Characterization of Sympathetic Nerve Activity in Stress Cardiomyopathy

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.

Conditions

• Cardiomyopathy

Interventions

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.

Sponsors & Collaborators

• University of Missouri-Columbia

  lead OTHER

Principal Investigators

• Anand Chockalingam, MD · University of Missouri-Columbia

Study Design

Allocation

NON_RANDOMIZED

Purpose

BASIC_SCIENCE

Masking

NONE

Model

SINGLE_GROUP

Eligibility

Min Age

21 Years

Max Age

90 Years

Sex

ALL

Healthy Volunteers

Yes

Timeline & Regulatory

Start

2009-08-31

Primary Completion

2012-07-31

Completion

2012-07-31

Countries

• United States

Study Locations