PubMed Health⌕ Search
Home/Archive/PubMed

PubMed · 10709224

How to program rate responsive pacemakers.

E M Greco·S Guardini·M Ferrario·S Romano
View original source ↗Export metadata ↓

Abstract

Because oxygen uptake (VO2) increases linearly with heart rate during exercise, the oxygen pulse reserve (OPR) method (VO2 reserve divided by heart rate reserve) may provide a valid guide for rate responsive parameter tailoring. Using custom-made software (Pacing Rate Profile Software [PRPS]) it is possible to predict the exercise pacing rate profile with significant accuracy, according to the patient's functional class when ergospirometry apparatus is not available for a cardiopulmonary stress test (CPX). PRPS for Windows is based on the OPR method and some known workload/metabolic cost of exercise relationships during effort. The present study had two aims; first, to evaluate the reliability of PRPS in accurately predicting pacing rate profiles; and second, the suitability of activity and metabolic rate responsive sensors in supplying pacing rates sufficiently near to those predicted using CPX or PRPS. To test the reliability of PRPS we studied 244 patients, NYHA Class I-II, under two different stress test protocols. In one, the bicycle protocol (25 W, 2-minute steps), we tested 137 normal patients (94 men and 43 women, mean age 67 +/- 15 years). Sixty-eight of these were simultaneously CPX tested. PRPS predicted pacing rates were matched against the patients' sinus rhythms or their theoretical CPX measured VO2 heart rates (OPR method). Linear regression analysis was highly significant (r = 0.93 and r = 0.97, respectively). The other, the treadmill protocol, consisted of three different protocols. (1) Speed Incremental Treadmill Stress Test (SITST): 57 patients underwent CPX (33 men and 24 women, mean age 67 +/- 15 years, NYHA Class I-II). All had been pacemaker implanted for SSS and/or advanced atrioventricular block (AVB). PRPS pacing rates were matched against CPX VO2 OPR calculated heart rates (r = 0.93), (linear regression analysis). (2) CAEP: 30 patients underwent CPX (26 men and 4 women, mean age 61 +/- 11 years, NYHA Class I-II). Thirteen of them had been pacemaker implanted for SSS and/or advanced AVB. In all 30 patients the PRPS rates were matched against CPX VO2 calculated rates (r = 0.90). In the 17 normal nonimplanted patients, the PRPS rates were also matched against sinus rhythms, (r = 0.80). (3) Weber: 20 patients underwent CPX (16 men and 4 women, mean age 68 +/- 8 years, NYHA Class I-II). As above, in six normal nonimplanted patients, statistical analysis between PRPS rates and sinus rhythms was performed (r = 0.89). The comparison between PRPS theoretical pacing rates and VO2 predicted rates in all 20 patients was also statistically significant (r = 0.93). Finally, to test the reliability of PRPS also in NYHA Class III-IV patients, we tested 22 implanted patients (15 men and 7 women, mean age 70 +/- 9 years) and compared PRPS predicted rates against VO2 CPX measured rates (r = 0.92). To determine if the wide variety of RR pacers were able to supply pacing rates near to those predicted, whether by means of CPX or PRPS, we studied a total of 89 patients: 49 of these (26 men and 23 women, mean age 66 +/- 12 years) had been implanted with activity sensors; 12 patients (11 men and one woman, mean age 70 +/- 7 years) had been implanted with metabolic sensors, and finally 28 patients (19 men and 9 women, mean age 70 +/- 12 years) had been implanted with dual sensors (activity + QT or minute ventilation). Linear regression analysis showed r = 0.93 for activity sensors, r = 0.94 for metabolic sensors, and r = 0.92 for dual sensor. In conclusion, when rate responsive pacing causes symptoms or functional impairment, physicians must provide a personalized rate response tailoring derived from precise, simple physiological testing. OPR is an easy physiological method for tailoring rate response settings, suitable for activity and metabolic sensors. When ergospirometry apparatus is not available, PRPS can successfully replace CPX testing for tailoring.

Explore related subjects

AgedCardiac Pacing, ArtificialExercise TestFemaleHumansLinear ModelsMaleOxygen ConsumptionPacemaker, ArtificialReproducibility of ResultsSoftwareComparative StudyJournal Article

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

E M Greco, S Guardini, M Ferrario, S Romano. 2000. How to program rate responsive pacemakers.. https://doi.org/10.1111/j.1540-8159.2000.tb00797.x

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related citations

PubMed2026

Prognostic Value of Blood-Based P-Tau217 Levels for Progression to Cognitive Impairment.

