DDDRP pacing with a new system for AT therapy was safe and associated with successful pace-termination of AT in 53% of episodes. Preventive pacing and atrial ATP algorithms represent two new functions that can be implemented safely into pacemaker systems for nonpharmacologic treatment of ATs in patients requiring pacemaker therapy.
The Type D personality pattern, consisting of negative affectivity and social inhibition, has been shown by Denollet et al. to predict adverse prognosis in patients with coronary heart disease. For measuring the Type D characteristics, Denollet has devised the 14 item Type D scale (DS14). In the present study, this instrument was translated into German. The validity, reliability and adequacy of the German DS14 were then tested in 2421 persons, including cardiological and psychosomatic patients as well as healthy factory workers. The results document sound psychometric properties of the scale. Cronbach's alpha was 0.87 for the negative affectivity subscale and 0.86 for social inhibition. The two-factor structure of the original instrument could be clearly replicated. The prevalence rates of the Type D pattern were lowest in cardiological patients (25 %) and highest in psychosomatic patients (62 %). The prevalence in this German sample of cardiology patients was also lower than the one observed in healthy factory workers (32.5 %) and in CHD samples reported in the literature. These group differences could not be accounted for by differences in age and sex distribution. In conclusion, the DS14 is a valid and reliable instrument that can be used for an economic evaluation of the Type D characteristics in patients and healthy persons. The possible meaningfulness of the low Type D prevalence in cardiac patients and the prognostic relevance of this pattern require further study.
The defects underlying the impairment of systolic pump function in human dilated cardiomyopathy (DCM) are not known. We isolated mitochondrial particles from 10 hearts of transplant recipients with DCM and from nine normal hearts not used for transplantation. Yield was similar in both groups (2.77 vs 2.81 mg mitochondrial protein per gram heart). Cytochrome content (difference spectrophotometry) was found reduced in DCM mitochondria, e.g. cytochrome c was 0.295 +/- 0.06 in the DCM group and 0.371 +/- 0.04 mumol g-1 in the control group (P less than 0.05). Enzymatic activity of the cytochrome-containing complexes III (3.77 +/- 0.82 vs 4.95 +/- 1.15 mumol min-1.mg-1) and IV (2.63 +/- 0.96 vs 3.65 +/- 0.6 mumol min-1.mg-1) of the respiratory chain was reduced in the DCM group (P less than 0.05). Complex IV, the cytochrome c oxidase, in the DCM group showed impaired activity also in whole heart homogenates (0.173 +/- 0.04 vs 0.258 +/- 0.8 mumol min-1.mg-1). Subunit composition of the cytochrome c oxidase on sodium dodecyl sulphate-gel electrophoresis did not differ between DCM and normal hearts. Activity of complexes II and V of the respiratory chain, not containing cytochromes, was unchanged in DCM mitochondria compared with the control group. The present data show a decrease in cytochrome content and in cytochrome-dependent enzyme activity in human dilated cardiomyopathy. Further studies are necessary to clarify whether these findings are specific for dilated cardiomyopathy or whether they are epiphenomena of failing hearts.
Background: An alert algorithm, based on intrathoracic impedance monitoring, has been incorporated into a cardiac resynchronisation device (CRT) to detect pulmonary fluid accumulation, and to audibly alert patients to decompensating chronic heart failure (CHF). Aims: To evaluate this algorithm, alert events were correlated with changes in NT-proBNP concentration and CHF status. Methods and results: In a prospective observational study of 62 patients (89% male, aged 67 ± 1 year), NT-proBNP plasma concentrations, clinical CHF status, and device data were collected at enrolment, during regular follow-up and at device alerts. Over a mean follow-up of 27 ± 2 weeks, pooled data indicated a weak, but significant inverse relationship between relative changes in intrathoracic impedance and NT-proBNP (r = −0.3; p b 0.001). In 52 device alerts from 35 patients, NT-proBNP increased by 66 ± 19% from 2039 ± 331 pg/ml (p b 0.001). The increase in NT-proBNP was higher in alerts with clinical signs of CHF deterioration (n = 30, 89 ± 25%; p b 0.001) than in alert events without clinical signs (n = 22, 25 ± 15%; p =n.s.). Conclusion: Intrathoracic impedance based alert events are associated with a significant increase in NT-proBNP concentration. These data indicate that intrathoracic impedance monitoring might facilitate the outpatient management of CHF patients with implanted CRT devices.
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