ATRIAL FIBRILLATION
Search on thrombocytopenia
on drug edoxaban. Types of stroke. Original paper with tables.
Maybe Section 7 (Sources of Evidence) in Nice-Edoxaban for other AF associations for in depth info on Physiology of AF
F-Patient Info leaflet Also treatment for venous embolisms
F-Global Study to assess the safety and efficacy of Edoxaban
Opthalmic surgery
Vaccine shingles and pneumonia and Edoxaban
Query - can HR adversely efefct ventricules? If not very sympotomatic pre-ablation is it case that could have a greater AF burden after?
Query - vagus manoeuvre
No reversal agent (for bleeds for Edoxaban
No interaction with fludrocortisone in BNF
Coffee
Cholesterol
Side-effects -dizzy, sick, d vision mentioned in one place.
Exercise-It's as if heart wasn't matching greater demands for the exercise when running. Tried many times but didn't get beyond a few minutes. (Originally, used to have trouble running around football pitch. Stopped at that time and haven't got back but thought may have been due to reducing fludrocortisone and low BP, but may not be. Systolic low and not much difference between it and diastolic - don't know if this means low cardiac output ( see AF folder HeartStructAndFunction) Im AF the heart cannot pump enough blood into the lower chambers and out to the rest of the body and this can affect cardiac output.)
I think of catheter ablation as being a treatment that addresses the cause ratjher than the effects of AF. and drugs as addressing the effects. In the video 'What are the treatment options (https://heartrhythmalliance.org/afa/uk/treatments/laser-balloon-ablation) he does it similarly but divides trreatments into controlling heart rate or irregularity and throws antiarrythmic drugs that control the the irregularity as well as catheter ablation into the causal side (cos preventing the irregularity in the first place, tho not addressing the cause of it in my view) and allots the rate controlling drugs such as beta blockers (maybe digoxin, and later if do not work a pacemaker (where atria disconnected from bottom chambers allowing them to be regular)) to treatments that address the complications of AF, Think Anti-coag also fall into this category (needed because clots can form due to reduced coordination of the flow of blood through the heart -till 8 yrs ago done mainly by Warfarin . NOACs are amongst the most effective treatments across any medical condition, across the whole of medicine, not just cardiology. Anyway like this in general cos confirms some of way the way I see it. Also points out that treatments (cath ablation, anti-arrythmic drugs not perfect cos older you get the more difficult to control the rythym - because of this treatment then focusses on managing the irregularity with drugs that manage the heart rate (which he says often lessens the problem even tho the irregularity is there (but in my case not really speed a problem and not sure in what sense it lessens the problem otherwise). Also this is an argument for doing ablation earlier before get too old or the arrythmia become too persistent and especially before heart remodelling starts to happen.
Dr Kelland - video (see link above) Catheter ablation to removove triggers .
Cather ablation:
Invasive procedure where trying to remove the triggers and alter the substarate within heart to inc p of maintaining Sinus rhythym. They isolate PVs to remove triggers causing the AF, and if necessary do further ablation - all with hope of maintaining SR. After tests such as ECG, 24hr Holter monitor, given a QOL AF questionnaire to assess how arrythmia and palpitations affect their daily lifeAF and also their concerns about the arrythmia.
Who is it for :
Patients with paroxysmal AF, i,e with relatively short lasting episodes are the patients who do best with catheter ablation, and they are often ones who have most troublesome symptoms (compared to those in AF all the time.)
If a patient having severe symptoms likely to be caused by AF, then should be referred at that point If a patient been tried on drugs, perhaps without much effect, or if the AF might be related to underlying heart isease, then they should definitely be referred.
