rapid wide QRS atrioventricular conduction in a patient following traditional surgical repair on atrial septal defect: a case study

One-to-one atrioventricular conduction (AVC) during atrial flutter (AFL) is one of the most life-threatening arrhythmias and hemodynamically perilous. We present the diagnostic and analytical strategy for a patient who developed a paroxysm of AFL with 1:1 AVC. We did Brugada’s stepwise approach and the ventricular tachycardia (VT) score for the diagnosis. Meanwhile, we did RS/QRS ratio in lead V6. Through observations of the dynamic changes during and after amiodarone treatment, we made the diagnosis. Firstly, we calculated the VT score, and the result showed score 1. Secondly, we made Brugada’s stepwise approach to exclude VT. Meanwhile, we did RS/QRS ratio in lead V6, and the result showed the rate of 0.369 (<0.41, cut off 0.41). The result also suggested that the wide QRS AV tachycardia was not VT. Finally, amiodarone was administered under the guidance of a cardiovascular physician. Through observations of the dynamic changes during and after amiodarone treatment, the electrocardiogram (ECG) showed AFL with 2:1 AVC. The AFL rate was the same as the rate of rapid arrhythmia attack. Retrospectively, the rapid arrhythmia ECG was diagnosed as AFL with 1:1 rapid wide QRS AVC. AFL with 1:1 AVC is an uncommon but challenging arrhythmia. Brugada’s stepwise approach and the VT score can assist clinical physicians in making the diagnosis. In our study, we also verify that the RS/QRS ratio in lead V6 is beneficial to differentiate supraventricular tachycardia (SVT) with a right bundle branch block (RBBB) pattern from VT. Through observation of the changes of ECG before and after amiodarone, we can make the diagnosis. One should be conscious of the different presentations of AFL with 1:1 wide QRS AVC to avoid misdiagnosis and mismanagement.