SUPRAVENTRICULAR TACHYCARDIA.pptx Slideshare

Arrhythmias are classified as supraventricular and ventricular arrhythmias. In the former there are different causes for it the most important being atrial fibrillation which is also a complication of many heat disease like mitral stenosis myocardial infarction etc..

1. SUPRAVENTRICULAR TACHYCARDIA ARRYTHMIAS

2. Supraventricular tachycardia SVT is a tachycardia which utilizes atrial or AV nodal tissue as a part of its mechanism (originating above bundle of His). It is a regular tachycardia with heart rate >100 beats per minute and conducts via the Purkinje His system. On ECG the QRS shape during tachycardia is normal but narrowed.

3. CAUSES OF SVT SINUS TACHYCARDIA AV NODAL RE ENTRY TACHYCARDIA ATRIAL FIBRILLATIONS ATRIAL FLUTTER ATRIAL TACHYCARDIA

4. Characterised by heart rate >100/min with normal P waves, PR interval and QRS complexes. Causes: due to increase in sympathetic activity associated with exercise, emotion, pregnancy. Pathological causes include anemia, thyrotoxicosis, drugs(bronchodilators) etc. Treatment: treat the underlying cause. SINUS TACHYCARDIA ECG

5. ATRIAL FLUTTER Characterised by an organized, regular, rapid atrial rate between 250-350/min. Causes: Organic heart disease(ischemic, rheumatic), pericarditis, following open heart surgery, acute respiratory failure . Management: Restoration of sinus rhythm Control of ventricular rate Prevention of recurrence and stroke. ECG: saw-toothed flutter waves(“F” waves) between QRS complexes. QRS complexes are regular. .

6. ATRIAL FIBRILLATION AF is an arrythmia characterized by disorganized atria and produces multiple atrial foci fire impulses at a rate of 350-600/min. Mechanism: Abnormal automatic firing Presence of multiple interacting re entry circuits looping around atria.

7. CAUSES OF ATRIAL FIBRILLATION CARDIAC Hypertensive heart disease Valvular heart disease(RHD) Ischemic heart disease Heart failure Cardiomyopathy Postcardiac surgery NONCARDIAC Pneumonia, COPD, pulmonary embolism Hyperthyroidism/thyrotoxicosis Drugs/alcohol LONE ATRIAL FIBRILLATION Younger patients No underlying cause Normal heart structure REVERSIBLE/TRANSIENT Acute respiratory tract infections, chest infections

8. CLINICAL FEATURES SYMPTOMS Palpitations Fatigue Syncope Angina Symptoms of cardiac failure and thromboembolism SIGNS Irregularly irregular pulse Hypotension Absence of ‘a’ waves on JVP Varying intensity of first heart sound

9. INVESTIGATIONS Electrocardiogram: No clear P waves Fine very irregular, disorganized atrial fibrillatory or F waves Atrial rate:350-500bpm Long R-R interval is followed by short R-R interval.

10. OTHER INVESTIGATIONS 2D ECHO HOLTER MONITORING EXERCISE STRESS TEST CATHETERISATION THYROID FUNCTION TESTS CHEST X RAY

11. TREATMENT ACUTE MANAGEMENT OF AF Ventricular rate control by drugs blocking AV node Cardioversion LONG TERM MANAGEMENTOF AF Rhythm control- pharmacological cardioversion by quinidine, amiodarone and electric cardioversion. Rate control- calcium channel blockers, digoxin, beta blockers. Prevention of thromboembolism- anticoagulants.

12. AN NODE RE ENTRY TACHYCARDIA AVNRT is the most common cause of paroxysmal supraventricular tachycardia(PSVT). It produces regular tachycardia with a rate of 120-240/min. Mechanism : Due to re entry in a circuit involving the AV node and there are two different right atrial pathways (superior fast and inferior slow pathway. If atrial impulses occurs early when fast pathway is still refractory, the slow pathway takes over in propagating atrial impulses to ventricles initiating slow, fast or typical AVNRT.

13. CLINICAL FEATURES Common in women than men It occurs suddenly without any structural heart disease. However exertion, coffee, alcohol may aggravate. Episodes/attacks may last for few seconds or hours and stop spontaneously or after intervention. During the attack patient is aware of rapid, very forceful, regular heartbeat and experience chest discomfort, dyspnea. ECG shows tachycardia 140-240/min with normal regular QRS complexes.

14. TREATMENT Episodes may be terminated in patients with hypotension by Valsalva maneuver. If maneuver unsuccessful, adenosine or verapamil will restore sinus rhythm. Recurrent SVT –catheter ablation

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