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Narrow complex tachycardia. Dr Julian Johny Thottian DM Cardiology Resident Govt. Medical College, Kozhikode. ANATOMY. OBLIQUE VIEW OF RT ATRIUM SHOWING RE ENTRANT PATHWAY IN ATRIAL FLUTTER. ANATOMY OF VARIOUS ACCESSORY PATHWAYS. ANATOMY OF KOCH`S TRIANGLE. PAC AND CONDUCTION.
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Narrow complex tachycardia Dr Julian JohnyThottian DM Cardiology Resident Govt. Medical College, Kozhikode
ANATOMY OBLIQUE VIEW OF RT ATRIUM SHOWING RE ENTRANT PATHWAY IN ATRIAL FLUTTER ANATOMY OF VARIOUS ACCESSORY PATHWAYS
PAC AND CONDUCTION • PAC –SINGLE/REPETITIVE OR UNIFOCAL / MULTIFOCAL IN ORIGIN • FATES OF PAC DEPENDS UPON 1) Coupling interval from the last P wave 2) Preceding cycle length or Heart rate.
What`s a supraventricular tachycardia? • Heart rhythm disturbance • Initiated either in atria or ventricle • Atrial rates > 100bpm • Requires a tissue above the His bundle to perpetuate it. NARROW COMPLEX TACHCARDIA – A TACHYCARDIA WITH QRS WIDTH <120ms
Characteristics • Symptomatic / asymptomatic • Slow/fast • Regular or irregular • Paroxysmal ,Persistent or Permanent • Generally not life threatening. • Impairs hemodynamics
Classification • AV NODE DEPENDENT • AVNRT 2. AVRT ANTIDROMIC ORTHODROMIC AV NODE INDEPENDENT • ATRIAL TACHYCARDIA • JUNCTIONAL ECTOPIC TACHYCARDIA • ATRIAL FLUTTER • ATRIAL FIBRILLATION
SINUS TACHYCARDIA • SYMPATHETIC ACTIVATION • GRADUAL ACCELERATION & DECELERATION • P WAVE MORPHOLOGY SIMILAR TO SINUS RHYTHM • RARELY EXCEED 200 RATE • ADENOSINE RESPONSE- SLOW AND THEN INCREASE GRADUALLY • INAPPROPRIATE- ST ABNORMAL TO SITUATION
ATRIAL FIBRILLATION Atrial activity is poorly defined & ventricular response is irregularly irregular. THEORY- Multiple wavelets, PV-automaticity, High frequency rotors, Autonomic innervation. A regular ventricular response with A-fib usually indicates high grade or complete AV block
PAROXYSMAL- Recurrent episodes( 2 or more)that terminate within 7 days of onset • PERSISTENT- Episodes that last for more then 7 days or require cardioversion regardless of duration • LONG STANDING PERSISTENT AF- Continuous episodes of persistent AF for> 1yr • PERMANENT – Restoration and maintenance of sinus rhythm has failed or not attempted. • An episode---Should last for 30s - clinical AF • Fine AF- f waves <0.5mv , coarse AF –f waves >0.5mv
Ashman phenomenon- follows a long short sequence Gouaux, JL; Ashman, R (Sep 1947). "Auricular fibrillation with aberration simulating ventricular paroxysmal tachycardia.". American heart journal34 (3): 366–73
ATRIAL FLUTTER • RENTRANT TACHY USUALLY FROM RT ATRIUM • ATRIAL RATE -200-350BPM • TYPE 1 – TERMINATED BY ATRIAL PACING, ATRIAL RATE UPTO 240 • TYPE II- CANNOT BE TERMINATED BY ATRIAL PACING ATRIAL RATE BETWEEN 240-330/MT • MC –COUNTERCLOCKWISE- SAW TOOTHED APPEARANCE IN II, III, AVF/ NO ISO ELECTRIC SEGMENT IN BETWEEN- 90% • 10%- CLOCKWISE • ATYPICAL FORMS- LOWER/UPPER LOOP RE ENTRY/ FIGURE OF EIGHT RE ENTRY
ATRIAL TACHYCARDIA • ORIGINATE- LT,RT ATRIUMS/ VENA CAVAE/PV • FOCAL-TRIGGERED/MICROREENTRANT/AUTOMATIC • P OF DIFFERENT MORPHOLOGY • PR VARIES • ATRIAL RATES- 120-200BPM • 1:1 CONDUCTION/AV BLOCK • ADENOSINE CAN OCCASIONALLY STOP TACHY • DIGOXIN TOXICITY- AT WITH AV BLOCK
Focal Atrial tachycardia • AUTOMATIC AT- GRADUAL ONSET(WARM UP)/OFFSET MAY NOT START WITH PREMATURE BEAT P WAVE DIFFERENT CONFUSION WITH ST & ASSOC ADENOSINE INSENSITIVITY TRIGGERED WITH ISOPROTERENOL & NOT WITH PROGRAMMED STIMULATION RAPID STIMULATION MAY NOT INITIATE THE TACHYCARDIA • TRIGGERED AT – SUDDEN ONSET/OFFSET ASSOC WITH RAPID PACING , DAD?? ADENOSINE TERMINATION CATECHOLAMINE DEPENDENT PERSISTENT TACHY- CARDIOMYOPATHY • MICRO ENTRY AT- TERMINATION WITH VERAPAMIL,INITATED AND TERMINATED BY PACING
Intra Atrial re entrant tachycardia • MACRO/MICRO REENTRY- SCAR INCISIONS LIKE FONTAN • DISCRETE P WAVES AND ISO ELECTRIC BASELINE • ADENOSINE MAY TERMINATE-15% CASES
SANRT • MICROREENTRANT TACHYCARDIA • P WAVE MORPHOLOGY SIMILAR • USUALLY PRECIPITATED AND TERMINATED BY PREMATURE ATRIAL COMPLEXES. • ATRIAL RATE IS USUALLY 120-150 BPM. • STOPS AND STARTS ABRUPTLY • AV BLOCK CAN OCCUR.
