arrythmia 1.pptx
Download as PPTX, PDF0 likes260 views
Cardiac arrhythmia refers to any abnormal heart rhythm and can cause the heart rate to be too fast, too slow, or irregular. Common types include sinus tachycardia, ventricular tachycardia, sinus bradycardia, paroxysmal supraventricular tachycardia, atrial flutter, atrial fibrillation, premature atrial contractions, premature ventricular contractions, and nodal rhythm. Treatment depends on the specific arrhythmia but may include medications, cardioversion, pacemakers, ablation, or defibrillation.
arrythmia 1.pptx
- 2. ARRHYTHMIA • CARDIAC ARRHYTHMIA (ALSO DYSRHYTHMIA) IS A TERM FOR ANY OF A LARGE AND HETEROGENEOUS GROUP OF CONDITIONS IN WHICH THERE IS ABNORMAL ELECTRICAL ACTIVITY IN THE HEART. • THE HEART BEAT MAY BE TOO FAST OR TOO SLOW, AND MAY BE REGULAR OR IRREGULAR. • NORMAL SINUS RHYTHM (60-90BPM), SA NODE PACEMAKER
- 3. NORMAL ELECTRICAL ACTIVITY IN THE HEART Each heart beat originates as an electrical impulse from a small area of tissue in the right atrium of the heart called the sinus node or Sino-atrial node or SA node. The impulse initially causes both of the atria to contract, then activates the atrioventricular (or AV) node which is normally the only electrical connection between the atria and the ventricles , which can be called as main pumping chambers. The impulse then spread through both ventricles via the Bundle of His and the Purkinje fibres causing a synchronised contraction of the heart muscle, and thus, the pulse
- 4. Normal electrical activity in the heart • Impulses originate regularly at a frequency of 60-100 beat/ min • SAN is considered the pacemaker of the heart . • SAN is characterized by its own automaticity (ability to generate impulse) So nerve supply of the heart aims at regulation of heart rate not initiation of rhythm. SAN AVN
- 5. Depolarization repolarization Phase 4 Cardiac Action Potential
- 7. Mechanisms of Cardiac Arrhythmias Mechanisms of bradicardias: Sinus bradycardia is a result of abnormally slow automaticity while bradycardia due to AV block is caused by abnormal conduction within the AV node or the distal AV conduction system. Mechanisms generating tachycardias include: - Accelerated automaticity. - Triggered activity - Re-entry (or circus movements)
- 8. ACCELERATED AUYOMATICITY Pacemaker cells are present in the SA node, atria, AV node, and the His-Purkinje system. In the human heart, the normal rate of discharge of the SA node is between 60 and 100 beats per min (bpm). Enhanced automaticity of pacemaker cells can increase the rate of action potential discharge When this occurs in the SA node, it can lead to an increase in heart rate, termed sinus tachycardia. This can be physiological, due to increased sympathetic tone during exercise, or pathophysiological, due to hypovolemia, fever, ischemia, or electrolyte disturbances.
- 9. TRIGGERED ACTIVITY Triggered activity results from the premature activation of cardiac tissues Myocardial damage can result in oscillations of the transmembrane potential at the end of the action potential. These oscillations, which are called 'after depolarizations', may reach threshold potential and produce an arrhythmia. The abnormal oscillations can be exaggerated by pacing, catecholamines, electrolyte disturbances, and some medications. Examples as atrial tachycardias produced by digoxin toxicity and the initiation of ventricular arrhythmia in the long QT syndrome.
- 10. Re-entry (or circus movement) The mechanism of re-entry occurs when a 'ring' of cardiac tissue surrounds an inexcitable core (e.g. in a region of scarred myocardium). Tachycardia is initiated if an ectopic beat finds one limb refractory , resulting in unidirectional block and the other limb excitable, circus movement will be maintained, producing a run of tachycardia. The majority of paroxysmal tachycardias are produced by this mechanism.
