MALIGNANT ARRHYTHMIAS: ECG IDENTIFICATION DR.SIVAKUMAR ARDHANARI MD

Normal sinus rhythm Impulse formation beginning in the sinus node Impulse formation beginning in the sinus node At frequencies between 60 to 100 per minute At frequencies between 60 to 100 per minute P is always upright in I, II and aVF and inverted in aVR P is always upright in I, II and aVF and inverted in aVR Though rhythm is regular, minor variation in PP interval exists & longest and shortest PP differ< 0.16 except in sinus arrhythmia Though rhythm is regular, minor variation in PP interval exists & longest and shortest PP differ< 0.16 except in sinus arrhythmia

Normal sinus rhythm Every P is followed by a QRS complex Every P is followed by a QRS complex Every QRS is preceded by a P wave Every QRS is preceded by a P wave P and its following QRS is separated by fairly regular PR interval P and its following QRS is separated by fairly regular PR interval TO BE VERY PRECISE P AND QRS ARE IN SIMPLE HARMONY TO BE VERY PRECISE P AND QRS ARE IN SIMPLE HARMONY

NORMAL ECG

When the rhythm deviates from the above said normalcy it is called ARRHYTHMIA When the rhythm deviates from the above said normalcy it is called ARRHYTHMIA Broadly it is classified as brady and tachy arrhythmia Broadly it is classified as brady and tachy arrhythmia Arrhythmogenesis may be due various causes Arrhythmogenesis may be due various causes

Some arrhythmias are considered MALIGNANT Some arrhythmias are considered MALIGNANT Because if not properly and immediately treated, it can be LETHAL to the sufferer Because if not properly and immediately treated, it can be LETHAL to the sufferer This is important in understanding the concept of SUDDEN CARDIAC DEATH This is important in understanding the concept of SUDDEN CARDIAC DEATH

SUDDEN CARDIAC DEATH

Anatomy of the conduction system

Sinus node- Sinus node- –RCA (55-60%) –left circumflex (40-45%)artery AV node- AV node- –RCA (85-90%) –left circumflex (10-15%) artery

ACUTE RVMI+IWMI

Anatomy of conduction system The conduction system is densely innervated by The conduction system is densely innervated by –Cholinergic fibers- parasympathetic –Adrenergic fibers- sympathetic This is important in understanding This is important in understanding –variability of cardiac function with autonomic influence –effect of parasympathetic stimulation in terminating arrhythmias

BRADYARRHYTHMIAS Sinus nodal Sinus nodal  Sinus bradycardia  Sinus arrhythmia  Sinus pause/arrest  Sinoatrial exit block  Sick sinus syndrome AV nodal blocks AV nodal blocks  First degree  Second degree(MOBITZ type 1 and 2)  Complete heart block

SINUS ARREST

SICK SINUS SYNDROME

ATRIO VENTRICULAR BLOCK I degree -conduction time prolonged: all impulses are conducted I degree -conduction time prolonged: all impulses are conducted II degree -2 forms II degree -2 forms oMobitz type I (WENCKEBACH)- progressive lengthening of conduction time until an impulse is failed to be conducted oMobitz type II- occasional or repetitive sudden block in conduction without prior measurable lengthening of conduction time Complete or III degree -no impulses are conducted Complete or III degree -no impulses are conducted

FIRST DEGREE AV BLOCK

FIRST DEGREE HB

IWMI+FIRST AV BLOCK

2:1 AV BLOCK

COMPLETE AV BLOCK Occurs when no atrial activity is conducted to the ventricles Occurs when no atrial activity is conducted to the ventricles So atria and ventricles are controlled by independent pacemakers So atria and ventricles are controlled by independent pacemakers One type of complete AV dissociation One type of complete AV dissociation Ventricular focus is usually just below the site of block Ventricular focus is usually just below the site of block If focus near HIS bundle the rhythm is more stable If focus near HIS bundle the rhythm is more stable

CHB can occur at various levels CHB can occur at various levels –AV Node-usually congenital bpm –Bundle of HIS –Purkinje sys-usually acquired-

