¼±Åà - È­»ìǥŰ/¿£ÅÍŰ ´Ý±â - ESC

 

Tachyarrhythmia

1. Mechanism

* 2 mx i) disorders of impulse propagation = reentry

ii) disorders of impulse formation = enhanced automaticity, triggered activity

1) Reentry

- sustained paroxysmal tachyarrhythmiaÀÇ mc mx

- reentry¸¦ ½ÃÀÛÇϱâ À§Çؼ­´Â ´ÙÀ½ »çÇ×µéÀÌ ÇÊ¿äÇÏ´Ù.

i) electrophysiologic inhomogeneity°¡ ÇϳªÀÇ circuitÇü¼º

: closed loopÀ¸·Î ¿¬°áµÇ¾î ÀÖ´Â 2°÷ À̻󿡼­ conduction and/or refractorinessÀÇ

Â÷À̰¡ ÀÖ¾î¾ß ÇÑ´Ù.

ii) unidirectional block in one pathway

iii) slow conduction over an alternative pathway

óÀ½¿¡ blocked pathway°¡ ÈïºÐ¼ºÀ» ȸº¹ÇÒ ½Ã°£À» Á¦°øÇÑ´Ù.

iv) ÇѹÙÄû activationÀ» ¸¶Ä£ initially blocked pathwayÀÇ reexcitation

- reentrant arrhythmia´Â premature complex³ª rapid stimulation¿¡ ÀÇÇØ ½ÃÀ۵ǰųª

Á¾·áµÉ¼ö ÀÖ´Ù.

2) Enhanced automaticity

- myocardial cellÀº Á¤»óÀûÀ¸·Î´Â pacemaker activity¸¦ °®Áö ¾Ê´Â´Ù.

- ´ÙÀ½°ú °°Àº pathophysiologic state¿¡¼­ latent pacemaker fiberÀÇ normal automaticity

°¡ Áõ°¡µÇ°Å³ª potential depolarization¿¡ ÀÇÇÑ resting membraneÀÇ abnormal

automaticity°¡ ¹ß»ýÇÒ¼ö ÀÖ´Ù.

i) endogenous or exogenous catecholamine¡è

ii) electrolyte disturbance(¿¹, hypokalemia)

iii) hypoxia or ischemia

iv) mechanical effect(¿¹, stretch)

v) drug(¿¹, digitalis)

- automaticity¿¡ ÀÇÇØ À¯¹ßµÈ tachycardia´Â pacing¿¡ ÀÇÇØ ½ÃÀ۵ǰųª ÁߴܵÇÁö ¾Ê´Â´Ù.

3) Triggered activity

early afterdepolarizationȤÀº delayed afterdepolarization¿¡ ÀÇÇØ ¹ß»ýÇÒ¼ö ÀÖ´Ù.

¨ç early afterdepolarization

action potential phase 2,3µ¿¾È¿¡ ¹ß»ý

´ÙÀ½ »óȲ¿¡¼­ triggered activity°¡ ¹ß»ýÇÒ¼ö ÀÖ´Ù.

: bradycardia, hypokalemia, or action potentialÀ» ¿¬Àå½ÃŰ´Â »óÅÂ

¿¹> TdP

¨è delayed afterdepolarization

phase 3°¡ Á¾·áµÈ ÀÌÈÄ¿¡ ¹ß»ý

´ÙÀ½ »óȲ¿¡¼­ ¹ß»ýÇÒ¼ö ÀÖ´Ù.

: local catecholamine concentration¡è, hyperkalemia, hypercalcemia,

digitalis intoxication

¿¹> tachycardia associated with digitalis intoxication

accelerated idioventricular rhythm in acute infarction and/or reperfusion

exercise-induced VT

2. Premature complexes

1) APC (Fig 230-2)

- 24h Holter monitoring»ó Á¤»ó¼ºÀÎÀÇ 60% À̻󿡼­ ¹ß°ßµÈ´Ù.

- susceptible pt´Â PSVT·Î °¡±âµµ ÇÑ´Ù.

- early P wave´Â ÇüŰ¡ sinus P wave¿Í´Â ´Ù¸£°í, cardiac cycleÀÇ Èı⿡´Â ventricle

·Î Àüµµ°¡ °¡´ÉÇÏÁö¸¸ early APCs´Â relative refractory period¿¡ °É¸®°Ô µÇ¾î Àüµµ°¡

Áö¿¬µÇ¾î PR intervalÀÌ prolongationµÇ¾î ³ªÅ¸³­´Ù.

- pre- & post extrasystolic PP intervalÀº two sinus PP intervalÀÇ ÇÕº¸´Ù °£°ÝÀÌ ÀÛ´Ù.

- ´ëºÎºÐ ¹«Áõ»óÀ̸ç Ä¡·á°¡ ÇÊ¿ä¾ø´Ù.

- palpitation or PSVT¸¦ À¯¹ßÇϸé Ä¡·á°¡ ÇÊ¿äÇÒ¼ö ÀÖ´Ù.

- À¯¹ßÀÎÀÚ(alcohol, tobacco, or adrenergic stimulation)¸¦ ¾ø¾Ö°í, ¾ø´Ù¸é mild sedation

½ÃÄѺ¼¼ö ÀÖ°í, ¥â-blocker¸¦ »ç¿ëÇØ º¼¼öµµ ÀÖ´Ù.

2) AV junctional complexes

- normal AV node´Â automaticity°¡ ¾ø±â ¶§¹®¿¡ AV junctional complexÀÇ ±â¿øÀº

His bundle·Î »ý°¢µÈ´Ù.

- APC³ª VPCº¸´Ù´Â ´ú ÈçÇϸç ÈçÈ÷ cardiac disease or digitalis intoxication°ú °ü·Ã

ÀÖ´Ù.

- antegradely & retrogradely µÑ´Ù Àüµµ °¡´ÉÇÏ´Ù.

- premature AV junctional complexes´Â ¼±ÇàÇÏ´Â P wave¾øÀÌ normal appearing QRS

complexes¿¡ ÀÇÇØ ÀÎÁöµÇ±âµµ Çϰí retrograde P wave(lead II, III, aVF¿¡¼­ inverted)

°¡ ³ªÅ¸³ª±âµµ ÇÑ´Ù.

- ÁÖ·Î asymptomaticÇÏÁö¸¸ palpitation°ú cannon a wave¿Í °ü·ÃµÇ±âµµ Çϸç ÀÌ´Â neck

pulsationÀ¸·Î ³ªÅ¸³ª±âµµ ÇÑ´Ù. Áõ»óÀÌ ÀÖÀ¸¸é APCó·³ Ä¡·áÇÑ´Ù.

