Transvenous pacing by way of a left superior vena cava.
D006801:Humans; D008297:Male; D008875:Middle Aged; D010138:Pacemaker, Artificial / Q000009:adverse effects*; D013350:Subclavian Vein; D013927:Thrombosis / Q000209:etiology; D014683:Vena Cava, Superior / Q000002:abnormalities*