heart block seminar by sanjana aagate

presented by sanjana aagate, masters in critical care nursing

1. SEMINAR ON HEART BLOCK SANJANA AAGATE. Msc . Nursing 1 st year.

2. DYSRHYTHMIA Dysrhythmia is defined as the abnormal or irregular heartbeat, the heart beat too fast or too slow and rhythm can be disrupted leading to feel like heart skipped a beat.

3. definition Heart block is defined as an abnormal heart rhythm where the heart beats too slowly, which results in electrical signals being partially or totally blocked between the upper chambers (atria) and lower chambers (ventricles). Heart block is also called atrioventricular block.

4. Types of heart block First-degree heart block: The electrical impulse still reaches the ventricles, but moves more slowly than normal through the AV node. The impulses are delayed. This is the mildest type of heart block.

5. Second-degree heart block: It is classified into two categories: Type I and Type II. In second-degree heart block, the impulses are intermittently blocked. Type I, also called Mobitz Type I or Wenckebach’s AV block: This is a less serious form of second-degree heart block. The electrical signal gets slower and slower until your heart actually skips a beat. Type II, also called Mobitz Type II:  While most of the electrical signals reach the ventricles every so often, some do not and your heartbeat becomes irregular and slower than normal.

6. Third-degree   heart block: The electrical signal from the atria to the ventricles is completely blocked. To make up for this, the ventricle usually starts to beat on its own acting as a substitute pacemaker but the heartbeat is slower and often irregular and not reliable.

7. etiology Disturbances in automaticity is used here to describe the disturbance in normal process of generating a heart rhythm. I f the AV junction cannot take over as the pacemaker because of disease. Disturbances in conduction is the speed the impulse travels through the sinus node atrioventricular node and purkinje fibres .. Latent pacemaker cells can also fire at rates above or below their inherent rate. a rhythm slower than intrinsic rate is called bradycardia. The rhythm faster than the intrinsic rate is called accelerated or tachycardia. Reentry of impulses occurs when cardiac tissue is depolarised multiple times by the same impulse. normally the impulse enters into the tissue, excites the tissue causing depolarization and leaves the tissue. Reentry of impulses creates problems because some cells have been repolarisation sufficiently so that they can prematurely depolarise again, producing ectopic beats and rhythm disturbances.

8. Clinical manifestation Fainting, feeling dizzy. Chest pain. Feeling tired. Shortness of breath. Heart palpitations. Rapid breathing. Nausea.

9. Diagnostic evaluation Holter monitor electrocardiography An implantable loop recorder   An electrophysiology study Blood investigations

10. Medical management DEFIBRILLATION: Defibrillation means a applying an electric charge or current to heart to restore a normal heart beat. If heart rhythm stops due to cardiac arrest, also known as sudden cardiac arrest, a defibrillator may help heart to start beating again.

11. Interventional medical management Ablating Conduction Pathways A variety of procedures can be used to treat dysthythmias when medications are not successful in bringing about conversion of the abnormal rhythm to a normal rhythm Interventions include (1) chemical and (2) mechanical ablation.

12. Chemical Ablation: Alcohol or phenol is inserted into involved areas of the myocardium through an angioplasty catheter leading to myocardial necrosis. Recurrences of tachycardia after successful chemical ablation are common. Chemical ablation is used only when other ablative approaches have failed and no other options are available Postprocedural care is the same as that for angioplasty, with the exception of expected cardiac enzyme elevation following chemical ablation Mechanical Ablation: The abnormal pathway is surgically removed or treated with a cryoprobe to interrupt its effect on heart rhythms. SVT, atrial fibrillation. atrial flutter, and WPW syndrome may be treated with this method when the client does not respond to medication.

13. PACEMAKER DESIGN: A pacemaker provides an external energy source for impulse formation and delivery. each with unique capabilities, every pacemaker consists of a pulse generator with circuitry, the lead(s), and the electrode system. Single chamber pacemakers pace either the atria or the ventricles, dual-chamber pace- makers pace both the atria and the ventricles. The pulse generator is essentially the pacemaker's power source. The pulse generator can be external or internal.

14. PACEMAKER: Pacemakers provide an artificial SA node and/or Purkinje system. A pacemaker is indicated if the conduction system fails to transmit impulses from the sinus node to the ventricles, to generate an impulse. There are 2 modes of pacemaker: Fixed rate pacemakers Demand pacemakers

15. There are 2 types of pacemakers: Temporary pacemaker: Temporary cardiac pacing involves electrical cardiac stimulation to treat a dysrhythmia until it resolves or until long term therapy can be initiated. The purpose of temporary pacing is to reestablish normal hemodianamics that are acutly compromised by a slow or fast heart rate. Permanent pacemaker: A permanent pacemaker is a small device that is inserted under subcutaneous tissue under clacicular region on left or right side and catheter is inserted through subclavian vein, cephalic vein, internal jugular vein or femoral vein.

16. Nursing management Monitoring for response to the pacemaker. Maintenance of electrical safety. Monitoring for pacing parameters (sensing, capturing, threshold). Protection against injury and infection

17. 1. Assess your wound daily and keep the incision clean and dressing until it heals. 2. Report any fever redness drainage warmth, discoloration. or swelling to the physician. 3. Avoid constrictive clothing teg tight brassiere straps), which puts excessive pressure on the wound and the pulse generator. 4. Avoid extensive toying with the pulse generator because this may cause pacemaker malfunction and local skin inflammation. 5. At all times carry a pacemaker identity card (including Programming information, pacemaker manufacturer, emergency phone numbers). 6. Wear a medical alert bracelet. 7. Avoid activity that might damage the pulse generator.