Cardiac Arrhythmias: An Cardiac Arrhythmias: An UpdateUpdate

Dr N.M.GandhiDr N.M.GandhiConsultant CardiologistConsultant Cardiologist

Spire Gatwick Park Hospital, HorleySpire Gatwick Park Hospital, HorleyEast Surrey Hospital, RedhillEast Surrey Hospital, Redhill

Royal Sussex County Hospital, BrightonRoyal Sussex County Hospital, Brighton

ObjectivesObjectives

• Identify common arrhythmias encountered Identify common arrhythmias encountered by the family physicianby 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 Which patients needs to be referred? ECG examplesexamples

THE CONDUCTION SYSTEMTHE CONDUCTION SYSTEM

Atrial DepolarizationAtrial Depolarization

Ventricular DepolarizationVentricular Depolarization

CARDIAC ARRHYTHMIASCARDIAC ARRHYTHMIAS

Disturbances of either :Disturbances of either :

• Impulse generationImpulse generation

• Impulse propagationImpulse propagation

ARRHYTHMIAS

ELECTROPHYSIOLOGIC PRINCIPLES

BRADYARRHYTHMIAS

• SINUS NODE DYSFUNCTION• AV CONDUCTION DISTURBANCES

TACHYARRHYTMIAS

•ATRIAL TACHYCARDIAS•VENTRICULAR TACHYCARDIA

BradyarrhythmiasBradyarrhythmias

• Impulse formation:Impulse formation:– Decreased automaticity: Sinus Decreased automaticity: Sinus

bradycardiabradycardia

• Impulse conduction:Impulse conduction:– Conduction blocks: 1º, 2º, 3º AV blocksConduction blocks: 1º, 2º, 3º AV blocks

TachyarrythmiasTachyarrythmias

• Impulse formationImpulse formation– Enhanced automaticity:Enhanced automaticity:

• Sinus node: sinus tachycardiaSinus node: sinus tachycardia• Ectopic focus: Ectopic atrial tachycardiaEctopic focus: Ectopic atrial tachycardia

– Triggered activityTriggered activity• Early afterdepolarization: torsades de pointesEarly afterdepolarization: torsades de pointes• Digitalis-induced SVTDigitalis-induced SVT

• Impulse conductionImpulse conduction– Reentry: Paroxysmal SVT, atrial flutter and Reentry: Paroxysmal SVT, atrial flutter and

fibrilation, ventricular tachycardia and fibrillation.fibrilation, ventricular tachycardia and fibrillation.

Normal Sinus RhythmNormal 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 60-100 bpm

Each QRS complex is proceeded by a P wave

P wave is upright in lead II & downgoing in lead aVR

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PACPAC

• Benign, common cause of perceived Benign, common cause of perceived irregular rhythmirregular rhythm

• Can cause sxs: “skipping” beats, Can cause sxs: “skipping” beats, palpitationspalpitations

• No treatment, reassuranceNo treatment, reassurance• With sxs, may advise to stop smoking, With sxs, may advise to stop smoking,

decrease caffeine and ETOHdecrease caffeine and ETOH• Can use beta-blockers to reduce Can use beta-blockers to reduce

frequencyfrequency

PVCPVC

• Extremely common throughout the population, Extremely common throughout the population, both with and without heart diseaseboth with and without heart disease

• Usually asymptomatic, except rarely dizziness or Usually asymptomatic, except rarely dizziness or fatigue in patients that have frequent PVCs and fatigue in patients that have frequent PVCs and significant LV dysfunctionsignificant LV dysfunction

PVCPVC

• ReassuranceReassurance

• Optimize cardiac and pulmonary Optimize cardiac and pulmonary disease managementdisease management

• Beta-blockerBeta-blocker

• Ablation in a small number of casesAblation in a small number of cases

BradyarrhythmiasBradyarrhythmias

• Impulse formation:Impulse formation:– Decreased automaticity: Sinus Decreased automaticity: Sinus

bradycardiabradycardia

• Impulse conduction:Impulse conduction:– Conduction blocks: 1º, 2º, 3º AV blocksConduction blocks: 1º, 2º, 3º AV blocks

Sinus BradycardiaSinus Bradycardia

• HR< 60 bpm; every QRS narrow, preceded by p HR< 60 bpm; every QRS narrow, preceded by p wavewave

• Can be normal in well-conditioned athletesCan be normal in well-conditioned athletes

• HR can be 30 bpm in adults during sleep, with up HR can be 30 bpm in adults during sleep, with up to 2 sec pausesto 2 sec pauses

Sinus arrhythmiaSinus arrhythmia

• Usually respiratory--Increase in heart rate Usually respiratory--Increase in heart rate during inspirationduring inspiration

• Exaggerated in children, young adults and Exaggerated in children, young adults and athletes—decreases with ageathletes—decreases with age

• Usually asymptomatic, no treatment or Usually asymptomatic, no treatment or referralreferral

• Can be non-respiratory, often in normal or Can be non-respiratory, often in normal or diseased heart, seen in digitalis toxicitydiseased heart, seen in digitalis toxicity

• Referral may be necessary if not clearly Referral may be necessary if not clearly respiratory, history of heart diseaserespiratory, history of heart disease

Sick Sinus SyndromeSick 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.

