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Basic ECG & Arrhythmias

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Basic ECG & Arrhythmias Basic ECG & Arrhythmias Damronggpyj, Sukitpunyaroj, MD ECG • 12 lead ECG • ECG strip (Rhythm strip) ECG • 12 ldECGlead ECG • ECG s tri p – Complete – Limited information information • RtRate, r hthhythm, + Ischemia • Rate, rhythm, axis, hthhypertrophy, – Easy to get ischemia, • Monitor : Telemetry, miscellaneous Defibrillator – Longer strip give – Takes more time more information – May not obtained about rhythm = from telemetry rhythm strip monitor Cardiac Cycle R ST P T PR Q S QT interval P wave: Atrial contraction (<2.5 small box) PR interval: AV conduction time (< 1 large box) QRS complex: Ventricular depolarization(< 3 small box ) Twave: Ventricular repolarization Five Aspects for ECG Reading •Rate • Rhythm • AiAxis • Hypertrophy • Infarction ECG Paper 5 big box = 1 sec 0.1 mV • ECG paper runs by a machine with the rate of 25 mm/sec •Standardization 10 mm = 1 mVolt Rate = 300/N = 1500/n R 0 R1 300 150 100 75 60 50 43 กระดาษว่ิงดวยความเร็ว 25 mm ใน 1 วินาที ” ” 1 ” 1/ 25 = 0.04 ” ” ” 5 ” 0.04 x 5 = 0.2” จาก R0 ถึง R1 : 0.2 sec ได = 1 cardiac cycle 60 sec = 60/ 0.2 = 300/ 1 Quick rate determination Rate = ???? Marked Bradyygycardia or Total Irregular Rhythm 3 second marks 6 second strip Rate = Cardiac cycle in 6 second strip x 10 Rate = ??? Rate = ??? Five Aspects for ECG Reading • RtRate •Rhyth m • Axis • Hypertrophy • Infarction Rhyy(thm(Arrh ythmia ) “ Always Measure P-R In terva l an d QRS C ompl ex ” Varying Rhythm : sinus arrhythmia, Wandering pacemaker, AF Extra Beats and Skips : premature beats, escape beats, sinus arrest Rapid Rhythm : PSVT, AFl, AF, VT, VFl, VF Heart Blocks : SA blockk, AV block, BBB การอการอานจงหวะการเตนหวใจานจังหวะการเตนหัวใจ • ตองมองหา P waves และ QRS complexes – Rate – Regular or Irregular – MhlMorphology • สังเกตุความสัมพันธระหวาง P waves และ QRS complexes -> PR interval 1. มองหา QRS complex • ไมเห็็น QRS comp lex • เห็น QRS complex –Rate – Asystole • < 60 Bradycardia – Ventricular fibrillation • 60-100 normal • >100 tachycardia (VF) – Regularity • Totally irregular Æ likely – Connector problem AF – Narrow or Wide • Wide QRS – Ventricular rhythm e.g VT – Pacemaker rhythm – Pre-existing BBB – Aberrant conduction –WPW Quick Approach to Rhythm • Loo k for QRS – No QRS identified : Asystole, VF, connector problems – QRS iden tifie d Æ Iden tify hear t ra te • Normal resting heart rate: 60 – 100 bpm • Tachycardia: >100 bpm • Bradycardia: <60 bpm – Regular or irregular • Totally irregular Æ likely AF – Wide or narrow QRS complex • Wide QRS complex : Ventricular rhythm e. g. VT; pre-existing BBB or aberrant conduction; pre-excitation (WPW), pacemaker rhythm Quick Approach to Rhythm • Look for P wave and association of P wave to QRS (PR interval) – P wave : not identified • P