Variations of heart rate variability parameters prior to the onset of ventricular tachyarrhythmia and sinus tachycardia in ICD patients. Results from the heart rate variability analysis with automated ICDs (HAWAI) registry.

The HAWAI registry evaluated the role of heart rate variability in predicting the occurrence of ventricular tachycardia and fibrillation (VT/VF) and sinus tachycardia in patients with an implantable cardioverter-defibrillator (45 patients with 155 RR recordings). A significant decrease of the mean value of all RR intervals (MeanNN) was observed in the period starting 20 and 40 min prior to VT/VF and sinus tachycardia, respectively. The standard deviation of RR intervals (SDNN) and the power at low frequency (LF) were the only parameters with significant changes prior to VT/VF. For sinus tachycardia, the root mean square of successive differences of all successive RR intervals (r-MSSD) and the power at low and high frequency (HF) decreased, whereas SDNN and the power at very low frequency increased. Comparison of RR recordings preceding VT/VF and sinus tachycardia revealed significant differences of the MeanNN, SDNN, r-MSSD, LF and HF. Based on a classification and regression tree analysis, MeanNN, SDNN and r-MSSD showed a sensitivity of 94.4% and a specificity of 50.6% as predictors of VT/VF. Our results suggest that the temporal changes in heart rate before an arrhythmic event can be used to predict the occurrence of VT/VF. These parameters may be used to optimize pacing therapies designed to prevent VT/VF recurrences as well as for improving device-based discriminators for VT/VF and sinus tachycardia.

[Pseudoexfoliation syndrome. Clinical and statistical studies]. / Pseudo-Exfoliations-Syndrom. Klinisch-statistische Untersuchungen.

Between July 1, 1980 and December 31, 1982, out of 26 825 patients treated in both the outpatient and inpatient departments at the University Eye Clinic of Erlangen-Nürnberg, 107 (i.e., 0.4%) were found to have pseudo-exfoliation syndrome. In 51 cases only one eye was affected, in 56 cases both. Of these patients 49 were male and 58 female. They were between 54 and 89 years old, the average age being 73.2 years. In 61.3% of the cases the initial symptom was ocular hypertension. In about 75% the most important finding on slit-lamp examination, with the pupil undilated, was atrophy of the pupillary margin. A central disc was only seen in 39.3%, while the peripheral band was present in all cases. Fistulating operations had to be performed in 43 out of 100 cases diagnosed as having capsular glaucoma. This corresponds to 18.5% of all fistulating procedures performed for primary chronic open-angle glaucoma.