11stst Degree AV Block Degree AV Block

• PR interval >200msPR interval >200ms

• If accompanied by wide QRS, refer to cardiology, If accompanied by wide QRS, refer to cardiology, high risk of progression to 2high risk of progression to 2ndnd and 3 and 3rdrd deg block deg block

• Otherwise, benign if asymptomaticOtherwise, benign if asymptomatic

22ndnd Degree AV Block Mobitz Degree AV Block Mobitz type I (Wenckebach)type I (Wenckebach)

• Progressive PR longation, with eventual Progressive PR longation, with eventual non-conduction of a p wavenon-conduction of a p wave

• May be in 2:1 or 3:1 May be in 2:1 or 3:1

22ndnd degree block Type II degree block Type II (Mobitz 2)(Mobitz 2)

• Normal PR intervals with sudden failure of a p wave to Normal PR intervals with sudden failure of a p wave to conductconduct

• Usually below AV node and accompanied by BBB or Usually below AV node and accompanied by BBB or fascicular blockfascicular block

• Often causes pre/syncope; exercise worsens sxsOften causes pre/syncope; exercise worsens sxs• Generally need pacing, possibly urgently if symptomaticGenerally need pacing, possibly urgently if symptomatic

33rdrd Degree AV Block Degree AV Block

• Complete AV disassociation, HR is a ventricular rateComplete AV disassociation, HR is a ventricular rate

• Will often cause dizziness, syncope, angina, heart failureWill often cause dizziness, syncope, angina, heart failure

• Can degenerate to Vtach and VfibCan degenerate to Vtach and Vfib

• Will need pacing, urgent referralWill need pacing, urgent referral

TachyarrythmiasTachyarrythmias

• Impulse formationImpulse formation– Enhanced automaticity:Enhanced automaticity:

• Sinus node: sinus tachycardiaSinus node: sinus tachycardia• Ectopic focus: Ectopic atrial tachycardiaEctopic focus: Ectopic atrial tachycardia

– Triggered activityTriggered activity• Early afterdepolarization: torsades de pointesEarly afterdepolarization: torsades de pointes• Digitalis-induced SVTDigitalis-induced SVT

• Impulse conductionImpulse conduction– Reentry: Paroxysmal SVT, atrial flutter and Reentry: Paroxysmal SVT, atrial flutter and

fibrilation, ventricular tachycardia and fibrillation.fibrilation, ventricular tachycardia and fibrillation.

SUPRAVENTRICULAR T. SUPRAVENTRICULAR T.

• Sinus TachycardiaSinus Tachycardia

• Atrial flutterAtrial flutter

• Atrial fibrilationAtrial fibrilation

• Paroxysmal SupraventricularParoxysmal Supraventricular

• Multifocal Atrial T.Multifocal Atrial T.• Preexcitation Syndrome Preexcitation Syndrome (Wolff-Parkinson-(Wolff-Parkinson-

white Sy.)white Sy.)

Sinus tachycardiaSinus tachycardia

• HR > 100 bpm, regularHR > 100 bpm, regular

• Often difficult to distinguish p and t wavesOften difficult to distinguish p and t waves

Paroxysmal Paroxysmal Supraventricular T.Supraventricular T.

• Sudden onset and terminationSudden onset and termination

• Atrial rates of 140 to 250 /minAtrial rates of 140 to 250 /min

• Normal QRS complexes Normal QRS complexes

• The mechanism is most often The mechanism is most often reentry.reentry.

Paroxysmal Supraventricular Paroxysmal Supraventricular TachycardiaTachycardia

• Refers to supraventricular tachycardia Refers to supraventricular tachycardia other than afib, aflutter and MATother than afib, aflutter and MAT

• Usually due to reentry—AVNRT or AVRTUsually due to reentry—AVNRT or AVRT

PSVTPSVT

• CSM or adenosine commonly CSM or adenosine commonly terminate the arrhythmia, esp, AVRT terminate the arrhythmia, esp, AVRT or AVNRTor AVNRT

• Can also use CCB or beta blockers to Can also use CCB or beta blockers to terminate, if availableterminate, if available

• Counsel to avoid triggers, caffeine, Counsel to avoid triggers, caffeine, Etoh, pseudoephedrine, stressEtoh, pseudoephedrine, stress

Multifocal Atrial T.Multifocal Atrial T.

