1. Anatomy
    2. 1. Mediastinum
    2. The Heart Development
    3. Pericardium
    4. Features of the Heart
    5. Arterial Supply of Heart
    6. Venous Drainage of the Heart
    7. Conducting System of Heart
    8. Nervous System of Heart
    9. Foetal Circulation and Changes at Birth
    10. Microscopic Structure of Heart
    11. Arteries
    12. Arch of Aorta
    13. Descending Thoracic Artery
    14. Abdominal Aorta
    15. Subclavian Artery
    16. Axiallary Artery
    17. Internal Thoracic Artery
    18. Brachial Artery
    19. Radial Artery
    20. Ulnar Artery
    21. Palmar Arches
    22. External Iliac Artery
    23. Internal Iliac Artery
    24. Femoral Artery
    25. Popliteal Artery
    26. Posterior Tibial Artery
    27. Anterior Tibial Artery
    28. Dorsalis Pedia Artery
    29. Common Carotid Artery
    30. External Carotid Artery
    31. Internal Carotid Artery
    32. Veins
    33. Internal Jugular Vein
    34. External Jugular Vein
    35. Superior Venacava
    36. Inferior Venacava
    37. Brachiocephali vein
    38. Subclavian vein
    39. Axillary vein
    40. Cephalic vein
    41. Basilic vein
    42. Azygous vein
    43. Hemiazyous vein
    44. Accessory Hemiazyoug Vein
    45. Internal Hemiazygous Vein
    46. Internal Iliac Vein
    47. Femoral Vein
    48. Popliteal Vein
    49. Long Saphenous Vein
    50. Small or Short Saphenous Vein
    51. Hepato-portal System
    52. Lymphatic System
    53. Spleen
    54. Thymus
    55. Thoracic duct
  2. Pharmacology
    3. 56. Congestive Heart Failure
    57. Therapy of Arrhythmiasis
    58. Angina pectoris
    59. Therapy of Hypertension
    60. Therapy of Shock
    61. Haemostatic Agents
    62. Therapy of Thromboembolic Disorder
    63. Thrombolytic or Fibrinolytics
    64. Antifibrinolytics
    65. Antiplatelet Drugs
    66. Therapy of Iron Deficiency Anemia
    67. Therapy of Megaloblastic Anaemia
    68. Hypolipidemic Drugs and Plasma Expanders
  3. Physiology
    4. 69. Properties of Myocardial Cells
    70. Heart - A Mechanical Pump
    71. Cardiac Cycle
    72. Electrocardiogram (ECG)
    73. Cardiac Output (CO)
    74. Haemodynamics of Circulation
    75. Heart Sounds
    76. Arterial Pulse
    77. Blood pressure
    78. Regional circulation
    79. Cardiovascular chanes during exercise
    80. Edema Dropsy of fluid retention
    81. Shock
    82. Hematology
  4. Pathology
    5. 83. Anaemia
    84. Hypertension
    85. Hypertensive Heart Disease
    86. Ischemic Heart Disease
    87. Angina pectoris
    88. Myocardial infarction
    89. Rheumatic Fever and Rheumatic Heart Disease (RHD)
    90. Acute Pericarditis
    91. Myocarditis
    92. Infective Endocarditis (IE)
    93. Congenital Heart Disease
    94. Cardiomyopathies
    95. Arteriosclerosis
    96. Atherosclerosis
    97. Inflammatory Disease of Blood Vessels
    98. Aneurysms and Dissection
    99. Congestive Heart Failure
    100. Iron Deficiency Anaemia
    101. Megaloblastic anaemia
    102. Pancytopenia
    103. Leucocytosis and Leucopenia
    104. Aplastic anaemia
    105. Haemolytic anaemia
    106. Hereditary Spherocytosis
    107. Haemoglobinipathies
    108. Thalassemia syndrome
    109. Sickle Cell Disease
    110. Leukaemia
    111. Leukemoid reaction
    112. Lymphadenitits
    113. Hodgkin lymphoma
    114. Non-hodgkin lymphoma
    115. Myeloproliferative disorders
    116. Myelofibrosis
    117. Multiple myeloma
    118. Bleeding disorders
    119. Coagulation disorders
    120. any
    121. Blood grouping
  5. Microbiology
    6. 122. Introduction of Blood borne infections
    123. Infective Endocarditis
    124. Brucella
    125. Rickettsiae
    126. Leishmania donovani
    127. Plasmodium
    128. Wuchereria bancrofti
  6. Biochemistry
    7. 129. Metabolism in Blood Cells
    130. Iron metabolism
    131. Haemoglobin
    132. Lipoprotein metabolism
    133. Biochemical aspect of MI
Pharmacology
57. Therapy of Arrhythmiasis

1.

