Respiratory cycle-dependent atrial tachycardia: prevalence, electrocardiographic and electrophysiologic characteristics, and outcome after catheter ablation

Speech induced atrial tachycardia - Case report and review of literature

Speech induced atrial tachycardia is peculiar and an extremely uncommon clinical situation. Though the exact patho-mechanism for such an association cannot be ascertained. It is postulated to be caused by cardiac autonomic modulation by vagal innervation around the ganglionated plexus (GP) of the heart. We hereby present a unique case of atrial tachycardia which could be induced only by speech and was successfully mapped and ablated on to the floor of left atrium (LA), which is a possible site of posteromedial left atrial ganglionated plexus.

The characteristics and efficacy of catheter ablation of focal atrial tachycardia arising from an epicardial site

BACKGROUND

Although epicardial structures around the atrium such as adipose tissue possess arrhythmogenicity, little is known about atrial tachycardias (ATs) originating from epicardial sites (Epi-ATs). This study aimed to elucidate the prevalence, characteristics, and outcome after radiofrequency catheter ablation (RFCA) of Epi-ATs and to reveal the association between Epi-ATs and the epicardial structures.

METHODS

The electrocardiographic, electrophysiologic, and anatomical properties and results of RFCA were analyzed in 42 patients with a total of 49 ectopic ATs.

RESULTS

Six Epi-ATs (12%) were observed in six patients (14%). Four of six were respiratory cycle-dependent ATs and one was a swallowing-induced AT. The Epi-AT origins were adjacent to a pulmonary vein (five cases) and vein of Marshall (one case). A Valsalva maneuver or atropine infusion to define the arrhythmia mechanism affected the appearance of the Epi-ATs. The congruity rate between epicardial adipose tissue and the AT origin was significantly higher (100% vs. 44%, p = .045), and the epicardial adipose tissue volume of the atrium was significantly larger (104.1 vs. 64.6 ml, p = .04) in the Epi-AT group. Endocardial RFCA targeting the AT foci resulted in acute success in five of five cases. However, electrical isolation including of the AT foci resulted in acute failures (two of three cases) or a recurrence (one of one case).

CONCLUSIONS

Six Epi-ATs were associated with thoracic veins and epicardial arrhythmogenic structures. The main cause provoking the Epi-ATs was associated with autonomic nerve activity.

Respiratory cycle-dependent atrial tachycardia originating from the left atrial roof

Respiratory cycle-dependent atrial tachycardia (RCAT) is rare. RCAT can be associated with severe symptoms and trigger atrial fibrillation. Focal radiofrequency ablation of RCAT can be a successful method of treatment. In the presented case RCAT originated from the roof of the left atrium - the site not previously reported in the literature. Ablation led to complete elimination of arrhythmia with no recurrence during follow up.