Risk factors associated with the development of osteoradionecrosis (ORN) in Head and Neck cancer patients in Ireland: A 10-year retrospective review.

BACKGROUND AND PURPOSES: To assess osteoradionecrosis (ORN) incidence in a population of Irish Head and Neck cancer (HNC) patients, and assess precipitating factors that may contribute to ORN development to aid prevention. MATERIALS AND METHODS: Review of 1050 HNC patients attending the Dental Oncology Clinic, CUDSH between 2010 and 2021 identified 47 cases of ORN. Medical, dental and radiotherapy records of these forty-seven patients were retrospectively reviewed. Patient-, tumour-, and treatment-related variables were investigated in association with osteoradionecrosis development. Analysis conducted using SPSS, Pearson's Chi-square test (p < 0.05), and ordinal regression model. RESULTS: ORN incidence was 4.4 %. Median time from radiotherapy (RT) to ORN development was 9.5 months (range 1-98.5 months). ORN development within the mandibular surgical site was significant (p <.001), presenting at a higher Notani grade (p =.002), in mid-mandibular body region (p =.028), at radiation doses ≥ 60 Gy (p =.035), due to induced causes (p =.029), and without resolution (p =.019). CONCLUSION: This is the first retrospective study of ORN in HNC patients in Ireland over 10-year period. ORN incidence was extremely low (4.4%). As patients reported high smoking/alcohol use and poor dental attendance pre-diagnosis, this suggests intensive dental intervention pre/post-diagnosis contributed to low ORN rates. Mandibular surgery pre-RT increased risk of developing ORN at the surgical site. Therefore, we recommend future treatment planning should contour the surgical site, designating it an organ at risk (OAR), assigning a dose constraint, where oncologically possible, with emphasis on reducing the hot-spot to this region; findings reinforce importance of life-long expert dental care to reduce ORN incidence.

Effect of ß-blockers on triggering of symptomatic atrial fibrillation by anger or stress.

BACKGROUND: Anger and stress can trigger episodes of atrial fibrillation (AF) in patients with a history of AF. OBJECTIVE: The purpose of this study was to determine whether ß-blockers can protect against emotionally triggered AF. METHODS: In this prospective, controlled, electronic diary-based study of emotions preceding AF, patients with a history of paroxysmal or persistent AF (N = 91) recorded their rhythm on event monitors at the time of AF symptoms and completed a diary entry querying mood states (eg, anger and stress) for the preceding 30 minutes (pre-AF "case period") for 1 year. Also, patients underwent monthly 24-hour Holter monitoring during which they were prompted to complete a diary entry twice per hour. Diaries recorded during sinus rhythm comprise controls. Patients' exposure to each emotion was compared between the pre-AF case period and control periods by using generalized estimating equation modeling, as well as interactions between ß-blocker use and emotion tested. RESULTS: Sixty percent were prescribed ß-blockers. A total of 163 symptomatic AF episodes (in 34 patients) and 11,563 Holter-confirmed sinus rhythm control periods had associated diary data. Overall, the likelihood of an AF episode was significantly higher during anger or stress. This effect, however, was significantly attenuated in patients on ß-blockers (odds ratio 22.5; 95% confidence interval 6.7-75.4, P < .0001 for patients not prescribed ß-blockers vs odds ratio 4.0, 95% confidence interval 1.7-9.5, P = .002 for those prescribed ß-blockers; P = .02 for the interaction). Exclusion of patients on sotalol did not affect findings. CONCLUSION: Anger or stress can trigger AF, but use of ß-blockers greatly attenuates this deleterious physiological response.

Cumulative stress and autonomic dysregulation in a community sample.

Whether cumulative stress, including both chronic stress and adverse life events, is associated with decreased heart rate variability (HRV), a non-invasive measure of autonomic status which predicts poor cardiovascular outcomes, is unknown. Healthy community dwelling volunteers (N = 157, mean age 29 years) participated in the Cumulative Stress/Adversity Interview (CAI), a 140-item event interview measuring cumulative adversity including major life events, life trauma, recent life events and chronic stressors, and underwent 24-h ambulatory ECG monitoring. HRV was analyzed in the frequency domain and standard deviation of NN intervals (SDNN) calculated. Initial simple regression analyses revealed that total cumulative stress score, chronic stressors and cumulative adverse life events (CALE) were all inversely associated with ultra low-frequency (ULF), very low-frequency (VLF) and low-frequency (LF) power and SDNN (all p < 0.05). In hierarchical regression analyses, total cumulative stress and chronic stress each was significantly associated with SDNN and ULF even after the highly significant contributions of age and sex, with no other covariates accounting for additional appreciable variance. For VLF and LF, both total cumulative stress and chronic stress significantly contributed to the variance alone but were not longer significant after adjusting for race and health behaviors. In summary, total cumulative stress, and its components of adverse life events and chronic stress were associated with decreased cardiac autonomic function as measured by HRV. Findings suggest one potential mechanism by which stress may exert adverse effects on mortality in healthy individuals. Primary preventive strategies including stress management may prove beneficial.

Slow QT interval adaptation to heart rate changes in normal ambulatory subjects.

BACKGROUND: Clinical formulas for QT correction utilize instantaneous HR. We showed previously that longer-term HR affects QT duration. We extend these findings, identifying more accurate models of QT behavior. METHOD: Multiple models of QT dependence on HR were tested in 2 independent populations. Holter recordings were analyzed in population A (healthy volunteers, n = 14, 6 males, age 26.9 ± 12.3 yr). The hypotheses generated in population A were tested in an independent group population B, healthy volunteers, n = 15, 9 males, age 52.9 ± 15.6 yr). Linear models of QT interval dependence on a weighted average of RR intervals in the preceding 3 minutes were compared to models based on the immediately preceding RR interval (instantaneous HR). RESULTS: In population A, linear models based on RR intervals over the preceding minute performed better than the best nonlinear model based on the single RR interval immediately preceding the QT interval. Linear models including HR values preceding the QT interval by more than 60 s further improved model fit. This model hierarchy was confirmed in population B. Linear formula for QT correction based on exponential decay of HR effect with 60 s time constant outperformed Bazett and Fridericia formulas in both populations. CONCLUSIONS: QT duration in normal ambulatory subjects is affected by noninstantaneous HR, including HR history dating back more than 60 s. Exponential decay of this "memory effect" with time constant of 1 minute provides an accurate description of QT adaptation. This may be of clinical importance when HR is not steady.