COMP HEART BLOCK

COMP HB

CHB

CHB

IWMI+CHB

APPROACH TO TACHYCARDIA

ATRIAL FLUTTER F waves: rapid regular undulations F waves: rapid regular undulations SAW TOOTH APPEARANCE Atrial rate: bpm Atrial rate: bpm Rate & regularity of ventricles: variable and depend on AV conduction sequence Rate & regularity of ventricles: variable and depend on AV conduction sequence QRS may be normal or abnormal as a result of preexisting intraventricular conduction defect or aberrancy QRS may be normal or abnormal as a result of preexisting intraventricular conduction defect or aberrancy

ATRIAL FLUTTER

SVT VS VT

Differentiating a VT from SVT can be difficult at times Differentiating a VT from SVT can be difficult at times Golden rule in ER Golden rule in ER ANY WIDE QRS TACHYCARDIA IS VENTRICULAR TACHYCARDIA UNTIL PROVED OTHERWISE ESP`LY WHEN THE PATIENT HAS A STRUCTURAL HEART DISEASE

Diagnosis of VT Arises distal to the bifurcation of the HIS bundle Arises distal to the bifurcation of the HIS bundle Diagnosis is by the occurrence of a series of 3 or more consecutive, abnormally shaped PVCs whose duration exceeds 120 ms, with ST-T vector pointing opposite the major QRS deflection Diagnosis is by the occurrence of a series of 3 or more consecutive, abnormally shaped PVCs whose duration exceeds 120 ms, with ST-T vector pointing opposite the major QRS deflection

VENTRICULAR ECTOPICS

RR can be exceedingly regular or can vary RR can be exceedingly regular or can vary Atrial activity can be independent of ventricular activity or can be depolarized retrograde (VA association) Atrial activity can be independent of ventricular activity or can be depolarized retrograde (VA association)

Fusion beats and capture beats provide the maximum support for the diagnosis of VT Fusion beats and capture beats provide the maximum support for the diagnosis of VT FUSION BEATS-activation of ventricles from 2 foci FUSION BEATS-activation of ventricles from 2 foci CAPTURE BEATS- capture of the ventricle by supraventricular rhythmwith normal confguration of the captured QRS at intrvl shorter than tachycardia in question- indicates origin of impulse is supraventricular CAPTURE BEATS- capture of the ventricle by supraventricular rhythmwith normal confguration of the captured QRS at intrvl shorter than tachycardia in question- indicates origin of impulse is supraventricular

FUSION AND CAPTURE BEATS FUSION AND CAPTURE BEATS

QRS contours can be QRS contours can be –Unchanging (MONOMORPHIC) –Vary randomly (POLY OR PLEOMORPHIC) –Vary repetitively (TORSADES DE PONTES) –Vary in alternative cplxs (BIDIRECTIONAL)

MONOMORPHIC VT

POLYMORPHIC VT

TORSADES DE POINTES

TYPES OF VT VT can be SUSTAINED- lasting longer than 30 seconds or requiring termination due to hemodynamic collapse SUSTAINED- lasting longer than 30 seconds or requiring termination due to hemodynamic collapse NON SUSTAINED- stops spontaneously within 30 seconds NON SUSTAINED- stops spontaneously within 30 seconds

NON-SUSTAINED VT

SUSTAINED VT

HYPER ACUTE EXT ALMI

DIGITALIS EFFECT

PROLONGED QT(U) INTERVAL

Ventricular flutter & fibrillation Represent severe derangement of heart beat that usually terminate fatally within 3-5 mts if corrective measures are not undertaken promptly. Represent severe derangement of heart beat that usually terminate fatally within 3-5 mts if corrective measures are not undertaken promptly.

VENTRICULAR FLUTTER Manifested as sine wave in appearance Manifested as sine wave in appearance Regular large oscillations occurring at a rate of (usually 200)/min Regular large oscillations occurring at a rate of (usually 200)/min

VENTRICULAR FLUTTER

VENTRICULAR FIBRILLATION Irregular undulations of varying contour & amplitude Irregular undulations of varying contour & amplitude Distinct QRS, ST or T are absent Distinct QRS, ST or T are absent Fine amplitude fibrillatory waves (0.2mV) with prolonged VF: worse prognosis: confused with asystole Fine amplitude fibrillatory waves (0.2mV) with prolonged VF: worse prognosis: confused with asystole

VENTRICULAR FIBRILLATION