Ignite Creation Date:
2024-05-05 @ 6:32 PM
Last Modification Date:
2024-10-26 @ 9:34 AM
Study NCT ID:
NCT00504647
Status:
UNKNOWN
Last Update Posted:
2007-07-20
First Post:
2007-07-18
Brief Title:
Biventricular Pacing in Hypertrophic Cardiomyopathy
Sponsor:
University Hospital Birmingham
Organization:
University Hospital Birmingham
Study Overview
Official Title:
Diastolic Ventricular Interaction and the Effects Of Biventricular Pacing in Hypertrophic Cardiomyopathy
Status:
UNKNOWN
Status Verified Date:
2007-07
Last Known Status:
RECRUITING
Delayed Posting:
No
If Stopped, Why?:
Not Stopped
Has Expanded Access:
False
If Expanded Access, NCT#:
N/A
Has Expanded Access, NCT# Status:
N/A
Acronym:
None
Brief Summary:
Hypertrophic Cardiomyopathy is an inherited condition characterized by thickening hypertrophy of the heart muscle Many patients who have this condition have a reduced ability to exercise because of breatlessness which can in some cases be severe This appears in most cases to be due to an impairment of the filling of the heart especially on exercise this limits the amount of blood the heart is able to pump Several factors may contribute to this slow filling of the heart including 1 The heart contracts and relaxes in an incoordinate way called dyssynchrony which is inefficient and 2 The filling of the main pumping chamber the left ventricle may be impeded by high pressure in the other ventriclethe right ventricle- in other words the left ventricle is squashed by the right ventricle This is known as diastolic ventricular interaction
Although drugs can improve the filling of the heart and relieve symptoms some patients remain very symptomatic despite these drugs
The mechanisms responsible for the filling abnormality in patients with Hypertrophic Cardiomyopathy are similar to those seen in the much more common condition known as Heart Failure A special type of pacemaker technique called Biventricular Pacing has been shown to markedly improve symtoms in patients with heart failure This form of pacing has been shown to improve both dyssynchrony incoordination and ventricular interaction squashed left heart in patients with Heart Failure
We propose that Biventricular pacing may similarly improve these abnormalities in patients with Hypertrophic Cardiomyopathy resulting in an improvement of symptoms The study will focus on patients with the condition who have severe symtoms despite being on optimal currently available drug therapy
Although drugs can improve the filling of the heart and relieve symptoms some patients remain very symptomatic despite these drugs
The mechanisms responsible for the filling abnormality in patients with Hypertrophic Cardiomyopathy are similar to those seen in the much more common condition known as Heart Failure A special type of pacemaker technique called Biventricular Pacing has been shown to markedly improve symtoms in patients with heart failure This form of pacing has been shown to improve both dyssynchrony incoordination and ventricular interaction squashed left heart in patients with Heart Failure
We propose that Biventricular pacing may similarly improve these abnormalities in patients with Hypertrophic Cardiomyopathy resulting in an improvement of symptoms The study will focus on patients with the condition who have severe symtoms despite being on optimal currently available drug therapy
Detailed Description:
SUBJECTS Forty Participants who fufil the entry criteria will be selected These Participants will be recruited from Cardiomyopathy clinics run at two sites These are the Cardiomyopathy Clinics at the Heart Hospital University College London and from the Queen Elizabeth Hospital Birmingham
CONSENT Written informed consent will be obtained from all participants
CLINICAL ASSESSMENT
A History will be taken and a Clinical Examination will be carried out A validated Quality of life questionaire will be completed Minnesota Living with Heart Failure
Maximal Cardiopulmonary exercise testing will be performed on a treadmill with breath by breath respiratory gas sampling using a face mask
A 12 lead ECG will be obtained 48hr Ambulatory Heart Rhythm Monitoring
CARDIAC ULTRASOUND SCAN ASSESSMENT
To assess the function of the Heart during its contraction and filling phases including the degree of incoordination of the Heart muscle
PACEMAKER IMPLANTATION
A pacemaker capable of Biventricular pacing will be implanted using a standard established technique at one of three sites The Heart Hospital London St Peters Hospital Chertsey or Queen Elizabeth Hospital Birmingham
24hr POST PACEMAKER IMPLANT Assessment of mechanical dyssynchrony will be made using Ultrasound techniques which will include 2D M mode Echocardiography Doppler studies and Tissue doppler imaging This assessment will be made with the Pacemaker off and in Left and Right heart pacing mode
HAEMODYNAMIC STUDIES
These will be carried out approximately two weeks following pacemaker implantation
The test will involve Nuclear Heart Scans Gated Equilibrium Radionuclide Ventriculography and Acute Volume Unloading of the right and left heart chambers
