Flecainide-induced QRS complex widening correlates with negative inotropy.

BACKGROUND: The negative inotropic effect of Class IC antiarrhythmic drugs limits their use for acute cardioversion of atrial fibrillation (AF). OBJECTIVE: The purpose of this study was to examine, in an intact porcine model, the effects of pulmonary and intravenous (IV) administration of flecainide on left ventricular (LV) contractility and QRS complex width at doses that are effective in converting new-onset AF to sinus rhythm. METHODS: Flecainide (1.5 mg/kg bolus) was delivered by intratracheal administration and compared to 2.0 mg/kg 10-minute IV administration (European Society of Cardiology guideline) and to 0.5 and 1.0 mg/kg 2-minute IV doses in 40 closed-chest, anesthetized Yorkshire pigs. Catheters were fluoroscopically positioned in the LV to monitor QRS complex width and contractility and at the bifurcation of the main bronchi to deliver intratracheal flecainide. RESULTS: Peak flecainide plasma concentrations (Cmax) were similar, but the 30-minute area under the curve (AUC) of plasma levels was 1.4- to 2.8-fold greater for 2.0 mg/kg 10-minute IV infusion than for the lower, more rapidly delivered intratracheal and IV doses. AUC for LV contractility (ie, negative inotropic burden) was 2.2- to 3.6-fold greater for 2.0 mg/kg 10-minute IV dose than for the lower, more rapidly delivered doses. QRS complex widening by flecainide was highly correlated with the decrease in LV contractility (r2 = 0.890, P <.0001, for all IV doses; r2 = 0.812, P = .01, for intratracheal flecainide). CONCLUSION: QRS complex widening in response to flecainide is strongly correlated with decrease in LV contractility. Rapid pulmonary or IV flecainide delivery reduces the negative inotropic burden while quickly achieving Cmax levels associated with conversion of AF.

Optimizing flecainide plasma concentration profile for atrial fibrillation conversion while minimizing adverse ventricular effects by rapid, low-dose intratracheal or intravenous administration.

BACKGROUND: We investigated whether rapid administration of a low dose of flecainide, either intratracheally or intravenously (IV), could accelerate conversion of atrial fibrillation (AF) while reducing adverse ventricular effects. METHODS: Flecainide was delivered via intratracheal administration at 1.5 mg/kg bolus and compared to IV infusion at 1.0 mg/kg over 2 min (lower-dose, rapid) and 2.0 mg/kg over 10 min (ESC guideline) in closed-chest, anesthetized Yorkshire pigs. Catheters were fluoroscopically positioned in right atrium to measure atrial depolarization (Pa) duration and left ventricle (LV) to measure QRS complex duration and contractility (LV dP/dt) during atrial pacing at 140 beats/min. Flecainide was delivered intratracheally via a catheter positioned at the bifurcation of the main bronchi. AF was induced by intrapericardial administration of acetylcholine followed by burst pacing. RESULTS: Flecainide reduced AF duration similarly by intratracheal and IV delivery. Peak plasma levels were comparable but Tmax differed and coincided with peaks in Pa prolongation. The area under the curve indicating sustained plasma levels was greater for higher-dose, slow IV flecainide than for either intratracheal instillation (by 32%) or lower-dose, rapid IV infusion (by 88%). As a result, higher-dose, slow IV flecainide caused 58% (p < 0.03) and 48% (p < 0.006) greater increases in QRS complex duration and 61% and 96% (both, p < 0.02) greater reductions in contractility compared to intratracheal and lower-dose, rapid IV flecainide, respectively. CONCLUSION: Lower-dose, rapid flecainide, delivered either intratracheally or IV, optimizes the plasma concentration profile for effective conversion of AF while minimizing adverse effects on QRS complex duration and LV contractility.

