Atrial Fibrillation, Heart Failure, Ventricular Tachycardia
Conditions
Keywords
Endocardial pacing, Multi site pacing
Brief summary
We are investigating ways to help patients with heart failure, which is caused by damaged hearts which function less well, and cause symptoms of breathlessness, fatigue, lack of energy and swelling. Cardiac Resynchronisation Therapy (CRT) pacemakers are used to improve the pumping function of the main heart chamber in certain suitable people with heart failure. CRT requires a pacemaker with 2 wires, one placed inside the right heart chamber and one normally placed on the outside of the left heart chamber. These two wires act together to re-time the coordination of the heartbeat, which is known to improve heart function. The investigators are assessing whether they might be able to improve heart function even more by placing two wires on the inside of the left heart chamber, rather than one around the outside. The investigators wish to assess whether: 1. Using two wires within the left side of the heart gives a greater increase in heart function than one. 2. It is possible to choose the best spot inside of the heart by measuring the pattern of the heart beat. 3. Is it possible to use a different type of heart monitor placed outside the body instead of a monitor wire inside the heart to assess improvement in heart function? They are investigating this in people with hearts that beat less effectively than normal.
Interventions
PROCEDUREAtrial Fibrillation/flutter (AF) or Ventricular Tachycardia (VT) ablation with multi-site pacing protocol
Pacing at several endocardial sites in isolation and individually will be performed, with response to this assessed by LV dp/dt max
Sponsors
Oxford University Hospitals NHS Trust
Study design
Allocation
NA
Intervention model
SINGLE_GROUP
Primary purpose
BASIC_SCIENCE
Masking
NONE
Eligibility
Sex/Gender
ALL
Age
60 Years to 85 Years
Healthy volunteers
No
Inclusion criteria
* Participant is willing and able to give informed consent for participation in the study. * Male or Female, aged 60 years or above. * Having a suitable Atrial Fibrillation/flutter or Ventricular Tachycardia ablation procedure * Evidence of abnormal Left Ventricular structure and function, as shown by Left Ventricular ejection fraction of less than 40%
Exclusion criteria
* Severe peripheral vascular disease (that would make arterial access more risky) * Haemodynamic instability (such that a longer procedure is inadvisable)
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Acute Haemodynamic Response to Dual Left Ventricular Pacing | Mean of multiple recordings in each patient as detailed above | Acute haemodynamic response to pacing (change in Left Ventricular dP/dt max) between dual site Left Ventricular pacing and biventricular pacing Pacing protocols were performed with a baseline of 30 seconds of right ventricular pacing followed by two 30-second test configurations, and then a further baseline. The pacing configurations were tested, in a randomized order, 3 times each. Electrophysiology catheters were positioned at the right ventricular mid septum for baseline pacing, and at the left ventricular septum and at the left ventricular lateral wall, at the site of latest electrical activation i identified from a left ventricular electrical activation map This provided two single-site left ventricular pacing configurations, which could be combined to allow right ventricular and left ventricular lateral (Biventricular pacing) and left ventricular septal and left ventricular lateral (dual left ventricular pacing) |
Countries
United Kingdom
Participant flow
Participants by arm
| Arm | Count |
|---|---|
| Participants Having an ablation procedure with access to the left side of the heart
Atrial Fibrillation/flutter (AF) or Ventricular Tachycardia (VT) ablation with multi-site pacing protocol: Pacing at several endocardial sites in isolation and individually will be performed, with response to this assessed by LV dp/dt max | 15 |
| Total | 15 |
Baseline characteristics
| Characteristic | Participants |
|---|---|
| Age, Continuous | 68 years STANDARD_DEVIATION 7 |
| Ischaemic aetiology of left ventricular dysfunction | 12 Participants |
| Left ventricular ejection fraction | 27 % STANDARD_DEVIATION 8 |
| Region of Enrollment United Kingdom | 15 participants |
| Sex: Female, Male Female | 0 Participants |
| Sex: Female, Male Male | 15 Participants |
Adverse events
| Event type | EG000 affected / at risk |
|---|---|
| deaths Total, all-cause mortality | — / — |
| other Total, other adverse events | 0 / 15 |
| serious Total, serious adverse events | 1 / 15 |
Outcome results
Primary
Acute Haemodynamic Response to Dual Left Ventricular Pacing
Acute haemodynamic response to pacing (change in Left Ventricular dP/dt max) between dual site Left Ventricular pacing and biventricular pacing Pacing protocols were performed with a baseline of 30 seconds of right ventricular pacing followed by two 30-second test configurations, and then a further baseline. The pacing configurations were tested, in a randomized order, 3 times each. Electrophysiology catheters were positioned at the right ventricular mid septum for baseline pacing, and at the left ventricular septum and at the left ventricular lateral wall, at the site of latest electrical activation i identified from a left ventricular electrical activation map This provided two single-site left ventricular pacing configurations, which could be combined to allow right ventricular and left ventricular lateral (Biventricular pacing) and left ventricular septal and left ventricular lateral (dual left ventricular pacing)
Time frame: Mean of multiple recordings in each patient as detailed above
| Arm | Measure | Value (MEAN) |
|---|---|---|
| Participants | Acute Haemodynamic Response to Dual Left Ventricular Pacing | 3.7 % difference |
Comparison: The data derived from this study was complex multi-level data with errors due to patient-level and intra-patient repeat factors. Accordingly, we used generalized multi-level modelling (GLMM) with random effects.p-value: <0.0595% CI: [1, 6.3]Mixed Models Analysis