This will be carried out at the University Of Birmingham Department of Cardiovascular Sciences We shall apply these techniques while the heart is paced in four different modes
The nuclear heart scan is a method by which we can measure the volume of the left heart chamber The study will involve the placement of small needle into a vein of the patients forearm Through this we will inject a primer which will make participants red blood cells very sticky After twenty minutes we will take a blood sample from the same needle This sample of blood will be mixed with a radioactive tracer The tracer will be re-injected through the same needle into the participants vein This tracer will allow us to measure the amount of blood inside the chambers of the participants heart with a special camera a gamma camera The pictures will be taken with the participants lying on a bed throughout
The bed we will ask participants to lie on is called a Lower Body Negative Pressure Bed When lying on this bed the participants legs will be inside a see through plastic dome A belt will be placed around the participants waist in order to create an airtight seal around their legs The bed is attached to a vacuum that allows us to create a low pressure environment around participants legs This causes blood to pool inside the veins of participants legs This leads to Acute Volume unloading of the right and left heart chambers
Once participants have received the injection of the radioactive tracer and are lying comfortably in the Lower Body Negative Pressure Bed we will then take measurements of the amount of blood in the participants heart We shall do this using the special camera
We shall take measurements with the pacemaker in its four different pacemaker modes and then repeat these measurements but this time with a low pressure environment produced around participants legs in order to reduce the pressure on your heart The test is painless apart from mild discomfort from placing one needle at the beginning The whole test will take between one and one and half hours
The method of administration has been performed safely by our team for a number of years now
After a 1 hour break the Participants will do Exercise component of the Nuclear Heart Scan This component of the study will involve no further doses of radiation and no new needles
Participants will be asked to lie semi-erect on an exercise bed for up to 90 minutes The exercise will be in the form of a pedal bike The pacemaker will be programmed into four different modes of heart pacing Whilst in each mode participants will be asked to exercise to three different stages of exercise Each stage will last 4 minutes The levels of difficulty will be worked out from a treadmill exercise test completed by the participants prior to the pacemaker implantation Participants will be allowed to rest between each stage of exercise If participants complete the whole study they will have cycled for a total of 48 minutes During each stage 4ml of blood will be taken from the needle that will have been placed in a vein during the earlier part of the study
During each stage of exercise an image of the heart will be taken with the gamma camera as done earlier in the study
From these measurements we will be able to calculate the effect of the different pacing modes on the ability of the heart to pump blood on exercise
Participants are free to stop the exercise at any time they feel they cannot continue
RANDOMISATION AND FOLLOW UP Following pacemaker implant pressure studies and Ultrasound assessment participants will be randomized in a double blind fashion to have their pacemaker programmed to either one of the following 1 Pacemaker Off mode 2 Left and Right Heart chamber pacemaker mode The Participants will be paced in that specific mode for four months before repeat Clinical and Cardiac Ultrasound assessments The mode of pacing will then be changed and maintained for a further four months before repeat Clinical and Ultrasound assessment The pacing mode will be randomly selected but no pacing mode will be repeated in any one participant The participant and the member of the research team performing the Clinical and Ultrasound assessment of the participant shall be blinded to the pacemaker mode
CONSENT Written informed consent will be obtained from all participants
CLINICAL ASSESSMENT
A History will be taken and a Clinical Examination will be carried out A validated Quality of life questionaire will be completed Minnesota Living with Heart Failure
Maximal Cardiopulmonary exercise testing will be performed on a treadmill with breath by breath respiratory gas sampling using a face mask
A 12 lead ECG will be obtained 48hr Ambulatory Heart Rhythm Monitoring
CARDIAC ULTRASOUND SCAN ASSESSMENT
To assess the function of the Heart during its contraction and filling phases including the degree of incoordination of the Heart muscle
PACEMAKER IMPLANTATION
A pacemaker capable of Biventricular pacing will be implanted using a standard established technique at one of three sites The Heart Hospital London St Peters Hospital Chertsey or Queen Elizabeth Hospital Birmingham