Comparación de la eficacia y seguridad de flecainida y dronedarona como terapias antiarrítmicas para mantenimiento de ritmo sinusal en fibrilación auricular / Comparison of the efficacy and safety of dronedarone and flecainide as maintenance antiarrhythmic therapy for sinus rhythm in atrial fibrillation

Resumen Introducción y objetivos: Dronedarona y flecainida son antiarrítmicos de primera elección para reducir recurrencias de fibrilación auricular (FA), sin existir estudios que los comparen entre sí. Nuestro objetivo es comparar la eficacia en cuanto a prevención de recurrencias y seguridad de ambos fármacos. Métodos: Estudio retrospectivo en el que se incluyeron 123 pacientes de forma consecutiva en tratamiento con flecainida o dronedarona desde octubre de 2010 hasta febrero de 2013 por FA paroxística (76.4%) y FA persistente (23.6%). Se realizó cardioversión eléctrica en un 7.3% de los pacientes y farmacológica en un 16.3%. La mediana (rango intercuartílico) de seguimiento fue de 301 días (92-474), con una media de 2.8 revisiones por paciente. Se realizó análisis de tiempo hasta el primer evento mediante Kaplan-Meier y regresión de Cox ajustada por un índice de propensión. Resultados: De entre los 123 sujetos incluidos con FA, 71 fueron tratados con flecainida y 52 con dronedarona. Durante el seguimiento se registraron 36 recurrencias y 20 efectos adversos. Se documentaron un 36.6% de recurrencias en los pacientes tratados con flecainida en comparación con un 21% en los tratados con dronedarona (p = 0.073). En el análisis multivariante, dronedarona se mostró al menos tan eficaz como flecainida para prevenir recurrencias de FA (HR: 0.53, IC 95%: 0.20-1.44, p = 0.221) y demostró un perfil de seguridad comparable al de flecainida (HR: 0.68, IC 95%: 0.18-2.53, p = 0.566). Conclusiones: Según nuestra experiencia, dronedarona resulta al menos tan eficaz como flecainida para el mantenimiento de ritmo sinusal, con un buen perfil de tolerabilidad, a pesar de pautarse en pacientes con un perfil clínico más desfavorable.

Abstract Introduction and objectives: Dronedarone and flecainide are the first pharmacological choice to reduce recurrence of atrial fibrillation (AF); however, there are no studies comparing them. A study was performed to compare the efficacy in terms of recurrence of AF and safety of both drugs. Methods: A retrospective cohort study was conducted that included 123 consecutive patients treated with flecainide or dronedarone due to paroxysmal AF (76.4%) or persistent AF (23.6%), from October 2010 to February 2013. Electrical cardioversion was performed in 7.3% of patients and pharmacological cardioversion in 16.3%. The median (interquartile range) follow-up was 301 days (92-474) with a mean of 2.8 reviews per patient. Time to first event analysis was performed using Kaplan-Meier and Cox regression, adjusted for propensity score. Results: Of the 123 consecutive patients with AF included, 71 were on dronedarone and 52 on flecainide. During the follow-up, there were 36 AF recurrences and 20 safety events. There were recurrences in 36.6% of patients treated with flecainide, compared with 21% of those receiving dronedarone (P = .073). Dronedarone showed to be at least as effective as flecainide in preven- ting recurrence of atrial fibrillation (HR: 0.53, 95% CI: 0.20-1.44, P = .221), and demonstrated an acceptable safety profile when compared with flecainide (HR: 0.68, 95% CI: 0.18-2.53, P = .566). Conclusions: In our experience, dronedarone has been at least as effective and safe as flecainide, despite it was most frequently prescribed in patients with worse baseline risk profile.

Comparative Pharmacokinetic and Electrocardiographic Effects of Intratracheal and Intravenous Administration of Flecainide in Anesthetized Pigs.

