Iatrogenic ventricular tachycardia from endocardial pacemaker late after repair of tetralogy of Fallot

A 34-year-old woman, who had undergone radical repair for tetralogy of Fallot at the age of 8 years, was left with moderate-to-severe pulmonary regurgitation. VT developed after endocardial pacing for symptomatic pauses and atrial flutter. The possibility that the new VT originated from the apical endocardial lead was suggested by the unusual morphology of the VT, which was similar to paced. Surgical removal of the lead, which was deeply embedded at the same time as a pulmonary valve was replaced, cured the arrhythmia. This unusual cause of VT highlights possible risks associated with setting up a dangerous reentry circuit by inserting a right ventricular endocardial pacemaker lead.     

Successful radiofrequency catheter ablation of left ventricular tachycardia following surgical correction of tetralogy of Fallot

A 13-year-old boy had recurrent ventricular tachycardia following surgical correction of tetralogy of Fallot. Pharmacological management with multiple antiarrhythmic drugs failed, and the patient underwent electrophysiological evaluation. A reentrant tachycardia involving a slowly conducting region in the left ventricular outflow tract was demonstrated. We performed radiofrequency catheter ablation after identifying the essential components of the reentrant circuit. The ventricular tachycardia could no longer be induced and did not recur spontaneously during a 13-month follow-up.     

Routine primary repair of tetralogy of Fallot in the neonate

Uncertainty surrounds both the timing and ideal form of early management of tetralogy of Fallot. Some centers perform early complete repair in all patients regardless of age, symptoms and morphology. Others recommend a two-stage approach involving initial palliation in symptomatic neonates and young infants and those with unfavorable anatomy (anomalous coronary anatomy or hypoplastic pulmonary arteries). Advantages of early anatomic correction include alleviation of cyanosis, normal growth and organ development, removal of stimulus for right ventricular hypertrophy and avoidance of risks associated with initial palliation. With recent advances in anesthetic, operative and postoperative management, routine primary repair of tetralogy of Fallot in the neonate and young infant can be accomplished with excellent early and mid-term results. However, long-term follow-up is necessary to assess the impact of early repair on late right ventricular function, arrhythmias and need for reintervention.     

Septal Origin of Sustained Ventricular Tachycardia in a Patient with Right Ventricular Outflow Tract Obstruction After Correction of Tetralogy of Fallot

Right ventricular hypertension and ventricular arrhythmias are risk factors for sudden death after correction of tetralogy of Fallot, but sustained ventricular tachycardia has been reported only in patients without residual hemodynamic abnormalities. A patient with right ventricular hypertension and hypotensive ventricular tachycardia tolerated the arrhythmia better after relief of right ventricular outflow tract obstruction. This case provides insight into the relationship between hemodynamic abnormalities and the clinical consequences of arrhythmias. To our knowledge, it is the first report of ventricular tachycardia originating in scar adjacent to the ventricular septal defect patch after correction of tetralogy of Fallot.     

Multiple distinct right atrial endocardial origins in a patient with atrial tachycardia: mapping and ablation using noncontact mapping

Noncontact mapping identified the endocardial origins of four distinct atrial tachycardias in a young patient with drug refractory palpitations and effected successful ablation with no recurrence of symptoms in 5 months of follow-up.     

Late infective endocarditis after cholecystectomy in a patient with repaired tetralogy of Fallot: a case report

Late endocarditis after surgical repair of tetralogy of Fallot is rare. We describe a case of endocarditis following cholecystectomy in a 22-year old patient with repaired tetralogy of Fallot. After cholecystectomy, the patient was referred to a cardiology clinic with unexplained fever and suspicion of endocarditis. Echocardiography revealed a large mass at the basal level of interventricular septum. Endocarditis was diagnosed on the basis of clinical and echocardiographic findings and antibiotic treatment was initiated immediately. Nine days later, the clinical status of the patient deteriorated and urgent surgery was performed. Patch dehiscence which mimicked a large vegetation, and multiple vegetations on the patch were found during operation. The patch was removed and ventricular septum defect was repaired with a new dacron patch. Enterobacter agglomerans was isolated in the vegetation cultures.     

