Characterization of Sympathetic Nerve Activity in Stress Cardiomyopathy

This study has been withdrawn prior to enrollment.
(no enrollment)
Sponsor:
Information provided by:
University of Missouri-Columbia
ClinicalTrials.gov Identifier:
NCT01048125
First received: January 11, 2010
Last updated: January 3, 2013
Last verified: January 2013
  Purpose

Stress (Takotsubo) cardiomyopathy (SC) is a peculiar form of acute, reversible myocardial dysfunction predominantly affecting the apical and mid left ventricular segments. This was originally described in Japan but is increasingly recognized all over the world especially in older women. There is evidence to support that excess sympathetic activation and catecholamine surges are potential mechanisms that cause this temporary myocardial 'stunning'. The amount of catecholamines in circulation of patients with SC was 2 to 3-fold higher when compared to subjects with acute myocardial infarction related equivalent cardiac dysfunction [Wittstein, et al. NEJM, 2005].

In our institution over the last two to three years we have identified more than a dozen patients with stress cardiomyopathy. This diagnosis has been confirmed by echocardiographic documentation of normalization of left ventricular function over a course of few days to weeks. Our overarching goal is to further characterize these individuals with the hope of identifying risk factors and developing strategies to prevent the occurrence of SC in situations where the likelihood in susceptible individuals may be high.


Condition Intervention
Stress-induced (Takotsubo) Cardiomyopathy
Device: Sympathetic Nerve Activity
Behavioral: Mental Stress Test (Color Word Test)
Drug: The Modified Oxford Technique for Baroreflex Sensitivity
Other: Cold Pressor Test
Device: Echocardiographic evaluation

Study Type: Interventional
Study Design: Allocation: Non-Randomized
Endpoint Classification: Safety Study
Intervention Model: Single Group Assignment
Masking: Open Label
Primary Purpose: Basic Science
Official Title: Characterization of Sympathetic Nerve Activity in Stress Cardiomyopathy

Resource links provided by NLM:


Further study details as provided by University of Missouri-Columbia:

Primary Outcome Measures:
  • Identifying risk factors and developing strategies to prevent the occurrence of stress cardiomyopathy in situations where the likelihood in susceptible individuals may be high. [ Time Frame: 2 years ] [ Designated as safety issue: No ]

Enrollment: 0
Study Start Date: August 2009
Estimated Study Completion Date: August 2011
Estimated Primary Completion Date: August 2011 (Final data collection date for primary outcome measure)
Arms Assigned Interventions
Experimental: Study group
Subjects with documented stress cardiomyopathy who would serve as the study group.
Device: Sympathetic Nerve Activity
Resting Sympathetic Nerve Activity
Behavioral: Mental Stress Test (Color Word Test)
A printed word will be shown to the subject, displayed in a color different from the color it actually names. The subject will be asked to say the color that the word is printed in as quickly as possible. For example if the word "green" is written in blue ink, they will say "blue." This mental stress procedure will be used to cause brief changes in heart rate and blood pressure.
Drug: The Modified Oxford Technique for Baroreflex Sensitivity
Sodium nitroprusside (100 µg) will be infused intravenously as a bolus, followed 60 seconds later by a bolus of phenylephrine hydrochloride (150 µg). Infusion of nitroprusside will decrease blood pressure approximately 10-15 mmHg below baseline values. Subsequent phenylephrine infusion will increase blood pressure approximately 10-15 mmHg above baseline values. Nitroprusside and phenylephrine have been used extensively to assess baroreflex sensitivity in healthy as well as heart failure populations. Additionally, the dosages being used have been shown to minimize the risk of excessive decreases or increases in blood pressure.
Other: Cold Pressor Test
The subject will be asked to place their hand in ice water for 2 minutes. This procedure will be used to cause transient changes in sympathetic nerve activity, heart rate and blood pressure.
Device: Echocardiographic evaluation
Transthoracic echocardiography with 2D, color and pulse Doppler will be employed in all of our subjects. Baseline left ventricular function, systolic as well as diastolic, will be quantified.
Active Comparator: Control
Control subjects will be age and sex matched otherwise healthy people with no prior cardiac disease or other severe medical conditions.
Device: Sympathetic Nerve Activity
Resting Sympathetic Nerve Activity
Behavioral: Mental Stress Test (Color Word Test)
A printed word will be shown to the subject, displayed in a color different from the color it actually names. The subject will be asked to say the color that the word is printed in as quickly as possible. For example if the word "green" is written in blue ink, they will say "blue." This mental stress procedure will be used to cause brief changes in heart rate and blood pressure.
Drug: The Modified Oxford Technique for Baroreflex Sensitivity
Sodium nitroprusside (100 µg) will be infused intravenously as a bolus, followed 60 seconds later by a bolus of phenylephrine hydrochloride (150 µg). Infusion of nitroprusside will decrease blood pressure approximately 10-15 mmHg below baseline values. Subsequent phenylephrine infusion will increase blood pressure approximately 10-15 mmHg above baseline values. Nitroprusside and phenylephrine have been used extensively to assess baroreflex sensitivity in healthy as well as heart failure populations. Additionally, the dosages being used have been shown to minimize the risk of excessive decreases or increases in blood pressure.
Other: Cold Pressor Test
The subject will be asked to place their hand in ice water for 2 minutes. This procedure will be used to cause transient changes in sympathetic nerve activity, heart rate and blood pressure.
Device: Echocardiographic evaluation
Transthoracic echocardiography with 2D, color and pulse Doppler will be employed in all of our subjects. Baseline left ventricular function, systolic as well as diastolic, will be quantified.

  Eligibility

Ages Eligible for Study:   21 Years to 90 Years
Genders Eligible for Study:   Both
Accepts Healthy Volunteers:   Yes
Criteria

Inclusion Criteria:

  • Diagnosis of stress cardiomyopathy in the past

Exclusion Criteria:

  • CAD, PCI or CABG
  • Cardiac dysfunction
  • Heart failure
  • Significant arrhythmias
  • Severe COPD
  • Diabetic neuropathy
  • Pregnancy
  Contacts and Locations
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Please refer to this study by its ClinicalTrials.gov identifier: NCT01048125

Locations
United States, Missouri
University of Missouri
Columbia, Missouri, United States, 65212
Sponsors and Collaborators
University of Missouri-Columbia
Investigators
Principal Investigator: Anand Chockalingam, MD University of Missouri-Columbia
  More Information

No publications provided

Responsible Party: Anand Chockalingam, MD, Assistant Professor of Clinical Medicine, University of Missouri
ClinicalTrials.gov Identifier: NCT01048125     History of Changes
Other Study ID Numbers: 1141858
Study First Received: January 11, 2010
Last Updated: January 3, 2013
Health Authority: United States: Institutional Review Board

Additional relevant MeSH terms:
Cardiomyopathies
Takotsubo Cardiomyopathy
Cardiovascular Diseases
Heart Diseases
Ventricular Dysfunction
Ventricular Dysfunction, Left

ClinicalTrials.gov processed this record on October 23, 2014