Cardiac Arrhythmias: An Update Dr N.M.Gandhi Consultant Cardiologist Spire Gatwick Park Hospital, Horley East Surrey Hospital, Redhill Royal Sussex County Hospital, Brighton Royal Sussex County Hospital, Brighton

Objectives Identify common arrhythmias encountered by the family physician Identify common arrhythmias encountered by the family physician Discuss initial Mg options Discuss initial Mg options AF and Ventricular arrhythmias case studies AF and Ventricular arrhythmias case studies Which patients needs to be referred? ECG examples Which patients needs to be referred? ECG examples

THE CONDUCTION SYSTEM

Atrial Depolarization

Ventricular Depolarization

CARDIAC ARRHYTHMIAS Disturbances of either : Impulse generation Impulse generation Impulse propagation Impulse propagation

ARRHYTHMIASARRHYTHMIAS  ELECTROPHYSIOLOGIC PRINCIPLES  BRADYARRHYTHMIAS SINUS NODE DYSFUNCTION AV CONDUCTION DISTURBANCES  TACHYARRHYTMIAS ATRIAL TACHYCARDIAS VENTRICULAR TACHYCARDIA

Bradyarrhythmias Impulse formation: Impulse formation: –Decreased automaticity: Sinus bradycardia Impulse conduction: Impulse conduction: –Conduction blocks: 1º, 2º, 3º AV blocks

Tachyarrythmias Impulse formation Impulse formation –Enhanced automaticity: Sinus node: sinus tachycardia Sinus node: sinus tachycardia Ectopic focus: Ectopic atrial tachycardia Ectopic focus: Ectopic atrial tachycardia –Triggered activity Early afterdepolarization: torsades de pointes Early afterdepolarization: torsades de pointes Digitalis-induced SVT Digitalis-induced SVT Impulse conduction Impulse conduction –Reentry: Paroxysmal SVT, atrial flutter and fibrilation, ventricular tachycardia and fibrillation.

Normal Sinus Rhythm Implies normal sequence of conduction, originating in the sinus node and proceeding to the ventricles via the AV node and His-Purkinje system. EKG Characteristics: Regular narrow-complex rhythm Rate bpm Each QRS complex is proceeded by a P wave P wave is upright in lead II & downgoing in lead aVR

PAC Benign, common cause of perceived irregular rhythm Benign, common cause of perceived irregular rhythm Can cause sxs: “skipping” beats, palpitations Can cause sxs: “skipping” beats, palpitations No treatment, reassurance No treatment, reassurance With sxs, may advise to stop smoking, decrease caffeine and ETOH With sxs, may advise to stop smoking, decrease caffeine and ETOH Can use beta-blockers to reduce frequency Can use beta-blockers to reduce frequency

PVC Extremely common throughout the population, both with and without heart disease Extremely common throughout the population, both with and without heart disease Usually asymptomatic, except rarely dizziness or fatigue in patients that have frequent PVCs and significant LV dysfunction Usually asymptomatic, except rarely dizziness or fatigue in patients that have frequent PVCs and significant LV dysfunction

PVC Reassurance Reassurance Optimize cardiac and pulmonary disease management Optimize cardiac and pulmonary disease management Beta-blocker Beta-blocker Ablation in a small number of cases Ablation in a small number of cases

Bradyarrhythmias Impulse formation: Impulse formation: –Decreased automaticity: Sinus bradycardia Impulse conduction: Impulse conduction: –Conduction blocks: 1º, 2º, 3º AV blocks

Sinus Bradycardia HR< 60 bpm; every QRS narrow, preceded by p wave HR< 60 bpm; every QRS narrow, preceded by p wave Can be normal in well-conditioned athletes Can be normal in well-conditioned athletes HR can be 30 bpm in adults during sleep, with up to 2 sec pauses HR can be 30 bpm in adults during sleep, with up to 2 sec pauses

Sinus arrhythmia Usually respiratory--Increase in heart rate during inspiration Usually respiratory--Increase in heart rate during inspiration Exaggerated in children, young adults and athletes—decreases with age Exaggerated in children, young adults and athletes—decreases with age Usually asymptomatic, no treatment or referral Usually asymptomatic, no treatment or referral Can be non-respiratory, often in normal or diseased heart, seen in digitalis toxicity Can be non-respiratory, often in normal or diseased heart, seen in digitalis toxicity Referral may be necessary if not clearly respiratory, history of heart disease Referral may be necessary if not clearly respiratory, history of heart disease

Sick Sinus Syndrome All result in bradycardia Sinus bradycardia with a sinus pause Often result of tachy-brady syndrome: where a burst of atrial tachycardia (such as afib) is then followed by a long, symptomatic sinus pause/arrest, with no breakthrough junctional rhythm.

