ECG diagnosis and mechanism of third degree atrioventricular block with accelerated dual ventricular escape rhythm and normalized fusion wave

Objective To investigate the electrocardiographic diagnosis and mechanism of third degree atrioventricular block with accelerated dual ventricular escape rhythm and normalized fusion wave. Methods The clinical data of 15 patients with triple atrioventricular block with accelerated dual ventricular escape rhythm and normalized fusion wave in BenQ Medical Center of Nanjing Medical University from May 2008 to November 2018 were retrospectively analyzed by routine electrocardiogram and dynamic electrocardiogram. Results In 15 patients with third degree atrioventricular block , there were two origins of escape QRS waves, which resulted in two forms of escape QRS waves. Thirteen cases of escape beat originated from left and right ventricles respectively. Two cases could not accurately determine the origin of escape beat. They could only preliminarily determine the two parts of the ventricle. All 15 patients had two-source escape pulses at the same time or almost at the same time, which resulted in the normalization of QRS morphology of escape pulses. Conclusions Normalization of ventricular fusion wave in complete atrioventricular block with accelerated dual ventricular escape rhythm suggests the presence of ectopic foci in both ventricles, and the stability of escape rhythm is poor. Mastering the mechanism of this ECG phenomenon is helpful for further analysis and accurate diagnosis and avoiding misdiagnosis.