Introduction: Radiofrequency catheter ablation (RFCA) of severely symptomatic monomorphic ventricular premature beats (VPBs) is reported to be a safe and effective treatment option. However, the chronic hemodynamic effects of these VPBs have not been precisely evaluated.
Methods and results: We sought to investigate chronic effects after decreasing the number of VPBs by RFCA. A total of 47 patients who had no underlying heart disease and frequent monomorphic VPBs, consisting of more than 10,000 beats per day (24,194 +/- 12,516 beats per day), were enrolled. Patients were treated with RFCA and followed up over 6 months as outpatients. Echocardiography and serum B-type natriuretic peptide (BNP) level were repeatedly checked before and after RFCA. In 38 patients, whose VPBs were dramatically decreased to less than 1,000 beats per day by successful RFCA, left ventricular (LV) end-diastolic dimension (LVEDd) and end-systolic dimension (LVESd) measured by echocardiography decreased significantly (LVEDd: 50 +/- 5 to 48 +/- 5 mm, P < 0.01; LVESd: 33 +/- 7 to 30 +/- 6 mm, P < 0.01) in association with improvement of BNP level (39.9 +/- 34.1 to 16.8 +/- 10.3 pg/mL, P = 0.0001). In nine patients, whose VPBs were treated unsuccessfully by RFCA or that recurred, LV dimensions and BNP level did not change during the follow-up period.
Conclusion: Significant improvement in LV dimensions and serum BNP level appeared to indicate that RFCA of VPBs ameliorated occult cardiac dysfunction induced by frequent VPBs.