1 st Degree AV Block PR interval >200ms PR interval >200ms If accompanied by wide QRS, refer to cardiology, high risk of progression to 2 nd and 3 rd deg block If accompanied by wide QRS, refer to cardiology, high risk of progression to 2 nd and 3 rd deg block Otherwise, benign if asymptomatic Otherwise, benign if asymptomatic

2 nd Degree AV Block Mobitz type I (Wenckebach) Progressive PR longation, with eventual non- conduction of a p wave Progressive PR longation, with eventual non- conduction of a p wave May be in 2:1 or 3:1 May be in 2:1 or 3:1

2 nd degree block Type II (Mobitz 2) Normal PR intervals with sudden failure of a p wave to conduct Normal PR intervals with sudden failure of a p wave to conduct Usually below AV node and accompanied by BBB or fascicular block Usually below AV node and accompanied by BBB or fascicular block Often causes pre/syncope; exercise worsens sxs Often causes pre/syncope; exercise worsens sxs Generally need pacing, possibly urgently if symptomatic Generally need pacing, possibly urgently if symptomatic

3 rd Degree AV Block Complete AV disassociation, HR is a ventricular rate Complete AV disassociation, HR is a ventricular rate Will often cause dizziness, syncope, angina, heart failure Will often cause dizziness, syncope, angina, heart failure Can degenerate to Vtach and Vfib Can degenerate to Vtach and Vfib Will need pacing, urgent referral Will need pacing, urgent referral

Tachyarrythmias Impulse formation Impulse formation –Enhanced automaticity: Sinus node: sinus tachycardia Sinus node: sinus tachycardia Ectopic focus: Ectopic atrial tachycardia Ectopic focus: Ectopic atrial tachycardia –Triggered activity Early afterdepolarization: torsades de pointes Early afterdepolarization: torsades de pointes Digitalis-induced SVT Digitalis-induced SVT Impulse conduction Impulse conduction –Reentry: Paroxysmal SVT, atrial flutter and fibrilation, ventricular tachycardia and fibrillation.

SUPRAVENTRICULAR T. Sinus Tachycardia Sinus Tachycardia Atrial flutter Atrial flutter Atrial fibrilation Atrial fibrilation Paroxysmal Supraventricular Paroxysmal Supraventricular Multifocal Atrial T. Multifocal Atrial T. Preexcitation Syndrome (Wolff-Parkinson-white Sy.) Preexcitation Syndrome (Wolff-Parkinson-white Sy.)

Sinus tachycardia HR > 100 bpm, regular HR > 100 bpm, regular Often difficult to distinguish p and t waves Often difficult to distinguish p and t waves

Paroxysmal Supraventricular T. Sudden onset and termination Sudden onset and termination Atrial rates of 140 to 250 /min Atrial rates of 140 to 250 /min Normal QRS complexes Normal QRS complexes The mechanism is most often reentry. The mechanism is most often reentry.

Paroxysmal Supraventricular Tachycardia Refers to supraventricular tachycardia other than afib, aflutter and MAT Refers to supraventricular tachycardia other than afib, aflutter and MAT Usually due to reentry—AVNRT or AVRT Usually due to reentry—AVNRT or AVRT

PSVT CSM or adenosine commonly terminate the arrhythmia, esp, AVRT or AVNRT CSM or adenosine commonly terminate the arrhythmia, esp, AVRT or AVNRT Can also use CCB or beta blockers to terminate, if available Can also use CCB or beta blockers to terminate, if available Counsel to avoid triggers, caffeine, Etoh, pseudoephedrine, stress Counsel to avoid triggers, caffeine, Etoh, pseudoephedrine, stress

Multifocal Atrial T. Is due to enchanced automaticity within the atria, resulting in abnormal discharges from several ectopic foci Is due to enchanced automaticity within the atria, resulting in abnormal discharges from several ectopic foci Most often occurs in the setting of severe pulmonary disease and hypoxemia. Most often occurs in the setting of severe pulmonary disease and hypoxemia. EKG: irregular rhythm with multiple (at leats 3) P waves morphologies EKG: irregular rhythm with multiple (at leats 3) P waves morphologies

Atrial flutter Is caracterized by rapid coarse “sawtooth” appearing atrial activity, at rate of 250 to 350 x min. Is caracterized by rapid coarse “sawtooth” appearing atrial activity, at rate of 250 to 350 x min. –Many of these fast impulses reach the AV node during its refractory period, so that the ventricular rate is generally lower. Frequently it degenerates into atrial fibrilation Frequently it degenerates into atrial fibrilation –The most expiditious therapy is electrical cardioversion, which is undertaken directly for highly symptomatic patients. (to revert chronic refractory atrial flutter that has not responded to other approaches )

Preexcitation Syndrome Wolff-Parkinson-White Syndrome Wolff-Parkinson-White Syndrome EKG: Although different types of bypass tracts have been identified, the bundle of Kent, is the most common and can usually conduct in both the anterograde and retrograde directions. EKG: Although different types of bypass tracts have been identified, the bundle of Kent, is the most common and can usually conduct in both the anterograde and retrograde directions.

