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APPROACH TO THE PATIENT WITH CADIAC ARRHYTHMIA. Masoud Eslami MD Imam Khomeini Hospital. ANY VARIATION FROM THE NORMAL RHYTHM OF THE HEART BEAT IS CALLED ARRHYTHMIA. WHAT IS THE NORMAL RHYTHM OF THE HEART BEAT ?. IT IS CALLED NORMAL SINUS RHYTHM ( NSR )
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APPROACH TO THE PATIENT WITH CADIAC ARRHYTHMIA Masoud Eslami MD Imam Khomeini Hospital
ANY VARIATION FROM THE NORMAL RHYTHM OF THE HEART BEAT IS CALLED ARRHYTHMIA
WHAT IS THE NORMAL RHYTHM OF THE HEART BEAT ? IT IS CALLED NORMAL SINUS RHYTHM ( NSR ) • THE IMPULSE ORIGINATES IN THE SINUS NODE • THE RATE IS BETWEEN 60-100 • THE P WAVE IS UPRIGHT IN I , II AND aVf , NEGATIVE IN aVr AND POSITIVE IN V3-V6 • THE PR INTERVAL IS BETWEEN 120-220MS
ARRHYTHMIAS ARE CLASSIFIED INTO: 1-BRADYARRHYTHMIAS 2-TACHYARRHYTHMIAS
TACHYARRHYTHMIAS • ATRIAL TACHYARRHYTHMIAS • AV JUNCTIONAL TACHYARRHYTHMIAS • VENTRICULAR TACHYARRHYTHMIAS
ATRIAL TACHYARRHYTHMIAS PREMATURE ATRIAL COPMLEXES ( PAC OR APD ) • PREMATURE COMPLEXES ARE AMONG THE MOST COMMON CAUSES OF AN IRREGULAR PULSE • COMMONLY ARISE IN NORMAL HEARTS,BUT THEY ARE MORE OFTEN ASSOCIATED WITH STRUCTURAL HEART DISEASE AND INCREASE IN FREQUENCY WITH AGE
Premature Beats Premature Atrial Contraction (PAC) Origin: Atrium (outside the Sinus Node) Mechanism: Abnormal Automaticity Characteristics: An abnormal P-wave occurring earlier than expected, followed by compensatory pause
Premature Beats Premature Junctional Contraction Origin: AV Node Junction Mechanism: Abnormal Automaticity Characteristics: A normally conducted complex with an absent p-wave, followed by a compensatory pause
PAC PACs CAN OCCUR DURING • INFECTION • INFLAMMATION • MYOCARDIAL ISCHEMIA • BY MEDICATIONS • TENSION STATES • TOBACCO • ALCOHOL • CAFFEINE THEY CAN PRECIPITATE OR PRESAGE THE OCCURRENCE OF SUSTAINED SUPRAVENTRICULAR TACHYARRHYTHMIAS
PAC MANAGEMENT • PACs GENERALLY DO NOT REQUIRE THERAPY • IN SYMPTOMATIC PATIENTS OR WHEN PACs PRECIPITATE TACHYCARDIAS,TREATMENT WITH DIGITALIS,A BETA BLOCKER,OR A CALCIUM ANTAGONIST CAN BE TRIED
PREMATURE VENTRICULAR COMPLEXES( PVC ) • PREMATURE OCCURRENCE OF A QRS COMPLEX THAT IS ABNORMAL IN SHAPE AND HAS A DURATION OF MORE THAN 120 ms • THE PREVALENCE OF PVC INCREASES WITH AGE • SYMPTOMS OF PALPITATIONS OR DISCOMFORT IN THE NECK OR CHEST
Premature Beats Premature Ventricular Contractions (PVCs) Origin: Ventricles Mechanism: Abnormal Automaticity Characteristics: A broad complex occurring earlier than expected, followed by a compensatory pause
PVC Patterns • Bigeminy • Every other beat • Trigeminy Every third beat • Quadrigemin Every fourth beat
Multifocal PVC • Origin: Varies within the Ventricle • Mechanism: Abnormal Automaticity • Characteristics: Each premature beat changes axis; implies a different focus origin for each beat
PVC THE IMPORTANCE OF PVC DEPENDS ON THE CLINICAL SETTING IN THE ABSENCE OF UNDERLYING HEART DISEASE,THE PRESENCE OF PVC HAS NO IMPACT ON LONGEVITY THE SYMPTOMATIC PATIENT SHOULD BE ASSURED
PVC • REASSURANCE AND AVOIDANCE OF POTENTIALLY AGGRAVATING FACTORS ( TOBACCO,COFFEE,CAFFEINE-CONTAINING SOFT DRINKS ),SHOULD BE TRIED FIRST • MILD ANXIOLYTIC DRUGS OR BETA-BLOCKERS ARE PREFERRED
Paroxysmal Supraventricular Tachycardia (PSVT) • Usually at a rate of 150-250 bpm • No organic heart disease in the majority • Presentations • Palpitations • Chest discomfort,dyspnea, lightheadedness • Frank syncope • SCD
AV Nodal Reentrant Tachycardia • The most common form of paroxysmal supraventricular tachycardia (about 70%) • More common in women (66%) • Usually a regular narrow QRS complex tachycardia • No P wave is usually evident during the tachycardia. Retrograde P waves may occasionally be seen at the end of QRS.