We compared the pharmacokinetic (PK) profile and electrocardiographic (ECG) changes in response to intratracheal instillation of flecainide acetate into the left atrium and ventricle with intravenous (IV) flecainide acetate administration. In 12 closed-chest anesthetized Yorkshire pigs, we monitored the QRS complex and PR, JTc, and QTc intervals during sinus rhythm and correlated changes with venous plasma drug concentrations before and at 2, 5, 10, 15, and 30 minutes after drug administration. Intratracheal instillation of flecainide (0.75 and 1.5 mg/kg, rapid bolus) caused dose/concentration-dependent increases in the QRS complex duration of 10% and 19%, respectively, at 2 minutes, coinciding with peak venous plasma levels (1688 ± 177 and 2808 ± 217 ng/mL, respectively). IV infusion of flecainide (2 mg/kg) over 2 or 10 minutes similarly prolonged QRS complexes and PR intervals (both, P < 0.001). Intratracheal flecainide instillation increased PR interval briefly at 5 minutes. Neither intratracheal nor IV flecainide affected JTc or QTc intervals. Thus, the PK pattern of intratracheal instillation of flecainide is comparable to IV administration, although the absolute plasma concentrations were higher with IV infusion. Both modes of delivery elicited ECG changes that were consistent with the expected pharmacological activity of flecainide.

[Comparison of the efficacy and safety of dronedarone and flecainide as maintenance antiarrhythmic therapy for sinus rhythm in atrial fibrillation]. / Comparación de la eficacia y seguridad de flecainida y dronedarona como terapias antiarrítmicas para mantenimiento de ritmo sinusal en fibrilación auricular.

INTRODUCTION AND OBJECTIVES: Dronedarone and flecainide are the first pharmacological choice to reduce recurrence of atrial fibrillation (AF); however, there are no studies comparing them. A study was performed to compare the efficacy in terms of recurrence of AF and safety of both drugs. METHODS: A retrospective cohort study was conducted that included 123 consecutive patients treated with flecainide or dronedarone due to paroxysmal AF (76.4%) or persistent AF (23.6%), from October 2010 to February 2013. Electrical cardioversion was performed in 7.3% of patients and pharmacological cardioversion in 16.3%. The median (interquartile range) follow-up was 301days (92-474) with a mean of 2.8 reviews per patient. Time to first event analysis was performed using Kaplan-Meier and Cox regression, adjusted for propensity score. RESULTS: Of the 123 consecutive patients with AF included, 71 were on dronedarone and 52 on flecainide. During the follow-up, there were 36 AF recurrences and 20 safety events. There were recurrences in 36.6% of patients treated with flecainide, compared with 21% of those receiving dronedarone (P=.073). Dronedarone showed to be at least as effective as flecainide in preventing recurrence of atrial fibrillation (HR: 0.53, 95% CI: 0.20-1.44, P=.221), and demonstrated an acceptable safety profile when compared with flecainide (HR: 0.68, 95% CI: 0.18-2.53, P=.566). CONCLUSIONS: In our experience, dronedarone has been at least as effective and safe as flecainide, despite it was most frequently prescribed in patients with worse baseline risk profile.

Eleclazine, an inhibitor of the cardiac late sodium current, is superior to flecainide in suppressing catecholamine-induced ventricular tachycardia and T-wave alternans in an intact porcine model.

