Cardiac arrhythmia caused by a novel type of atrial conduction block: A case report

INTRODUCTION: We report an extremely rare case of atrial conduction block with unusual electrocardiogram (ECG) results, which has never been reported before. There are 2 types of atrial conduction block that result in atrial irregularities or complete atrial conduction block. The former is similar to other types of cardiac blocks such as sinus node to atrial block, atrial to ventricular block, or bundle branch blocks, which are characterized by 2 P waves at a specific frequency. This is due to the complete inner atrial block that results in the atrial muscle being divided into 2 parts without conduction between them so that each part has its rhythm generator. The objective of this report is to examine the cause of inner atrial conduction block and to promote awareness of this disorder. PATIENT CONCERNS: An 81-year-old Chinese male patient was examined after complaining about chest discomfort, and it was found that he had atrial tachycardia; ECG results revealed a P wave loss at specific intervals (or P wave separation). DIAGNOSIS: A diagnosis of P wave loss at specific intervals (or P wave separation) was made based on ECG results. INTERVENTIONS: An ECG was performed on the patient OUTCOMES: It was unclear whether this patient has atrial separation or a new type of atrial conduction block, but our results revealed that this case presents a novel type of atrial conduction block, which we named ‘P wave block.’ CONCLUSION: The type of EKG shown in this case has never been reported. This EKG shows a new type of conduction block in the atrium, temporarily named as a new type of P wave block.