AVNRT Origin: AV Node Mechanism: Reentry Rate: 150 - 230 BPM, faster in teenagers Characteristics: Normal QRS with absent P-waves; most common SVT in adults
Atrium Slow Pathway Fast Pathway His Bundle Longitudinal Dissociation Within AV Node
AV Reentrant Tachycardia • Incorporates a bypass tract as part of the tachycardia circuit. • Surface ECG: • Manifest with short PR interval and delta wave (preexcitation) • Concealed with normal ECG • Prevalence of ECG pattern: 0.1% to 0.3%.
Wolff-Parkinson-White Origin: Outside the AV Node Mechanism: Reentry Rate: 180-260 BPM – can be faster Characteristics: Short PR Interval (< 120 ms),wide QRS (> 110 ms), obvious delta wave
AVRT • Mechanism: Reentry • Rate: 180 - 260 BPM, sometimes faster • Characteristics: Extra electrical pathway to ventricles Wolf-Parkinson-White (WPW) Syndrome is most common
PSVTTreatment • Vagal maneuvers particularly carotid sinus massage • AV nodal blocking drugs • Adenosine • Verapamil • Propranolol • Digoxin • DC cardioversion if hypotensive • Radiofrequency ablation
Atrial Flutter • Regular atrial tachyarrhythmia with atrial rate between 250-350 bpm. • Flutter waves are seen as saw-tooth like atrial activity
Atrial Flutter • Typically the ventricular rate is half the atrial rate, but the ventricular response may be 4:1, 1:1, etc. • Atrial Flutter is a form of atrial reentry localized to right atrium.
Atrial Flutter • More common in men (4.7:1) • Most often in patients with organic heart disease • Usually less long-lived than AF and may convert to AF. • Control of ventricular rate is difficult in atrial flutter • The most effective treatment is DC cardioversion
Atrial Fibrillation • The most common sustained arrhythmia • Incidence increases progressively with age. • Prevalence: 0.4% of overall population • Mortality ratedouble that of control • Hypertension and CAD, the most frequent underlying heart diseases • AF is characterized by disorganized atrial activity without discrete P waves
Atrial Fibrillation • Undulating baseline or atrial deflections of varying amplitude and frequency ranging from 350 to 600 bpm. • Irregularly irregular ventricular response.
Atrial Fibrillation • Morbidity related to: • Excessive ventricular rate • Pause following cessation of AF • Systemic embolization • Loss of atrial kick • Anxiety secondary to palpitations • Irregular ventricular rate
Atrial Fibrillation • Persistent AF usually in patients with cardiovascular disease • Valvular heart disease • Hypertensive heart disease • Congenital heart disease • Paroxysmal AF may occur with acute hypoxia, hypercapnia or metabolic or hemodynamic derangements • Normal people with emotional stress or surgery or acute alcoholic intoxication • Lone AF
Atrial Fibrillation • Therapeutic Goals: • Control of ventricular rate • Restoration and maintenance of sinus rhythm • Prevention of thromboembolism