None listed
Conditions
Brief summary
Cardiac amyloidosis is a significant health issue associated with high rates of heart failure and heart rhythm issues, including the need for pacemaker devices. Up to 40% of patients with cardiac amyloidosis need a heart pacemaker at some point, but the best heart rate to set the pacemaker at is not established. In similar conditions, higher heart rate pacemaker settings have been shown to be safe but also improve heart function, symptoms and exercise tolerance. Heart MRI (magnetic resonance imaging) is a technique widely used to understand the mechanisms and changes in flow in many heart conditions and we believe this is the best technique available to study heart function in response to different heart rates. Unlike most medical imaging methods, MRI does not use radiation but instead used magnetic fields and radiofrequency waves to produce images of the internal structure of the human body. We propose to assess MRI findings of heart flow and function at three different pacing heart rates to determine which heart rate provides the best possible heart output.
Interventions
Prospective pilot study of cardiac pacing augmented myocardial dynamics in patients with transthyretin cardiac amyloidosis. The study includes enrolment then two site study visits and a final phone call at 1 year. During the first visit a patient will undergo clinical assessment with physical examination, quality of life survey, 6 minute walk test, electrocardiogram (ECG), echocardiogram and cardiac magnetic resonance imaging (CMR) at three different pacing rates, assessing the cardiac response
Prospective pilot study of cardiac pacing augmented myocardial dynamics in patients with transthyretin cardiac amyloidosis. The study includes enrolment then two site study visits and a final phone call at 1 year. During the first visit a patient will undergo clinical assessment with physical examination, quality of life survey, 6 minute walk test, electrocardiogram (ECG), echocardiogram and cardiac magnetic resonance imaging (CMR) at three different pacing rates, assessing the cardiac response to each heart rate. Cardiac device pacing rate will then be set to the individually optimised pacing rates as per CMR for one month. The second visit at one month will include brief physical examination, quality of life survey, 6 minute walk test, electrocardiogram (ECG), echocardiogram. Cardiac devices will be interrogated to confirm the heart rate paced during the prior intervention period and reprogrammed to their original settings. Patients will receive a brief follow up phone call at 1 year.
Sponsors
St Vincent's Hospital Sydney
Study design
Allocation
Non-randomised trial
Primary purpose
Treatment
Masking
Open (masking not used)
Eligibility
Sex/Gender
All
Age
18 Years to No maximum
Healthy volunteers
No
Inclusion criteria
• People who meet diagnostic criteria for transthyretin cardiac amyloidosis • Cardiac implantable electronic device (pacemakers or defibrillator) which is MRI compatible. • Underlying native heart rate of 60 beats per minute or less. • Willingness to give written informed consent and willingness to participate to and comply with the study.
Exclusion criteria
• Patients with any contraindications for CMR imaging including: o Patients with previous allergy to gadolinium. o Patients with a history of significant renal impairment (eGFR< 30ml/min/1.73m2). o Patients who are medically unstable. o Patients with claustrophobia. o Cardiac pacemakers or implantable cardioverter defibrillator not deemed to be MRI compatible. o Pregnancy or lactating. o Orbital foreign bodies from metal injury to the eye. o Intracranial metal clips. o Non-MRI compatible stapes implants. o Programmable Hydrocephalus Shunts. o Large metal implants. • Patients with a history of a psychological illness or condition such as to interfere with the patient's ability to understand the requirements of the study.
Outcome results
None listed