• Is due to enchanced automaticity Is due to enchanced automaticity within the atria, resulting in within the atria, resulting in abnormal discharges from several abnormal discharges from several ectopic fociectopic foci

• Most often occurs in the setting of Most often occurs in the setting of severe pulmonary disease and severe pulmonary disease and hypoxemia.hypoxemia.

• EKG: irregular rhythm with multiple EKG: irregular rhythm with multiple (at leats 3) P waves morphologies(at leats 3) P waves morphologies

Atrial flutterAtrial flutter

• Is caracterized by rapid coarse “sawtooth” appearing Is caracterized by rapid coarse “sawtooth” appearing atrial activity, at rate of 250 to 350 x min.atrial activity, at rate of 250 to 350 x min.

– Many of these fast impulses reach the AV node Many of these fast impulses reach the AV node during its refractory period, so that the ventricular during its refractory period, so that the ventricular rate is generally lower.rate is generally lower.

• Frequently it degenerates into atrial fibrilationFrequently it degenerates into atrial fibrilation

– The most expiditious therapy is electrical The most expiditious therapy is electrical cardioversion, which is undertaken directly for cardioversion, which is undertaken directly for highly symptomatic patients. (to revert chronic highly symptomatic patients. (to revert chronic refractory atrial flutter that has not responded to refractory atrial flutter that has not responded to other approachesother approaches))

Preexcitation SyndromePreexcitation Syndrome

• Wolff-Parkinson-White SyndromeWolff-Parkinson-White Syndrome

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

Atrial FibrillationAtrial Fibrillation

• Irregular rhythm Irregular rhythm • Absence of definite p wavesAbsence of definite p waves• Narrow QRSNarrow QRS• Can be accompanied by rapid ventricular responseCan be accompanied by rapid ventricular response

Atrial fibrillation--Atrial fibrillation--managementmanagement• Rhythm vs Rate control—if onset is within last Rhythm vs Rate control—if onset is within last

24-48 hours, may be able to arrange 24-48 hours, may be able to arrange cardioversion—use heparin around procedurecardioversion—use heparin around procedure

• Need TEE if valvular disease (high risk of Need TEE if valvular disease (high risk of thrombus)thrombus)

• If unable to If unable to definitely definitely conclude onset in last conclude onset in last 24-48 hours: need 4-6 weeks of 24-48 hours: need 4-6 weeks of anticoagulation prior to cardioversion, and anticoagulation prior to cardioversion, and warfarin for 4-12 weeks afterwarfarin for 4-12 weeks after

Atrial Fibrillation: Clinical Atrial Fibrillation: Clinical ProblemsProblems

• Embolism and stroke (presumably due to LA clot)Embolism and stroke (presumably due to LA clot)

• Acute hospitalization with onset of symptomsAcute hospitalization with onset of symptoms

• Anticoagulation, especially in older patients (> 75 yr.)Anticoagulation, especially in older patients (> 75 yr.)

• Congestive heart failureCongestive heart failure

– Loss of AV synchronyLoss of AV synchrony

– Loss of atrial “kick”Loss of atrial “kick”

– Rate-related cardiomyopathy due to rapid Rate-related cardiomyopathy due to rapid ventricular responseventricular response

• Rate-related atrial myopathy and dilatationRate-related atrial myopathy and dilatation

• Chronic symptoms and reduced sense of well-beingChronic symptoms and reduced sense of well-being

AF: Medical ManagementAF: Medical Management

• Treatment of underlying causeTreatment of underlying cause

• Ventricular rate controlVentricular rate control

• AnticoagulationAnticoagulation

• Antiarrhythmics with a view to restore Antiarrhythmics with a view to restore sinus rhythmsinus rhythm

Control of Ventricular Rate Control of Ventricular Rate in in Atrial FibrillationAtrial Fibrillation• BetablockersBetablockers

• Calcium channel blockersCalcium channel blockers

Verapamil, diltiazemVerapamil, diltiazem

• Digoxin Digoxin

• AmiodaroneAmiodarone

AnticoagulationAnticoagulation

AnticoagulationAnticoagulation

• Assessment of bleeding risk should be part of the Assessment of bleeding risk should be part of the clinical assessment of AF patients prior to starting clinical assessment of AF patients prior to starting anticoagulationanticoagulation

• Antithrombotic benefits and potential bleeding risks of Antithrombotic benefits and potential bleeding risks of long-term coagulation should be explained and discussed long-term coagulation should be explained and discussed with the patientwith the patient

• Aim for a target INR of between 2.0 and 3.0Aim for a target INR of between 2.0 and 3.0

NICE 2006NICE 2006

CHADS 2 scoringCHADS 2 scoring

• Any patients with AF with a score of Any patients with AF with a score of =/>2 would benefit from being on =/>2 would benefit from being on WarfarinWarfarin

