Management – Overview

Atrial Fibrillation

• The acute management priorities for AF are assessing hemodynamic stability, controlling ventricular rate, considering options for rhythm control when appropriate, and initiating anticoagulation based on stroke risk.

• Rate control involves use of AV nodal blocking agents to achieve a target heart rate of <110 bpm at rest for asymptomatic patients or <80 bpm for symptomatic patients.

• Rhythm control is achieved with electrical cardioversion or pharmacological cardioversion using antiarrhythmic medications. This is indicated for patients who remain symptomatic despite adequate rate control or in hemodynamically unstable patients.

• Anticoagulation with warfarin or direct oral anticoagulants reduces the risk of stroke and systemic embolism. The decision is based on stroke risk stratification using CHA2DS2-VASc score.

Beyond the acute setting, the goals also include managing comorbidities, reducing AF burden, and preventing recurrences. Ablation procedures may be considered when antiarrhythmic medications fail to maintain sinus rhythm.

Supraventricular Tachycardia

The goals of managing AVNRT are to acutely terminate episodes and prevent recurrences. Acute treatment focuses on restoration of normal sinus rhythm, while long-term therapy aims to modify the arrhythmia substrate. Management options include:

• Vagal maneuvers
• Pharmacologic therapy
• Electrical cardioversion
• Catheter ablation

Vagal maneuvers and/or intravenous adenosine are recommended as first-line acute treatment in hemodynamically stable patients. Synchronized electrical cardioversion is indicated for those who are unstable. Long-term management options include pharmacotherapy with antiarrhythmic medications or catheter ablation. Catheter ablation is generally preferred over lifelong drug therapy given its high efficacy and low risk. However, antiarrhythmic medications may be considered in patients with infrequent recurrences or who are not candidates for ablation.

Ventricular Tachycardia

The management of ventricular tachycardia encompasses several key principles. For monomorphic ventricular tachycardia, the immediate goal is stabilization and prevention of recurrence, involving:

1. Assessing hemodynamic stability – Urgent cardioversion is required for unstable patients.
2. Identifying and correcting reversible causes such as electrolyte abnormalities.
3. Administering antiarrhythmic medications for rate control or rhythm conversion.
4. Considering catheter ablation for recurrent VT unresponsive to medications.
5. Placement of an implantable cardioverter-defibrillator (ICD) for secondary prevention in cases with a high risk of sudden cardiac death.
6. Treating underlying heart disease, whether ischemic or nonischemic cardiomyopathy.

In the acute phase, electrical cardioversion is the primary intervention for hemodynamically significant VT, while intravenous antiarrhythmic medications are used for stable patients. In the chronic phase, management revolves around catheter ablation, ICD placement, and optimizing heart failure pharmacotherapy.

In contrast, the management of polymorphic ventricular tachycardia focuses on promptly terminating the arrhythmia to prevent its progression into ventricular fibrillation and cardiac arrest. Key interventions include:

1. Administering intravenous antiarrhythmic medications such as magnesium, amiodarone, or lidocaine as first-line treatment for acute termination.
2. Using electrical cardioversion or defibrillation for medication-refractory cases.

Additionally, it’s crucial to identify and correct any reversible triggers:

1. Repleting electrolytes like potassium and magnesium, especially in cases induced by hypokalemia or hypomagnesemia.
2. Removing any offending drugs that may prolong the QT interval.
3. Treating underlying bradycardia, if contributing to the condition.

For long-term management, ICDs are indicated for secondary prevention in survivors of cardiac arrest or recurrent polymorphic VT. Refractory and recurrent cases may be managed with quinidine or catheter ablation. In congenital long QT syndrome, it is important to avoid drugs that prolong the QT interval, restrict strenuous activity, and perform family screening.

In summary, the management of ventricular tachycardia necessitates both acute termination and long-term prevention, with a focus on reducing arrhythmia triggers and the risk of sudden death.