Should post ablation medications be prescribed:
At moment ablation is done mostly for a reduction in symptoms, rather than a reduction is stroke risk. Will need to be on anti-coag a bit after ablation cos of burns to the atrium
Post ablation support:
If they decide on an ablation, then may be seen at 3mths, then 6mths for 2 years. If do not decide on ablaiton, then may decide to alter drugs
Other symptoms you may experience if you have atrial fibrillation include:
Atrial fibrillation often arises from an ectopic focus or foci in the atria or pulmonary veins. (In addition to sites arising in the atria, the pulmonary veins can develop or possess sites that can trigger bursts of depolarizations in the heart). These foci are characterized by a rapid burst of depolarizations that spread throughout the atria. The effect on the atria is a process called “remodeling” in which electrical and structural properties of the tissue are changed. Electrical remodeling involves a reduction in the refractory period in the atria which, in turn, leads to re-entry in the remodeled conduction pathways. Conduction rates tend to vary in adjacent zones of the atria making depolarization very disorganized. Other conditions, such as atrial fibrosis due to heart failure, can contribute to the remodeling. Atrial fibrillation can be either sustained or non-sustained.
2005 First line Ablation paper. Why Atrial ablation should be considered first line treatment for some patients. Verma & Natale
".. the presence of sinus rhythm was 1 of the most powerful independent predictors of survival"
meaning that maintaining a proper rhythm is important. (not just rate,) Reduction in deaths however found to be offset by effects of AADs, They are also ineffective at maintaining sinus rhythm. which increased risk of death. (Amiodorone the most effective, but has limited ability to maintain SR. (also toxic and can cause dangerous arrythmias - see later*) AAMs like this and Sotalol and propafoneone have debilitating side effects, which most people cannot tolerate. Amioderone y can also cause serious problems like skin discolouration, pulmonary fibrosis, opthalmic problems
"AAMs clearly do not cure AF; at best, they are a palliative treatment used to reduce the burden of AF as opposed to eliminating it altogether."
"In contrast to AAM, catheter ablation directly eliminates the inciting factors for AF and offers the possibility of a lasting cure. "
Pulmonary veins trigger and maintain AF, so the goal of AF ablation is "to electrically “disconnect” the pulmonary veins (PVs) from the rest of the atrium by ablating around the origin of the veins." isolating the vein from the heart Better to ablate (and isolate)all 4 PVs cos triggering could come from any,
"AF ablation is an effective, safe, and established treatment for AF that offers an excellent chance for a lasting cure. Unlike other therapies, ablation tackles AF at its electrophysiological origin."
2021 Babikir Kheiri et al. Ablation v AADs first line treatment of PAF - a meta analysis
"...given the substantial adverse effects of AADs and their limited efficacy in maintenance of sinus rhythm, catheter ablation is an attractive strategy"
"AF is typically triggered by ectopic foci within the pulmonary veins. As AF progresses, significant atrial remodeling occurs which may lead to permanent atrial myopathy. " With the development of ablation techniques there is now interest in preventing these structural changes happening with consequent valuable outcomes.
2022 Bisignani et al First line approach for rhythm control in PAF (Belgian authors)
"The primary indication for rhythm control (restore and maintain sinus rhythm) is to reduce AF-related symptoms and improve QoL"
"... the efficacy of first-line AADs therapy is limited because of their deleterious side effects, such as proarrhythmia and organ toxicity, resulting in a substantial proportion of patients discontinuing therapy. "
"Based on these premises, a paradigm shift in the current guidelines is eagerly awaited. Indeed, data suggest that PVI might be considered as first-line rhythm control therapy in patients with paroxysmal AF. "
"Furthermore, the time between a first episode of AF and catheter ablation matters. In the EAST-AFNET 4, only early rhythm control (eg, <1 year from AF first diagnosis) has demonstrated to improve hard endpoints."
2021 UK author Alexander Bates -British cardiovascular society. Is it time for first line ablation inAF
AF is a progressive disease AF begets AF
Pathophysiologically "AF leads to multi-level changes including intracellular calcium dysregulation, and electrical, structural and autonomic nervous system remodelling11. These pathological changes are progressive, making episodes of AF more frequent and longer."