Atrial Fibrillation Irregular rhythm Irregular rhythm Absence of definite p waves Absence of definite p waves Narrow QRS Narrow QRS Can be accompanied by rapid ventricular response Can be accompanied by rapid ventricular response

Atrial fibrillation--management Rhythm vs Rate control—if onset is within last hours, may be able to arrange cardioversion—use heparin around procedure Rhythm vs Rate control—if onset is within last hours, may be able to arrange cardioversion—use heparin around procedure Need TEE if valvular disease (high risk of thrombus) Need TEE if valvular disease (high risk of thrombus) If unable to definitely conclude onset in last hours: need 4-6 weeks of anticoagulation prior to cardioversion, and warfarin for 4-12 weeks after If unable to definitely conclude onset in last hours: need 4-6 weeks of anticoagulation prior to cardioversion, and warfarin for 4-12 weeks after

AF: Medical Management Treatment of underlying cause Treatment of underlying cause Ventricular rate control Ventricular rate control Anticoagulation Anticoagulation Antiarrhythmics with a view to restore sinus rhythm Antiarrhythmics with a view to restore sinus rhythm

Control of Ventricular Rate in Atrial Fibrillation Betablockers Betablockers Calcium channel blockers Calcium channel blockers Verapamil, diltiazem Digoxin Digoxin Amiodarone Amiodarone

Anticoagulation Anticoagulation Assessment of bleeding risk should be part of the clinical assessment of AF patients prior to starting anticoagulation Assessment of bleeding risk should be part of the clinical assessment of AF patients prior to starting anticoagulation Antithrombotic benefits and potential bleeding risks of long-term coagulation should be explained and discussed with the patient Antithrombotic benefits and potential bleeding risks of long-term coagulation should be explained and discussed with the patient Aim for a target INR of between 2.0 and 3.0 Aim for a target INR of between 2.0 and 3.0 NICE 2006 NICE 2006

CHADS 2 scoring Any patients with AF with a score of =/>2 would benefit from being on Warfarin Any patients with AF with a score of =/>2 would benefit from being on Warfarin CCFHypertension Age > 75 DiabetesStroke/TIA 1 point 1point 2 points

Cardioversion Cardioversion results in SR in at least 90% of cases Cardioversion results in SR in at least 90% of cases SR is only maintained in 30-50% at one year SR is only maintained in 30-50% at one year Class 1a, 1c and III agents increase likelihood of maintained SR from 30-50% to 50-70% at one year Class 1a, 1c and III agents increase likelihood of maintained SR from 30-50% to 50-70% at one year

Follow-up Follow-up after cardioversion should take place at 1 month, and the frequency of subsequent reviews should be tailored to the patient Follow-up after cardioversion should take place at 1 month, and the frequency of subsequent reviews should be tailored to the patient Reassess the need for anticoagulation at each review Reassess the need for anticoagulation at each review

VENTRICULAR ARRHYTHMIAS Ventricular tachycardia Ventricular tachycardia Torsades De Pointes Torsades De Pointes Ventricular fibrillation Ventricular fibrillation

Ventricular tachycardia Is divided in 2 categories: Is divided in 2 categories: –If it persist for more than 30 seconds “sustained VT” –Less than 30 seconds: “nonsustained VT” Symptoms vary depending on the duration. Symptoms vary depending on the duration. –Major manifestations are hypotension and loss of consciousness.

Non-sustained ventricular tachycardia Need to exclude heart disease with Echo and stress testing Need to exclude heart disease with Echo and stress testing May need anti-arrhythmia treatment if sxs May need anti-arrhythmia treatment if sxs In presence of heart disease, increased risk of sudden death In presence of heart disease, increased risk of sudden death Need referral for EPS and/or prolonged Holter monitoring Need referral for EPS and/or prolonged Holter monitoring ICD may be life saving ICD may be life saving

Torsades De Pointes Varying amplitudes of the QRS. Varying amplitudes of the QRS. It can be produced by afterdepolarizations (triggered activity). It can be produced by afterdepolarizations (triggered activity). Particularly in prolonged QT interval. Particularly in prolonged QT interval. Occur with some drugs (quinidine), electrolite disturbances, and congenital prolongation of the QT interval. Occur with some drugs (quinidine), electrolite disturbances, and congenital prolongation of the QT interval.

Specialist Referral ECG Examples

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