Search

Modern dual chamber ICD systems are able to overcome various sensing problems. However, improvement of their performance is still required. The aim of this study was to assess the sensing function in 101 consecutive patients (84 men, 17 women; mean age 63 +/- 12 years; mean follow-up 24 +/- 4 months) implanted with dual chamber defibrillators and integrated (IB) or dedicated bipolar (DB) lead systems. Follow-up data were analyzed for the presence of ventricular oversensing. Oversensing occurred in 25 (25%) patients, significantly more frequent in patients implanted with IB compared to DB lead systems (21/52 vs 4/49, P = 0.0002). Patients with cardiomyopathies (CMs) were more prone to sensing malfunctions than patients with no CM (12/30 vs 13/71, P = 0.04). T wave oversensing (n = 14), respirophasic ventricular oversensing (n = 4), and P wave oversensing (n = 6) were the most common pitfalls of ventricular sensing. P wave oversensing was unique to the IB lead system. CT scans performed in these patients disclosed the position of the RV coil to be proximal to the tricuspid area. Four patients received inappropriate ICD shocks due to oversensing. In all but two patients who received lead revision, oversensing was resolved by noninvasive means. In conclusion: (1) ventricular oversensing is a common problem occurring in up to 25% of patients with dual chamber ICDs; (2) P wave oversensing is a ventricular sensing problem affecting function of 11% of dual chamber devices with IB lead systems; (3) IB leads are significantly more susceptible to T wave and P wave oversensing than DB leads; and (4) patients with cardiomyopathies are more prone to oversensing than patients with other heart diseases. [ABSTRACT FROM AUTHOR]

Background: Despite successful resuscitation with return of spontaneous circulation (ROSC), the prediction of survival in patients suffering out-of-hospital cardiac arrest (OHCA) remains difficult. Several studies have shown alterations in sublingual microcirculation in the critical ill. We hypothesized that early alterations in sublingual microcirculation may predict short-term survival after OHCA., Methods: We prospectively included all adults admitted to our university hospital between April and September 2019 with ROSC following OHCA. Sidestream dark-field microscopy to obtain sublingual microcirculation was performed at admission and after 6, 12 and 24 hours. Primary outcome was survival until discharge., Results: Twenty-five patients were included. Six hours after ROSC, the proportion of perfused small vessels (PPV small ) was lower in non-survivors than in survivors (85 ± 7.9 vs. 75 ± 6.6%; p = .01). PPV small did not correlate with serum lactate. Stratification for survival with cutoff values >78.4% for PPV small 6 h post-admission and <5.15 mmol/l for initial serum lactate as suggested by ROC-Analyses results in a positive predictive value of 100% and a negative one of 67% for our study population., Conclusion: Estimating short-term prognosis of OHCA patients with ROSC may be supported by measuring the PPV small at the sublingual microcirculation 6 hours after admission., (© 2021 The Authors. Microcirculation published by John Wiley & Sons Ltd.)