24hr POST PACEMAKER IMPLANT Assessment of mechanical dyssynchrony will be made using Ultrasound techniques which will include 2D M mode Echocardiography Doppler studies and Tissue doppler imaging This assessment will be made with the Pacemaker off and in Left and Right heart pacing mode
HAEMODYNAMIC STUDIES
These will be carried out approximately two weeks following pacemaker implantation
The test will involve Nuclear Heart Scans Gated Equilibrium Radionuclide Ventriculography and Acute Volume Unloading of the right and left heart chambers
This will be carried out at the University Of Birmingham Department of Cardiovascular Sciences We shall apply these techniques while the heart is paced in four different modes
The nuclear heart scan is a method by which we can measure the volume of the left heart chamber The study will involve the placement of small needle into a vein of the patients forearm Through this we will inject a primer which will make participants red blood cells very sticky After twenty minutes we will take a blood sample from the same needle This sample of blood will be mixed with a radioactive tracer The tracer will be re-injected through the same needle into the participants vein This tracer will allow us to measure the amount of blood inside the chambers of the participants heart with a special camera a gamma camera The pictures will be taken with the participants lying on a bed throughout
The bed we will ask participants to lie on is called a Lower Body Negative Pressure Bed When lying on this bed the participants legs will be inside a see through plastic dome A belt will be placed around the participants waist in order to create an airtight seal around their legs The bed is attached to a vacuum that allows us to create a low pressure environment around participants legs This causes blood to pool inside the veins of participants legs This leads to Acute Volume unloading of the right and left heart chambers
Once participants have received the injection of the radioactive tracer and are lying comfortably in the Lower Body Negative Pressure Bed we will then take measurements of the amount of blood in the participants heart We shall do this using the special camera
We shall take measurements with the pacemaker in its four different pacemaker modes and then repeat these measurements but this time with a low pressure environment produced around participants legs in order to reduce the pressure on your heart The test is painless apart from mild discomfort from placing one needle at the beginning The whole test will take between one and one and half hours
The method of administration has been performed safely by our team for a number of years now
After a 1 hour break the Participants will do Exercise component of the Nuclear Heart Scan This component of the study will involve no further doses of radiation and no new needles
Participants will be asked to lie semi-erect on an exercise bed for up to 90 minutes The exercise will be in the form of a pedal bike The pacemaker will be programmed into four different modes of heart pacing Whilst in each mode participants will be asked to exercise to three different stages of exercise Each stage will last 4 minutes The levels of difficulty will be worked out from a treadmill exercise test completed by the participants prior to the pacemaker implantation Participants will be allowed to rest between each stage of exercise If participants complete the whole study they will have cycled for a total of 48 minutes During each stage 4ml of blood will be taken from the needle that will have been placed in a vein during the earlier part of the study
During each stage of exercise an image of the heart will be taken with the gamma camera as done earlier in the study
From these measurements we will be able to calculate the effect of the different pacing modes on the ability of the heart to pump blood on exercise
Participants are free to stop the exercise at any time they feel they cannot continue
RANDOMISATION AND FOLLOW UP Following pacemaker implant pressure studies and Ultrasound assessment participants will be randomized in a double blind fashion to have their pacemaker programmed to either one of the following 1 Pacemaker Off mode 2 Left and Right Heart chamber pacemaker mode The Participants will be paced in that specific mode for four months before repeat Clinical and Cardiac Ultrasound assessments The mode of pacing will then be changed and maintained for a further four months before repeat Clinical and Ultrasound assessment The pacing mode will be randomly selected but no pacing mode will be repeated in any one participant The participant and the member of the research team performing the Clinical and Ultrasound assessment of the participant shall be blinded to the pacemaker mode
Study Oversight
Has Oversight DMC:
None
Is a FDA Regulated Drug?:
None
Is a FDA Regulated Device?:
None
Is an Unapproved Device?:
None
Is a PPSD?:
None
Is a US Export?:
None
Is an FDA AA801 Violation?:
None