3) VPCs

: wide(>0.14s), bizarre QRS complex, P wave(-)

- °¡Àå ÈçÇÑ ºÎÁ¤¸ÆÁß ÇϳªÀ̸ç, heart dsÀ¯¹«¿¡ »ó°ü¾øÀÌ ¹ß»ýÇÒ¼ö ÀÖ´Ù.

- ¼ºÀÎ ³²¼ºÀÇ 60% À̻󿡼­ VPCs°¡ º¸ÀδÙ.

- heart disease°¡ ¾ø´Ù¸é mortality, morbidityÁõ°¡¿Í °ü·ÃÀÌ ¾ø´Ù.

- previous MIȯÀÚÀÇ 80%°¡±îÀÌ VPC°¡ ¹ß»ýÇϴµ¥ À̶§

frequent(>10ȸ/1hr) and/or complex(couplets) VPCÀ϶§´Â mortalityÁõ°¡¿Í °ü·ÃÀÖ´Ù.

±×·¯³ª ±×·± ȯÀÚ¿¡¼­ cardiac mortality´Â ÈçÈ÷ impaired LV dysfunction°ú °ü·ÃÇÏ¿©

¹ß»ýÇÑ´Ù.

- frequent & complex VPC°¡ independent risk factorÀÌÁö¸¸ impaired LV dysfx¸¸Å­

°­ÇÑ risk factor´Â ¾Æ´Ï´Ù.

- spontaneous ectopy¿Í life-threatening VT or VF¿ÍÀÇ ¿øÀÎ-°á°ú »çÀÌÀÇ °ü·Ã¼ºÀº

È®¸³µÇ¾î ÀÖÁö ¾Ê´Ù.

- very early cycle(R-on-T) VPCs´Â sudden deathÀÇ risk°¡ ³ô´Ù°í ÇÏ¿´´Ù.

- ºñ·Ï R-on-T°¡ acute ischemia¿Í QT prolongation¶§ º¼¼ö ÀÖÁö¸¸ ÈçÈ÷ VT or VF°¡

prior beatÀÇ T waveÈÄ¿¡ ¹ß»ýÇÏ´Â VPC¿¡ ÀÇÇØ À¯¹ßµÈ´Ù.

- ¼±ÇàÇÏ´Â sinus complex¿Í fixed relationshipÀÌ ÀϹÝÀûÀÌÁö¸¸ VPC»çÀÌ¿¡ °£°ÝÀÌ ÀÏÁ¤

ÇÑ °æ¿ìµµ ÀÖ´Ù.(=ventricular parasystole, Fig 230-4)

ÀÌ·± °æ¿ì VPC´Â ventricular focus¿¡¼­ abnormal automaticity¸¦ º¸ÀδÙ.

* VPCÀÇ ÇüÅÂ

singly

bigeminy : sinus beat-VPC°¡ ¹ø°¥¾Æ ³ª¿È

trigeminy : sinsu beat-sinus beat-VPC

2 successive VPCs = pairs or couplets

3°³ ÀÌ»ó ¿¬¼ÓÇØ ³ª¿À¸é¼­ rate°¡ 100/minÀÌ»óÀ϶§ = VT

* ¸ð¾ç¿¡ µû¶ó : monomorphic(=uniform) or polymorphic(=multiformed)

- ÈçÈ÷ VPC´Â retrograde·Î´Â ÀüµµµÇÁö ¾Ê°í SA node¸¦ reset½ÃŰÁöµµ ¾Ê´Â´Ù.

±×·¯¹Ç·Î VPC´Â fully compensated pause¸¦ ¸¸µç´Ù.

Áï, 2 basic RR interval = RR¡Ç

- ventricular impulse°¡ retrograde conductionÇÏ¿© inverted P wave¸¦ ¸¸µé±âµµ ÇÑ´Ù

(lead II, III, aVF).

À̶§´Â sinus node¸¦ reset½ÃÄÑ less compensatory result¸¦ ÃÊ·¡ÇÑ´Ù.

- ¸¹Àº ¿¹¿¡¼­, VPC´Â retrograde VA conduction°ú´Â °ü·ÃÀÌ ¾ø°í AV node¿¡¼­

retrogradely blockµÈ´Ù.

- subsequent sinus beat¿¡ ´ëÇÑ AV node refractoriness´Â slowed conductionÀ» À¯¹ß

ÇѰųª(=PR prolongation) or next P wave¸¦ block½ÃŲ´Ù.

ÀÌ·¯ÇÑ prolonged PR intervalÀº ventricular impulseÀÇ AV node·ÎÀÇ concealed

retrograde conductionÀ» ÀǹÌÇÏ´Â °ÍÀÌ´Ù.

* interpolated VPC : retrograde concealed conductionÀ» ÀÏÀ¸Å°Áö ¾Ê°í, oncoming sinus

impulse¿¡ ¿µÇâÀ» ÁÖÁö ¾Ê¾Æ¼­.

- VPCs´Â palpitation ¶Ç´Â cannon a wave, ventricular contractility·Î ¼öÃà·ÂÀÌ

Áõ°¡µÇ¾î neck pulsationÀ» ÀÏÀ¸Å³¼ö ÀÖ´Ù.

- frequent VPC or bigeminy´Â syncope or lightheadedness¸¦ °ÅÀÇ ÀÏÀ¸Å°Áö ¾Ê´Âµ¥

ÀÌ´Â VPC°¡ HR¸¦ "halving"(¹ÝÀ¸·Î) ÇÔÀ¸·Î½á S.V & C.OÀ» °¨¼Ò½ÃŰÁö ¾Ê±â ¶§¹®ÀÌ´Ù.

<Ä¡·á>

¨ç cardiac disease°¡ ¾ø°í, isolated asymptomatic VPC : Ä¡·á Çʿ䡿

¨è symptomatic

i) anxiety¶§¹®À¸·Î »ý°¢

ii) ¥â-blocker : ³·¿¡ ÁÖ·Î »ý±â°Å³ª, stressful situationÀÏ ¶§,

MVP & thyrotoxicosisÀ϶§ È¿°úÀû

¨é cardiac dsÀÖÀ» ¶§

frequent VPC = sudden & nonsudden cardiac death risk¡è

¿¹¹æÀû Ç׺ÎÁ¤¸Æ ¾àÁ¦´Â Àüü »ç¸Á·üÀ» ¿ÀÈ÷·Á Áõ°¡(¡ñproarrhythmic effect)

½ÃŰ¹Ç·Î »ç¿ë±ÝÁö(Cardiac Arrhythmia Suppression Trial, CAST)

¨ê EPS & ICD

high risk of sudden death

LVEF<40% & nonsustained VTȯÀÚ¿¡¼­ Ä¡·á

¨ë IV ¥â-blocker : primary VT ºóµµ¸¦ °¨¼Ò½ÃÄ×´Ù°í º¸°í

3. Tachycardia

1) Sinus tachycardia

HR > 100/min, primary arrhythmia°¡ ¾Æ´Ï´Ù.