MULTIFOCAL ATRIAL TACHYCARDIA • ALSO KNOWN AS CHAOTIC ATRIAL TACHYCARDIA • ACTIVATION FROM MULTIPLE PLACES • ATLEAST 3 DIFFERENT P WAVE MORPHOLOGIES • ISOELECTRIC BASELINE BETWEEN P WAVES • ATRIAL RATE -110-170BPM • COPD,ELDERLY ,SEPSIS,HT • EXACERBATED BY THEOPHYLLINE
AVNRT • PRESENCE OF 2 PHYSIOLOGICAL/ANATOMICAL AV NODAL PATHWAYS • 65% OF REGULAR SVT • ACTIVATION- VIA SLOW FIRST THEN FAST • RATES 150-200BPM • BEGINS WITH PREMATURE ATRIAL DEPOLARISATION • PSEUDO R`- V1,PSEUDO S-II III AVF • W>M MORE IN ADULTS • STOPS WITH VAGAL MANEUVRES ABRUPTLY
AVNRT • NO P waves • P waves are retrograde and are inverted in leads II,III,AVF. • P waves are buried in the QRS complexes –simultaneous activation of atria and ventricles – most common presentation of AVNRT –66%. • If not synchronous –pseudo s wave in inferior leads ,pseudo r’ wave in lead V1---30% cases . • P wave may be farther away from QRS complex distorting the ST segment ---AVNRT ,mostly AVRT.
AVRT • Typical – RP interval < PR interval • RP interval > 80 milli sec • Atypical –RP interval > PR interval • Concealed bypass tract – only retrograde conduction • Manifest bypass tract– both anterograde and retrograde. • Electrical alternans –the amplitude of QRS complexes varies by 5 mm alternatively. • Rate related BBB occuring and the rate of tachycardia is decreasing –then the bypass tract is on the same side of the block.
PRinterval PR interval RP interval
AVRT • MACRO RE ENTRANT CIRCUIT • TYPICAL- ANTEGRADE –AV NODE RETROGRADE VIA ACCESSORY PATHWAY- ORTHODROMIC -30% REGULAR SVT • QRS ALTERNANS • CAN BE CONCEALED/MANIFEST • DELTA WAVE • STOPS WITH VAGAL MANEUVRES ABRUPTLY
PRE EXCITATION SYNDROMES • WPW PATTERN-MANIFEST ANTEGRADE CONDUCTION THROUGH AP-PRE EXCITE THE VENTRICLE-WPW PATTERN • ASSOC WITH PALPITATIONS –WPW SYNDROME • ORTHODROMIC SVT IS THE MOST COMMON • IN 10% ANTEGRADE CONDUCTION VIA AP
WPW syndrome • Two types • Orthodromic • Antidromic • Antidromic is wide complex tachycardia • In NSR detected by delta wave. • Can ppt AF and VF on use of AV nodal blockers • MEMBRANE ACTIVE ANTIARRHTYHMIC DRUGS are safe. • CONCEALED WPW syndrome – no delta wave .less risk of AF
OTHER PRE EXCITATIONS • MAHAIM- ATRIOFASCICULAR PATHWAY CONNECTS ATRIUM TO RT BUNDLE BYPASSING AV NODE • DECREMENTAL PROPERTIES • SHORT PR WITH NO MANIFEST PRE EXCITATION • LAD & LBBB- RA TO RT BUNDLE • MAHAIM CONDUCT IN ANTEROGRADE DIRECTION ONLY
PERMANENT JUNCTIONAL RECIPROCATING TACHYCARDIA • PJRT- PERSISTENT AVRT CONDUCTION VIA AV NODE>> POSTEROSEPTAL SLOW AP • LONG RP TACHCARDIA • P FAR AFTER QRS
JUNCTIONAL ECTOPIC TACHYCARDIA • AUTOMATIC / TRIGGERED • ORIGINATES AROUND AV NODE • PERSISTENT RHYTHM • DOESNOT GENERALLY TERMINATE WITH ADENOSINE • CHILDREN POST CARDIAC SX, AMI, CARDIOVERSION OF AF, MYOCARDITIS ,DIGOXIN TOXICITY • SVT WITH AV DISSOCIATION
DIAGNOSIS • ABRUPT RAPID PALPITATIONS • DIZZINESS • SYNCOPE WITH VERY FAST RATE • DYSPNOEA • CHEST DISCOMFORT • RELIEF WITH VAGAL MANEUVRES • CANNON WAVES- TYPICAL AVNRT • IRREGULAR PULSE ,PULSE DEFICIT> 10 IN AF