Heart Block.pptx

For 2nd year B.Sc. Nursing students

1. HEART BLOCK Presented By: Mr. Nandish.S Asso. Professor Mandya Institute of Nursing Sciences

2. DEFINITION : It is a condition where the heart beats more slowly or with an abnormal rhythm. It is a disorder in the heart’s rhythm due to fault in the natural pacemaker. Atrioventricular block is a disruption in the electrical signals that control heartbeat. It is a disturbance of impulse conduction that can be permanent or transient contributing to anatomical or functional impairment.

3. ETIOLOGY & RISK FACTORS : Medications like digitalis, calcium channel blockers, beta blockers …. Lyme disease Myocardial Infarction & Ischemia Valvular disorders Cardiomyopathy Endocarditis & Myocarditis Increased Vagal Tone. Rheumatic Heart Disease Hyperthyroidism

4. TYPES OF HEART BLOCK : First degree AV Block Second Degree AV Block - Mobitz type I or Wenckebach phenomena Mobitz type II AV Block 3. Third Degree AV Block

5. FIRST DEGREE AV BLOCK : It occurs when all the impulses are conducted through AV Node into the ventricles at a rate slower than normal. It is a disease of electrical conduct system in which PR interval is lengthened than 0.20 seconds.

6. Causes for First Degree Heart Block : Intrinsic AVN Disease Acute Myocardial Infarction Myocarditis Hypokalemia Medications (that increase refractory time of AVN)

7. SECOND DEGREE HEART / AV BLOCK Type I or Mobitz Type I or Wenckebach phenomena It is characterized by disturbance, delay or interruption of atrial impulse conduction through the AV Node to ventricles. PR interval prolongs with each beat until a dropped beat is seen. After each dropped beat, new cycle begins which is normal.

8. Causes for Mobitz type I AV Block : Cardiomyopathy Rheumatic Fever Varicella zoster infection Hyperkalemia Hypothyroidism Hypoxia Inferior wall MI Medications like Beta blockers, calcium channel blockers, Amiodarone …

9. Type II or Mobitz type II AV Block : It occurs when only some of the atrial impulses are conducted through AV Node into ventricles. PR interval is usually regular & constant, but may be irregular. Occasionally a dropped beat is seen. It is more significant disease.

10. Third Degree AV Block : It is also called as complete heart block, it is a serious disorder of conductive system, where there is no conduction through the Atrio -Ventricular node. Complete failure of AV Node. No impulses from sinus node will pass through to the ventricles. Complete dissociation between P wave & QRS Complex, where more P waves are seen before one QRS complex .

11. Types of Infra – Hisian Block : Left Bundle Branch Block Left Anterior Fascicular Block Left Posterior Fascicular Block Right Bundle Branch Block

12. Left Bundle Branch Block : In this condition, activation of Left ventricle is delayed which results in the left ventricle contracting later than right ventricle. It is caused due to Aortic stenosis, Cardiomyopathy, Acute MI, Coronary Artery Disease, Aortic Regurgitation. It is manifested by prolongation of QRS complex, duration is more than 120 ms in ECG.

13. Right Bundle Branch Block : In is the right ventricle is not directly activated by impulses travelling through right bundle branch block. Heart beat is originated above the ventricle. It is manifested by QRS complex less than 100 ms in ECG.

14. CLINICAL FEATURES : Decreased heart rate or Bradycardia Irregular Heart beat Shortness of breath Syncope or Fainting Fatigue Chest pain Light headedness Seizures In severe cases : breathlessness Breathlessness on exertion

15. DIAGNOSTIC STUDIES : History collection & physical examination ECG Echocardiography Holter monitor Stress Test Continuous cardiac monitoring Blood examination (cardiac markers)

16. Management : For asymptomatic patients, decreasing or eliminating the cause is planned by holding the medications. For symptomatic patients, medications such as Atropine, Epinephrine, Isoproterenol, Dopamine are given to increase BP and Heart rate. Temporary Pacing can be initiated for advanced AV Block, acute MI. Permanent Pacemaker is planned if the block persists.

17. PACE MAKER THERAPY Definition : It is an electric instrument that provides electrical stimuli to the heart muscle. They are usually used when a patient has a slower than normal impulse formation or a conduction disturbances that cause symptoms. Types : Temporary Permanent

18. Temporary Pacemaker : It is used until long term therapy can be initiated. Indications : Cardiac catheterization Coronary Angioplasty Before implantation of permanent Pace maker After open heart surgery Acute Anterior MI with 2 nd or 3 rd Degree block Acute Inferior MI Ventricular Tachycardia Atrial Flutter Brady or Tachy Arrhythmias

19. Types of Temporary Pacemaker Transcutaneous pacing (External) Transvenous pacing Transthoracic pacing Transesophageal pacing

20. Transcutaneous Cardiac Pacing : It is a non invasive & delivers electricity from the external power source. This causes the depolarization of excitable myocardial tissue by pulsed electrical current conducted through the chest wall, between e lectrodes adherent to the skin.

21. Transvenous Pacing : An intravenous catheter electrode is positioned endocardially through subclavian or external Jugular venous route and this is then connected to an external Generator by a lead connector. Types : Bipolar Electrodes – both anode & cathode are intra thoracic. Unipolar – anode is extra thoracic. Insertion Site : - Right External Jugular vein - Left Subclavian vein - Femoral vein - Brachial vein .

22. Transthoracic Cardiac Pacing : It is a technique of pacing the heart with an electrode introduced percutaneously into the ventricular cavity using a needle Trocar introducer. It was used in patients with acute unstable dysrhythmia until transcutaneous pacing is introduced.

23. Trans esophageal pacing : Trans esophageal pacing & recording is done by using specialized or simple catheters. There are 2 types. The pill electrode , connected to flexible wire that patient swallows with water, which needs patient's collaboration. A flexible catheter that can be used in unconscious or intubated patients. Bipolar flexible catheter is introduced into esophagus through nose after local anaesthesia / throat anaesthesia. Lead is introduced with guide wires. It is positioned into esophagus in order to record posterior paraseptal atrial electro gram.

24. Complications : Haemo or Pneumothorax Rupture of major blood vessels Perforation of right ventricle VT or VF Cardiac Arrest Heart Failure

25. THANK YOU