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Heterogeneity Of AF Not all AF are the same!!!!!!. Dr.Mervat Aboulmaaty Prof. of cardiology Ain Shams university 2008. Heterogeneity Of AF Not all AF are the same!!!!!!.
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Heterogeneity Of AFNot all AF are the same!!!!!! Dr.Mervat Aboulmaaty Prof. of cardiology Ain Shams university 2008
AF HeterogeneityPrevalence • AF prevalence doubling with each decade • 0.55 at age 50-59 years • 9% at age 80-89 years • 3-fold increase in men • New onset AF: men are 1. 5 times as likely as women to develop it
Associated conditions with AF • Reversible Causes of Atrial Fibrillation • alcohol intake (“holiday heart syndrome”), surgery, electrocution, • MI, pericarditis, myocarditis, • PE, pulmonary diseases, • hyperthyroidism • with Atrial flutter, WPW,AVNRT, AVRT • complication of cardiac or thoracic surgery
Associated conditions with AF • Acute and chronic coronary disease • HTN • Hypertrophic ,dilated & restrictive CM • ASD • Valvular Rheumatic 40% MS 75% MR
Atrial Fibrillation Without Associated Heart Diseaselone AF • Lone AF before age 60 yrs without HTN or overt structural HD (clinical exam, ECG and echo) • 30% to 45% of paroxysmal AF and 20% to 25% of persistent AF occur in younger patients without underlying disease • AF can present as an isolated or familial arrhythmia • In elderly, • myocardial stiffness may be associated with AF, • Heart disease may be coincidental and unrelated to AF.
AF and autonomic influence • Vagalpredominance in the minutes preceding the onset of AF • Vagally mediated AF occurs at night or after meals • Cholinergic agents such as disopyramide are helpful to prevent recurrent vagally mediated AF • Adrenergically induced AF occurs during daytime in pts with organic HD • Beta blockers for adrenergically induced AF
Autosomal dominant hereditary AF Mapping analysis of the AF family
ECG and missense mutation DNA and amino acid sequence of KCNQ1 missense mutation associated with affected members in the AF family. DNA sequence analysis revealed an A to G substitution causing an S140G mutation in the S1 segment of KCNQ1.
AF family with an autosomal recessive inheritance pattern • AF in the family manifests with early onset at fetal stage and is associated with neonatal sudden death • Some cases ventricular tachyarrhythmias and cardiomyopathy. • Heterozygous carriers have significant prolongation of P-wave duration compared with non-carriers • The maximum multipoint LOD score of 4.10 was obtained for 4 markers: D5S426, D5S493, D5S455, and D5S1998. Circulation. 2004;110:3753-3759
Genetic map with chromosome 5p13 markers and locationof putative arAF1 gene
Mechanisms of AF Rapidly firing atr automatic foci PV triggers Anatomical substrate for reentry within the PV
Symptoms of AF • Embolic complication • Exacerbation of HF • Palpitations, chest pain, dyspnea, fatigue, lightheadedness • Syncope. • upon conversion in patients with SSS • rapid ventricular rates in patients with HCM, AS, WPW • Polyuria with the release of ANP as episodes of AF begin or terminate. • Tachycardia-mediated cardiomyopathy
Pharmacological and non pharmacological Treatment • Drugs and ablation are effective for both rate and rhythm control • Ryhtm control vs Rate control • For rhythm control, drugs are typically the first choice and LA ablationis a second-line choice ( symptomatic lone AF young pts , no structrual HD) • RF ablation for WPW, AVRT, Atrial Flutter • RF ablation in association with cardiac surgery face a unique opportunity during MV Replacement, LAA obliteration • Standalone Surgical procedure (maze III orLA ablation)
Circumferential Pulmonary-Vein Ablation RF Pulmonary Vein Isolation Oral, H. et al. N Engl J Med 2006;354:934-941
Pharmacological and Non-Pharmacological Treatment • “Ablate and pace” strategy that often yields remarkable symptomatic relief ( the negative effect of long-term RV) BIV Pacing • Atrial pacing, either in RA alone or Biatrial to prevent recurrent paroxysmal AF in pts with Bradycardic indication for Pacing (SSS AAI vs VVI) • Atrial pacing ISNot a primary therapy for prevention of AF • Atrial defibrillators for patients with LV dysfunction who are candidates for implantable ventricular defibrillators
Mortality and Morbidity with AF Death • AF Increases Mortality with AMI • AF Increases mortality 50% Men 90% Women • Highest death 1st yr after AF diagnosis Stroke • Risk 35% • 1.5% at age 50-59 y • 23.5% at age 80-89 • AF+HF+CAD increase risk of a stroke 2 fold
Risk of Stroke • CHADS2 Risk Criteria Score • Prior stroke or TIA 2 • Age 75 y 1 • Hypertension 1 • Diabetes mellitus 1 • Heart failure I • aspirin (325 mg) associated with 44% stroke rate reduction • Warfarin 50% more effective than aspirin for prevention of ischemic stroke
Predictors of AF • HTN and DM were significant independent predictors of AF increasing the risk 1.5 fold. (Framingham Study) • HTN is responsible for more AF (14%) than any other risk factor
Predictors of AF • Independent ECHO predictors of AF : • LA enlargement, ( 5mm AF 39%) • LV fractional short. ( 5% AF 34%) • LV wall thickness ( 4mm AF 24%) • ECG evidence of: • LVH was also a powerful age adjusted predictor
Mortality results N Engl J Med 2002;347:1825-33.