BACKGROUND: The capacity of catecholamines to induce ventricular tachycardia (VT) is well documented. OBJECTIVE: The effectiveness of the novel cardiac late sodium inhibitor eleclazine in suppressing catecholamine-induced VT in a large animal model was compared with that of flecainide. METHODS: In 13 closed-chest anesthetized Yorkshire pigs, spontaneous VT and surges in T-wave alternans (TWA) level measured using the Modified Moving Average method were induced by epinephrine (2.0 µg/kg, i.v., bolus over 1 minute). Effects of eleclazine (0.3 mg/kg, i.v., infused over 15 minutes; n = 6) or flecainide (1 mg/kg, i.v., bolus over 2 minutes followed by 1 mg/kg/hr, i.v., for 1 hour; n = 7) on VT incidence and TWA level were measured from right intraventricular electrogram recordings. RESULTS: Epinephrine reproducibly elicited hemodynamically significant spontaneous VT in all 13 pigs and increased TWA level by 33-fold compared to baseline (P < .001). Eleclazine reduced the incidence of epinephrine-induced ventricular premature beats and couplets by 51% (from 31.3 ± 1.91 to 15.2 ± 5.08 episodes; P = .038) and the incidence of 3- to 7-beat VT by 56% (from 10.8 ± 3.45 to 4.7 ± 3.12 episodes; P = .004). Concurrently, the drug reduced the peak epinephrine-induced TWA level by 64% (from 217 ± 22.2 to 78 ± 15.3 µV; P < .001). Flecainide also reduced the incidence of epinephrine-induced ventricular premature beats and couplets by 53% (from 40.4 ± 6.37 to 19.0 ± 2.73 episodes; P = .024) but did not affect the incidence of VT (from 15.0 ± 3.08 to 11.6 ± 2.93 episodes; P = .29) or the peak TWA level (from 207 ± 30.6 to 172 ± 26.2 µV; P = .34). CONCLUSION: Selective inhibition of cardiac late sodium current with eleclazine is more effective than flecainide in reducing catecholamine-induced VT and TWA in an intact porcine model.

Manejo terapeútico de algunas arritmias fetales / Therapeutic management of some fetal arrhythmias

Introducción: la electrocardiografía fetal constituye la prueba de oro para el diagnóstico de las arritmias en la vida posnatal, algo difícil de lograr en la vida prenatal incluso con la ecografía prenatal de alta resolución. Las taquiarritmias supraventriculares son las que se manifiestan con frecuencias cardíacas superiores a 180 latidos por min y pueden asociarse a mortalidad fetal en un tercio de los casos, sobre todo cuando se asocia a hidropesía fetal o cuando se establece por más de 15 días. El tratamiento permite la reversión de la arritmia o el control ventricular en el menor tiempo posible.Objetivos: comprobar la respuesta intraútero de la taquiarritmia al tratamiento farmacológico.Métodos: se realizó un estudio descriptivo prospectivo observacional de un universo de 24 fetos con el diagnóstico de taquiarritmia fetal que se diagnosticaron y atendieron en el Departamento Provincial de Genética de La Habana y en el Hospital Ginecobstétrico Ramón González Coro entre los años 2003 y 2012.Resultados: las taquiarritmias se observaron en 24 fetos (40,6 por ciento). Las madres menores 30 años fueron las más representadas en el grupo de mujeres del estudio, unido al índice de masa corporal sobrepeso y específicamente las pacientes nulíparas. Casi la mitad de la muestra no requirió tratamiento farmacológico (45,8 por ciento) todas con el diagnóstico ecocardiográfico de extrasístoles y sola una con compromiso orgánico del corazón.Conclusiones: la flecainida se utilizó, en la cuarta parte de la muestra y mostró una resolutividad de 83,3 por ciento en los fetos intraútero. La sobrevida de los fetos tratados farmacológicamente por vía oral fue 100 por ciento(AU)

Introduction: fetal electrocardiography is the gold standard for diagnosis of arrhythmias in postnatal life. This is difficult to achieve in prenatal life even with high-resolution prenatal ultrasound. Supraventricular tachyarrhythmias are manifested with heart rates above 180 beats per min and may be associated with fetal death in one third of cases, especially when associated with fetal hydrops or when it is set for over 15 days. Treatment allows the reversal of ventricular arrhythmia or control in the shortest possible time. Objective: to test tachyarrhythmia in uterus response to drug treatment. Methods: an observational prospective descriptive study was conducted in a universe of 24 fetuses with the diagnosis of fetal tachyarrhythmia that were diagnosed and treated at the Provincial Department of Genetics, Havana and at the Ramón González Coro Maternal Hospital from 2003 to 2012. Results: tachyarrhythmias were observed in 24 fetuses 40.6 percent. Mothers younger than 30 were the most represented in this study group, together with BMI overweight and nulliparous patients specifically. Almost half of the sample did not require drug 45.8 percent treatment, all with extrasystoles echocardiographic diagnosis and only one with organic heart involvement. Conclusions: flecainide was used in a quarter of the sample and showed 83.3 percent resoluteness of fetuses in uterus. Survival of fetuses pharmacologically orally treated was 100 percent(AU)

Vernakalant: Perception of state of health in patients with a recent-onset atrial fibrillation.

