Biomedical subjects

M Dayer

Publications and source records attributed to M Dayer.

4 recordsLinked to original sources

PubMed2006

A high prevalence of sleep disordered breathing in men with mild symptomatic chronic heart failure due to left ventricular systolic dysfunction.

BACKGROUND: Sleep disordered breathing (SDB) is common in severe chronic heart failure (CHF) and is associated with increased morbidity and mortality. The prevalence of SDB in mild symptomatic CHF is unknown. AIM: The aim of this study was to determine the prevalence and characteristics of SDB in male patients with NYHA class II symptoms of CHF. METHODS AND RESULTS: 55 male patients with mild symptomatic CHF underwent assessment of quality of life, echocardiography, cardiopulmonary exercise, chemoreflex testing and polysomnography. 53% of the patients had SDB. 38% had central sleep apnoea (CSA) and 15% had obstructive sleep apnoea. SDB patients had steeper VE/VCO(2) slope [median (inter-quartile range) 31.1 (28-37) vs. 28.1 (27-30) respectively; p=0.04], enhanced chemoreflexes to carbon dioxide during wakefulness [mean+/-sd: 2.4+/-1.6 vs. 1.5+/-0.7 %VE Max/mmHg CO(2) respectively; p=0.03], and significantly higher levels of brain natriuretic peptide and endothelin-1 compared to patients without SDB. No differences in left ventricular ejection fraction, percent predicted peak oxygen uptake, or symptoms of SDB were observed. CONCLUSIONS: A high prevalence of SDB was found in men with mild symptomatic CHF. Patients with SDB could not be differentiated by symptoms or by routine cardiac assessment making clinical diagnosis of SDB in CHF difficult.

Aged↗

PubMed2006

Can heart rate variation rule out sleep-disordered breathing in heart failure?

In patients with obstructive sleep apnoea (OSA), the very low frequency power spectral density index (VLFI) derived from analysis of heart rate correlates with the severity of obstructive apnoeas. VLFI is also associated with Cheyne-Stokes respiration/central sleep apnoea (CSR/CSA) in congestive heart failure (CHF). The present authors have tested the hypothesis that per cent VLFI, derived from a standard Holter ECG recording, can be used to detect the presence of OSA and CSR/CSA in patients with mild-to-moderate CHF. In total, 60 CHF patients underwent polysomnography with monitoring of heart rate. Data from 33 patients were analysed for per cent VLFI. Of the 60 patients, 27 were excluded due to atrial fibrillation, extensive pacing or frequent ventricular extra systoles. Receiver operator characteristic curves were constructed to establish the per cent VLFI that would optimally identify the presence or absence of sleep-disordered breathing. Using an apnoea-hypopnoea index>20 events.h-1 and setting the per cent VLFI at 2.23% yielded a sensitivity of 85%, specificity of 65%, positive predictive value of 61% and a negative predictive value of 87%. The latter increased to 100% when using an apnoea-hypopnoea cut-off of 30 events.h-1. In conclusion, these results suggest that spectral analysis of heart rate may be useful as a "rule-out test" for sleep-disordered breathing in patients with mild-to-moderate congestive heart failure.

Female↗

PubMed2004

General medicine.

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Anti-Inflammatory Agents, Non-Steroidal↗

PubMed1993

The reliability and validity of two HIV-specific health-related Quality-of-Life measures: a preliminary analysis.

OBJECTIVE: To evaluate the reliability and validity of two HIV-specific Quality-of-Life (QoL) questionnaires in a UK sample. METHOD: Subjects were 99 HIV-seropositive gay men (23 were asymptomatic, 41 were asymptomatic, 35 had AIDS). QoL was measured using two HIV-specific QoL questionnaires. MEASURES: An adaptation of the Medical Outcomes Study questionnaire and a self-completion version of the Health-Related Quality-of-Life Questions. Affect was measured using the Hospital Anxiety and Depression (HAD) Scale. Disease measures included Centers for Disease Control and Prevention (CDC) stage, and CD4 and CD8 cell count. RESULTS: Both QoL instruments showed good internal reliability on all scales used. Many of the scales, particularly those related to physical health and functional performance, showed significant correlations with CD4 cell count and other measures of disease progression. Measures of physical health showed a deterioration in QoL as disease progressed from asymptomatic disease to AIDS. In contrast, most subscales purporting to measure psychological aspects of QoL did not correlate significantly with measures of disease progression, nor was there any difference between CDC stages. Subjects' global ratings of QoL were most strongly correlated with the HAD depression scale, although there were also significant correlations with most other QoL scales. CONCLUSION: This study provides further evidence for the reliability and validity of two HIV-specific QoL questionnaires in a wider range of disease stages than hitherto reported and raises issues relevant to the practical use of QoL scales in HIV disease.

CD4 Antigens↗