Variability of digitized left ventricular M-mode echocardiography: a study in healthy subjects and patients with repaired tetralogy of Fallot

Summary. To assess possible factors affecting the variability of digitized left ventricular M-mode echocardiograms, the influence of respiration and the variability due to different beats and observers were analysed in 11 healthy subjects and 11 patients with repaired tetralogy of Fallot. Left ventricular end-diastolic dimension (LVEDD) decreased from end-expiration to end-inspiration in the healthy subjects, but not in the patients. The maximal rate of dimension change decreased in both healthy subjects and patients from end-expiration to end-inspiration. The beat-to-beat variability assessed by the coefficient of variation (CV,%) between measurements of one cardiac cycle was twice the CV for three cycles, whereas the CV for three and five cardiac cycles was not different. The CV for intraobserver variability was less than 5.0% for dimensions and less than 13 0% for the rates of dimension change, whereas the interobserver variability had CV of 17.1% for rates of dimension changes. The influence of respiration and different observers on the variability of LV end-systolic dimension and shortening fraction was larger in the patients than in the healthy subjects. Thus, to obtain optimal technique for analysis of digitized LV M-mode echocardiograms in serial patient studies, the number of observers should be kept at a minimum and at least 3 beats at end-expiration should be used.     

Radiofrequency Catheter Ablation as a Primary Therapy for Treatment of Ventricular Tachycardia in a Patient After Repair of Tetralogy of Fallot

A 20-year-old man with previous surgical repair of tetralogy of Falht was admitted with hemodynamically significant ventricular tachycardia that was terminated witb cardioversion. He was found at electropbysiological study to bave easily inducible ventricular tacbycardia that was mapped to the rigbt ventricular outflow tract. Radiofrequency catheter ablation of tbe ventricular tacbycardia focus rendered tbe patient's arrbytbmia noninducible. Tbis case represents a successful radiofrequency catbeter ablation of a ventricular tacbycardia focus associated witb tetralogy of Fallot repair.     

Ablation of noninducible idiopathic left ventricular tachycardia using a noncontact map acquired from a premature complex with tachycardia morphology

We describe use of a novel noncontact system to permit mapping in a noninducible patient from a single premature ventricular complex with tachycardia morphology, thus guiding successful ablation after two previously failed conventional efforts. The instantaneous global electroanatomic map demonstrated fascicular macroreentry. Subsequent to ablation at an inferolateral site, there has been no clinical recurrence despite difficult arrhythmia control preprocedure. This case demonstrated that noncontact mapping can be used to create a potential map to guide successful ablation from a single premature ventricular complex in a patient with idiopathic left ventricular tachycardia that became noninducible at electrophysiological study.     

Idiopathic calcific constrictive pericarditis causing pulmonary stenosis associated with a ventricular septal defect mimicking tetralogy of Fallot

We describe an unusual case of pulmonary stenosis caused by calcific constrictive pericarditis associated with a congenital ventricular septal defect in a 16-year-old boy who had a 2-week history of progressive dyspnea, cyanosis, fatigue, and bilateral leg edema. Echocardiographic findings led to an initial diagnosis of tetralogy of Fallot; however, findings on chest radiography and CT were suggestive of calcific constrictive pericarditis with pulmonary stenosis, which was then confirmed on cardiac catheterization. Total pericardiectomy and repair of the ventricular septal defect resulted in a satisfactory outcome. Follow-up examinations at 6 and 20 months showed that the patient was asymptomatic and considered to have class I New York Heart Association functional status. To our knowledge, this is the first reported case of calcific constrictive pericarditis with pulmonary stenosis associated with a ventricular septal defect.     

Transcatheter Radiofrequency Ablation of Ventricular Tachycardia Following Surgical Correction of Tetralogy of Fallot

Ventricular arrhythmias occur in up to 13.5% of patients after tetralogy of Fallot repair. We describe a patient with a 30-year history of recurrent ventricular tachycardia, which followed the surgical repair of tetralogy of Fallot. Findings at electrophysiological study were consistent with reentry involving an area of slow conduction in the right ventricular outflow tract. Following the transcatheter application of radiofrequency energy in the right ventricular outflow tract, ventricular tachycardia could no longer be induced and has not occurred spontaneously during follow-up (28 months). Thus, transcatheter radiofrequency ablation is an acceptable therapeutic option in some patients with ventricular tachycardia after the surgical repair of tetralogy of Fallot.     