IMPORTANCE: Blood-based biomarkers for Alzheimer disease, particularly plasma phosphorylated tau 217 (p-tau217), accurately reflect early Alzheimer disease brain pathology in cognitively unimpaired individuals, but estimates of absolute risk of progression to cognitive impairment across multiple cohorts are needed. OBJECTIVE: To estimate absolute risk of progression to cognitive impairment and rates of cognitive decline based on plasma p-tau217 across cognitively unimpaired older adults. DESIGN, SETTING, AND PARTICIPANTS: Longitudinal cohort study using harmonized data from 2684 cognitively unimpaired older adults (defined within cohort) across 6 observational and clinical trial cohorts based in North America, Japan, and Australia. The earliest enrollment was in 2004, with most recent follow-up in 2025. EXPOSURE: Baseline plasma p-tau217. MAIN OUTCOMES AND MEASURES: The primary outcome was time to progression to cognitive impairment (mild cognitive impairment, dementia, or 2 consecutive global Clinical Dementia Rating scores ≥0.5). The secondary outcome was longitudinal change on the latent Preclinical Alzheimer Cognitive Composite (PACC; higher values indicate better performance). RESULTS: Among the 2684 participants (median [IQR] age, 69.6 [66.2-74.2] years; 1697 [63%] female), there were 478 events of progression to cognitive impairment over a median follow-up of 5.4 years (maximum follow-up of 13.5 years). Each 1-SD increase in baseline p-tau217 level was associated with an increased risk of progression to cognitive impairment (hazard ratio, 1.38 [95% CI, 1.30-1.46]), and the association remained significant after adjustment, including β-amyloid positron emission tomography scan Centiloids (hazard ratio, 1.32 [95% CI, 1.24-1.41]). Participants with high (1.1-2.4 SD) and very high (>2.5 SD) baseline p-tau217 had 24% (95% CI, 20%-28%) and 38% (95% CI, 33%-43%) absolute risk of progression over 5 years, respectively, and risk was markedly higher over 10 years, although longer-term estimates were constrained by limited data. Elevated p-tau217 was also associated with faster cognitive decline based on change in latent PACC score. Among the overall sample, baseline latent PACC scores ranged from -0.8 to 2.7. The 5-year annualized decline for the very high p-tau217 group was -0.07 latent PACC units/y (95% CI, -0.10 to -0.05), relative to 0.03 units/y (95% CI, 0.02-0.04) in the low p-tau217 group. CONCLUSIONS AND RELEVANCE: In a pooled sample of multiple selected cohorts of cognitively unimpaired older adults, higher plasma p-tau217 levels were consistently associated with increased risk of clinical progression and accelerated cognitive decline. By providing time-specific absolute risk estimates, these findings support the potential of p-tau217 for prognostic model development, with direct implications for future trial design. Further validation in unselected populations is needed to inform individual prognosis and clinical decision-making in cognitively unimpaired individuals.

Aged↗
PubMed2026

Lifestyle, anthropometric factors and clinically significant prostate cancer diagnosis in men with suspected prostate cancer.

OBJECTIVE: Lifestyle and anthropometric factors may influence prostate cancer (PCa) risk, yet evidence remains inconclusive. This study reports the associations between lifestyle and anthropometric factors and clinically significant PCa (csPCa; ISUP grade > 1) among men with clinical suspicion of PCa. MATERIALS AND METHODS: In this registered (NCT06116851), single-institution, prospective cohort trial, men referred for PCa diagnostics due to elevated prostate-specific antigen or abnormal digital rectal examination were included. Subjects underwent prostate diagnostics and completed detailed surveys of lifestyle, medical and family history. Physical activity was measured using a triaxial accelerometer. Anthropometric assessments included body mass index, waist circumference and magnetic resonance imaging-based body composition analyses. RESULTS: Among 298 included men, 143 (48%) were diagnosed with csPCa. In multivariate logistic regression, higher physical activity, measured by step count (odds ratio [OR]: 0.91, 95% confidence interval [CI]: 0.82-0.99) and active smoking compared to never-smokers (OR: 0.38, 95% CI: 0.14-0.96) were inversely associated with detection of csPCa. Higher prostate-specific antigen density was associated with increased risk (OR: 1.78, 95% CI: 1.39-2.35). Body composition was not associated with csPCa. Study strengths include comprehensive data collection. Primary limitation is partial reliance on self-reported data. CONCLUSIONS: Higher measured physical activity was inversely associated with detection of csPCa in men with suspicion of PCa. Active smoking also showed an inverse association. Both findings merit further investigation.

Aged↗
PubMed2026

Oral and gut microbiota profiles in patients with locally advanced rectal cancer with varying responses to neoadjuvant chemoradiotherapy.

Recent research has focused on gut bacteria in colorectal cancer, but the influence of other microbiota, including oral and nonbacterial gut microbiota, on treatment efficacy remains insufficiently explored. This study aimed to investigate their relationship with the efficacy of neoadjuvant chemoradiotherapy (nCRT) in locally advanced rectal cancer (LARC). Saliva and fecal samples were collected from patients with LARC before treatment. Shotgun metagenomic sequencing was used to profile bacterial, archaeal, eukaryotic, and viral taxonomic groups and to examine oral and gut microbial functions. An artificial intelligence-based prediction model was developed by integrating oral and gut microbiome data with clinical information. Statistical analyses compared diversity and response-associated microbial features between responders and non-responders to nCRT. Response-associated differences were observed in bacterial and nonbacterial taxonomic profiles and in oral and gut microbial functional profiles. In the internal test subset, the integrated analysis yielded an observed AUC of 0.917. Given the small cohort and the exploratory comparison of candidate classifiers, this estimate requires confirmation in larger, independent cohorts. Baseline oral and gut microbiome profiles were associated with response to nCRT. Integrating microbiome and clinical features showed potential for response prediction, but the model remains exploratory and requires validation in larger, independent cohorts before clinical application. Retrospectively registered on 01/08/2026, NCT07346729.

Aged↗