BACKGROUND: Vernakalant is a new, safe and effective drug used intravenously, which has proved to be more rapid in converting recent onset atrial fibrillation (AF) to sinus rhythm compared to placebo, amiodarone, propafenone, and flecainide in clinical studies. Until now no study has been conducted comparing the perception of state of health in patients who received vernakalant versus propafenone or flecainide for conversion of recent-onset AF. The aim of our study is to compare the change of perception of state of health from screening to hour 2 in patients treated with vernakalant and propafenone or flecainide for conversion of recent-onset AF. METHODS: Eighty hemodynamically stable patients with recent onset AF without structural heart disease were prospectively included. A single oral dose of propafenone 600 mg was administered to 30 patients, 30 patients received intravenous vernakalant and the remaining 20 patients received a single oral dose of flecainide 300 mg. Clinical, laboratory variables and perception of state of health from screening to hour 2 treated with these drugs measured by the EQ-5 D quality-of-life assessments visual analog scale were recorded. RESULTS: Baseline characteristics were similar in the three groups. Treatment with vernakalant resulted in a significantly greater improvement in patient perception of state of health at hour 2 compared with propafenone and flecainide. In the vernakalant group, a mean increase (from baseline) of 12.1 points was seen compared with a mean increase of 5.4 points in the propafenone group or 5.2 points in flecainide group (p < 0.01). CONCLUSIONS: The change of perception of state of health from screening to hour 2 treated with vernakalant had a significantly statistical improvement compared with propafenone or flecainide for conversion recent-onset AF.

Single oral flecainide dose to unmask type 1 Brugada syndrome electrocardiographic pattern.

BACKGROUND: Brugada syndrome (BrS) includes a group of patients with a typical pattern of ST segment elevation in right precordial leads who are at risk for sudden cardiac death. The electrocardiogram pattern may be intermittent and unmasked by sodium channel blockers. The main objective of this study is to describe a serie of consecutive patients in whom oral administration of flecainide was used to unmask BrS type I electrocardiographic pattern. METHODS: We prospectively studied 14 symptomatic (palpitations/syncope) patients referred to our laboratory presenting a suggestive but not diagnostic Brugada ECG or family history of sudden death. Single oral dose of flecainide 400 mg was administered. Resting 12-lead ECG with upper and standard right precordial leads were performed after flecainide administration at 15, 30, 60 and 90 min and hourly until ECG became normal. RESULTS: Median age was 37.5 years (range = 22-50). None of them had structural heart disease. In 7 patients (50%) the typical coved-type ECG pattern of BrS was unmasked. PR interval, QRS duration and QTc median difference after-before test was 20 msec (min-max = -17-+57), 21 ms (min-max = 0 to +59) and 20 ms (min-max = -11-+77), respectively. There were no episodes of AV block, atrial or ventricular tachyarrhythmia. CONCLUSIONS: In our experience we found that oral administration of flecainide in a single dose of 400 mg is useful to unmask type 1 Brugada electrocardiographic pattern.

Flecainide suppresses bidirectional ventricular tachycardia and reverses tachycardia-induced cardiomyopathy in Andersen-Tawil syndrome.

