AIM:To study patients with atrial fibrillation and hypertension who had successful catheter ablation for changes in blood pressure 1 year later.METHODS:A retrospective study was performed on patients who had catheter ablation for atrial fibrillation(AF)and hypertension(HTN)which included local autonomic ganglionated plexi denervation and pulmonary veins isolation.Of the records of 119 patients,followup data was found in order to determine the presence of sinus rhythm and data on systolic(SBP)and diastolic blood pressure at 2 wk,3 mo,6 mo and 1 year after the ablation procedure.Transthoracic echocardiograms were taken at the time of the catheter procedure to determine left atrial dimensions(LADs)and left ventricular size.RESULTS:There was no significant difference in the preablation mean blood pressures between the two groups(P=0.08).After 1 year 33 of the 60 with AF and HTN were in sinus rhythm,of whom 12 had normal LADs,≤4 cm Group 1,and 21 had enlarged left atria(LADs>4 cm,Group 2).For Group 1,at 1 year of follow up,there was a significant difference in the SBP(119.2±13 mmHg)compared to pre-ablation(142.6±13.7 mmHg,P=0.001).For Group 2,there was no significant difference in the SBP,pre-ablation(130.3±17.5 mmHg)and at 1 year of follow up(130.4±13.4 mmHg,P=0.75).All patients were on similar anti-hypertensive medications.There was a trend for a greater left ventricular size in Group 2 compared to Group 1.CONCLUSION:We suggest that Group 1 had HTN due to sympathetic hyperactivity,neurogenic HTN;whereas HTN in Group 2 was based on arterial vasoconstriction.