Cardiovascular Effects of Selective I(f)-Channel Blockade

March 18, 2009 updated by: Hannover Medical School

Einfluss Selektiver I(f)-Blockade Auf Orthostase-Toleranz Und Sympathikusaktivität Bei Gesunden

The study compares three treatment modalities in a human model of Postural orthostatic tachycardia syndrome (POTS): beta-blockers, I(f)-blockers, and placebo.

Study Overview

Status

Unknown

Conditions

Intervention / Treatment

Detailed Description

Elevated heart rate may lead to cardiac disease in the long-term. Therefore, drugs lowering heart rate are useful. Beta-blockers are an established treatment modality. They not only lower heart rate but also contractility, which might be undesirable in certain tachycardic disorders.

Postural orthostatic tachycardia syndrome (POTS) patients complain about dizziness, weakness, headache, lightheadedness, fatigue, nausea, and presyncope. In some patients there is elevated heart rate even during supine rest. In POTS patients it is preferable to lower heart rate without reducing cardiac contractility which can be achieved by using so-called I(f)-blockers. Thus, they might be superior to beta-blockers in POTS.

In our study, we artificially generate POTS in healthy male subjects for about 48 hours. We want to compare the cardiovascular effects and orthostatic tolerance of the following treatments: beta-blocker, I(f)-blocker, and placebo.

Moreover, we will quantify changes in cardiovascular autonomic regulation brought about by I(f)-blockade versus placebo.

Study Type

Interventional

Enrollment (Anticipated)

40

Phase

  • Phase 2

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • Germany
      • Berlin, Germany, 13125
        • Recruiting
        • Franz-Volhard Centrum für Klinische Forschung
        • Contact:
          • Heidrun Mehling, MD
          • Phone Number: 94171296 +49(0)30
      • Hannover, Germany, 30625
        • Recruiting
        • Medizinische Hochschule Hannover
        • Contact:
          • Jens Tank, MD
          • Phone Number: 5322723 +49(0)30
        • Contact:
          • Karsten Heusser, MD
          • Phone Number: 5322723 +49(0)30

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

18 years to 40 years (Adult)

Accepts Healthy Volunteers

No

Genders Eligible for Study

Male

Description

Inclusion Criteria:

  • healthy male
  • age 18-40 years
  • BMI: 18-30 kg/m²
  • arterial blood pressure <=160/100 mm Hg
  • co-operativity
  • voluntariness

Exclusion Criteria:

  • conditions in which treatment might be ineffective or insecure
  • co-medication within the last 4 weeks
  • participation in another clinical trial within the last 4 weeks
  • unability to understand the study's aim
  • drug or alcohol abuse
  • secondary hypertension
  • creatinine > 130 μM (1.47 mg/dl)
  • GOT/GPT > 2 times normal
  • GGT > 3 times normal
  • contraindications against reboxetine, beta-blocker, ivabradine
  • asthma, psoriasis
  • diabetes
  • heart failure (NYHA III or IV)
  • coronary artery disease
  • peripheral occlusive disease
  • cerebrovascular disease
  • ventricular extrasystoles (Lown III-V)
  • atrial fibrillation
  • resting heart rate <60/min
  • neurologic/psychiatric disorder
  • pulmonary hypertension
  • dysthyroid metabolism

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Basic Science
  • Allocation: Randomized
  • Interventional Model: Crossover Assignment
  • Masking: Double

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Placebo Comparator: 3
Placebo
Drug: Placebo
matching appearance
Active Comparator: 1
beta-blocker
Drug: beta-blocker (Metoprolol)
Metoprolol 95 mg once per day
Experimental: 2
I(f)-blocker
Drug: I(f)-blocker (ivabradine)
ivabradine 7.5 mg once per day

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Time Frame
Sub-study 'Orthostatic tolerance': Change in heart rate after 20 mins of passive orthostasis. Sub-study 'Sympathetic system': arterial pressure related heart rate
Time Frame: 12-18 hours
12-18 hours

Secondary Outcome Measures

Outcome Measure
Time Frame
'Orthostatic tolerance': Hemodynamics during head-up tilt. Time to presyncope.
Time Frame: 12-18 hours
12-18 hours
'Sympathetic system': Muscle sympathetic nerve activity (MSNA).
Time Frame: 12-18 hours
12-18 hours

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Hannover Medical School

Collaborators

Charite University, Berlin, Germany

Investigators

  • Study Director: Jens Jordan, MD, Hannover Medical School

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start

November 1, 2008

Primary Completion (Anticipated)

November 1, 2010

Study Completion (Anticipated)

December 1, 2010

Study Registration Dates

First Submitted

March 18, 2009

First Submitted That Met QC Criteria

March 18, 2009

First Posted (Estimate)

March 19, 2009

Study Record Updates

Last Update Posted (Estimate)

March 19, 2009

Last Update Submitted That Met QC Criteria

March 18, 2009

Last Verified

March 1, 2009

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • CCB-CRC-07-02

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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