wave hidden in T wave, QRS complex, small P wave • No P wave with flat line : sinus arrest, sinus block • No P wave with fibrillation/flutter wave: AF, A flutter – PidtifidP wave: identified • Is it sinus P wave? – P wave + in II, III, aVF – Not sinus P wave : ectopic atrial rhythm (bradycadia or normal HR), atrial tachycardia (tachycardia) • Retrograde P wave? – Junctional rhythm, SVT, VT • Association of P wave to QRS -- > PR interval is consistent? – No association : AV Block Vs AV dissocitation – Some associtation but not consistent : 2nd degree AVB – Consistent association but long PR: 1st degree AVB Mechanism of Cardiac Arrhythmias • Abnormal Impulse Formation – Increase Automaticity – Triggered Activity • Abnormal– Reentry Impulse Conduction • Combination Classification of Cardiac arrhythmia Supraventricular in Origin SA node, Atrium, AV node, etc. VtilVentricular in Origin Normal Sinus Rhythm 1. Rate 60-100 beats / min 2. Rhy thm regular ECG 3. P waves upright in I, II and aVF and uniform Criteria 4. PR interval 0.12-0.20 sec and constant from beat to beat 5. QRS duration 0.10 sec or less Normal Sinus Rhythm 1. ทกทกุ P waves มี QRS complexes ตามมา 2. QRS แคบเปนปกตคิ อไมื เกิน 0.12 วินาที 3. ระยะระหวระยะระหวางแตละางแตละ complexes สมสมาเสมอ่ําเสมอ 4. PwaveP wave หหวตงในัวตงในั้ lead 2,3,aVF, aVF 5. อตราการเตั น 60-100 ครงั้ /นาที Sinus Bradycardia ECG 1. Same NSR criteria 2. RtRate < 60 BPM Sinus Bradycardia • อาจพบใปในคนปกติได โดยเฉพาะถาเตนไมช ามาก และไมม ีอาการใดๆ – High vagal tone เชน นักกีฬา – Nocturnal bradycardia • กรณีที่ชีพจรชามาก เชน นอยกวา 40 ครั้งตอนาที และมอาการจี ําเปนตองไดรับ การดูแลรักษาโดยเฉพาะหากเปน unstable bradycardia – Vagovagal reflex Æ cardioinhibitory – Sinus node disease – Drug effects • B-blocker, Ca blocker, antiarrhythmic ( Amiodarone, digoxin, etc) – Electrolyte imbalance, acid-base abnomality – Acute coronary syndrome – Etc. Sinus Tachycardia ECG 1. Same NSR Criteria 2. Rate: greater than 100 bpm Sinus tachycardia • มกเั ปนการสสสนองตอบทางสรระของรางกายตามี ปกต ิ ไมจาเ ํ ปนตองรกษา ั จาเพาะํ แตควรไปแก สาเหตุที่กระตนุ หัวใจจึงจะเตนชาลงจนเปนปกติเอง เวนเสียแต ภาวะ Sinus tachycardia เกิดขึ้นมากเกินไปโดยไมเหมาะสมแก สาเหตุ อาจรักษาโดยใชยา Beta blocker ได • สาเหตุที่พบบอย Æ มีตัวกระตุนตอ sinus node – ไข – ภาวะติดเชื้อ – ฮาการเหนื่อยจากโรคปอด น้ําทวมปอด etc – ภาวะเครภาวะเครยดียด – ธัยรอยดเปนพิษ – ยาหรือสารพษิ – ความผความผดปกตทางเมตาโบลคิดปกติทางเมตาโบลิค เชเชนน นนาตาลตา้ําตาลต่ํา ฯลฯ • Sinus node reentry, Inappropriate sinus tachycardia Æ พบไดไมบอย Sinus Arrhythmia ECG 1. Rate usually 60-100 2. Rhythm irregular, phasic with respiration (increase Criteria during inspiration) 3. Other same NSR Sinus arrhythmia • ภาวะที่คลื่นหัวใจเหมืือน normalil sinus แต มีอัตราการเตนไมสม่ําเสมอ คือเร็วและชาโดย สัมพันธกับการหายใจ • เมื่อตรวจดู P wave แลวจะมีีลัักษณะ เหมเหมอนเดมตลอดือนเดิมตลอด • พบไดในคนปกติทอายี่ ุนอย • ไมจําเปนตองใหการรักษา