Long-term effects of dynamic atrial overdrive pacing on sleep-related breathing disorders in pacemaker or cardioverter defibrillator recipients.

INTRODUCTION: Sleep-related breathing disorders occur in 20-30% of Europeans and North Americans, including 10% of sleep apnea syndrome (SAS). A preliminary study suggested that atrial overdrive pacing with a fixed heart rate might alleviate SAS. However, it is not known whether dynamic atrial overdrive pacing alleviates SAS. METHODS: Patients with indications for a dual chamber pacemaker or implantable cardioverter-defibrillator (ICD) were screened for SAS using the Pittsburgh Sleep Quality Index (PSQI) questionnaire. If PSQI was >5, cardio-respiratory polygraphy was performed before and 4 and 7 months after device implantation. Patients were randomized to algorithm ON-OFF (group A) or OFF-ON (group B) and the apnea-hypopnea index (AHI) was measured. RESULTS: Out of 105 consecutive patients, 46 (44%) had a positive PSQI. This analysis included 12 patients (mean age = 61 +/- 10 years, body mass index 28.9 +/- 6.5 kg/m(2), left ventricular ejection fraction = 38.3 +/- 13.6%; 10 men). All patients suffered from obstructive or mixed SAS. There were no significant differences in PSQI or AHI between baseline and follow-up or between the two study groups. Therefore, the study was terminated ahead of schedule. CONCLUSIONS: The prevalence of obstructive or mixed SAS was high in pacemaker or ICD recipients and reduced left ventricular ejection fraction. In these patients, long-term dynamic atrial overdrive pacing using did not improve PSQI or SAS. Therefore, patients with relevant obstructive or mixed SAS should not be offered atrial pacing therapy.

High impact of depression in heart failure: early diagnosis and treatment options.

Depressive syndromes in chronic heart failure (CHF) are common and are associated with a poorer prognosis, particularly with increased morbidity and mortality. CHF as a severe physical disorder may increase the risk of developing depressive syndromes or vice-versa as an interaction of possible common psycho-organic etiological aspects. Depression in CHF is associated with impaired NYHA status and daily activities, resulting in enhanced hospitalisation rates and medical costs with a great impact on long-term health. Only a fraction of comorbid patients receives antidepressants. Therefore, identification of risk factors and prevention by optimizing cardiological and psychiatric therapeutic strategies appear essential for these patients. Early diagnosis and treatment of both CHF and depression may prevent further pathophysiological effects on the heart and brain. This review gives a comprehensive overview of the occurrence, risk factors and shared pathophysiology of depression in CHF, and focuses on improving insufficient diagnosis and therapy of depression. Special attention is given on the cardiac effects of psychopharmacological and alternate non-pharmacological antidepressant therapy in CHF. Recommendations are made for treating depression in CHF patients for a better prevention of this disabling physical and psychosocial condition.