- 11. Damaged tissue is usually depolarized → ↓ conduction velocity
- 12. ETIOLOGY: 1. Blocked arteries in the heart (coronary heart disease) 2. Scaring from a previous heart attack (myocardial infarction) 3. Changes to the heart's structure (congenital heart disease) 4. Diabetes 5. High blood pressure 6. Overactive thyroid gland 7. Underactive thyroid gland 8. Certain medications (digitalis, symathomimetics, sympatholytics) 9. Stress or anxiety 10. smoking
- 13. CLINICALPICTURE: ARRHYTHMIA SYMPTOMS: • Asymptomatic • Rapid heartbeat or irregular heartbeat • A fluttering feeling in your chest • Chest pain • Troubled breathing • Weakness • Dizziness or light headedness • Fainting • Fatigue • Sweating • Embolic Manifestations • Sudden cardiac death
- 14. Investigations for arrhythmia 1. Resting ECG 2. Holter ECG 3. Loop Recorder 4. Stress ECG 5.Electrophysiological study (EPS) 6. Investigations for the cause a. Echo b. Cardiac MRI (Myocardial Scarring in VT-VF) c. Serum electrolytes- CBC-Thyroid functions
- 15. Treatment of arrhythmia A. Emergency ttt (if hemodynamically unstable PT) 1. Atropine then Temporary Pacemaker in high grade AV- block 2. DC-Cardioversion in Tacchyarrythmia N.B (Never to give DC-shock to pt with sinus tachycardia B. Long term 1. TTT of the Cause (IHD-Thyroid dysfunction- Electrolyte imbalance) 2. AV-blocking agents and anti-arrhythmics for tachyarrhythmia . 3. Anti-coagulation (AF-flutter) 4. Intervention (PPM for HB- Ablation for tacch
- 16. Sinus tachycardia • Definition Atrial and ventricular rates are more than 100 beats per minute • Management Identify the cause of the tachycardia Decrease the heart rate to normal by treating the cause ß blockers and sedatives may be needed
- 18. • Definition It is a paroxysmal condition in which there is abnormal focus in the ventricle that discharge impulses more than SAN(150– 250/ min) Since the focus in the ventricle and there is no retrograde conduction in AVN, sow the ventricles will follow the ectopic focus and the atria will follow the SAN (AV dissociation). Can cause cardiac arrest Ventricular tachycardia
- 19. • Management 1. STABLE PATEINT WITH SUSTAINED VT: Administer antiarrhythmics (AMIODARONE, LIDOCAINE) 2. UNSTABLE CLIENT WITH VT antidysrhythmic therapy Prepare for synchronized cardioversion 3. PULSELESS CLIENT Defibrillation and cardiopulmonary resuscitation (CPR)
- 20. P wave : - normal but hidden by the QRS QRS: - rapid, regular with wide abnormal bizzare shape No fixed relation between P wave & QRS due to AV dissociation.
- 21. SINUS BRADYCARDIA • DEFINITION IT IS A CONDITION AT WHICH THE SAN DISCHARGE IMPULSES BY A RATE LESS THAN 60/MIN • CAUSES 1. PHYSIOLOGICAL : DUE TO STRONG VAGAL TONE OR ATHELETIC TRAINING. 2. EXTRINSIC CAUSES ;HYPOTHERMIA, HYPOTHYROIDISM, CHOLESTATIC JAUNDICE AND DRUG THERAPY WITH BETA-BLOCKERS, DIGITALIS AND OTHER ANTIARRHYTHMIC DRUGS. 3. INTRINSIC CAUSES; ACUTE ISCHEMIA AND INFARCTION
- 22. • MANAGEMENT 1. ATTEMPT TO DETERMINE CAUSE AND IF A MEDICATION IS SUSPECTED AS CAUSING THE BRADYCARDIA, HOLD THE MEDICATION . 2. ADMINISTER ATROPINE SULFATE TO INCREASE THE HEART RATE TO 60 BEATS PER MINUTE 3. MONITOR FOR HYPOTENSION AND ADMINISTER IV FLUIDS AS NEEDED. 4. DEPENDING ON THE CAUSE OF THE BRADYCARDIA, THE PATIENT MAY NEED A PERMANENT PACEMAKER
- 24. Paroxysmal Supraventricular tachycardia • Definition A condition in which there is abnormal focus in the atrium other than SAN which discharge regular impulses in a rate ( 150- 250 / min.) This abnormal focus may initiated in any area of the atria (paroxysmal atrial tachycardia) or even in AVN (paroxysmal nodal tachycardia). • Management Vagal stimulation Drugs : A, B, C, D Adenosine ß blockers Ca channel blockers(verapamil) Digitalis If there is no response or hemodynamically unstable : DC cardioversion
- 25. P wave : - in atrial tachycardia : deformed - In nodal tachy cardia : absent QRS: - rapid, regular with normal shape
- 26. Atrial flutter • Definition A condition in which there is abnormal focus in the atrium that discharges rapid regular impulses in a rate ( 250- 350 / min.), but due to physiological block of AVN not all atrial impulses are conducted to the ventricles – only ½.1/3, ¼ .. Of the atrial impulses will pass to the ventricles. • Management Drugs : to control the ventricular rate (↓ AVN conduction) ß blockers Ca channel blockers(verapamil) Digitalis If there is no response or hemodynamically unstable : DC cardioversion
- 28. Atrial fibrillation • Definition A condition in which there is rapid irregular impulses (400-600/min) arise from the atria by multiple ectopic foci (so the atria don’t contract effectively) & due to physiological delay at the AVN, not all impulses are conducted to the ventricles. • Management Administer oxygen Administer anticoagulants as prescribed because of the risk of emboli Administer cardiac medications as prescribed to control the ventricular rhythm and assist in the maintenance of cardiac output Prepare the patient for cardioversion as prescribed Instruct the patient in the use of medications as prescribed to control the dysrhythmia
- 29. P wave : -absent & replaced by fibrillation wave QRS: - normal in shape but irregular rhythm
- 30. premature atrial contractions (PAC) A condition in which an atrial pacemaker site above the ventricles sends out an electrical signal early. The ventricles are usually able to respond to this signal, but the result is an irregular heart rhythm. PACs are common and may occur as the result of stimulants such as coffee, tea, alcohol, cigarettes, or medications. Treatment is rarely necessary.