CCF CCF

HypertensionHypertension

Age > 75Age > 75

DiabetesDiabetes

Stroke/TIAStroke/TIA

1 point1 point

1 point1 point

1point1point

1 point1 point

2 points2 points

CardioversionCardioversion

Cardioversion Cardioversion

• Cardioversion results in SR in at least 90% Cardioversion results in SR in at least 90% of casesof cases

• SR is only maintained in 30-50% at one SR is only maintained in 30-50% at one yearyear

• Class 1a, 1c and III agents increase Class 1a, 1c and III agents increase likelihood of maintained SR from 30-50% to likelihood of maintained SR from 30-50% to 50-70% at one year50-70% at one year

Follow-up Follow-up

• Follow-up after cardioversion should take Follow-up after cardioversion should take place at 1 month, and the frequency of place at 1 month, and the frequency of subsequent reviews should be tailored to subsequent reviews should be tailored to the patientthe patient

• Reassess the need for anticoagulation at Reassess the need for anticoagulation at each revieweach review

Catheter Ablation for AFCatheter Ablation for AF

AF AblationAF Ablation

• Success rates – approx 70% but may require repeat Success rates – approx 70% but may require repeat procedureprocedure– Often increase in symptoms for first 3-6 months Often increase in symptoms for first 3-6 months

after procedure does not indicate failureafter procedure does not indicate failure

• Risks Risks

– – damage to existing conduction mandating pacingdamage to existing conduction mandating pacing– Cardiac perforation/tamponadeCardiac perforation/tamponade– BleedingBleeding– Stroke/thromboembolismStroke/thromboembolism– DeathDeath

Catheter Ablation: IndicationsCatheter Ablation: Indications

• Symptomatic patientsSymptomatic patients

• Refractory to AntiarrhythmicsRefractory to Antiarrhythmics

• Medical therapy contraindicated due to co-Medical therapy contraindicated due to co-morbidities or intolerancemorbidities or intolerance

NICE 2006NICE 2006

Which AF patients need Which AF patients need Specialist Referral?Specialist Referral?• Patients with:Patients with:

- WPW syndrome- WPW syndrome

- Uncontrolled ventricular rate (> 200/min)- Uncontrolled ventricular rate (> 200/min)

- Tachy-brady syndrome- Tachy-brady syndrome

- For rhythm control strategy- For rhythm control strategy

- CCF- CCF

- Intolerant to Drugs- Intolerant to Drugs

- Invasive options - Invasive options

VENTRICULAR VENTRICULAR ARRHYTHMIASARRHYTHMIAS

• Ventricular tachycardiaVentricular tachycardia

• Torsades De PointesTorsades De Pointes

• Ventricular fibrillationVentricular fibrillation

Ventricular tachycardiaVentricular tachycardia

• Is divided in 2 categories:Is divided in 2 categories:– If it persist for more than 30 seconds If it persist for more than 30 seconds

“sustained VT”“sustained VT”– Less than 30 seconds: “nonsustained VT”Less than 30 seconds: “nonsustained VT”

• Symptoms vary depending on the Symptoms vary depending on the duration.duration.– Major manifestations are hypotension and Major manifestations are hypotension and

loss of consciousness.loss of consciousness.

Non-sustained ventricular Non-sustained ventricular tachycardiatachycardia

• Need to exclude heart disease with Echo Need to exclude heart disease with Echo and stress testingand stress testing

• May need anti-arrhythmia treatment if sxsMay need anti-arrhythmia treatment if sxs

• In presence of heart disease, increased In presence of heart disease, increased risk of sudden deathrisk of sudden death

• Need referral for EPS and/or prolonged Need referral for EPS and/or prolonged Holter monitoringHolter monitoring

• ICD may be life savingICD may be life saving

Torsades De PointesTorsades De Pointes

• Varying amplitudes of the QRS.Varying amplitudes of the QRS.

• It can be produced by It can be produced by afterdepolarizations (triggered activity).afterdepolarizations (triggered activity).

• Particularly in prolonged QT interval.Particularly in prolonged QT interval.

• Occur with some drugs (quinidine), Occur with some drugs (quinidine), electrolite disturbances, and congenital electrolite disturbances, and congenital prolongation of the QT interval.prolongation of the QT interval.

Specialist ReferralSpecialist Referral

ECG Examples ECG Examples

http://upload.wikimedia.org/wikipedia/commons/7/7d/ECG_long-QT_bionerd.jpg

Contact...Contact...

* E-mail: * E-mail: nandkumar.gandhi@sash.nhs.uk

drnmgandhi@hotmail.com

* Fax: 01737 231938* Fax: 01737 231938

* Phone: Spire - 01293 785511* Phone: Spire - 01293 785511

ESH - 01737 768511, ext.6333ESH - 01737 768511, ext.6333