Twin Atrioventricular Nodal Reentrant Tachycardia Associated with Heterotaxy Syndrome with Malaligned Atrioventricular Canal Defect and Atrioventricular Discordance

There are limited data on the experience of transbaffle access for catheter ablation in patients who have undergone a Fontan palliation for complex congenital heart. Nevertheless, these issues will be encountered more frequently, because patients who have undergone Fontan palliation continue to survive into adulthood and develop a variety of arrhythmias that may be refractory to medical therapy.

Ivemark Syndrome

Ivemark syndrome or right atrial isomerism is a rare syndrome of asplenia / hyposplenia with malformation of heart and abnormal arrangement of internal organs of chest and abdomen and is classified under heterotaxy disorder. We describe here the case of a 14 year old boy diagnosed with asplenia, dextrocardia with double outlet right ventricle and midline liver.

An adult case of polysplenia syndrome associated with sinus node dysfunction, dextrocardia, and systemic venous anomalies

A 54-year-old woman was referred to our hospital for symptomatic sinus bradyarrhythmia with a sinus pause of 8 seconds. She was diagnosed with dextrocardia during childhood and discovered to have heterotaxy syndrome when she had an appendectomy during her teenager years. Chest and abdominal examinations by computed tomography showed multiple spleens located on the right side and abnormal drainages of the superior and inferior vena cava. Left isomerism was diagnosed by bilaterally bilobed lungs. Because of a patent bilateral superior vena cava, pacemaker leads were implanted using the right cephalic vein approach. Her fainting symptoms disappeared after pacemaker implantation.

Perinatal outcome in fetuses with heterotaxy syndrome and atrioventricular block or bradycardia

Congenital atrioventricular (AV) block is commonly associated with heterotaxy syndrome; together they have reportedly low survival rates (10-25%). However, information about perinatal outcome and predictors of non-survival after prenatal diagnosis of this association is scarce. Therefore, we studied fetuses with heterotaxy syndrome and bradycardia or AV-block diagnosed between 1995 and 2011, and analyzed pre and post-natal variables. The primary outcome was death and the secondary outcome was pacemaker placement. Of the 154 fetuses with heterotaxy syndrome, 91 had polysplenia syndrome, 22/91(24%) with bradycardia or AV-block. Thirteen (59%) patients had sinus bradycardia at diagnosis, 8 (36%) complete AV block, and 1 (5%) second-degree AV-block. Three patients elected for termination of pregnancy (3/22, 14%), 4 had spontaneous fetal demise (4/22, 18%), and 15 (15/22, 68%) were live-born. Of the fetuses with bradycardia/AV-block, 30% presented with hydrops, 20% had ventricular rates <55 beats/min, and 10% had cardiac dysfunction. Excluding termination of pregnancy, 15/19 fetuses (79%) survived to birth. Among the 15 live-born patients, 4 had bradycardia and 11 had AV-block. A further 3 patients died in infancy, all with AV-block who required pacemakers in the neonatal period. Thus, the 1-year survival rate, excluding termination of pregnancy, was 63% (12/19). Of the remaining 12 patients, 9 required pacemaker. Predictors of perinatal death included hydrops (p < 0.0001), ventricular dysfunction (p = 0.002), prematurity (p = 0.04), and low ventricular rates (p = 0.04). In conclusion, we found a higher survival rate (63%) than previously published in patients with heterotaxy syndrome and AV block or bradycardia diagnosed prenatally. Hydrops, cardiac dysfunction, prematurity and low ventricular rates were predictors of death.