Paradigms in Atrial Fibrillation Sunthosh V. Parvathaneni, MD, - PowerPoint PPT Presentation

Paradigms in Atrial Fibrillation Sunthosh V. Parvathaneni, MD, FACC, FHRS Clinical Cardiac Electrophysiology Assistant Professor in Clinical Medicine, University of Missouri School of Medicine Mercy Hospital Springfield Objectives � To understand the Clinical Considerations of the Physician Assistant when dealing with Atrial Fibrillation � To understand the Mechanisms and Causes of Atrial Fibrillation � To learn to visualize Significant Anatomy relevant to Atrial Fibrillation � To discuss Tools and Techniques relevant to treating Atrial Fibrillation Clinical Considerations • Epidemiology • Atrial fibrillation (AF) is the most common clinically significant cardiac arrhythmia in the world. • Approximately one third of hospitalizations for cardiac rhythm disturbance • 2.3 million people in the United States and 4.5 million in the European Union have paroxysmal or persistent AF • Hospital admissions for AF have increased by 66% due to the aging population Issa, Z.F ., Miller, J.M., & Zipes, D.P . (2009). Atrial Fibrillation. In Z.F . Issa, J.M. Miller & D.P . Zipes, Clinical Arrhythmology and Electrophysiology (208-284). Philadelphia: Saunders Elsevier

Clinical Considerations • Epidemiology • AF is associated with an increased long- term risk of stroke, heart failure, and all- cause mortality, especially in women • The mortality rate of patients with AF is approximately double that of patients in sinus rhythm and is linked to the severity of underlying heart disease • The most devastating consequence of AF is stroke as a result of thromboembolism • 1 out of every 6 strokes occurs in patients with AF ACCF/AHA Pocket Guideline. Management of Patients with Atrial Fibrillation. Adapted from the 2006 ACC/AHA/ESC Guidline and the 2011 ACCF/AHA/HRS Focused Updates) Clinical Considerations • Risk Stratification • CHADS 2 VASc Score • Prior Stroke/TIA (2 points) • Age > 65 and < 74 (1 point) • Hypertension (1 point) • Diabetes Mellitus (1 point) • Heart failure (1 point) • Vascular Disease (1 point) • Prior MI, PAD, Aortic Plaque • Age > 75 (2 points) • Female Sex ( 1 point) ACCF/AHA Pocket Guideline. Management of Patients with Atrial Fibrillation. Adapted from the 2006 ACC/AHA/ESC Guideline and the 2011 ACCF/AHA/HRS Focused Updates) Clinical Considerations � Anticoagulation � If CHADS2-Vasc < 2, discussion with the patient should be had whether they would be content with ASA alone or anticoagulation with Coumadin or DOAC (Direct Oral Anticoagulation) � If CHADS2-VASc > 2, anticoagulation is preferred with either Coumadin or DOAC (Pradaxa, Eliquis, Xarelto, etc.). They have been shown to be superior in reduction of both ischemic and hemorrhage stroke and bleeding � Pradaxa has a sight increase in evidence of GI bleeding compared to Coumadin � Pradaxa does offer a reversal agent that can reverse in less than 1 second ACCF/AHA Pocket Guideline. Management of Patients with Atrial Fibrillation. Adapted from the 2006 ACC/AHA/ESC Guidline and the 2011 ACCF/AHA/HRS Focused Updates)

Clinical Considerations • Clinical Presentation • Symptomatic or asymptomatic , even in the same patient • up to 21% of newly diagnosed patients with AF are asymptomatic • Symptoms associated with AF vary with: • ventricular rate • underlying functional status • duration of AF • presence and degree of structural heart disease • individual patient perception • Most patients with AF complain of palpitations, angina, dyspnea, fatigue, or dizziness Issa, Z.F ., Miller, J.M., & Zipes, D.P . (2009). Atrial Fibrillation. In Z.F . Issa, J.M. Miller & D.P . Zipes, Clinical Arrhythmology and Electrophysiology (208-284). Philadelphia: Saunders Elsevier Clinical Presentation • Initial Evaluation • Characterize the pattern of the arrhythmia • How long have they had it? • How long have they experienced symptoms? • Cardioversions in the past? • What drugs are are they on (prescription, OTC, recreational)? • Determine underlying causes (heart failure, pulmonary problems, hypertension, or hyperthyroidism) • Define associated cardiac and extracardiac conditions Classification of Atrial Fibrillation First detected episode Permanent Recurrent (After 2 (Cardioversion failed) episodes) AF Paroxysmal Persistent (self- 7days – 1 year terminates) ACCF/AHA Pocket Guideline. Management of Patients with Atrial Fibrillation. Adapted from the 2006 ACC/AHA/ESC Guidline and the 2011 ACCF/AHA/HRS Focused Updates