Clinically - Paroxysmal AF over time and increasing burden (think time not in Sinus Ryhthm (SR)) changes to PEAF (Persistent) where episodes of arythmias continue longer than 7 days. So PAF changes to PEAF and "This is accompanied by left atrial (LA) structural remodelling, demonstrated in 3D electroanatomical mapping studies where increased low voltage areas (a representation of fibrosis), are seen in patients with PeAF over PAF" "PAF patients with high AF burdens have larger LA dimensions and reduced contractile properties than those with low burden"
AF progression is associated with worse outcomes "--- in their meta-analysis of 70,447 patients receiving anticoagulation ....the risks of stroke, systemic embolism and mortality were all significantly higher in those with PeAF over PAF" And retrospective analyses "consistently show lower rates of stroke in PAF versus PeAF in anticoagulated patients irrespective of baseline risk factors"
Time in SR associated with better outcomes (but offset when achieved using AADs ".. the specific achievement of SR maintenance is associated with improvements in mortality, stroke, heart failure and quality of life. On average, these benefits are however diminished by the increase mortality associated with the use of AADs themselves." "In summary, AF progression is associated with LA pathophysiological changes and adverse patient outcomes. Maintenance of SR is associated with improved patient outcomes. Therefore, it stands to reason that establishing SR as swiftly as possible should be a priority to maximise this."
AADs have limited efficacy "As was shown in the post hoc AFFIRM analysis, the benefit of SR maintenance was offset by the adverse effects of AADs.These adverse effects are a key limiting factor in their use. Furthermore, the efficacy of AADs in achieving SR is limited, the most effective but most toxic being amiodarone...the authors of AFFIRM say, “Inability to maintain SR and drug intolerance were chief reasons for abandonment of a rhythm control .strategy"""
Catheter ablation slows progression and decreases recurrence over medical therapy
Catheter ablation has beneficial physiological and clinical effects over medical therapy "So although catheter ablation is not associated with decreased mortality for all patients , It is associated with improved quality of life, decreased , decreased risk of dementia, improved physiological markers and for select groups decreased adverse cardiovascular outcomes, all compared to the use of medical therapy and maintaining an acceptable safety profile"
Catheter Ablation as a first line treatment for PAF 2021 systematic review
Conclusion
=================END First Line Ablation Notes
AF and Stroke- 2 types of stroke : Ischaemic, Haemorrhagic
Emboli can occur many places inc in the heart, arteries,aorta, infrequently a vein from lower limbs or pelvis with the presence of a cardiac shunt (right to left as in Patent foramen Ovale PFO) ) resulting in a paradoxycal embolism.
Emboli can form thru different mechanisms inc blood stasis (pooling) in an enlarged left chamber (e.g. ventricular aneurysm) where thrombin then forms, structurally abormal valves or embol from a vein to artery in presence of a cardiac shunt
Ischaemic strokes of cardiac source are generally most severe. Tho emboli can vary in size, those due to blood stasis within the left cardiac chambers can be large, and at greater risk of recurrence.
Risk of embolism varies with the condition with the most common potential high risk cardiac conditions inc AF,being the most common high risk, followed by, M infarction, prosthetic valve...
"AF is the most common sustained cardiac arrhythmia and cause of cardioembolic stroke. This is related to associated low cardiac output, blood stasis which is associated with increased concentration of prothrombotic fibrinogen, D-dimer, and von Willebrand factor, and results in thrombus formation within the atrial appendage and hence increased risk for cardioembolic strokes. Prevalence of AF increases with age particularly in people over 65 years reaching a peak of 5% in this group age. Hypertensive heart disease remains the most common underlying cause of AF in developed countries. Other associated causes of AF include heavy alcohol drinking, valvular heart disease, especially in developing countries, and thyrotoxicosis.[8] "Ncbi
(Stroke.org-AtrialFib)
NHS->https://madeinheene.hee.nhs.uk/Portals/57....
Is age really independent of the other factors such as obesity, high blood pressure, artherosclerosis - or are they being used as indicative of problems when age. (Healthline-US What)
NHS site - some of my original queries or to dos or notes - which are answered either here or above or in AtrialFibrillationFrank