A catheter (10) for use in a patients heart, especially for mapping a tubular region of the heart, has a catheter body (12), a deflectable intermediate section (14) and a distal tip section (15) including a mapping assembly that has a generally circular portion adapted to sit on or in a tubular region of the heart. A control handle (16) of the catheter allows for single-handed manipulation of various control mechanisms that can deflect the intermediate section and contract the mapping assembly by means of a deflection control assembly and a linear control assembly. The deflection control assembly has a deflection arm (75) and a rocker member (78). The linear control assembly has a linear control member, an inner rotational member and a cam. A pair of puller members are responsive to the deflection control assembly to bi-directionally deflect the intermediate section. A third puller member is responsive to the linear control assembly to contract the generally circular portion of the mapping assembly.