Bidirectional ventricular tachycardia (BVT), although a rare arrhythmia in the general population, is frequently observed in patients with Andersen-Tawil syndrome and long QT interval. However, the pharmacologic treatment of this arrhythmia remains unknown. In the present study, we documented the favorable antiarrhythmic action of flecainide in a young woman with sustained BVT and Andersen-Tawil syndrome. She presented with incessant BVT that could only be terminated with flecainide. During sinus rhythm, a prolonged QT interval was observed. Genetic studies revealed a mutation in the K(+) channel gene KCNJ2. Over a 4-year follow-up period, recurrence of her arrhythmia occurred twice. The first episode was due to noncompliance and resolved with resumption of flecainide therapy. The second recurrence was associated with a tachycardia-induced cardiomyopathy and resolved when the dose of flecainide was increased from 200 to 300 mg daily. This report suggests that flecainide can be effective in controlling BVT associated with Andersen-Tawil syndrome and indicates that the left ventricular dysfunction is secondary to the arrhythmia and not due to an associated phenotypic manifestation of the disorder.

Propanolol: una alternativa cercana para el tratamiento de la taquicardia supraventricular del feto / Propanolol: a close alternative for the treatment of fetal supraventricular tachycardia

Las taquiarritmias son las alteraciones del ritmo cardiaco más comunes en el feto que pueden generar complicaciones fatales. En general, se recomienda tratamiento cuando son persistentes. Los medicamentos más usados para el tratamiento de esta arritmia en los fetos son digoxina, flecainida, sotalol y amiodarona. Si bien son efectivos, su aplicación en los fetos se fundamenta en las características mecánicas y no electrofisiológicas, con riesgo de generar arritmias fatales o de más difícil control. El fenómeno pro-arritmogénico y los efectos secundarios, comprometen también a las gestantes. La hipotensión y arritmias como el flutter auricular, exigen una vigilancia comprometida. Es importante considerar un medicamento más seguro que pueda ser útil en las formas más simples y comunes de taquiarritmias del feto...

Tachyarrhythmias are common alterations of cardiac rhythm in the fetus that may generate fatal complications. In general, when they are persistent, treatment is advised. The more used drugs for the treatment of this arrhythmia in fetuses are digoxin, flecainide, sotalol and amiodarone. Even though they are effective, its use in fetuses is based on mechanical and not in electrophysiological characteristics, with the risk of generating fatal arrhythmias or some of more difficult control. The pro-arrhythmogenic phenomenon and the secondary effects involve also the pregnant women. Hypotension and arrhythmias such as auricular flutter demand a compromised vigilance. It is important to consider a safer drug that may be useful in the simpler and more common forms of fetal tachyarrhythmias. Objetivo: to show by means of a clinical case and by revision of relevant articles, that propanolol can be part of the group of drugs for the treatment of fetal supraventricular tachycardia. A series of alternatives have been imposed with adequate results; nevertheless, these are exigent in its knowledge and control and definitely not exempt of risks. Our objective is to show that propanolol is still an alternative for specific cases of tachyarrhythmias in fetuses, isolated or combined with other drugs.

[Fetal supraventricular tachyarrhythmias refractory to initial therapy]. / Taquiarritmias supraventrículares fetales refractarias al tratamiento inicial.

Fetal arrhythmia is an unusual cause of admission in critical care unit. We report three cases of pregnant patients with gestational age of 27 to 32 weeks, with diagnosis of fetal sustained supraventricular tachyarrhymias; which were resistant to digoxin as first line therapy. Two fetuses had supraventricular tachycardia and were converted with flecainide in association with digoxin. A remaining hydropic fetus suffering atrial flutter with 2:1 auriculo-ventricular conduction, failed to restore sinus rhythm with digoxin alone or in association with flecainide nor amiodarone, and required premature c-section at 30a week of gestation. Due to amiodarone administration the neonate suffered transient neonatal hypothyroidism.

