Flutter Ic as a complication after taking flecainide
Introduction
The flutter Ic appears in the transition to sinus rhythm in pharmacological cardioversion. It has been described mainly with group Ic antiarrhythmics (flecainide and propafenone). The slowing of the atrial activity of the fibrillation generates organized activity and at a lower frequency than the common flutter, but it can lead 1: 1 in the atrio-ventricular node, with a very high ventricular response, poor tolerance and sometimes aberrant conduction. Aberrant conduction (wide QRS), consists in the transient appearance of an intraventricular block secondary to a functional alteration without there being a fixed organic lesion. The aberrant type of right bundle branch block is the most frequent being rare the aberrance of the left branch that usually associates to organic heart disease. The most frequent causes are changes in heart rate (tachycardia or bradycardia), antiarrhythmic drugs of group Ic and hydro-electrolytic alterations, especially of potassium.
Clinical case
We attend a 58-year-old woman without drug allergies, episode of paroxysmal atrial fibrillation (AF) treated with flecainide 100 mg / 12 hours, and bisoprolol 2.5 mg / 12 hours, electrical cardioversion is programmed but when cited is in sinus rhythm .She visited the doctor by episode of general malaise along with palpitations, dissension sensation and chest discomfort, was attended by the emergency services detecting in the electrocardiogram (ECG) regular tachycardia at 150 beats per minute (lpm) QRS 120 msec with complete blocking morphology of right branch (BCRDHH) that after administering 6-12-12 of adenosine passes to sinus rhythm at 80 bpm with incomplete blockade of the right branch (BIRDHH), then in the hospital initiates rhythm compatible with atrial fibrillation (AF) at 120 bpm, and BIRDHH. Negates clinically compatible with heart failure or angina. It remains asymptomatic and hemodynamically stable.Jucio Clinico: suspected atrial flutter precipitated by flecainide. CHA2DS2-VASc: 0.It was decided to initiate a protocol with amiodarone, which reverted to sinus rhythm, indicating high dronedarone 400 mg / 12 hours and maintaining bisoprolol 2.5 / 12 hours.
Conclusions
Treatment with group Ic antiarrhythmic drugs (Flecainide, Propafenone) can transform episodes of AF into episodes of atrial flutter, known as flutter Ic. The guidelines and reference consensus documents are not sufficiently explicit in the means to be taken to prevent it. The use of AV node-containing drugs (beta-blockers or non-dihydropyridine calcium antagonists) should be generalized and protocolized as a step prior to chemical cardioversion with flecainide, propafenone or vernakalant.Currently, it is considered that the treatment of choice for this disorder is catheter ablation, provided that the patient has not presented hardly any recurrence of AF under the pharmacological treatment responsible for the flutter and that after ablation the patient will continue with the same antiarrhythmic drug in combination with another that controls the ventricular response in case of recurrence.
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