¿©·¯ °¡Áö stress¿¡ ´ëÇÑ physiologic responseÀÌ´Ù.

: fever, volume depletion, anxiety, exercise, thyrotoxicosis, hypoxemia

hypotension, congestive heart failure

P wave°¡ QRS complex¾Õ¿¡ Ç×»ó ¼±ÇàÇÑ´Ù.

*Ä¡·á : primary arrythmia¸¦ Ä¡·áÇØ¼± ¾ÈµÇ°í primary disorder¸¦ Ä¡·áÇØ¾ß ÇÑ´Ù.

¿¹> HF¿¡ ´ëÇØ¼± digitalis or diuretics

hypoxemia -> O2, thyrotoxicosis tx

fever -> aspirin, emotional upset -> tranquilizer

2) Atrial fibrillation

- paroxysmal form & persistent form

- Á¤»óÀο¡¼­µµ º¼¼ö ÀÖ´Ù.

: ƯÈ÷ emotional stress, ¼ö¼úÈÄ, exercise, vagal tone¡è(vasovagal response)

- heart or lung disease pt¿¡¼­µµ º¼¼ö ÀÖ´Ù.

: hypoxia, hypercapnea, metabolic or hemodynamic derangement

- Persistent AF : cardiovascular dsȯÀÚ¿¡¼­ ÈçÇÏ´Ù.

: RHD, nonrheumatic MV ds, hypertensive cardiovascular ds, chronic lung ds, ASD

- lone AF : underlying heart disease¾øÀÌ AF´Üµ¶À¸·Î ¿Ã¶§.

- thyrotoxicosisÀÇ Ã¹ ¼Ò°ßÀϼöµµ ÀÖ´Ù.

* AF¿Í °ü·ÃÇÑ morbidity 5°¡Áö

i) excessive ventricular rate -> hypotension, pul. congestion, angina pectoris

ii) AF cessationÈÄÀÇ pause -> syncope

iii) systemic embolization : RHD¿¡¼­ °¡Àå ÈçÈ÷ ¹ß»ý

iv) C.O¿¡ atrial contractionÀÇ ±â¿©¡¿ -> fatigue

v) palpitation -> secondary anxiety

- persistnent rapid rate¿¡¼­´Â ¶ÇÇÑ cardiomyopathy¸¦ ÀÏÀ¸Å³¼ö ÀÖ´Ù.

: tachycardia-induced cardiomyopathy

* EKG

i) disorganized atrial activity ; ºÐ¸íÇÑ P wave°¡ ¾ø´Ù.

ii) undulating baseline

iii) sharply inscribed atrial deflection of varying amplitude & frequency(350-600 bpm)

iv) ventricular response : irregulary irregular

¡ñ AV node¸¦ Áö³ª´Â ¸¹Àº atrial impulse°¡ refractory period¿¡ °É¸®±â ¶§¹®

nonconducted atrial impulse´Â ´ÙÀ½ atrial impulse¿¡ ¿µÇâÀ» ¹ÌÄ¡´Âµ¥ ÀÌ·¯ÇÑ È¿°ú¸¦

"concealed conduction"À̶ó ÇÑ´Ù.

±× °á°ú ventricular response´Â atrial rateº¸´Ù ´À¸®´Ù.

- AF°¡ atral flutter·Î ÀüȯµÇ±âµµ ÇÑ´Ù. ƯÈ÷ quinidineÀ̳ª flecainide°°Àº antiarrhythmic

drug¿¡ ¹ÝÀÀÇØ¼­.

- AF°¡ atrial flutter·Î Àüȯ½Ã atrial rate´Â ´À·ÁÁø´Ù. ±× °á°ú concealed conductionÀÌ °¨¼Ò

ÇÏ°Ô µÇ°í ventricular responseÀÇ paradoxic increase°¡ ¹ß»ý³­´Ù.

- AFÁ¸ÀçÇÏ¿¡¼­ ¸¸¾à ventricular rhythmÀÌ regular & slow(30-60 bpm)ÇÏ´Ù¸é

=> complete heart blockÀǽÉÇϰí

regular & rapid(100 bpm¡è)ÇÏ´Ù¸é

=> AV junction or ventricle¿¡¼­ À¯¹ßµÈ tachycardia¸¦ ÀǽÉÇÑ´Ù.

: À§ µÎ°¡Áö Çö»óÀÇ ÈçÇÑ ¿øÀÎÀº digitalis intoxication ÀÌ´Ù.

- JVP : a wave¼Ò½Ç

- LA enlargement : LA >4.5cmÀ϶§ sinus rhythmÀ¸·ÎÀÇ ÀüȯÀº ºÒ°¡´É

*Ä¡·á : i) precipitating factor ã¾Æ¼­ Á¦°Å

- fever, pneumonia, alcoholic intoxication, thyrotoxicosis, pul. emboli,

CHF, pericarditis

ii) ÀÓ»ó»óŰ¡ ½ÉÇÏ°Ô À§Å·οì¸é electrical cardioversion : TOC

iii) severe cardiovascular compromise°¡ ¾ø´Ù¸é

ventricular rate¸¦ ³·Ãß´Â °ÍÀÌ Ã³À½ Ä¡·áÀÇ ¸ñÇ¥

: ¥â-blocker and/or Ca channel blocker = AV refractory period¡è

catecholamine levelÀÌ Áõ°¡ÇÑ °æ¿ì¿£ ¥â-blocker°¡ ´õ ÁÁ´Ù.

digitalis : less effective

iv) cardioversion to sinus rhythm

drug : type IA(quinidine-like) or flecainide-like type IC drug

electrical : medical tx¿¡ ½ÇÆÐ½Ã. 200J

anticoagulation½ÃÇà, 3ÁÖÀüºÎÅÍ cardioversion 4ÁÖÈıîÁö.

v) cardioversion ¾ÈµÉ¶§ÀÇ Ä¡·á¸ñÇ¥ : ventricular response control

: digitalis, ¥â-blocker, Ca channel blocker

¾à¹°·Î ¾ÈµÉ¶§´Â radiofrequency catheter ablationÀ¸·Î complete AV block

À¯¹ßÈÄ permanent pacemaker implantation

vi) sinus rhythmÀ¸·Î Àüȯ½Ã Àç¹ß¹æÁö

: quinidine, Ic(flecainide), amiodarone

vii) anticoagulation (Tab 230-1,3)

viii) Ablation tx

3) Atrial flutter

- ÈçÈ÷ organic herat ds°¡ ÀÖ´Ù.

