To examine the effects of antihypertensive therapy causing regression of left ventricular hypertrophy on cardiac arrhythmias, 26 hypertensive subjects were treated with ramipril with felodipine if required, and followed for 6 months after blood pressure control. Compared with baseline, left ventricular mass index (LVMI) was significantly reduced both at blood pressure control and after a further 6 months of treatment (baseline, blood pressure control, 6 months after blood pressure control; LVMI 142 +/- 3.6, 131 +/- 3.4, 123 +/- 3.8* g/m2, *P < .01 compared with baseline). There was a significant relationship between the decrease in systolic blood pressure and the decrease in LVMI after 6 months of blood pressure control compared with baseline (r = 0.41, P = .05). Compared with baseline, the average total number of ventricular ectopics decreased after blood pressure was controlled (88 +/- 59 and 21 +/- 12 respectively); however this reduction was not maintained after 6 months of further treatment, either before (78 +/- 50) or after drug washout (86 +/- 40). Compared with baseline (639 +/- 590) supraventricular ectopic total was not initially reduced after blood pressure control (650 +/- 604), but was reduced after a further 6 months of treatment (294 +/- 261). This reduction was maintained after drug washout (267 +/- 254), although this did not reach statistical significance. Radionuclide scanning at baseline was not a predictor of patients with the highest risk of arrhythmia and there was no correlation between improvement or worsening of a defect with changes in ventricular ectopic total. In conclusion, antihypertensive therapy with ramipril and felodipine, although causing regression of left ventricular hypertrophy did not lead to a sustained reduction in ventricular ectopic total.