title: Impact of rapid ventricular pacing during TAVI on microvascular tissue perfusion.
abstract: BACKGROUND
  Rapid ventricular pacing (RVP) is an established technique to temporarily reduce left ventricular output during transcatheter aortic valve implantation (TAVI). The purpose of this study was to evaluate the impact of RVP on microvascular tissue perfusion (MTP) in patients undergoing TAVI.
  
  
  RESULTS
  We studied 42 patients (mean age 81.8 ± 6.9 years, n = 18 females. EuroSCORE 33 ± 12 %) during TAVI. MTP was analyzed using Sidestream-Darkfield imaging, of the sublingual microvasculature. Microvascular flow index (MFI) was continuously measured in small (10-25 μm)- and medium (26-50 μm)-sized vessels, starting 10 s before and ending 12 s after RVP. Further, perfused capillary density, total vessel density and the proportion of perfused vessels were assessed. After a mean RVP duration of 14.3 s (range 6-29), mean arterial pressure decreased from 68 ± 05 to 40 ± 7 mmHg (p < 0.001). This was associated with a significant decrease of MFI in small- and medium-sized vessels from 2.29 ± 0.64 and 2.36 ± 0.6 to 0.87 ± 0.66 (p < 0.001) and 1.0 ± 0.83 (p < 0.001), respectively. MFI remained significantly below baseline values (small: 1.75 ± 0.8, p = 0.001 vs. baseline; medium: 1.77 ± 0.85; p = 0.005 vs. baseline) at 12 s after end of RVP.
  
  
  CONCLUSIONS
  The study demonstrates a time-dependent effect of RVP on microflow, leading to 50 and 25 % of baseline at 8 and 18 s of RVP, respectively. In a substantial proportion of patients, RVP is associated with microcirculatory arrest and a delayed recovery of microflow. Although the impact of these findings on outcome is yet unclear, TAVI operators should be aware of the potentially adverse effects of even short periods of RVP.
authors.affiliation: Department of Internal Medicine I (Cardiology, Angiology, Pneumology), University Hospital Jena, Erlanger Allee 101, 07740, Jena, Germany.
authors.forename: Anna
authors.initials: A
authors.lastname: Selle
authors.forename: Hans R
authors.initials: HR
authors.lastname: Figulla
authors.forename: Markus
authors.initials: M
authors.lastname: Ferrari
authors.forename: Wilma
authors.initials: W
authors.lastname: Rademacher
authors.forename: Bjoern
authors.initials: B
authors.lastname: Goebel
authors.forename: Ali
authors.initials: A
authors.lastname: Hamadanchi
authors.forename: Marcus
authors.initials: M
authors.lastname: Franz
authors.forename: Andrea
authors.initials: A
authors.lastname: Schlueter
authors.forename: Thomas
authors.initials: T
authors.lastname: Lehmann
authors.forename: Alexander
authors.initials: A
authors.lastname: Lauten
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001024:Aortic Valve Stenosis / Q000000981:diagnostic imaging / Q000401:mortality / Q000601:surgery*; D002304:Cardiac Pacing, Artificial / Q000379:methods*; D015331:Cohort Studies; D016001:Confidence Intervals; D015150:Echocardiography, Doppler; D005260:Female; D006350:Heart Valve Prosthesis; D017052:Hospital Mortality; D006801:Humans; D007430:Intraoperative Care / Q000379:methods*; D016015:Logistic Models; D008297:Male; D008833:Microcirculation / Q000502:physiology; D016017:Odds Ratio; D010477:Perfusion; D011379:Prognosis; D012189:Retrospective Studies; D018570:Risk Assessment; D012720:Severity of Illness Index; D016019:Survival Analysis; D065467:Transcatheter Aortic Valve Replacement / Q000379:methods* / Q000401:mortality*; D016896:Treatment Outcome