- paroxysmalÇÑ °æ¿ì¿£ ÈçÈ÷ À¯¹ßÀÎÀÚ°¡ ÀÖ´Ù: pericarditis, acute resp. failure

- AF, Atrial flutterµÑ´Ù open heart surgeryÈÄ 1ÁÖÀϵ¿¾È ¾ÆÁÖ ÈçÇÏ´Ù.

- Atrial flutter°¡ 1ÁÖÀÌ»ó Áö¼Ó½Ã AF·Î ÀüȯÇϸç systemic embolizationÀº AFº¸´Ù ´ú ÈçÇÏ´Ù.

- atrial rate : 250-350 bpm

typical ventricular rate : 1/2 ¡¿ atrial rate(´ë·« 150 bpm)

- quinidine°°Àº Ç׺ÎÁ¤¸Æ ¾à¹°·Î atrial rate¸¦ 220ȸ ÀÌÇÏ·Î ¶³¾î¶ß¸®¸é ventricular rate°¡

°©ÀÚ±â Áõ°¡ÇÑ´Ù. ¡ñ 1:1 conduction¶§¹®

- ÀüÇüÀûÀÎ flutter wave ; regular sawtooth-like atrial activity(inf. lead¿¡¼­ °¡Àå Àú¸í)

*Ä¡·á

i) °¡Àå È¿°úÀûÀÎ Ä¡·á: direct-current(DC) cardioversion (25-50J) under mild sedation

100-200Jµµ »ç¿ë

ii) ȯÀÚ»óŰ¡ Áï°¢ÀûÀÎ cardioversionÀ» ÇÒ¼ö ¾øÀ»¶§

AV node¸¦ block½ÃÄÑ ventricular rate¸¦ ´À¸®°Ô ÇÑ´Ù.

: ¥â-blocker, Ca antagonist, digitalis cf. digitalis - least effect, °¡²û AF·Î Àüȯ

ÀÏ´Ü rate¸¦ ´À¸®°Ô ÇÑÈÄ sinus rhythmÀ¸·Î ÀüȯÀ» ½Ãµµ: class IA or IC, or

amiodarone

iii) Àç¹ß¹æÁö: quinidine, or other IA, flecainide, propafenone, amiodarone, sotalol

iv) radiofrequency ablation - highly effective

4) PSVT (Fig 230-7)

- AV nodeÀÇ conduction & refractorinessÀÇ Â÷ÀÌ(AVNRT) ȤÀº bypass tract(AVRT)¿¡ ÀÇÇØ

PSVT°¡ ¹ß»ýÇÑ´Ù(Á¾Àü¿¡´Â paroxysmal atrial tachycardia¶ó°í ºÎ¸§).

- PSVTÀÇ ´ëºÎºÐÀº reentry°¡ ¿øÀÎÀÌ´Ù.

- conduction

: AV node¸¦ ÅëÇÑ antegrade conduction, bypass tractÀ» ÅëÇÑ retrograde conduction

- WPW syndrome¿¡¼­´Â bypass tractÀ» ÅëÇÏ¿© antegrade conductionµÉ¼ö ÀÖ´Ù.

- bypass tractÀ¸·Î retrograde conduction¸¸ µÉ¶§¸¦ "concealed bypass tract"À̶ó ÇÑ´Ù.

- WPW syndromeÀÌ ¾øÀ»¶§, AV node¸¦ ÅëÇÑ reentry ȤÀº concealed bypass tractÀ» ÅëÇÑ

reentry°¡ Àüü PSVTÀÇ 90%ÀÌ»óÀ» Â÷ÁöÇÑ´Ù.

5) AVNRT - PSVTÀÇ °¡Àå ÈçÇÑ ¿øÀÎ (Fig230-8)

- Àß ¹ß»ýÇÏ´Â ¿¬·ÉÀ̳ª disease predispositionÀº ¾øÀ¸³ª(¾îµð¼­³ª ¹ß»ýÇÑ´Ù) ¿©¼º¿¡¼­

´õ ÈçÇÏ´Ù.

- SVTÀÇ °¡Àå ÈçÇÑ ÇüÅÂÀ̸ç 120-150 bpmÀÇ regular narrow QRS complex tachycardia·Î

³ªÅ¸³­´Ù.

- retrograde P wave´Â ¾ø°Å³ª ¹¯Çô ÀÖ°í ȤÀº QRS ³¡ºÎºÐ¿¡ ³ªÅ¸³¯¼ö ÀÖ´Ù.

: retrograde atrial activation°ú antegrade ventricular activationÀÌ µ¿½Ã¿¡ ÀϾ¸é

P wave´Â surface ECG¿¡¼­ º¸ÀÌÁö ¾Ê°Ô µÈ´Ù.

- AVNRT°¡ ½ÃÀÛÇÏ´Â APCs´Â °ÅÀÇ Ç×»ó PR intervalÀÌ prolongationµÇ¾î ÀÖ´Ù.

ÀÌ´Â APCÈÄ¿¡ ½ÉÇÑ AV nodal conduction delay(prolonged AH interval)°¡ ¿À±â ¶§¹®À̸ç

AVNRT¹ß»ý¿¡ ¾ÆÁÖ Áß¿äÇÏ´Ù.

ÀÌ·¯ÇÑ AH intervalÀÇ °©ÀÛ½º·± ¿¬ÀåÀº dual AV nodal pathway·Î ÀÌÇØÇØ¾ß ÇÑ´Ù.

: reentry circuit = AV node, HR = 120-250ȸ

dual AV nodal pathway

¥á pathway = slow but short refractory period

¥â pathway = rapid but long refractory period

* Fig 230-8

A. NSR¿¡¼­´Â ¥á,¥â pathway·Î ¸ðµÎ conductionÇÏÁö¸¸ ¥â(fast) pathway°¡ ¿ì¼¼ÇÏ´Ù.

¡Å PR intervalÀº normalÀÌ´Ù. 0.16sec

B. atrial premature depolÀÌ ¿Â´Ù¸é ¥â pathway´Â refractory period°¡ ±æ±â ¶§¹®¿¡ block

µÇ°í ¥á pathway¸¦ ÅëÇÏ¿© slow conductionµÉ°ÍÀÌ´Ù.

C. ¸¸¾à ¥á pathway·ÎÀÇ conductionÀÌ ³Ê¹« ´À·Á refractory ¥â pathway°¡ excitability¸¦

ȸº¹ÇÒ ½Ã°£À» °®´Â´Ù¸é impulse´Â ¥â pathway·Î retrograde conductionµÇ¾î single atrial

echoȤÀº sustained tachycardia¸¦ Çü¼ºÇÑ´Ù.

* ÀÓ»óƯ¡

: palpitation, syncope & heart failure

ventricular filling¿¡ ±â¿©ÇÏ´Â atrial contributionÀÌ °©ÀÚ±â ¼Ò½ÇµÇ¾î ¹ß»ýÇÑ´Ù.

