Rhythm Disorders PDF

Clinical aspect of RHYTHM DISORDERS  Definition Bradycardia is decrease HR < 60/min Tachyarrhythmia :refer to a heart rate that is faster than normal. It includes several specific types of arrhythmias where the heart beats more than 100 /min Heart block is defined as block of...

Clinical aspect of RHYTHM DISORDERS  Definition Bradycardia is decrease HR < 60/min Tachyarrhythmia :refer to a heart rate that is faster than normal. It includes several specific types of arrhythmias where the heart beats more than 100 /min Heart block is defined as block of impulse transmission any where allover the conducting system of the heart Sino-atrial block A-V Block Intra ventricular block BBB  Classification of Brdaycardia 1. Sinus Bradycardia 2. Atrioventricular (AV) Block  Sinus Bradycardia Definition: A heart rate of 60/min. or less provided that the heart is activated by a sinus mechanism. Causes of Sinus Bradycardia:  Clinical picture: 1. Usually no symptoms. 2. Rarely: symptoms of low cardiac output. 3. Syncope may occur due to excessive bradycardia as in vasovagal syncope. 4. Heart rate may be increased by exercise, emotion or atropin i.e. factors which may increase the symptomatic flow or Decrease vagal tone. Treatment: 1. No therapy is needed in most conditions. 2. Correction of the underlying condition is needed i.e. treatment of the etiology. 3. Only in sick sinus syndrome, cardiac pacemaker is essential  Heart Block Detention : Heart block is a condition in which the electrical signals that control the heartbeat are partially or completely blocked as they travel through the heart. This can slow down the heart rate or cause irregular heartbeats. Heart block can range in severity from mild to life-threatening Aetiology: 1. Acute: Cardiac: a. AMI. b. Myocarditis. c. Bacterial endocarditis. Drug intoxication or over-dosage.- a. Digitalis. b. Anti-arrhythmic drugs. c. Tricyclic antidpressant. d. Phenothiazines. Electrolyte Disorders: Hyperkalaemia. 2. Recurrent or chronic: 1.Cardiac: 1. CAD. 2. Cardiomyopathy. 3. Aortic valve disease. 4. Congenital. 5. Idiopathic fibrosis of the conductive system. 2. Connective tissue disorders: 1. Scleroderma. 2. Systemic lupus. 3. Endocrinal: Myxoedema.  Classification: A.First-Degree Heart Block: def: Prolonged A-V conduction, manifested by prolonged P-R interval in the ECG (> 0.22 msec). Symptoms: Usually asymptomatic, but if symptomatic, may include lightheadedness or dizziness. Treatment: Often, no treatment is needed unless associated with other heart conditions. B.Second-Degree Heart Block: a) Mobitz Type I (Wenckebach ) b) Mobitz Type II  1. Wenckbach or Mobitz type I: It is manifested as progressive prolongation of the P-R interval until there is a dropped QRS complex. Symptoms: Often asymptomatic, but can cause fatigue, dizziness, or lightheadedness. Treatment: 1. No treatment required 2. If symptoms are present, reducing or discontinuing medications that slow heart conduction may be beneficial. 3. Pacemaker: In rare cases where symptomatic bradycardia occurs, a pacemaker may be necessary. 2. Mobitz type II: It is manifested by dropping of some beats but the conducted one has a fixed P-R interval. Symptoms: More likely to cause symptoms such as fatigue, dizziness, syncope (fainting), and in some cases, it can progress to complete heart block. Treatment: Pacemaker: Due to the risk of progression to complete AV block and symptomatic bradycardia, a permanent pacemaker is usually recommended, even if symptoms are mild. B.Complete or third degree A-V block: There is complete dissociation between atrial rate and ventricular rate. The atrium is controlled by the SAN rate and the ventricle by the idioventricular rate. No impulse conduction from the atria to the ventricles ventricular rate = 37 BPM Atrial rate = 130 BPM Symptoms: Severe symptoms like fatigue, dizziness, syncope, or sudden cardiac arrest due to extremely slow ventricular rates. Treatment: Permanent Pacemaker: The most effective treatment. A pacemaker is implanted to ensure a reliable heart rate and prevent life- threatening slow heart rhythms. Tachyarrhythmias  Tachyarrhythmias Classification of Tachyarrhythmia: ❑ Tachyarrhythmias could be classified based on the rhythm: 1. regular 2. irregular) ❑ Could be classified based on electrocardiogram (ECG) 1. narrow complex 2. broad complex) ❑ Tachyarrhythmias Could be classified based on their origin within the heart: 1. Supraventricular Tachyarrhythmias (SVTs) 2. Ventricular Tachyarrhythmias  Sinus tachycardia Causes of Sinus Tachycardia: a) Physiological Causes: The heart rate increases naturally in response to certain stimuli, such as: 1. Exercise. 