Results
Patient Characteristics: A total of 166 atrial arrhythmia cases were guided by the HD Grid from May 2018 to December 2019, with 151 patient procedures meeting our inclusion criteria accounting for 142 patients. Fifteen patients were excluded due to AVRT (7) and typical cavotricuspid isthmus dependent flutter (8). Atrial fibrillation (AF) accounted for the majority of cases (68.9%), with 66 paroxysmal cases and 38 persistent cases; the remainder of the cases were classified as atrial tachycardia (including a focal or re-entrant, incisional pathology), 29 (19.2%) cases and atypical atrial flutter (macro-reentrant), 18 (11.9%) cases. The majority of patients were male (67.8%) with a mean age of 61.1 ± 11.2 years. A detailed summary of patient demographics are described in Table 1.
Procedural Details: General anaesthesia was administered for 84 cases with a mean procedure time of 237.8 ± 75.6 minutes and mean cumulative fluoroscopy dose of 137.9 ± 134.8 mGy. Intracardiac echocardiography was employed for 23 procedures. Radiofrequency (RF) lesions applied for each respective atrial arrhythmia case are described in Table 2. Acute procedural success was observed in all patients, defined as pulmonary vein isolation, the identification and termination of clinical arrhythmia, and demonstration of bidirectional block when applicable.
Post-operative Complications: Three patients experienced major complications within 30 days post-procedure including pericardial tamponade, TIA, and stroke. Both embolic events occurred 3 days post-procedure; the TIA occurred in a patient non-compliant with anticoagulation upon returning home and the stroke patient had significant co-morbidities. Both patients made a complete neurological recovery. Minor complications were reported for three patients including one reported case of urinary retention and two cases of pericarditis that responded to conservative management without any prolonged hospital stay.
Follow-up and Arrhythmia Recurrence: Patients were followed-up for a mean 185.2 ­± 134.3 days post-procedure and one patient was lost to follow-up. One patient died from complications of septic arthritis 183 days post procedure. Long-term outcome data is presented for the remaining 150 patients described in Table 3; 32 (21.2%) reported an arrhythmia recurrence with 12 (8.1%) of these cases reporting recurrence of atrial fibrillation and 20 (13.4%) for any atrial arrhythmia. Five patients had immediate arrhythmia recurrence with two patients receiving cardioversion within one week and one month post-procedure, one recorded event of atrial fibrillation lasting 1-hour, two undocumented episodes of atrial fibrillation reported by the patient without later recurrence, and atrial tachycardia 24 hours post-procedure in the context of urinary retention with no further recurrence. There was no significant differences for any demographic, procedural, or complication data between recurrent and no recurrent arrhythmia cases.