Treatment of Reduced Heart Rate Variability Associated With Major Depression With Electroconvulsive Therapy
Condition: Major Depressive Disorder
MeSH terms: Depression; Depressive Disorder; Depressive Disorder, Major
Study type: Observational

Summary: 
      The purpose of this study is to evaluate alterations in sympathetic tone in patients with
      major depression with and without ischemic heart disease and then to reevaluate these
      patients after 8 treatments with electroconvulsive therapy(ECT). We expect to support the
      hypothesis that HRV are pathophysiologically associated with the state of major depression.
      We hypothesize the following:

        1. Heart rate variability (HRV) will be decreased prior to treatment of depression in
           comparison to post-treatment measures of HRV.

        2. After 8 treatments with ECT, HRV will be increased under basal conditions.
    

Detailed description: 
      There is considerable evidence that patients with ischemic heart disease (IHD) and concurrent
      major depression have a less favorable prognosis than patients with IHD alone. Indeed, a
      number of recent studies implicate major depression in the pathophysiologic progression of
      cardiovascular disease as an independent risk factor, rather than a reaction to
      cardiovascular illness. This conclusion is supported by multiple recent studies (Anda et al;
      1993; Markowitz and Matthews, 1991; Musselman et al., 1994, 1995).

      Increased sympathetic tone and subsequent diminished heart rate variability secondary to
      elevated circulating levels of catecholamines provides a possible pathophysiologic link
      between IHD and depression. For example, Carney et al (1988) have established the correlation
      of increased heart rate and decreased heart rate variability (HRV) in patients with major
      depression and IHD. Thus it follows that enhancement of sympathetic tone may be important in
      the independent development of IHD and major depression. The interplay among these systems
      remains to be investigated. The present study seeks to determine the relationship between
      major depression and sympathetic tone.

      The primary objective of the Research Protocol is to determine the effects of major
      depressive disorder (MDD) (see Specific Aim 1), and its treatment, on autonomic function (see
      Specific Aim 2). Twenty-five depressed patients with and 25 depressed patients without a
      history of ischemic cardiovascular disease will be recruited to this study.

      To be determined is whether the exaggerated platelet reactivity and diminished HRV exhibited
      by depressed patients are affected by treatment with ECT. Autonomic function in depressed
      patients will be studied longitudinally before and after ECT. Heart rate variability (HRV) in
      depressed patients who exhibit a therapeutic response to ECT and who exhibited diminished HRV
      prior to treatment will support the hypothesis that HRV are pathophysiologically associated
      with the state of major depression. Successful ECT treatment of depressed mood that is not
      associated with normalization of HRV may indicate that: a) HRV is unrelated to Major
      Depressive Disorder, or b) HRV may reflect a pre-existing "trait" phenomena of major
      depressive disorder, or c) directly improve HRV.
    

Observational model: Cohort
Time perspective: Prospective
Sampling method: Non-Probability Sample
Study population: 
        Patients with major depressive disorder presenting for a course of electroconvulsive
        therapy.
      
Keywords: Major Depressive Disorder; Electroconvulsive Therapy; Platelet Activation