2. Stress: 3. Fever: 4. Pain: 5. Dehydration: 6. Hypovolemia: b) Pathological Causes: Some medical conditions can lead to sinus tachycardia: 1. Anemia: Reduced oxygen-carrying capacity of the blood prompts the heart to beat faster. 2. Hyperthyroidism: Excess thyroid hormone increases metabolism and heart rate. 3. Infections: Systemic infections or sepsis can cause an elevated heart rate as part of the body's response to fight the infection. 4. Pulmonary embolism: A blood clot in the lungs can lead to tachycardia as the heart struggles to pump blood effectively. 5. Drug use: Certain medications (e.g., stimulants, decongestants) and substances (e.g., caffeine, nicotine) can cause sinus tachycardia. 6. Postural orthostatic tachycardia syndrome (POTS): A condition in which the heart rate increases abnormally upon standing. Symptoms Of the cause Palpitations Anxiety Pulse rate : 100-180 / min ECG Normal PQRST sequence Usually narrow QRS Normal sinus P wave Normal PR interval Management Of the cause Undue sinus tachycardia : B Blockers or Ca blockers  Atrial tachycardia Symptoms Of the cause Palpitations Anxiety Pulse rate :150-300 / min ECG Normal PQRST sequence Usually narrow QRS complex Abnormal P wave Shape different from base line sinus initiated P wave Normal PR interval Management Of the cause beta-blockers or calcium channel blockers Mg sulphate  Atrial Fibrillation Pulse rate :100-180 / sec Most common irregularly irregular rhythm Multiple impulses from different areas move toward the AV node. Symptoms 1.Palpitations 2.Dizziness 3.Ligh theadedness 4. more severe symptoms:Dyspnea at rest ,Angina ,Symptoms of heart failure Management : Rate control with chronic anticoagulation is for the majority 1. Rate Control a) Beta-blockers (e.g., metoprolol, atenolol) b) Calcium channel blockers (e.g., diltiazem, verapamil) c) Digoxin 2. Rhythm Control The goal of rhythm control is to restore and maintain normal sinus rhythm. a) pharmacologic cardioversion -Amiodarone -Sotalol b)Electrical Cardioversion: 3. Anticoagulation – warfarin  Atrial flutter atrial rate is typically around 250 to 350 beats per minute Atrial flutter is closely related to atrial fibrillation (but while atrial fibrillation is characterized by irregular atrial activity, atrial flutter tends to be more organized and regular, though still abnormally fast. Treatment of Atrial Flutter: Rate Control: Medications commonly used to control the heart rate include: Beta-blockers (e.g., metoprolol, propranolol) Calcium channel blockers (e.g., diltiazem, verapamil) Digoxin: Sometimes used in combination with other medications Rhythm Control: Cardioversion: This is a procedure used to restore normal sinus rhythm Electrical cardioversion: Pharmacological cardioversion: Antiarrhythmic drugs like amiodarone,  AV nodal reentrant tachycardia AVNRT Pulse rate : 180-250 / min ECG QRST sequence Usually narrow QRS complex No P wave Usually hidden in QRS Management IV ca blockers or B blockers DC cardioversion in hemodynamic unstability Prevention of recurrence by B blockers or Ca blockers  Ventricular tachycardia Pulse rate :100-250 / sec ECG Usually regular Wide QRS complex AV dissociation Capture & fusion beats Management Hemodynamically stable IV lidocaine IV amiodarone Hemodynamically unstable DC cardioversion Prophylactic Amiodarone  Ventricular fibrillation (VF) is a life-threatening cardiac arrhythmia where the ventricles of the heart in a rapid and ineffective manner instead of contracting normally Symptoms of Ventricular Fibrillation: VF causes an immediate cessation of effective circulation, and symptoms develop very quickly. These include: a. Sudden loss of consciousness: b. No pulse: c. No breathing or agonal respirations: d. Seizure-like activity: Treatment of Ventricular Fibrillation: 1. Defibrillation: 2. Cardiopulmonary Resuscitation (CPR): 3. Long-term treatment: Implantable cardioverter-defibrillator (ICD):