Clinical Presentation Patient Management • Four Main Issues that must be addressed • Prevention of systemic embolization (clot) 1. Rate control 2. Rhythm control 3. Choosing between rhythm and rate control 4. Choice of therapy is influenced by: • Patient preference • • Associated structural heart disease Severity of symptoms • • Whether the AF is recurrent paroxysmal, recurrent persistent, or permanent (chronic) • In addition, patient education is critical, given the potential morbidity associated with AF and its treatment. Electrocardiographic Features • Characterized by rapid and irregular atrial fibrillatory waves (f waves) and lack of clearly defined P waves • Best seen � Lead V1 and in the inferior leads (II, III, and AVF). • Rate of the fibrillatory waves -- between 350 and 600 beats/min • The atrium is in a state of chaos • Ventricular response is typically irregularly irregular Issa, Z.F ., Miller, J.M., & Zipes, D.P . (2009). Atrial Fibrillation. In Z.F . Issa, J.M. Miller & D.P . Zipes, Clinical Arrhythmology and Electrophysiology (208-284). Philadelphia: Saunders Elsevier Mechanisms • Two concepts of the underlying mechanism of AF have received considerable attention: Factors that trigger the onset of AF 1. Factors that perpetuate AF 2. • Patients with frequent, self-terminating episodes of AF are likely to have a predominance of factors that trigger AF • Patients with AF that does not terminate spontaneously are more likely to have a predominance of factors that perpetuate AF • This generalization has clinical usefulness, but there is considerable overlap of these mechanisms in the typical AF patient Issa, Z.F ., Miller, J.M., & Zipes, D.P . (2009). Atrial Fibrillation. In Z.F . Issa, J.M. Miller & D.P . Zipes, Clinical Arrhythmology and Electrophysiology (208-284). Philadelphia: Saunders Elsevier

Mechanisms of Initiation • Stable focus (PAC) or reentrant circuit with activation arising from this focus too rapid to be conducted uniformly throughout the atria • Rapid propagation of the wave fronts breaks up into irregular wavelets • Mechanism of initiation of AF is not certain in most cases and likely is multifactorial Murgatroyd, F .D., Krahn, A.D., Klein, G.J., Yee, R.K, & Issa, Z.F ., Miller, J.M., & Zipes, D.P . (2009). Atrial Skanes, A..C(2001). Atrial Arrhythmias. In Murgatroyd, Fibrillation. In Z.F . Issa, J.M. Miller & D.P . Zipes, Clinical F .D., Krahn, A.D., Klein, G.J., Yee, R.K, & Skanes, Arrhythmology and Electrophysiology (208-284). Handbook of Cardiac Electrophysiology (55-71). London: Philadelphia: Saunders Elsevier ReMEDICA Publishing Limited Mechanisms of Initiation • AF Triggers • Premature Atrial Complexes (PACs) from the Pulmonary Veins (PVs), Coronary Sinus (CS), Superior Vena Cava (SVC), Ligament of Marshall, Left Atrial chamber, RA chamber (crista terminalis) • Sympathetic or Parasympathetic stimulation • Other Supraventricular Tachycardia (SVT) , AFL, AVNRT • AVRT • Identification and treatment of triggers may be curative Issa, Z.F ., Miller, J.M., & Zipes, D.P . (2009). Atrial Fibrillation. In Z.F . Issa, J.M. Miller & D.P . Zipes, Clinical Arrhythmology and Electrophysiology (208-284). Philadelphia: Saunders Elsevier Mechanisms of Initiation • Triggering foci of rapidly firing cells within the sleeves of atrial myocytes extending into the PVs have been clearly shown to be the underlying mechanism of most paroxysmal AF • Thoracic veins are highly arrhythmogenic • PV-LA Junction has discontinuous myocardial fibers separated by fibrotic tissues and, therefore, is highly anisotropic Nathan, H., et al. “The Junction Between the Left Atrium and the Pulmonary Veins: An Anatomic Study of Human Hearts.” Circ , Vol. 34, (1966): 412-422. Print.