Premature Contraction A. PAC B. PJC C. PVC Supraventricular Tachycardia (SVT) • From SA node (sinus node) – Sinoatrial node reentry tachycardia (SNRT) – Inappropriate sinus tachycardia • Atrial source – Ectopic atrial tachycardia (EAT) – Multifocal atrial tachycardia (MAT) – Atrial fibrillation with rapid ventricular response – Atrial flutter with rapid ventricular response (Without rapid ventricular response, fibrillation and flutter are usually not classified as SVT) • Atrioventricular source (AV node) • AV nodal reentry tachycardia (AVNRT) • AV recippgrogatin g tach ycardia (AVRT ) • Junctional ectopic tachycardia (JET) Supraventricular Tachycardia Nonsinus Atrial Rhythm (CS) 1. QRS Normal-looking ECG 2. Rhythm regular CiCriter ia 3. PwavesP waves negative in I, II, aVF 4. Rate normal, tachycardia Nonsinus Atrial Rhythm (Atrial ectopic rhythm) • จุกกําเนิดไฟฟาเกิดจากตําแหนงอ่ืนใน atrium นอก SA node • ECG – PwaveP wave ไมไมเปนบวกในเปนบวกใน II,III,aVF • พบไดในคนอายุนอย • โดยทวไปไมั่ อนตรายและไมั จําเปนตองร ักษา Wandering Pacemaker ECG 1. Normal-looking QRS 2. Rhythm:irregular Criteria 3. PthP waves:more than 3 contours Wandering pacemaker • Atrial arrhythmia ที่เกดจากจิ ุดกําเนดของิ ไฟฟาหว ั ใจสฃบั ไปมาระหวาง sinoatrial node (SA node), atrium, and/or the atrioventricular node (AV node) •ECG – เห็นการเปลี่ยนแปลงรูปรางของ P wave (upright, flattened, notched, biphasic) มักเห็นชัดใน lead II – Ventricular conduction ปกต ิ ÆQRS รูปรางปกติ • เกิดจากการเปลี่ยนแปลงขนลงของึ้ vagal tone ( varying vagal tone) – เมเมอื่อ vagal tone สงสงู SA node จะปลจะปลอยไฟฟาชาลงอยไฟฟาชาลง ทาใหมการปลอยไฟฟาจากจทําใหมีการปลอยไฟฟาจากจดกุดกาเนดไฟฟาําเนิดไฟฟา สํารองจากตําแหนงอื่นในหัวใจหองบน – เมื่อ vagal tone ลดลง SA node จะกลับมาทํางานอีก • พบไดพบไดในเดกในเด็ก คนชรา นนกกฬาักกีฬา • มักไมทําใหเกิดอาการและไมจําเปนตองรักษา Multifocal Atrial Tachycardia (MAT) Common in COPD ECG Cr iter ia 1. Same wandering pacemaker 2. Rate >100 bpm Multifocal atrial tachycardia • ECG –P wave มีลักษณธแตกตางกันตั้งแต 3 แบบขึ้นไป – PR intervals แตกตแตกตางกนางกัน – ชีพจรเร็วมากกวา 100 ครั้ง/okmu • สาเหตุ – พบบอยในผูปวยสูงอายุที่มโรคปอดี เชน COPD ภาวะ hypoxemia – อาจพบในภาวะ digitalis toxicity, AMI, hypokalemia, hihypomagnesemia • การรักษา – รรกษาสาเหตักษาสาเหต ุ การให Oxygen อาจชอาจชวยในบางรายวยในบางราย – ถาหัวใจเตนเร็วมากอาจพิจารณาใหยากล ุม Ca blocker เชน Verapamil, etc Atrial Flutter Rate atrium 250-400, ventricular vary usually 150 ECG Rhythm atrial reggyggular , vent may reg or irreg depending on AV conduction Criteria P wave saw-toothed or “flutter” waves PR interval not measurable QRS normal or BBB Atrial flutter • ECG : ลลกษณักษณะ PwaveP wave คลคลายฟนเลอยายฟนเลื่อย • หัวใจหองบนเตนผิดจังหวะ เกิจจาก macroreentry ในหัวใจหองบนขวาหรือซาย • มักพบในผูปวยโรคห ัวใจ แตบางครั้งพบในคนที่มหี ัวใจ ปกติได • บอยครั้งที่จะ degenerate เปร atrial fibrillation • อาการมักขนกึ้ึ ับอััตราการเตนของหััวใจหองลาง (ventricular