-> atrial pr»ó½Â, acute pul. edema

ventricular filling°¨¼Ò¸¦ ÀÏÀ¸Å³¼ö ÀÖ´Ù.

atrial & ventricular contractionÀÌ µ¿½Ã¿¡ ÀϾ¼­ cannon a wave°¡ »ý±æ¼öµµ ÀÖ´Ù.

* Ä¡·á

i) hypotensionÀÌ ¾ø´Ù¸é ¸ÕÀú vagal maneuver : carotid sinus massage - 80%¿¡¼­ Á¾°á

ii) hypotensionÀÌ ÀÖ´Ù¸é IV phenylephrine 0.1mg IV + carotid sinus massage

iii) À§ÀÇ ¹æ¹ýÀÌ ¼º°øÇÏÁö ¸øÇϸé IV verapamil(2.5-10mg) or IV adenosine(6-12mg)ÀÌ choice

: adenosineÀº ¹Ý°¨±â°¡ ª°í ºÎÀÛ¿ëÀÌ ÀûÀ¸¹Ç·Î ´õ ¼±È£µÈ´Ù.

iv) ¥â-blocker : 2nd choice

¡ÚÁÖÀÇ : Digitalis´Â ÀÛ¿ë½Ã°£ÀÌ ´À·Á¼­ acute tx·Î´Â »ç¿ëÇÏÁö ¸»°Í.

v) ¾à¹°Ä¡·á¿¡ ½ÇÆÐÇϰųª Àç¹ßÇÒ¶§

: temporary pacemaker¸¦ ÀÌ¿ëÇÑ atrial or ventricular pacing

vi) DC cardioversion

tachycardia¿¡ ÀÇÇØ severe ischemia and/or hypotension¹ß»ý½Ã °í·Á

vii) Àç¹ß¹æÁö

ÀÏÂ÷ÀûÀ¸·Î antegrade slow pathway¿¡ ÀÛ¿ëÇÏ´Â ¾à¹°(digitalis,¥â-blocker, CCB) or

fast pathway¿¡ ÀÛ¿ëÇÏ´Â ¾à¹°(class IA, IC)»ç¿ë.

: ¥â-blocker, CCB or digoxinÀÌ ´õ ³ªÀºµ¥ risk-benefit¸é¿¡¼­ IA, ICº¸´Ù ³´±â ¶§¹®.

viii) radiofrequency catheter modification

chronic tx¸¦ ÇÊ¿ä·Î ÇÏ´Â symptomatic pt¿¡¼­ °í·Á, 90%À̻󿡼­ ¼º°øÀû

permanent pacemaker¸¦ ÇÊ¿ä·Î ÇÒ´Â heart blockÀÇ risk : 1-2%

6) AVRT

- concealed AV bypass tractÀ» ÅëÇÑ reentry

- bypass tractÀº ´ëºÎºÐ ¿ÞÂÊ¿¡ ÀÖÀ¸¹Ç·Î ventricular pacingµ¿¾È earlist activation

sequence´Â LA(coronary sinus¿¡ ÀÖ´Â catheter)¿¡¼­ ±â·ÏµÈ´Ù.

- sinus rhythmÀ̳ª ´Ù¸¥ atrial tachyarrhythmiaµ¿¾È antegrade directionÀ¸·Î conduction

ÇÒ¼ø ¾ø´Ù.

- APCs³ª VPCs·Î ½ÃÀÛÇϰųª Á¾·áµÉ¼ö ÀÖÀ¸¸ç VPCs·Î PSVT°¡ ½ÃÀÛÇÒ¶§´Â AVRT·Î Áø´Ü

ÇÒ¼ö ÀÖ´Ù.

- AV reentry¶§ ventricular activationÈÄ¿¡ atrial activationÀÌ ÀϾ¹Ç·Î P wave´Â QRS

complexÈÄ¿¡ ³ªÅ¸³­´Ù.

- Ä¡·á´Â AVNRT¿Í µ¿ÀÏÇÏ´Ù.

7) Sinus node reentry & other atrial tachycardia

- APCs¿¡ ÀÇÇØ ½ÃÀ۵ǰí, underlying cardiac ds¿Í °ü·ÃÀÖ´Ù.

- sinus node reentryµ¿¾È¿¡ P wave´Â sinus rhythm¶§¿Í µ¿ÀÏÇÏÁö¸¸ sinus tachycardia¿Í´Â

¹Ý´ë·Î(=PR intervel shortening) PR intervalÀÌ ¿¬ÀåµÈ´Ù.

intraatral reentry¿¡¼­ P wave´Â sinus rhythm¶§¿Í ´Ù¸£¸ç PR intervalÀº ¿¬ÀåµÈ´Ù.

- Ä¡·á ; reentrant PSVTó·³ ÇÑ´Ù.

´Ù¸¸, multiple foci°¡ Á¸ÀçÇϹǷΠcatheter ablationÀº ¼º°øÀûÀÌÁö ¸øÇÏ´Ù.

8) Nonreentrant atrial tachycardia

¨ç ¿øÀÎ i) digitalis intoxication

ii) severe pul. or cardiac disease

iii) hypokalemia

iv) theophylline or adrenergic drugÅõ¿©

¨è MAT(multifocal atrial tachycardia) Fig 230-9

Á¤ÀÇ : ¼­·Î ´Ù¸¥ ¸ð¾çÀÇ P wave°¡ 3°³ ÀÌ»ó ¿¬¼ÓÇØ¼­ ³ª¿Ã¶§(rate>100ȸ/min)

theophylline Åõ¿© ÈÄ¿¡ ƯÈ÷ ÈçÇÏ´Ù.

´Ù¾çÇÑ AV conduction ¶§¹®¿¡ ventricular rate´Â ºÒ±ÔÄ¢ÀûÀÌ´Ù.

AF¹ß»ýºóµµ°¡ ³ô´Ù: 50-70%

Ä¡·á ; underlying disorderÄ¡·á

digitalis-induced arrhythmia´Â triggered activity¿¡ ÀÇÇØ ¹ß»ýÇϸç, Ä¡·á´Â ¾à Áß´ÜÀÌ´Ù.

¨é Automatic atrial tachycardia

dititalis¿¡ ÀÇÇØ ¹ß»ýÇÏÁö ¾Ê´Â autonomic atrial tachycardia´Â terminationÀÌ ¾î·Æ´Ù.

Ä¡·á¸ñÇ¥´Â ventricular rate control

i) drug : AV node¿¡ ÀÛ¿ëÇÏ´Â ¾à - digitalis, ¥â-blocker, calcium-channel blocker

ii) ablation technique

catheter ablation & surgery : arrhythmia focus¸¦ ¾ø¾Ö°Å³ª rate control¸ñÀûÀ¸·Î heart

block Çϱâ À§ÇØ »ç¿ëÇÒ¼ö ÀÖ´Ù.

