for (i = 0; i <= av_len(padn); ++i) {
    HE *hent;
    SV **nameptr = av_fetch(padn, i, 0);
    if (nameptr != NULL && SvPOKp(*nameptr)) {
        SV **field;
        U32 len;
        const char *name = SvPV(*nameptr, len);

        if ((field = hv_fetch(hvn, name, len, 0)) != NULL) {
            /* do something interesting with *field */
        }
    }
}