response) – Flutter rate 300 ms •2:1 AVB Æ V rate 150 bpm • 3:1 AVB Æ V rate 100 bpm • การรักษา – Rate control – Rhythm control : cardio version, drug, RF ablation – Embolic prevention เหมือน AF Atrial Fibrillation Atrial Fibrillation • เปน arrhythmia ทพบบอยี่ โสโดยเฉพาะคนสูงอาย ุ อาจพบรวมกบ ั sick sinus syndrom (SSS) • มสี วนนอยที่ พบในคนปกติ (lone AF) • ECG : ไมเห็น P wave (อาจเห็นปน fibrillatory activity) ; QRS ไมสม ่ําเสมอ – VtilVentricular ra te อาจเร็วหรืือชา ขึ้ึนกับ ventitricu lar con duc tion AF รวมกับ WPW syndrome Æ atrial activation ผานสู ventricle ผานทาง bypass tract แทน AVN อาจมี ventricular rate เร็วมาก จนเกิด VF ได • AF โดยท่ัวไปไมทําใหผปู วยเสีียชีีวิิต ยกเวน AF w ith WPW แตในกรณีีที่ี ventitricu lar ra te เร็ว มากๆ อาจทําใหดรคหัวใจหรือโรคอื่นที่เปนทรุดลงจนเกิดภาวะหัวใจลมเหลว ความดันต่ํา กระตุนใหเกิด acute coronary syndrome เปนตน • Co-morbidity สสาคญของําคัญของ AF คคอือ thromboembolism (Strokes; acute embolism) • AF management – Rhythm control : Cardioversion, antiarrhythmic drugs, RF ablation – Rate control – Embolic
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  • The Effects of Vasopressin in Isolated Rat Hearts
    IndiaD J Physiol Pharmacol 2001; 45 (I); 54-62 THE EFFECTS OF VASOPRESSIN IN ISOLATED RAT HEARTS ZIYA KAYGISIZ', T. ERDAL KABADERE", SADETTIN DERNEK'" AND SERDAR H. ERDEN···· Departments of "'Physiology, "''''Ophthalmology, no·Cardiovascular Surgery and nonoCheckup, Osmangazi University, Medical Faculty, 26480, Eskisehir, Turkey (Received on January 4, 2000) Abstract: The roles of cOMP, prostaglandins, the entry of extracellular ea2• through slow channels, endothelium and VI receptors in the negative inotropic, chronotropic and coronary vasoconstrictor responses to arginine vasopressin (AVP) have been investigated in isolated perfused rat hearts. The bolus injection of 5)(10·' M AVP produced a significant decrease in contractile force, heart rate and coronary now. AVP also significantly decreased conlractile force, heart rate and coronary now in hearts pretreated with an inhibitor of soluble guanylate cyclase methylene blue (IO-ll M), an effective drug for removing endothelium saponin (500 ~g/ml), an inhibitor of cyclooxygenasc indomethacin (10-5 M) or a calcium channel antagonist verapamil (5)( 10-1 M). The potent V. receptor antagonist (Deamino.Pen' , Val4, D-ArrJ·vasopressin (9xlO'" 11) did not alter effects of AVP but the very potent V. receptor antagonist II3·Mercapto-Ii, p­ cyc1opentamethylene-propionyl', O·Me.TyrZ, Arrl-vasopressin (8)(10'" M) abolished these effects. Our results suggest that AVP produces negative inotropic. chronotropic and coronary vasoconstrictor effects in isolated perfused rnt hearts. cOMPo prostaglandin release and C 0 2. entry does not involve in the effects of AVP. These effects are endothelium independent and mediated by V I receptors. The use of V l receptor antagonist [1}­ mercapto-I}.