9) Preexcitation(WPW) syndrome

- AV bypass tractÀ» ÅëÇÑ antegrade conduction

- congenital abnormaltiy¿Í °ü·ÃÀÖ´Ù: most important = Ebstein's anomaly

- triad : short PR interval(<0.12sec)

a slurred upstroke of the QRS complex(¥ä wave)

wide QRS complex

- PSVT in WPW

: ´ëºÎºÐ AV systemÀ¸·Î antegrade conduction, bypass tractÀ¸·Î retrograde

conduction

µå¹°°Ô(5%) bypass tractÀ¸·Î antegrade conduction, AV systemÀ¸·Î retrograde

conduction

- AF, atrial flutter in WPW : ÈçÇϸç ventricular fibrillationÀ» ÀÏÀ¸Å³¼ö ÀÖ´Ù.

* Ä¡·á

¨ç pharmacologic tx -> Fig 230-11

¨è PSVT with WPW : PSVT with concealed bypass tract°ú À¯»ç

¨é WPW & AF

i) life-threatening, rapid ventricular response : DC cardioversion

ii) non-life-threatening situation : lidocaine(3-5 mg/kg)

or procainamide(15 mg/kg) IV over 15-20min

ÃÖ±Ù ibutilide°¡ alternative tx

¡ÚÁÖÀÇ : digitalis or IV verapamilÀº accessory pathwayÀÇ ºÒÀÀ±â¸¦ ª°Ô ÇÏ¿©

ventricular rate¸¦ Áõ°¡½ÃÄÑ VF risk¸¦ Áõ°¡½Ãų¼ö ÀÖ´Ù.

chronic oral tx with verapamilÀº ÀÌ·¯ÇÑ riskÁõ°¡¿Í °ü°è¾ø´Ù.

¥â-blocker : È¿°ú°¡ ¾øÀ¸¸ç »ç¿ëÇÏÁö ¾Ê´Â´Ù.

¨ê atrial ventricular pacingÀÌ PSVT with WPWȯÀÚ¿¡¼­ PSVT¸¦ Á¾°á½Ãų¼ö´Â ÀÖÀ¸³ª

AF¸¦ À¯¹ß½Ãų¼ö ÀÖ´Ù.

¨ë radiofrequency catheter ablation : permanent cure, 90%ÀÌ»ó ¼º°ø·ü

most cost-effective

-> catheter ablation½ÇÆÐ½Ã surgical ablationÀÌ ÇÊ¿äÇÒ¼ö ÀÖ´Ù.

10) Nonparoxysmal junctional tachycardia

- AV junctionÀÇ autonomicity Áõ°¡ ¶Ç´Â triggered activity·Î ¹ß»ý

- most commonly : digitalis intoxication

inf. wall MI, myocarditis, endogenous or exogenous

catecholamine excess, acute rheumatic fever, valve surgeryÈÄ¿¡ ¹ß»ý

- onset : gradual, rate stabilization Àü¿¡ "warm-up" period

- rate : 70-150ȸ, faster rate´Â digitalis intoxication°ú °ü·ÃÀÖ´Ù.

- QRS complex : sinus rhythm°ú µ¿ÀÏ

* Ä¡·á i) underlying etiologyÁ¦°Å

ii) digitalis°¡ °¡Àå ÈçÇÑ ¿øÀÎÀ̹ǷΠdigitalisÁß´Ü

iii) atrial & ventricular irritability°¡ ÀÖ´Ù¸é active intervention with lidocaine or

¥â-blocker

ÀϺο¡¼­ digitalis Ab(Fab fragment) °í·Á

iv) cardioversionÀº ½ÃÇàÇÏ¸é ¾ÈµÊ. ƯÈ÷ digitalis intoxication¶§

v) AV conductionÀÌ intactÇÒ¶§ atrial pacingÀº junctional focus¸¦ capture & override

ÇÒ¼ö ÀÖ°í, C.OÀ» ÃÖ´ëÈ­Çϴµ¥ ÇÊ¿äÇÑ AV synchrony¸¦ Á¦°øÇÒ¼ö ÀÖ´Ù.

11) VT

¨ç Á¤ÀÇ ¹× ¿øÀÎ

sustained VT : 30ÃÊ ÀÌ»ó Áö¼ÓÇϰųª hemodynamic collapse¶§¹®¿¡ terminationÀÌ

ÇÊ¿äÇÑ °æ¿ì

i) ÀϹÝÀûÀ¸·Î structural heart ds¸¦ µ¿¹ÝÇÑ´Ù

(°¡Àå ÈçÈ÷ chronic ischemic heart ds associated with a prior MI)

ii) nonischemic cardiomyopathy

iii) metabolic disorders

iv) drug toxicity

v) prolonged QT syndrome

vi) heart ds³ª predisposing factor¾øÀÌ ¹ß»ýÇÒ¼öµµ ÀÖ´Ù.

nonsustained VT : 3 beats - 30ÃÊ

cardiac disease¿Í °ü·ÃÀÖÀ»¼öµµ ÀÖÁö¸¸ º¸ÅëÀº µ¿¹ÝµÇÁö ¾Ê´Â´Ù.

- stable VT°¡ VF³ª polymorphic VT·Î ÁøÇàÇÏ¸ç ´ëºÎºÐÀÇ VF´Â VT·Î ½ÃÀÛÇÑ´Ù.

¨è ECG diagnosis of VT

: wide-complex QRS tachycardia, rate>100 bpm

¸ð¾çÀº uniform(monomorphic) or polymorphic

cf. bidirectional tachycardia : QRS amplitude & axis alterationÀ» º¸ÀÌ´Â VT

ÀüÇüÀûÀ¸·Î sup(leftward) & inf(rightward) axis

- tachycardia onsetÀº ÀϹÝÀûÀ¸·Î abrupt, ±×·¯³ª nonparoxysmal tachycardia¿¡¼±

gradualÇÒ¼öµµ ÀÖ´Ù.

- paroxysmal VT´Â ÈçÈ÷ VPC·Î ½ÃÀ۵ȴÙ.

¨é SVT¿Í VTÀÇ °¨º°

- SVT c aberration°ú VTÀÇ intraventricular conductionÀ» ±¸º°ÇÏ´Â °ÍÀÌ Áß¿äÇÏ´Ù.

- VTÀÇ °¡Àå Áß¿äÇÑ clinical predictor´Â structural heart diseaseÀÇ Á¸ÀçÀÌ´Ù.

- intermittent cannon a wave & varying S1 soundµµ AV dissociationÀ» ÀǽÉÄÉ Çϰí

VT¸¦ Áø´ÜÇÏ°Ô ÇÏ´Â ¼Ò°ßÀÌ´Ù.

