Atrioventricular Nodal Reentry Tachycardia

The aim of the present work is to analyze the capacity of high resolution mapping systems to determine the precise location of the AV node and peri-nodal slow-conducting pathways, using standard recording parameters, but also off-line additional filter changes and additional techniques (conduction velocities, isochrones and dV/dt). The investigative team plan a prospective monocentric study. Detailed high resolution mapping of the Koch triangle and neighboring areas will be collected through the RHYTHMIA HDx 3D electro-anatomical mapping system and the multipolar ORION catheter. This sample will consist of 2 groups of patients: the first will include patients referred for AVNRT ablation and the second will include control patients (without AVNRT), referred for another indication requiring similar mapping system. If visualized, position of the slow pathway and AV node will be compared with the ablation areas, which will be set conventionally under fluoroscopy.

Supraventricular tachycardia (SVT) is a common heart rhythm disorder seen in emergency departments, causing a rapid heartbeat (typically 150-250 beats per minute). The current best non-drug treatment, the modified Valsalva maneuver (mVM), successfully restores normal rhythm in about 43% of cases. When these maneuvers fail, intravenous adenosine is used, which, while effective, can cause brief but distressing side effects such as chest tightness, shortness of breath, and intense anxiety. During the COVID-19 pandemic, some patients briefly fainted during nasal swab collection. This happens because inserting a swab into the back of the nasal cavity (nasopharynx) stimulates the trigeminal nerve, which then activates the vagus nerve and slows the heart - a phenomenon called the trigeminocardiac (or nasocardiac) reflex. One published case report described a patient whose SVT was terminated within 10 seconds using a nasal swab. This study compares the nasal swab technique with the modified Valsalva maneuver in patients presenting to the emergency department with SVT. Patients are randomly assigned to one of two groups. The primary outcome is whether a normal heart rhythm is restored within 1 minute of the procedure. Patient comfort and satisfaction are also measured. The study is conducted in two phases. The first (pilot) phase (30 patients per group) will assess whether the study can be successfully conducted and collect data to finalize the required sample size. The second (main) phase will use the pilot phase's actual data to determine the final number of participants needed.