Fetal permanent junctional reciprocating tachycardia with dilated cardiomyopathy, normal heart rate and transient fetal hydrops; a case report.

Permanent junctional reciprocating tachycardia (PJRT) is a rare form of congenital arrhythmia occurring predominantly in infants and children. Prenatal presentation is frequently characterized by incessant tachycardia leading to dilated cardiomyopathy (DCM). Some patients can have a normal heart rate which leads to a delayed diagnosis. We report a case of a neonate who was presented prenatally with DCM, fetal hydrops, and no signs of fetal arrhythmia. Diagnosis of PJRT was established after delivery with characteristic electrocardiographic patterns. Successful conversion to sinus rhythm with digoxin and amiodarone was achieved three months later. At 16 months of age, both echocardiography and electrocardiography were normal.

Permanent junctional reciprocating tachycardia: a rare, but not to be missed, cause of cardiogenic shock in adults.

We report the case of a 64-year-old woman who was admitted for cardiogenic shock caused by a permanent junctional reciprocating tachycardia. If this incessant and drug-refractory form of tachycardia is a well-known cause of tachycardia-induced cardiomyopathies in infants, its occurrence during adulthood is extremely rare. Catheter ablation is the recommended treatment of this condition.

Long-term results of atrial maze surgery in patients with congenital heart disease.

AIMS: Recurrent atrial tachycardia is common after repair of many types of congenital heart disease, and surgical ablation with a maze procedure represents a potential treatment strategy. The objective of this study is to report a single-centre 19 years' experience with maze surgery in congenital heart patients. METHODS AND RESULTS: Patients undergoing maze procedure concomitantly with cardiac surgical procedures were retrospectively analysed. The maze procedure was classified as therapeutic if the patient demonstrated preoperative atrial arrhythmias, or as prophylactic if done because the patient was considered high risk for post-operative arrhythmias. Acute outcomes and longer-term freedom from atrial arrhythmias were analysed. Maze surgery was performed in 166 patients: 137 in the therapeutic group, and 29 in the prophylactic group. The most common congenital heart lesion was single ventricle for the therapeutic group (27%) and Ebstein's anomaly for the prophylactic group (76%). Surgery consisted of a right atrial maze in 63%, left atrial maze in 4%, and bilateral maze in 33%. There were no direct complications or mortality related to the maze procedure itself. For the therapeutic group, freedom from arrhythmias was 82% and 67% at 1 and 5 years post-maze. Younger age at the time of surgery correlated with a lower long-term recurrence risk. CONCLUSION: Maze procedure at the time of an elective anatomic surgery is reasonably effective to prevent and treat atrial arrhythmias in patients with congenital heart disease at short- and mid-term, with low morbidity and mortality.

A case for ambidextrous doctors.

We report the case of a 30-year-old man with situs inversus totalis, recurrent orthodromic reciprocal tachycardia, and the Wolff-Parkinson-White syndrome. He underwent, in our department, radiofrequency ablation of an accessory pathway (AP) located in the lateral mitral atrioventricular ring. Ablation of the AP was carried out successfully through a patent foramen ovale under fluoroscopic guidance, in a right anterior oblique projection with a 30° tilt and in anteroposterior views. We also used a mirror reversal of electrocardiogram (ECG) leads to better judge the site of the AP by using existing ECG algorithms. Complete situs inversus is a rare disorder, which has no consequence for the patient in the absence of cardiac or extracardiac involvement. Ablation of APs in situs inversus has been previously reported in only three cases of complete situs inversus and one case of situs ambiguous. In patients with mirror-image dextrocardia, APs seem more often located on the 'left' free wall (mitral annulus), as in the normal population. Radiofrequency ablation is feasible and safe after mirror reversion of the ECG electrodes and fluoroscopy.

Fetal dilated cardiomyopathy caused by persistent junctional reciprocating tachycardia.

Ultrasound examination of a fetus at 32 weeks' gestation revealed dilated cardiomyopathy and a heart rate of 170 beats per minute. Prenatally, this mild tachycardia was not primarily suspected to be the cause of the myocardial changes. Postnatal electrocardiography revealed a persistent junctional reciprocating tachycardia (PJRT) and the diagnosis of tachycardia-induced cardiomyopathy (TICM) became apparent. After conversion to a sinus rhythm under digoxin and amiodarone, the cardiac changes regressed. PJRT is a rare form of supraventricular tachycardia. The prenatal findings in the condition have previously been described retrospectively, but it can only be diagnosed postnatally by its characteristic electrocardiographic properties. This case indicates that TICM can occur at lower heart rates than previously assumed. Even severe prenatal cardiomyopathy may be reversible once sinus rhythm has been restored.

Simulating the effects of atrial fibrillation induced electrical remodeling: a comprehensive simulation study.

Mechanisms underlying atrial fibrillation (AF) are poorly understood. In this study, we computationally evaluated the functional roles of AF induced electrical remodeling (AFER) on atrial electrical excitations. Experimental data of AFER on human atrial myocytes were incorporated into a biophysically detailed model of human atrial cells to simulate the effects of AFER at cellular and tissue levels. Our results show that AFER dramatically abbreviated atrial action potential duration (APD90) and effective refractory period that were quantitatively consistent with experimental data. A typical feature of loss in rate dependent accommodation of APD90 was observed. AFER slowed down atrial conduction velocity, but facilitated atrial conduction at high excitation rates. AFER increased tissue's spatial vulnerability for initiation and maintenance of AF remarkably. The overall susceptibility of human atrium to arrhythmia was increased. Most importantly AFER increased the stability of reentrant waves in 2D and 3D models prolonging their lifespan. While reentrant excitation waves self-terminated under Control conditions, the same became persistent or degenerated into multiple wavelets leading to spatio-temporal chaos under AFER conditions with accelerated re-entrant excitation rates. There was an increase in dominant frequency. In conclusion, our simulations substantiated a link between AFER and persistence of AF, providing mechanistic insights towards better understanding of "AF begets AF".