Characterization of Sympathetic Nerve Activity in Stress Cardiomyopathy - Full Text View

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:

MedlinePlus related topics: Cardiomyopathy Stress

U.S. FDA Resources

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.

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

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
Heart Diseases

Cardiovascular Diseases
Ventricular Dysfunction, Left
Ventricular Dysfunction

ClinicalTrials.gov processed this record on May 22, 2013