Transmembrane potential (V_m) responses in cardiac strands with different curvature were characterized during uniform electric-field stimulation with the use of modeling and experimental approaches. Linear and U-shaped strands (width 100-150 µm) were stained with voltage-sensitive dye. V_m was measured by optical mapping across the width and at sites of beginning curvature. Field pulses were applied transverse to the strands during the action-potential plateau. For linear strands, V_m contained 1) a rapid passive component (V_m^ar) nearly linear and symmetric across the width, 2) a slower hyperpolarizing component (V_m^as) greater and faster on the anodal side, and 3) at high field strengths a delayed depolarizing component (V_m^ad) greater on the anodal side. For U-shaped strands, V_m at sites of beginning curvature also contained rapid and slow components (V_m^br and V_m^bs, respectively) that included contributions from the linear strand response and from the fiber curvature. V_m^ar, V_m^br, and part of V_m^bs could be attributed to passive behavior that was modeled, and V_m^as, V_m^ad, and part of V_m^bs could be attributed to active membrane currents. Thus curved strands exhibit field responses separable into components with characteristic amplitude, spatial, and temporal signatures.