In this article, we will discuss the Treatment of Paroxysmal Supraventricular Tachycardia (PSVT). So, let’s get started.
1. Vagal maneuvers (e.g. carotid sinus massage, lowering the head between knees Valsalva maneuver, immersion of face in cold water induce coughing) can be performed to block the conduction in the AV node. They may terminate tachycardia. Carotid sinus massage is done by The physician avoiding it in old person’s with atherosclerosis. Firm pressure applied for 10-20 seconds on one side if unsuccessful, then apply on other side. continuous ECG or auscultatory monitoring for heart rate is done.
2. If vagal maneuvers are unsuccessful, the intravenous injection of a drug that prolongs the refractory period of AV node (adenosine, verapamil, diltiazem) and digitalis may be administered. Out of these, adenosine which interrupts the AV circuit is preferred because of its extremely short half-life and less side effects, other drugs constitute second-line agents. The flushing, bronchospasm and chest discomfort are side effects of adenosine. Calcium channel blocker example verapamil can be given as an alternative in the dose of 2.5 mg bolus followed by another 2.5 mg every 1-3 minutes till tachycardia is reverted or maximum dose of 20 mg is achieved. I.V. diltiazem 0.25 mg/kg over 2 minutes followed by a second bolus of 0.35 mg/kg if necessary then I.V. infusion (5-15 mg/hr) Esmolol I.V. (500 mg/kg) as bolus than 25-200 μg/min as infusion is also effective.
3. When these drugs fail to terminate the tachycardia or when tachycardia is recurrent but patient is still hemodynamically stable, atrial or ventricular pacing via a temporary pacemaker may be used to terminate tachycardia called overdrive suppression.
4. If the patient is symptomatic and has compromised state due to unstable tachycardia (e.g. hypotensive or in acute distress), synchronized cardioversion (100-200 J) may be performed immediately.
5. For chronic recurrent PSVT, radiofrequency ablation of micro re-entry circuit may be indicated.
The chronic drug therapy includes use of beta blocker or die channel blocker in absence of heart disease and class 1A, class 1C and class III (amiodarone) anti-arrhythmic drugs for patients with underlying heart disease.