Aleteo auricular con conducción auriculoventricular 1: 1 descripción de un caso atrial / Flutter with 1: 1 atrioventricular conduction. case report

El aleteo auricular (AA) con conducción auriculoventricular 1:1 es una condición de presentación infrecuente en la práctica clínica, se da debido a diversos factores entre los cuales los más importantes son la presencia de vías accesorias concomitantes o uso de ciertos medicamentos antiarrítmicos, el AA con conducción 1 a 1 cuando se desarrolla constituye una emergencia médica ya que tiene una frecuencia cardíaca regular y presenta QRS ancho puede confundirse con una taquicardia ventricular. Cuando se presenta esta condición se produce frecuentemente inestabilidad hemodinámica del paciente, por lo que se debe hacer su diagnóstico y tratamiento a la brevedad posible. En el presente reporte presentamos el caso de un paciente previamente portador de marcapasos que desarrolla una taquicardia de QRS ancho regular, que se diagnostica finalmente como AA con conducción 1 a 1, tratado con fármacos antiarrítmicos en primera instancia, logrando disminuir la frecuencia cardíaca y posteriormente la reversión del mismo.

The atrial flutter (AF) with 1 to 1 atrio-ventricular (AV) conduction it's a rare medical condition secondary to several factors among which the most important are the association whit AV accessory pathways, or secondary to the use of some antiarrhythmic drugs. The AF with 1 to 1 AV conduction is a medical emergency and since it has a regular heart rate and presents wide QRS complex it can be confused with a ventricular tachycardia. When this condition occurs, it leads to hemodynamic instability of the patient, and that is why the diagnosis and treatment of this entity should be made as soon as possible. In the present report we present the case of a patient whit a previous pacemaker implantation who develops a regular wide QRS tachycardia, which is diagnosed as AF with 1 to 1 conduction and treated with antiarrhythmic drugs, first achieving a reduction in the heart rate and subsequently reaching its reversion

Wide QRS tachycardia during treatment with class ic antiarrhythmic agents in a patient with atrial fibrillation: report of 2 cases / 대한내과학회지

Wide QRS tachycardia may represent a rare proarrhythmic effect of some antiarrhythmic agents. Class Ic antiarrhythmic agents produce rate- dependent ventricular conduction slowing due to use-dependent sodium channel blockade, causing QRS prolongation in cases with an increased heart rate. The authors describe two cases of atrial flutter with 1:1 atrioventricular conduction exhibiting a wide QRS tachycardia while on therapy using flecainide and propafenone, and the difficulty in interpreting the ECG.

Wide QRS tachycardia during treatment with class ic antiarrhythmic agents in a patient with atrial fibrillation: report of 2 cases / 대한내과학회지

Wide QRS tachycardia may represent a rare proarrhythmic effect of some antiarrhythmic agents. Class Ic antiarrhythmic agents produce rate- dependent ventricular conduction slowing due to use-dependent sodium channel blockade, causing QRS prolongation in cases with an increased heart rate. The authors describe two cases of atrial flutter with 1:1 atrioventricular conduction exhibiting a wide QRS tachycardia while on therapy using flecainide and propafenone, and the difficulty in interpreting the ECG.

Differential Diagnosis of Wide QRS Tachycardia by Electrocardiogram

The criteria for differentiation of wide QRS tachycardias by electrocardiogram were evaluated in 24 cases of ventricular tachycardia(VT) and 8 cases of supraventricular tachycardia with wide QRS of various causes. There were some differences in Koreans from western countries due to plenity of idiopathic ventricular tachycardias(VTs) and infrequency of VTs by ischemic heart diseases. The characteristics were as follows : 1) Heart rate, QRS duration, QRS axis, distribution of RBBB and LBBB patterns, and QRS configurations of V1 and V6 leads were of limited values for differentiation of wide QRS tachycardias. 2) AV dissociation with or without capture beat and fusion bear was found in 63 % of VTs and very useful for differential diagnosis. Concordance of precordial leads was not frequently noted(2 cases) and and usually favored VT. 3) In LBBB patterns, notching of S wave, interval from Q wave to nadir of S wave greater than or equal to 60 msec, and R wave duration greater than or equal to 30 msec in V1 or V2 lead were present in 60%, 90%, and 29% of VTs respectively. The findings were also noted in accessory pathway conduction of supraventricular tachycardia. 4) Electrical alternans was present in 71% of VTs but also found in accessory pathway conduction of atrial fibrillation.