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  • Drugs in Cardiology
    Drugs in Cardiology Fozia Ahmed Consultant Cardiologist Manchester Heart Centre What do you need to know about pharmacology for BHRS exam • Cardiac action potential • Vaughn William’s classification • Effects of drugs on pacing thresholds and DFTs • Indications for different drugs • Side effects of drugs – QT interval – Toxicity – contraindications • Drugs for heart failure Phase 4 (Cardiomyocyte AP) • Phase 4= Resting membrane potential – Horizontal line (non-pacemaker cells) – -90mV • In phase 4 membrane most permeable to K+ ions – Fast Na+ channels and slow Ca 2+ channels are closed • Stable vs. unstable phase 4 Phase 0 (depolarisation) • Phase 0=rapid depolarisation – Electrical stimulation of cell by adjacent cell undergoing depolarisation – The K+ channels are closed during phase 0 – Opening of Fast Na+ channels – Influx of Na+ – Increase in membrane potential • Potential inside the cell rises to +10mV Phase 1 (initial repolarisation) • Phase 1 represents initial repolarisation • Closure of fast Na+ channels • Net outflow of K+ – caused by opening of transient + outward K channel (Kto) – hyperpolarising outward K+ current(iKto) Phase 2 (plateau phase) • Phase 2 represents the “plateau phase” • Sustained by: – Inward movement of calcium through Slow (L-type) calcium channels – Slow outward movement of K+ thru the slow delayed rectifier K+ channel • Phase 2 differentiates cardiomyocyte action potentials from those of pacemaker cells, skeletal muscle and nerves Phase 3 (rapid repolarisation phase) • During phase 3, L-type Ca2+ channels
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  • Inotropic Drugs and Their Mechanisms of Action
    lACC Vol. ~ . No.2 389 August J98· ~ 389-97 BASIC CONCEPTS IN CARDIOLOGY Arnold M. Katz, MD, FACC, Guest Editor Inotropic Drugs and Their Mechanisms of Action HASSO SCHOLZ, MD Hamburg, West Germany This report describes various old and new positive ino­ The latter resemble theophylline and other methylxan­ tropic drugs with respect to their mechanisms of action. thines in that they appear to act mainly as phosphodi­ Drugs with established cardiotonic effects include car­ esterase inhibitors with a subsequent increase in cyclic diac glycosides, betaj-adrenergic agents, glucagon, his­ adenosine monophosphate (cAMP). The mechanism of tamine and the methylxanthines. New agents discussed the positive inotropic effect of alpha-adrenergic stimu­ art: prenalterol, betas- and alpha-adrenergic drugs, am­ lating agents (for example, phenylephrine) is unknown. rinone and sulmazole. Prenalterol is a betaj-adrenergic It is independent of the cAMP system and is not accom­ agent. Betaj-adrenerglc drugs, amrinone and sulmazole, panied by changes in frequency. combine a positive inotropic and a vasodilator effect. Agents that increase the force of contraction of the heart (Fig. I) (7-11). Depolarization of the sarcolemma, that is, are referred to as positive inotropic or cardiotonic drugs. the Na + -dependent upstroke of the action potential , is the The increase in the force of myocardial contraction is ul­ initial event. The depolarization of the cell membrane allows 2 z timately due to an increase in intracellular free Ca + [Ca + li CaZ+ to move down its electrochemical gradient and enter to interact with the contractile proteins or to an increased the cell from the extracellular space during the plateau phase sensitivi ty of the myofilaments for Caz+ , or both.
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  • Resuscitating the Exercise Stress Test
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