- ´ëºÎºÐ 12-lead ECG¸¦ close examinationÇÔÀ¸·Î½á Áø´ÜÇÒ¼ö ÀÖ´Ù.

- IV verapamil or adenosineÅõ¿©¿Í °°Àº pharmacologic maneuver ´Â ÇØ·Î¿ì¸ç ÇÇÇØ¾ß

ÇÑ´Ù.

- sinus rhythmµ¿¾È¿¡ tachycardia¶§¿Í °°Àº morphologic feature¸¦ °®´Â´Ù¸é PSVT with

aberrationÀ¸·Î Áø´ÜÇÒ¼ö ÀÖ´Ù.

* VT ½Ã»ç¼Ò°ß

i) QRS complex > 0.14sec

ii) AV dissociation c/s fusion or captured beats or variable retrograde conduction

iii) sup. axis + RBBB

iv) precordial lead¿¡¼­ QRS concordance

v) typical RBBB or LBBB pattern°ú ÀÏÄ¡ÇÏÁö ¾Ê´Â QRS pattern(prolonged duration)

- SVT c aberrant conduction°ú VT¸¦ °¨º°Çϱâ À§ÇØ verapamilÀ» »ç¿ëÇÏ´Â °ÍÀº cardiac

arrest¸¦ ÀÏÀ¸Å³¼ö Àֱ⠶§¹®¿¡ ±ØÈ÷ À§ÇèÇÏ´Ù.

- sustained uniform VT´Â programmed stimulationÀ̳ª rapid pacingÀ¸·Î Àû¾îµµ 75%¿¡¼­

terminationµÉ¼ö ÀÖ´Ù. ³ª¸ÓÁö´Â cardioversionÀÌ ÇÊ¿äÇÏ´Ù.

- ºÒÇàÈ÷µµ °¡Àå È¿°úÀûÀÎ Ä¡·áÀÎ rapid pacingÀº tachycardia¸¦ ¾ÇÈ­½Ãų¼ö ÀÖ°í VF¸¦

À¯¹ßÇÒ¼öµµ ÀÖ´Ù. ±×·¯¹Ç·Î antitachycardia pacingÀº pacing device¿¡ backup

defibrillation capability°¡ ÀÖÀ»¶§¿¡¸¸ ½ÃÇà°¡´ÉÇÏ´Ù.

¨ê ÀÓ»óƯ¡

¿¹ÈÄ´Â underying heart ds¿¡ ´Þ·Á ÀÖ´Ù.

AMIÈÄ Ã¹ 6ÁÖ³»¿¡ ¹ß»ýÇÑ sustained VT´Â ¿¹Èİ¡ ºÒ·®ÇÏ´Ù(1³â³» »ç¸Á·ü 75%)

MIÈÄ nonsustained VT ´Â »ç¸ÁÀ§ÇèÀÌ 3¹è ³ô´Ù.

±×·¯³ª nonsustained tachycardia¿Í subsequent sudden death»çÀÌÀÇ cause-and-effect

relationship¿¡ ´ëÇØ¼­´Â È®¸³µÈ °ÍÀÌ ¾ø´Ù.

heart disease¾øÀÌ uniform VT´Â ¿¹Èİ¡ ÁÁÀ¸¸ç sudden death risk°¡ ¾ÆÁÖ ³·´Ù.

¨ë Ä¡·á

i) without organic heart ds & asymptomatic, nonsustained VT : benign course

: Ä¡·áÇʿ䡿

¿¹¿Ü) congenital long QT syndromeÀº Ä¡·áÇØ¾ß ÇÑ´Ù.

¡ñ recurrent polymorphic VT·Î sudden deathÇÒ¼ö Àֱ⠶§¹®

ii) sustained VT without heart disease

arrhythmia°¡ Áõ»óÀ» ÀÏÀ¸Å°±â ¶§¹®¿¡ Ä¡·á°¡ ÇÊ¿äÇÏ´Ù.

: ¥â-blocker, verapamil, IA, IC or III agent, or amiodarone

iii) with organic heart disease

hemodynamic compromise ȤÀº ischemia, CHF, CNS hypoperfusion evidence(+)

=> Áï°¢ DC cardioversion

tolerableÇϸé pharmacologic tx ½ÃµµÇÒ¼ö ÀÖ´Ù

=> procainamide : most effective agnet of acute tx

iv) overdrive pacing

¾à¹°·Î terminationµÇÁö ¾Ê´Â stable pt´Â RV apex·Î pacing catheter¸¦ »ðÀÔÇÏ¿©

overdrive pacingÇÔÀ¸·Î½á termination½Ãų¼ö ÀÖ´Ù.

v) programmed stimulation

recurrent, sustained VT¸¦ ¿¹¹æÇϱâ À§ÇØ ÀûÀýÇÑ Ç׺ÎÁ¤¸Æ ¾àÁ¦¸¦ ¼±ÅÃÇϱâ À§ÇÑ °¡Àå

ÁÁÀº ¹æ¹ýÀÌ´Ù.

vi) automatic antitachycardia pacing

VT¸¦ ¾ÇÈ­½ÃÄÑ severe hemodynamic compromise¸¦ À¯¹ßÇÒ¼ö ÀÖÀ¸¹Ç·Î ´Üµ¶À¸·Î´Â »ç¿ë

ÇÏÁö ¾Ê´Â´Ù. ±×·¯³ª ICD°¡ ³»ÀåµÇ¾î ÀÖ´Â antitachycardia pacingÀº unstable arrhythmia

¸¦ termination ÇÒ¼ö ÀÖ´Â "backup"ÀåÄ¡¸¦ Á¦°øÇÑ´Ù.

¨ì Specific types of VT

©Í TdP (Fig 230-13)

amplitude & cycle length°¡ º¯ÇÏ´Â polymorphic QRS complex

oscillations around the baseline

QT prolongation°ú ¿¬°üÀÖ´Ù.

* QT prolongationÀ» ÀÏÀ¸Å°´Â »óȲ

i) electrolyte disturbance(ƯÈ÷ hypokalemia & hypomagnesemia)

ii) antiarrhythmic drug(ƯÈ÷ quinidine)

iii) phenothiazines & TCA

iv) liquid protein diets

v) intracranial events

vi) bradyarrhythmia(ƯÈ÷ 3rd-degree AV block)

- young age¿¡¼­´Â congenital anomaly°¡ TdP·Î ÀÚÁÖ ³ªÅ¸³­´Ù.

- ECG hallmark : marked QT prolongation(>0.6sec)ÈÄ¿¡ µû¶ó¿À´Â polymorphic VT

- VF·Î ÁøÇàÇÏ¿© sudden cardiac death¸¦ ÀÏÀ¸Å³¼ö ÀÖ´Ù.