List various drugs effective in atrial arrhythmia. Explain mechanism of action and specific adverse effects of adenosine.

[2071]

➤

2.

Classify anti-arrhythmic agents.

➤

INTRODUCTION
name
Anti-arrhythmic Drugs
CLASSIFICATION
    ◉ CLASS I:
    ■ Mechanism of action:
    1. They primarily limit the conductance of Na+ (and K+) across cell membrane i.e, exerts local anaesthetic action.
    2. They also reduce rate of phase 0 - depolarization in automatic cells.
    3. They exert 'Use dependent' blockade action i.e., acts more on rapidly firing fibres.
      • •
        Thus, they block more on partially depolarized fibres.
    CLASS IA
    CLASS IB
    CLASS IC
    MOA:
    All of them block Na+ channel and thus decrease the slope of 0 phase depolarization.
    1. Blocks Na+ channel at open state more than closed ones.
    2. Blocks K+ channel.
    1. Blocks Na+ channel at inactivated state more than open state.
    2. Opens K+ channel.
    1. Blocks Na+ channel at open state more than closed ones.
    2. Negligible effect on K+ channel.
    ◈ SUBCLASS IA:
    ● Mechanism of action:
    1. They are open state Na+ channel blockers with little effect on resting channels.
    2. They moderately
      1. delay channel recovery
      2. suppress AV conduction and
      3. prolong refractoriness.
    3. They serve to extinguish ectopic pacemakers that are often responsible for triggered arrhythmias.
    4. They also abolish reentry by converting unidirectional block into bidirectional block.
    ● Uses:
    1. Used to prevent acute, chronic ventricular and supraventricular arrhythmias expecially
      1. Paroxysmal Supraventricular Tachycardia (PSVT)
      2. Symptomatic ventricular premature beats
      3. Ventricular fibrillation
    ■ DISOPYRAMIDE:
    ● Mechanism of action:
    ■ PROCAINAMIDE:
    ● Mechanism of action:
    ■ QUINIDINE:
    ● Source: Cinchona plant
    Image 1
    Fig. Cinchona plant
    ● Mechanism of action:
    1. As above
    2. Blood vessels: Increases Blood pressure at high dose due to α1 blocking effect.
    3. Relaxes skeletal muscles.
    4. Has anti-malarial effect.
    5. Utrine contraction.
    ● Uses:
    1. Wide use in many arrhythmias
      1. Atrial flutter
      2. Atrial fibrillation
    2. Anti-malarial action
      • •
        It has weaker anti-malarial action than Quinine.
      • •
        It is used as a parenteral alternative to quinine for falciparum malaria.
    ● Adverse effects:
    1. Hypotension and Hypoglycemia
    2. GIT
      1. Nausea
      2. Vomiting
      3. Diarrhoea
    3. Hypersensitivity
      1. Fever
      2. Angioedema
      3. Shock
      4. Thrombocytopenia
    4. Cinchonism in overdose
      1. Ear
        1. Ringing in ear
        2. Vertigo
        3. Tinnitus (the perception of sound that does not have an external source)
        4. Deafness
      2. CNS
        1. Headache
        2. Visual disturbances and
        3. Delirium
        4. Mental changes
      3. Hypotension
    ● Drug interaction:
    1. Increase in blood levels and toxicity of Digoxin and Digitoxin
      1. Inhibition of Renal clearance of Digoxin
      2. Inhibition of Biliary clearance of Digitoxin
    ◈ SUBCLASS IB:
    ● Mechanism of action:
    ■ LIDOCAINE:
    ● Mechanism of action:
    ■ MEXILITINE:
    ● Mechanism of action:
    ◈ SUBCLASS IC:
    ● Mechanism of action:
    ■ PROPAFENONE:
    ● Mechanism of action:
    ◉ CLASS II:
    ■ Mechanism of action:
    ◈ ESMOLOL:
    ■ Mechanism of action:
    ◉ CLASS III:
    ■ Mechanism of action:
    ◈ AMIODARONE:
    ■ Mechanism of action:
    ◉ CLASS IV:
    ■ Mechanism of action:
    ◈ VERAPAMIL:
    ■ Mechanism of action:

Question Answers