- 31. Two PACs with a compensatory pause seen on an ECG rhythm strip. A "skipped beat" occurs and rhythm resumes 2 P-to-P intervals after the last normal sinus beat.
- 32. Premature ventricular contractions(PVCs) Definition A condition in which there is an ectopic impulse arising from the ventricles before the expected next beat causes what is called premature beat. Management • Identify the cause and treat based on the cause • Evaluate electrolytes, particularly the potassium level, since hypokalemia can cause PVCs • Administer lidocaine in emergency cases • Notify the cardiologist if the patient complains of chest pain, if PVCs increase in frequency, or occur in runs of ventricular tachycardia
- 34. Nodal ( junctional )Rhythm Definition A condition in which heart is controlled by the AVN. The impulses reach the atria & ventricles at the same time Management • Identify the cause and treat based on the cause • Atropine if needed. • Artificial peacemaker may be needed in sever cases.
- 35. P wave : -inverted & come approximately at the same time with QRS QRS: - normal in shape but slow & regular
- 36. Atrio ventricular block 1 st degree heart block Definition o It is just prolonged PR interval (PR interval ⍩ 0.2 second (2 small square) o Has no clinical significance. o May be associated with acute rheumatic fever, diphtheria, myocardial infarction or drugs as digoxin
- 38. 2nd degree heart block MOBITZ TYPE I (WENCHEBACH PHENOMENON): GRADUALLY INCREASING P-R INTERVALS LEADING FINALLY TO DROPOUT OF QRS & THEN THE CYCLE IS REPEATED IT IS USUALLY PHYSIOLOGICAL AND DUE TO INCREASED VAGAL TONE AND ABOLISHED BY EXERCISE AND ATROPINE. MOBITZ TYPE II THE AVN TRANSMIT ONE IMPULSE FOR EACH 2,3 OR 4 ATRIAL IMPULSES. PACING IS USUALLY INDICATED IN MOBITZ II BLOCK, WHEREAS PATIENTS WITH WENCKEBACH AV BLOCK ARE USUALLY MONITORED.
- 40. 3rd degree heart block Complete heart block Definition o In this condition all impulses from the atria don’t reach the ventricles , so the ventricles will be controlled by idioventricular rhythm. o Common in elderly age groups due to idiopathic bundle branch fibrosis. o Other causes include coronary heart disease, calcification from aortic valve, sarcoidosis or congenital. oTreatment is permanent pacing
- 42. MCQ Question 1. Which arrythmia will occur due to damage to the atrioventricular node(AVN): a) Atrial fibrillation(AF). b) Ventricular tachycardia. c) Complete heart block
- 43. answer 1. Which arrythmia will occur due to damage to the atrioventricular node(AVN): c) Complete heart block
- 44. Question 2. What risk is commonly associated with atrial fibrillation(AF) a) Cerebrovascular accident (CVA). b) hemorrhage. c) Myocardial infarction.
- 45. answer 2. What risk is commonly associated with atrial fibrillation(AF) a) Cerebrovascular accident (CVA).
- 46. Question 3. What is the most common cause of ventricular tachycardia(VT) a) Electrolyte imbalance. b) Myocardial infarction. c) Renal failure.
- 47. answer 2. What is the most common cause of ventricular tachycardia(VT) b) Myocardial infarction.