*Ä¡·á : À¯¹ßÀÎÀÚ Á¦°Å

¨ç drug-induced TdP : atrial or ventricular overdrive pacing & MgÅõ¿©°¡ È¿°úÀû

¨è congenital prolonged QT syndrome

i) ¥â-blocker(choice), phenytoin

ii) cervicothoracic sympathectomy : ´Üµ¶À¸·Î´Â È¿°ú°¡ ¾øÀ¸¸ç ¥â-blocker¿Í º´ÇÕ

Horner's syndromeÀ¯¹ß

iii) ICD with dual chambered pacing capability & ¥â-blocker

: ¥â-blocker¿¡µµ ºÒ±¸Çϰí recurrent episode¸¦ º¸À̴ ȯÀÚ¿¡¼­ TOC

©Î polymorphic VT associated with normal QT interval

ischemic heart dsȯÀÚ¿¡¼­ "R-on-T" VPCs¿¡ ÀÇÇØ ½ÃÀÛ.

ÈçÈ÷ reentry¿¡ ÀÇÇØ ¹ß»ý

TdP¿Í ´Ù¸£´Ù.

Ä¡·á> class I or III agent : most effective, full doseÅõ¿©ÇØ¾ß ÇÑ´Ù.

©Ï Accelerated idioventricular rhythm(=slow VT) 60-120 bpm

AMIÈÄ reperfusionµ¿¾È ÈçÈ÷ ¹ß»ý

±×¿Ü, cardiac opÈÄ, CMP, rheumatic fever, digitalis intoxication

cardiac disease°¡ ¾øÀ̵µ ¹ß»ýÇÒ¼ö ÀÖ´Ù.

´ëºÎºÐ Ä¡·á°¡ ÇÊ¿ä¾øÀ¸¸ç Áõ»óÀÌ »ý±ä´Ù¸é impaired hemodynamics¿¡ ÀÇÇÑ´Ù

(most commonly, AV dissociation)

´ëºÎºÐ atropine¿¡ Àß ¹ÝÀÀÇÑ´Ù.

12) Ventricular flutter & fibrillation

ÈçÈ÷ ischemic heart disease¸¦ °¡Áø ȯÀÚ¿¡¼­ »ý±ä´Ù.

±×¿Ü¿¡ antiarrhythmic drug Åõ¿©(ƯÈ÷ QT intervalÀ» Áõ°¡½ÃŰ´Â ¾àÁ¦)

Torsade de pointes(TdP)

severe hypoxia, ischemia

rapid ventricular response¸¦ °¡Áö´Â AF·Î ¹ßÀüÇÏ´Â WPW

Ä¡·áÇÏÁö ¾ÊÀ¸¸é »ç¸ÁÇÑ´Ù.

late coupled VPC·Î ½ÃÀ۵Ǵ rapid VT·Î ÇÏ¿© VF·Î ÁøÇà

acute infarction 48½Ã°£ ³»¿¡ primary VFÀÇ long-term Px´Â good

¡ñ Àç¹ß or sudden cardiac death¡é, ±×·¯³ª short-term mortality´Â ¾à°£ Áõ°¡.

acute MI¿Í °ü·Ã¾ø´Â VF´Â 20-30%°¡ Àç¹ß

Ventricular flutter´Â 150-300 bpmÀ¸·Î rapid VT¿Í ±¸ºÐÀÌ ºÒ°¡´ÉÇÏ´Ù.

*Ä¡·á

¨ç pharmacologic antiarrhythmic tx

Ä¡·á½ÃÀÛÀü¿¡ potential aggrevating factor¸¦ ±³Á¤ÇØ¾ß ÇÑ´Ù.

: transient metabolic abnormalities, CHF, or acute ischemia

*Ä¡·á¸ñÀû

i) acute arrhythmiaÀÇ terminateion

ii) arrhythmiaÀç¹ß¹æÁö

iii) life-threatening arrhythmia¿¹¹æ

*ÇöÀç ³Î¸® »ç¿ëµÇ´Â antiarrhythmic agent : Tab 230-4, 230-7(toxicity)

: ¸ðµç ¾àÀÌ proarrhythmic effect°¡ ÀÖ¾î underlying arrhythmia¸¦ ¾ÇÈ­½Ãų¼ö ÀÖ´Ù.

¨è classification of antiarrhythmic drug

Tab 230-2(Vaughan-Williams classification)

*ºÐ·ù±âÁØ

i) excitatory current(Na+ or Ca2+)

ii) action potential duration

iii) automaticity(phase 4 depolarization)

ÀÌ ºÐ·ù´Â ¸¹Àº ÇѰèÁ¡ÀÌ Àִµ¥, ¸ðµç ¾àÀÌ ÀÌ ºÐ·ù¿¡ ¸Â´Â °ÍÀº ¾Æ´Ï°í, ÀϺξà

(amiodaroneó·³) multiple class property¸¦ º¸ÀδÙ.

¨é electrical tx of tachyarrhythmia

i) pacemaker

ii) cardioversion & defibrillation

12cm Á÷°æÀÇ 2 paddles

1°³- 2nd rib levelÀÇ sternum right

´Ù¸¥ 1°³ - Lt midclavicular lineÀÇ 5th intercostal space

ÀǽÄÀÌ ÀÖÀ»¶§´Â short-acting barbiturate¸¦ Åõ¿©(¸¶Ãë or amnesic drug»ç¿ë,

¿¹=diazepam)

VF, ventricular flutter¸¦ Á¦¿ÜÇϰí´Â QRS complex¿Í synchronousÇÏ°Ô ½ÃÇà

¡ñ asynchronous shock -> VFÀ¯¹ß

* energy

AF¸¦ Á¦¿ÜÇÑ SVT : 25-50J

AF : 100J¡è

VT : 100J¡è

VF : 200J¡è

* Indication

a. hypotension, myocaridal ischemia, Ht failure¸¦ ÃÊ·¡ÇÏ´Â any 'tachycardia'

(sinus tachycardiaÁ¦¿Ü)

b. pharmacologic tx·Î ½ÇÆÐÇÑ arrhythmia

iii) ICD(Implanted cardioverter/defibrillator)

Tab 230-9 ACC/AHA guidelines for ICD implantation

* class I

a. cardiac arrest due to VF or VT(not transient or reversible cause)

b. spontaneous sustained VT

c. syncope of undetermined origin

+ EP¿¡¼­ significant sustained VT or VF

d. nonsustained VT with coronary ds, prior MI, LV dysfx

+ EP¿¡¼­ inducible VF or sustained VT

iv) Ablative tx for arrhythmia

´ë»ó :WPW, AVNRT, typical atrial flutter

poorly controlled ventricular response to atrial arrhythmia, most commonly AF