Taquiarritmias supraventrículares fetales refractarias al tratamiento inicial / Fetal supraventricular tachyarrhythmias refractory to initial therapy

Las arritmias fetales representan un motivo infrecuente de ingreso ala unidad de cuidados intensivos. Se presenta tres casos de gestantes entre 27 y 32 semanas, con el diagnóestico de taquiarritmias supraventriculares fetales sostenidas, que exhibían fracaso en el intento inicial de reversión con digoxina. Dos casos con taquicardia sapraventricular respondieron favorablemente cuando se asoció flecainida. Un feto hidrópico con aleteo auricular y bloqueo 2:1 no revirtió con la associón de flecainida ni amiodarona a la digoxina y requirió la interrupsión de la gestación en la 30 ¬ semana. El neonato presentó disfunción tiroidea transitória atribuída a la administración de amiodarona. (AU)

Taquiarritmias supraventrículares fetales refractarias al tratamiento inicial / Fetal supraventricular tachyarrhythmias refractory to initial therapy

Las arritmias fetales representan un motivo infrecuente de ingreso ala unidad de cuidados intensivos. Se presenta tres casos de gestantes entre 27 y 32 semanas, con el diagnóestico de taquiarritmias supraventriculares fetales sostenidas, que exhibían fracaso en el intento inicial de reversión con digoxina. Dos casos con taquicardia sapraventricular respondieron favorablemente cuando se asoció flecainida. Un feto hidrópico con aleteo auricular y bloqueo 2:1 no revirtió con la associón de flecainida ni amiodarona a la digoxina y requirió la interrupsión de la gestación en la 30 ª semana. El neonato presentó disfunción tiroidea transitória atribuída a la administración de amiodarona.

Flutter auricular fetal con hidrops en embarazo gemelar triple / Foetal atrial flutter with hydrops in a triplet pregnancy

Se presenta un caso de flutter auricular, con bloqueo auriculoventricular 2:1, asociado a hidrops en uno de los fetos de un embarazo gemelar triple, pesquisado por taquicardia fetal y confirmado con ecocardiografía a las 26 semanas de gestación. Se administró digoxina a la madre, sin exito, por lo que agregamos flecainida al decimo tercer dia de tratamiento, logrando conversión a ritmo sinusal y regresión del hidrops dentro del útero. Se discute la utilidad del flecainide como primera linea para este tipo de pacientes y la necesidad de profilaxis antiarritmica postnatal, considerando la favorable evolución en este periodo.

Diagnóstico y manejo de un caso de flutter auricular fetal con hidrops en embarazo gemelar triple / Diagnosis and handling of a case of fetal atrial flutter with hydrops in triplet pregnancy

Presentamos un caso de flutter auricular, con bloqueo auriculoventricular 2:1, asociado a hidrops en uno de los fetos de un embarazo gemelar triple, pesquisado por taquicardia fetal y confirmado con ecocardiografía a las 26 semanas de gestación. Iniciamos digoxina transplancetaria sin éxito por lo que agregamos flecainide al décimo tercer día, logrando conversión a ritmo sinusal y regresión del hidrops in útero. Se discute la utilidad del flecainide como primera línea para este tipo de pacientes y la necesidad de profilaxis antiarrítmica postnatal, considerando la favorable evolución en este período.

Supraventricular tachycardia: recent advances in children

Supraventricular tachycardia (SVT) is the most common arrhythmia in children, occurring in about 1/1000 live births. Symptoms may begin in utero or early infancy when there is a significant risk of death. In older children symptoms vary from mild to severely debilitating with a small risk for sudden death in patients with Wolfe-Parkinson-White Syndrome. A better understanding of pathophysiology and cellular mechanisms provided the basis of the new therapeutic strategies. New classes of antiarrhythmic drugs, both for acute termination of SVT (eg. adenosine) and control of recurrence (eg. amiodarone and flecainide), added to older medications such as digoxin and propranolol, resulted in better control in both fetus and child. The greatest innovation in therapy, however, is electrical mapping of atrio-ventricular bypass tracts and their permanent interruption by radio frequency energy catheter ablation. This form of therapy provides a complete cure with 95 percent success and a 1 percent risk for complications in older children and adults. The risk is significantly higher in infants. A thorough knowledge of cardiac anatomy, electrophysiology and natural history is necessary to select appropriate therapy for individual patients to achieve maximum efficacy with minimum complications.(AU)