Dual atrioventricular nodal conduction pattern with irregular double ventricular response: radiofrequency catheter ablation of the slow AV nodal pathway

A variety of electrocardiographic manifestations of dual AV nodal physiolog y have been reported. The specific subtype dual ventricular response is con sidered as a very rare phenomenon. We present the case of a 53 year old lady who suffered from paroxysmal regu lar tachycardias for more than seven years. In the last 6 months the sympto matology of the cardiac arrhythmia changed to more persistent und irregular rhythm disturbances. Treatment with class Ia antiarrhythmic drugs and beta -blocking agents failed. The latter even seemed to worsen her very disturbi ng palpitations. After examination of the ECG recordings, the diagnosis of dual AV nodal physiology with double ventricular response was made - the la dy was referred to our institution for electrophysiological testing and rad iofrequency catheter ablation of the slow pathway. An invasive electrophysiological study reconfirmed the diagnosis of a dual AV nodal conduction pattern with irregular double ventricular response. The radiofrequency catheter ablation of the the slow pathway achieved a comple te cessation of the double ventricular response. This satisfactory outcome was confirmed by analysis of a postinterventional 24 hour holter recording and an exercise stress test. During a follow-up period of three months, the patient remained free of sym ptoms and there was no recurrence of dual AV nodal conduction physiology in the surface EGG.