Cardiac Sympathetic Activity in Patients With the Apical Ballooning Syndrome

Study Overview
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Brief Summary
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Our hypothesis is that altered cardiac sympathetic activity is present and may contribute to the myocardial stunning observed in the apical ballooning syndrome. Aim: Assess the extent and reversibility of cardiac adrenergic neuronal dysfunction using carbon-11 hydroxyephedrine (C-11 HED), a positron emission tomography (PET) tracer, in patients with the apical ballooning syndrome.

Detailed Description
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General methods: Five patients will undergo PET scans within a few days of or during the initial hospital admission for apical ballooning syndrome and during follow-up at 4 to 6 weeks to evaluate regional perfusion using N-13 ammonia and cardiac sympathetic activity with C-11 HED. PET scanning protocol On the morning of the study, patients will arrive at the Mayo Clinic PET Imaging Center in a fasting state. The use of medications will be ascertained and recorded. An intravenous cannula will be placed in each arm. The subject will then be positioned in the PET scanner . After optimal positioning of the left ventricle within the field of view, a transmission scan will be performed with either a germanium-68 or CT source for subsequent attenuation correction. The PET scanning sequence is outlined below. Because 11C-HED uptake is dependent on flow characteristics, a flow study will be performed using N-13 ammonia. N-13 ammonia (10 to 20 mCi) will be injected over 20 seconds, and dynamic acquisition will be performed for 20 minutes with the following sequence:16 frames at 3 seconds, 10 frames at 12 seconds, and 2 frames at 240 seconds. Following a 50-minute period of N-13 ammonia decay, 11C-HED (20mCi) will be injected over 30 seconds, and a dynamic acquisition will be performed with the following sequence: 6 frames at 30 seconds, 2 frames at 60 seconds, 2 frames at 150 seconds, 2 frames at 300 seconds, 2 frames at 600 seconds, and 1 frames at 1,200 seconds. To correct for 11C-metabolites in the blood activity, venous samples will be drawn at 0, 1, 5, 10, 20, 40, and 60 minutes (total  25 ml of blood) after the injection of C-11 HED. Heart rate, systemic blood pressure, and a 12-lead electrocardiogram will be obtained noninvasively with each peak isotope activity.

Official Title
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Cardiac Sympathetic Activity in Patients With the Apical Ballooning Syndrome

Conditions
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Apical Ballooning Syndrome

Intervention / Treatment
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* Procedure: PET scan


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Transient akinesis or dyskinesis of the left ventricular apical and mid-ventricular segments with regional wall-motion abnormalities extending beyond a single epicardial vascular distribution. Absence of obstructive coronary disease or angiographic evidence of acute plaque rupture. New electrocardiographic abnormalities (either ST-segment elevation or T-wave inversion. Absence of recent significant head trauma, intracranial bleeding, pheochromocytoma, myocarditis, hypertrophic cardiomyopathy. Exclusion Criteria: Hemodynamically unstable patients (requiring pressor support) will be excluded. Breastfeeding women. Pregnant women (urine pregnancy test required within 48 hours prior to each set of PET scans.

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Intervention Model: Single Group Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: 1<br>The subject will then be positioned in the PET scanner . After optimal positioning of the left ventricle within the field of view, a transmission scan will be performed with either a germanium-68 or CT source for subsequent attenuation correction. | Procedure: PET scan<br>* The subject will then be positioned in the PET scanner . After optimal positioning of the left ventricle within the field of view, a transmission scan will be performed with either a germanium-68 or CT source for subsequent attenuation correction.<br>* Other names: Positron emission scan;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Assess the extent and reversibility of cardiac adrenergic neuronal dysfunction |  | During PET scan | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Ventricular Remodeling