Background: Catheter ablation for atrial fibrillation may require repeat procedures. The impact of extensive AF ablation procedures on left atrial diastolic dysfunction is not well defined or quantified. The stiff left atrial syndrome is characterised by a combination of heart failure symptoms, pulmonary hypertension and left atrial diastolic dysfunction. This is a pilot study documenting the trend of invasive haemodynamic parameters including left atrial pressure measurement, during AF ablation procedures. Further work is underway to investigate the specific contribution of AF ablation towards the development of pulmonary hypertension.
Methods: This is a single centre, prospective study. All patients receiving catheter ablation for AF have peri-procedural haemodynamic parameters measured and documented and blood gases taken for laboratory analysis to enable cardiac output via Fick’s method to be calculated. Patient demographics including age, sex, lung co-morbidities are recorded including the duration and type of AF and previous catheter ablation procedures. The characteristics of the current AF ablation procedure are also recorded. Pre and post study transthoracic echocardiography parameters will be measured. Pre and post study respiratory functional assessment will be measured, including the 6-minute walk test.
Results: At the time of writing, 51 patients are included in the study. The median age is 64 years, with n=17 female and n=35 male patients. The average LV ejection fraction was 55% as measured by trans-thoracic echocardiography. 17.3% of the study population had pre-existing chronic lung disease. 24/51 (47%) patients had paroxysmal AF and 27/51 (52.9%) had persistent AF. 20/51 (39.2%) had a prior AF ablation procedure. The majority, 32/51 (62.7%) had a PVI+ procedure at the time of invasive haemodynamic assessment. First time AF ablation patients and PAF had an average LA pressure of 14.9 mmHg versus repeat and persistent AF patients 15.5 mmHg.
Conclusion: At the time of presentation, we will be able to distinguish if there is a clear difference in peri-procedural haemodynamic parameters in those who have short burden of AF versus those with the longstanding form of the condition and also compare those who present for their index procedure versus those who have had a prior ablation procedure. Further long-term prospective study is being undertaken to answer the question of how AF ablation contributes to the development of pulmonary hypertension.