title: Development of an echocardiographic method for choosing the best fitting single-pass VDD lead.
abstract: To achieve stable single-lead VDD pacing, a selection of the electrode with the optimal distance between the lead tip and the floating atrial dipole (AV distance [AVD]) is important. The authors hypothesized that the size of the right heart chambers may affect atrial sensing, and that measurement of their internal dimension at end-diastole (RHIDd) in the apical four chamber view by transthoracic echocardiography may aid in choosing the proper AVD. Twenty-six consecutive cases that had undergone VDD pacer implantation using the conventional chest X ray were examined retrospectively by the echocardiographic method. The chest x-ray method properly selected a lead with optimal atrial sensing, defined as minimum P wave amplitude > or = 1.0 mV, for only 20 (77%) of 26 patients. By comparing these results with their respective RHIDd, a cut-off point of 13 cm was obtained that indicated a criterion for choosing the proper AVD. The indication was that if the RHIDd was > or = 13 cm, a lead with an AVD of 15.5/16 cm should have been used; if the RHIDd was < 13 cm, a lead with an AVD of 13/13.5 cm should have been chosen. Using the echocardiographic method, all six patients who had suboptimal atrial sensing could be identified and classified as having missized (four undersized; two oversized) permanent leads. In conclusion, the described method provides a promising preoperative assessment of the best fitting electrode length in single lead VDD pacing. A prospective study is ongoing to verify its applicability.
authors.affiliation: Heart Center, Cheng-Hsin General Hospital and the National Yang-Ming University, School of Medicine, Taipei, Taiwan. chinfung@dreamer.com.tw
authors.forename: Wei-Hsian
authors.initials: WH
authors.lastname: Yin
authors.forename: Hsu-Lung
authors.initials: HL
authors.lastname: Jen
authors.forename: Meng-Cheng
authors.initials: MC
authors.lastname: Chiang
authors.forename: Yi-Cheng
authors.initials: YC
authors.lastname: Chuang
authors.forename: Chung-Yi
authors.initials: CY
authors.lastname: Chang
authors.forename: Mason Shing
authors.initials: MS
authors.lastname: Young
authors.forename: Jeng
authors.initials: J
authors.lastname: Wei
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002304:Cardiac Pacing, Artificial / Q000379:methods*; D004452:Echocardiography / Q000379:methods*; D004567:Electrodes, Implanted; D005260:Female; D006321:Heart / Q000033:anatomy & histology* / Q000000981:diagnostic imaging; D006331:Heart Diseases / Q000000981:diagnostic imaging*; D006801:Humans; D008297:Male; D008875:Middle Aged; D011859:Radiography