The document discusses electrophysiology studies and the evaluation of heart rhythms, defining various cardiac terms and measurements related to heart rate and arrhythmias. It outlines types of arrhythmias, their characteristics, mechanisms, etiological factors, and treatment options. Additionally, it highlights different laboratory investigations and monitoring techniques used in diagnosing and managing cardiac conditions.

1. electrophysiology study
Dr. Enas Fathy, MD, PhD
Lecturer of cardiology
Aswan university
South valley university

2. electrophysiology study
• (EP study) is a test used to evaluate your heart's electrical
system and to check for abnormal heart rhythms.

3. Properties of cardiac muscle

10. Arrhythmia
BY
DR. ENAS FATHY, MD, PHD
LECTURER OF CARDIOLOGY
ASWAN UNIVERSITY
SOUTH VALLEY UNIVERSITY

17. EKG
HEART RATE
-To determine the ventricular rate, count
the QRS complex on a 6 sec paper and
multiply by 10
WAVES
-P wave: atrial depolarization
-QRS complex :ventricular depolarization
-Twave :Ventricular repolarization
INTERVALS
-PR :0.12-0.20 sec
-QRS :under 0.10sec
-QT:under 0.38 sec

21. How to measure heart rate from ECG
• For regular rhythm
Rate=300/number of large square between two RR
interval
or
=1500/number of small square(more accurate)
• Normal rate = 60-100 beats/minute
• >100beats/minute- tachycardia
• <60 beats/minute- bradycardia

24. • For irregular rhythm
• 6 seconds rule
• Count number of QRS complex during 6
seconds i.e. 30 large squares and multiply it
by 10.

30. QRS complex
• It represents ventricular depolarization.
• First negative wave is q or Q wave
• First positive deflection is r or R wave
• Second negative deflection is s or S wave
• Second positive deflection is r’ or R’ wave
• QRS complex normally lasts from 80 to 100
ms.

31. QRS nomenclature

32. • QRS: duration <0.12ms, shape, r wave progression
• ST segment: Isoelectric, depressed, raised
• T wave: upright, inverted
• QT interval: 350- 450 ms

33. Normal
Signal moves rapidly
through the ventricles
Abnormal
Signal moves slowly
through the ventricles

34. ST Segment Elevation

35. The Normal ECG
Rate: 50 – 100 bpm
Rhythm : regular
Sinus rhythm:(P present, look alike, P before QRS)
Axis +90o
to –30o
Intervals: PR .12-.20 sec
QRS <.12 sec
ST segment: Isoelectric
T wave: upright
QT : normal

37. Definition of aRRythmias
• It is any abnormality in the heart rate or rhythm
• including abnormalities of impulse formation
from Sinus Node (SAN), or site of impulse origin
or conduction disturbances.
• This disrupt the normal sequence and direction
of atrial and ventricular activation.
• Normal HR: 60-90 b/m
• Bradycardia <60 b/m Bradycardia
• Tachycardia >90 b/m Tachycardia

38. Basic arrhythmia
mechanisms
Automaticity
Reentry
Triggered activity

39. SAN action potential

40. Mechanism of Arrhthmogensis
1. Disorder of impulse formation.
a) Automaticity.
b) Triggered Activity.
1) Early after depolarization.
2) Delayed after depolarization.
2. Disorder of impulse conduction.
a) Block – Reentry.
b) Reflection.
3. Combined disorder.

41. Trigger Reentry substrate
Premature beat Two distinctly different pathways in
conduction velocity & RP
2. Re-entry (circus movement) in the form of wave of depolarization
forced to travel around a ring of cardiac tissue. This occurs in cases of
paroxysmal atrial tachycardia, junctional tachycardia, atrial flutter and
fibrillation, AVNRT, AVRT. Sudden onset & offset. Fixed rate.

42. 2. Triggered activity by digitalis, catecholamines or myocardial damage, this
occurs in ventricular arrhythmia or atrial tachycardia induced by digitalis
toxicity.

43. o Sinus Tachycardia (A)
o Focal Atrial Tachycardia/ extrasystole (PAC) (B)
(C)
o Atrioventricular tachycardia AVRT=
Accessory pathway arrhythmia (D)
AVNRT (E)
(H)
(Narrow QRS tachycardias)
(Wide QRS tachycardias)
⇐Irregular
}Regular
⇐Irregular
⇐Irregular
}Regular
}Atrial
c) AtrioVentricular junctional arrhythmia

