An unusual case of non-reentrant atrioventricular nodal tachycardia

Introduction Although uncommonly encountered, dual atrioventricular nodal non-reentrant tachycardia (DAVNNRT) is a well-described arrhythmia that can manifest in patients with dual atrioventricular nodal pathways physiology. This arrhythmia is characterized on electrocardiogram (ECG) by a single P wave followed by two conducted QRS complexes (so-called "double fire"), and on intracardiac electrograms by a single atrial electrogram followed by two separate His deflections and ventricular electrograms. Methods/Results We report a rare case of "triple-fire" atrioventricular non-reentrant tachycardia in which a patient was found to have three distinct atrioventricular nodal pathways and multiple triple fire responses, both on surface ECG and intracardiac electrograms. Conclusion Multiple pathways physiology and it's clinical ramifications are discussed.