The Effect of Right Ventricular Pacing on Myocardial Oxidative Metabolism and Efficiency

Bradycardia Clinical Trial

Official title:

The Effect of Right Ventricular Pacing on Myocardial Oxidative Metabolism and Efficiency

Clinical Trial Details — Status: Completed

Administrative data

• NCT number: NCT00704093
• Other study ID #: 2442007§149
• Status: Completed
• Phase: N/A
• First received: June 23, 2008
• Last updated: July 3, 2008
• Start date: January 2008
• Est. completion date: June 2008

Study information

• Verified date: July 2008
• Source: University of Turku
• Contact: n/a
• Is FDA regulated: No
• Health authority: Finland: Ethics Committee
• Study type: Interventional

Clinical Trial Summary

Right ventricular (RV) apical pacing induces a left bundle branch block (LBBB) type electrical activation sequence in the heart. This abnormal activation pattern of the ventricles may have detrimental effects on cardiac structure and function. RV pacing has been shown to impair left ventricular (LV) function both in normal and failing hearts. Importantly, it has been demonstrated that this deterioration in LV function is related to the presence of LV dyssynchrony during RV pacing.

The exact effects of RV pacing on myocardial perfusion, oxidative metabolism and cardiac efficiency have not been fully elucidated. The objective of the present study is to evaluate the effect of RV pacing on both global and regional oxidative metabolism and perfusion, and myocardial efficiency. In addition, the effect of RV pacing induced LV dyssynchrony on myocardial oxidative metabolism and efficiency will be studied.

Our hypothesis is that LV dyssynchrony during RV pacing results in regional abnormalities in LV perfusion and oxidative metabolism. LV dyssynchrony will also result in altered myocardial efficiency.

Description:

Right ventricular (RV) apical pacing induces a left bundle branch block (LBBB) type electrical activation sequence in the heart. This abnormal activation pattern of the ventricles may have detrimental effects on cardiac structure and function. Several clinical trials have demonstrated an association between RV pacing and an increased risk of heart failure and death. In addition, RV pacing has been shown to impair left ventricular (LV) function both in normal and failing hearts. Importantly, it has been demonstrated that this deterioration in LV function is related to the presence of LV dyssynchrony during RV pacing.

The exact effects of RV pacing on myocardial perfusion, oxidative metabolism and cardiac efficiency have not been fully elucidated. Importantly, the relation between the presence of LV dyssynchrony during RV pacing and changes in myocardial perfusion, oxidative metabolism and cardiac efficiency has not been studied.

Ten patients with normal LV ejection fraction and VVI/DDD pacemaker will be studied during AAI-pacing/sinus rhythm without RV pacing (pacing-OFF) and with RV-pacing (pacing-ON) at the same heart rate. Dynamic [15O]water and [11C]acetate positron emission tomography is used to measure perfusion and oxidative metabolism (kmono) of the LV. An echocardiographic examination is used to assess LV stroke volume (SV) and LV dyssynchrony.

The PET data will be first analyzed based on RV pacing mode only, comparing the two pacing conditions (pacing-ON vs. pacing-OFF). Thereafter, the study population will be divided into two groups, according to the presence of LV dyssynchrony during RV pacing.

Recruitment information / eligibility

• Status: Completed
• Enrollment: 10
• Est. completion date: June 2008
• Est. primary completion date: June 2008
• Accepts healthy volunteers: No
• Gender: Both
• Age group: 18 Years and older

Eligibility

Inclusion Criteria:

• Informed consent

• Age over 18 years

• Previously implanted permanent pacemaker (DDD or VVI)

• Normal left ventricular function

Exclusion Criteria:

• Pacemaker dependency

• Symptomatic coronary artery disease

• Pregnancy

Study Design

Endpoint Classification: Efficacy Study, Intervention Model: Single Group Assignment, Masking: Single Blind (Investigator), Primary Purpose: Basic Science

Related Conditions & MeSH terms

• Bradycardia

Intervention

Device:
• Right ventricular pacing
Right ventricular pacing vs. sinus rhythm or atrial pacing at the same rate

Locations

Country	Name	City	State
Finland	Turku PET Centre	Turku

Sponsors (2)

Lead Sponsor	Collaborator
University of Turku	Leiden University Medical Center

Country where clinical trial is conducted

Finland, 

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	myocardial perfusion, oxidative metabolism and efficiency		At baseline and at 2 hours	No