Characterization of Sympathetic Nerve Activity in Stress Cardiomyopathy

NCT ID: NCT01048125

Last Updated: 2016-11-23

Basic Information

• Recruitment Status: TERMINATED
• Clinical Phase: NA
• Total Enrollment: 2 participants
• Study Classification: INTERVENTIONAL
• Study Start Date: 2009-08-31
• Study Completion Date: 2012-07-31

Brief Summary

Stress (Takotsubo) cardiomyopathy (SC) is a peculiar form of acute, reversible myocardial dysfunction predominantly affecting the apical and mid left ventricular segments.

In this institution over the last two to three years the investigators have identified more than a dozen patients with stress cardiomyopathy. The investigators' overarching goal is to 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.

Detailed Description

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 this institution over the last two to three years the investigators 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. The investigators' 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.

Conditions

Cardiomyopathy

Keywords

Stress-induced cardiomyopathy; Takotsubo cardiomyopathy

Study Design

• Allocation Method: NON_RANDOMIZED
• Intervention Model: SINGLE_GROUP
• Primary Study Purpose: BASIC_SCIENCE
• Blinding Strategy: NONE

Study Groups

Study group

Subjects with documented stress cardiomyopathy who would serve as the study group. Sympathetic Nerve Activity; Mental StrCold Pressor Testess Test (Color Word Test); The Modified Oxford Technique for Baroreflex Sensitivity; Cold Pressor Test; Echocardiographic evaluation

Group Type: EXPERIMENTAL

Sympathetic Nerve Activity

Intervention Type: DEVICE

Resting Sympathetic Nerve Activity

Mental Stress Test (Color Word Test)

Intervention Type: BEHAVIORAL

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.

The Modified Oxford Technique for Baroreflex Sensitivity

Intervention Type: DRUG

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.

Cold Pressor Test

Intervention Type: OTHER

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.

Echocardiographic evaluation

Intervention Type: DEVICE

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.

Control

Control subjects will be age and sex matched otherwise healthy people with no prior cardiac disease or other severe medical conditions. Sympathetic Nerve Activity; Mental Stress Test (Color Word Test); The Modified Oxford Technique for Baroreflex Sensitivity; Cold Pressor Test; Echocardiographic evaluation

Group Type: ACTIVE_COMPARATOR

Sympathetic Nerve Activity

Intervention Type: DEVICE

Resting Sympathetic Nerve Activity

Mental Stress Test (Color Word Test)

Intervention Type: BEHAVIORAL

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.

The Modified Oxford Technique for Baroreflex Sensitivity

Intervention Type: DRUG

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.

Cold Pressor Test

Intervention Type: OTHER

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.

Echocardiographic evaluation

Intervention Type: DEVICE

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.

Interventions

Sympathetic Nerve Activity

Resting Sympathetic Nerve Activity

Intervention Type: DEVICE

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.

Intervention Type: BEHAVIORAL

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.

Intervention Type: DRUG

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.

Intervention Type: OTHER

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.

Intervention Type: DEVICE

Other Intervention Names

Sodium Nitroprusside; Phenylephrine hydrochloride

Eligibility Criteria

Inclusion Criteria

• Diagnosis of stress cardiomyopathy in the past

Exclusion Criteria

• Coronary artery disease (CAD), primary coronary intervention (PCI) or coronary artery bypass graft (CABG)
• Cardiac dysfunction
• Heart failure
• Significant arrhythmias
• Severe chronic obstructive pulmonary disease (COPD)
• Diabetic neuropathy
• Pregnancy

• Minimum Eligible Age: 21 Years
• Maximum Eligible Age: 90 Years
• Eligible Sex: ALL
• Accepts Healthy Volunteers: Yes

Sponsors

University of Missouri-Columbia

OTHER

Sponsor Role: lead

Responsible Party

Anand Chockalingam

Professor, Cardiology

Responsibility Role: PRINCIPAL_INVESTIGATOR

Principal Investigators

Anand Chockalingam, MD

Role: PRINCIPAL_INVESTIGATOR

University of Missouri-Columbia

Locations

University of Missouri

Columbia, Missouri, United States

Countries

United States

Other Identifiers

1141858

Identifier Type: -

Identifier Source: org_study_id