44. Major cardiac arrhythmias
SINUS RYTHMS ATRIAL
RYTHMS
VETRICULAR
RHYTHMS
ATRIO-
VENTRICULAR
(AV) RHYTHMS
SINUS BRADY PREMATURE
ATRIAL
CONTRACTION(PA
C)
PREMATURE
VENTRICULAR
CONTRACTION(PV
C)
1ST
DEGREE AV
BLOCK
SINUS
TACHICARDIA
ATRIAL FLUTTER VENTRICULAR
TACHICARDIA
2ND
DEGREE AV
BLOCK TYPE I
SINUS ARRYTHMIA ATRIAL
FIBRILATION
VENTRICULAR
FIBRILATION
2ND
DEGREE AV
BLOCK TYPE II
SINUS ARREST ASYSTOLE 3RD
DEGREE AV
BLOCK

45. o Sinus Bradycardia

48. Etiological Factors
Cardiac
IHD
Structural changes: RHD, CHD, Constrictive pericarditis,
myocarditis, aberrant conduction pathways.
Cardiomyopathies, HF.
Extracardiac
Physiological: pregnancy, exercise, sleep, atheletes, stress.
Pathological: fever, COPD, chest infection, thyrotoxicosis, anemia,
metabolic imbalance (K+, Ca2+, Mg2+, hypoxia, hypercapnia,
metabolic acidosis), excess catecholamine (phaeochromocytomal,
inherited excess catecholamine release, excess caffeine; smoking,
alcohol, coffee).
Genetic causes: inherited channelopathies (Brugada syndrome).
Drugs:

50. Tests
Laboratory investigations:
FBC (anaemia), renal function, thyroid function, glucose, Ca2+, Mg2+, Na,
K.
ECG monitoring including provocation tests:
1. 12 leads surface ECG
2. Holter (24 hours-7days ECG)
3. Exercise ECG
4. Loop recorder
5. Tilt table test
6. Video recorder
7. Interventional: electrophysiological study (EP study): intracardiac
procedure to determine location of triggering foci.
Echocardiography: to look for structural heart diseases

51. 12 leads surface ECG

53. Sotalol, Ibutilide
Magnesium, Ivabradine
PHARMACOLOGICAL TREATMENT OF
TACHYARRHYTHMIA

54. NON PHARMACOLOGICAL TREATMENT OF
TACHYARRHYTHMIA

55. Pharmacological Treatment of Bradyarrhythmia
• Adrenaline and noradrenaline in case of brady
asystole and in cardiac arrest.

56. NON PHARMACOLOGICAL TREATMENT OF
BRADYARRHYTHMIA

57. Atrial Tachyarrhythmia (Narrow QRS Tachycardia)

58. • Sinus tachycardia

59. SINUS TACHYCARDIA
• Rate: 101-160/min. P wave: sinus
• QRS: normal
• Conduction: normal
• Rhythm: regular or slightly irregular
• The clinical significance of this dysrhythmia depends on the
underlying cause. It may be normal.

60. Acute therapy (During attack)

61. PREAMATURE ATRIAL CONTRACTIONS
• Rate: normal or accelerated
• P wave: usually have a different morphology than sinus P waves
• QRS: normal
• Conduction: normal, however the ectopic beats may have a different P-R interval.
• Rhythm: REGULAR IRREGULARITY, Followed by compensatory pause.
• PAC's occur normally in a non diseased heart.
• However, if they occur frequently, they may lead to a more serious atrial dysrhythmias.
• They can also result from CHF, ischemia and COPD.

65. Premature Atrial Contractions (PAC)
• These ectopic beats originate in the atria (but not in the SA node),
therefore the contour of the P wave, the PR interval, and the timing
are different than a normally generated pulse from the SA node.
• Etiology: excitation of an atrial cell forms an
impulse that is then conducted normally
through the av node and ventricles.
Premature Ventricular Contractions (PVC)
• Ectopic beats originate in the ventricles resulting in wide and bizarre QRS
complexes.
• When there are more than 1 premature beats and look alike, they are
called “uniform”. When they look different, they are called “multiform”.
• Etiology: One or more ventricular cells are depolarizing and the impulses
are abnormally conducting through the ventricles.

67. Extrasystole: Premature Atrial and ventricular Contractions
(PAC/PVC)

73. Supraventricular tachycardia (SVT)

75. Paroxysmal supraventricular tachycardia (PSVT)
• The heart rate suddenly speeds up, often triggered
by a PAC (not seen here) and the P waves are lost.
• Etiology: there are several types of PSVT but all originate above the ventricles (therefore
the QRS is narrow).

76. PSVT: Acute Treatment Summary
• Hemodynamically unstable
(shock, pulmonary oedema, chest pain)…
…..DC cardioversion
• Stable: 1) Vagal maneuvers
– 2) Adenosine
– 3) CCB’S
– 4) BB’S
– 5) Amiodarone
– 6) digoxin
– If no response…..DC Cardioversion
PSVT: CHRONIC TREATMENT SUMMARY

77. Atrioventricular Junctional Arrhythmia
• AVRT (Accessory pathway)
• AVNRT
• Both similar to SVT

84. Good luck