Successful Radiofrequency Catheter Ablation for Macroreentrant Ventricular Tachycardias in a Patient with Tetralogy of Fallot After Corrective Surgery

CHINUSHI, M., et al .: Successful Radiofrequency Catheter Ablation for Macroreentrant Ventricular Tachycardias in a Patient with Tetralogy of Fallot After Corrective Surgery . Radiofrequency (RF) catheter ablation was applied to two macroreentrant ventricular tachycardias (VTs) documented after corrective operation for tetralogy of Fallot. The activation wavefront of VT with a right bundle branch block pattern was found to revolve in a clockwise manner around a presumed myotomy scar in the right ventricle, and VT with a left bundle branch block pattern revolved around the same anatomical obstacle in a counterclockwise manner. In both VTs, the biggest conduction delay was confirmed at the right ventricular outflow tract. RF applications to the slow conduction area terminated each VT within a few seconds but were insufficient to cure the VTs. RF lesions were then applied to the, slow conduction area in a line to intersect the macroreentrant circuit, and both VTs became noninducible.     

Noncontact mapping of ventricular tachycardia in a closed-chest animal model of chronic myocardial infarction

Treatment of ventricular tachyarrhythmias in the setting of chronic myocardial infarction requires accurate characterization of the arrhythmia substrate. New mapping technologies have been developed that facilitate identification and ablation of critical areas even in rapid, hemodynamically unstable ventricular tachycardia. A noncontact mapping system was used to analyze induced ventricular tachycardia in a closed-chest sheep model of chronic myocardial infarction. Twelve sheep were studied 96 +/- 10 days after experimental myocardial infarction. During programmed stimulation, 15 different ventricular tachycardias were induced in nine animals. Induced ventricular tachycardia had a mean cycle length of 190 +/- 30 ms. In 12 ventricular tachycardias, earliest endocardial activity was recorded from virtual electrodes, preceding the surface QRS onset by 30 +/- 7 ms. Noncontact mapping identified diastolic activity in ten ventricular tachycardias. Diastolic potentials were recorded over a variable zone, spanning more than 30 mm. Timing of diastolic potentials varied from early to late diastole and could be traced back to the endocardial exit site. Entrainment with overdrive pacing was attempted in nine ventricular tachycardias, with concealed entrainment observed in seven. Abnormal endocardium in the area of chronic myocardial infarction identified by unipolar peak voltage mapping was confirmed by magnetic resonance imaging. These data suggest that induced ventricular tachycardia in the late phase of myocardial infarction in the sheep model is due to macroreentry involving the infarct borderzone. The combination of this animal model with noncontact mapping technology will allow testing of new strategies to cure and prevent ventricular tachycardia in the setting of chronic myocardial infarction.     

Risk stratification in surgically repaired tetralogy of Fallot

Tetralogy of Fallot is the most common form of congenital heart disease in implantable cardioverter–defibrillator (ICD) recipients. Indeed, sudden death of presumed arrhythmic etiology is the most frequent mode of demise in patients with surgically repaired tetralogy of Fallot, often in early-to-mid adulthood. Nevertheless, the overall annual incidence of sudden death is actually low. Therein lies the major challenge of risk stratification. This review highlights some of the complexities involved in risk stratifying patients with tetralogy of Fallot, underscoring the importance of avoiding oversimplification by means of a rigid algorithm that dictates therapy. To complement sound clinical judgment, a quantitative probabilistic approach is presented, which considers the body of literature from primary prevention ICD trials, risk factors identified by observational studies, the value of programmed ventricular stimulation and insights gleaned from studying ICD recipients with tetralogy of Fallot.     

Case of tetralogy of Fallot associated with hypoplasia of the right pulmonary artery

A three-month-old girl was referred to pediatric cardiology unit for evaluation of mild cyanosis and murmur. Chest roentgenogram revealed a boot-shaped heart. Echocardiography demonstrated subaortic ventricular septal defect, aortic override and infundibular stenosis. Then, the patient diagnosed as tetralogy of Fallot (TOF). Cardiac catheterization and angiocardiography revealed infundibular narrowing, hypoplasia of the right pulmonary artery and the enlarged right internal mammary artery originating from the right subclavian artery supplied blood flow into the right lung. The patient was performed complete repair. Post-operative period was uneventful. This is the first report presented about a case which pulmonary blood flow is provided by the enlarged right internal mammary artery in TOF associated with hypoplasia of the right pulmonary artery.     

Prenatal diagnosis of complete atrioventricular canal associated with tetralogy of Fallot

A complete atrioventricular canal defect occurs when an embryonic common atrioventricular valve fails to divide completely into 2 common atrioventricular valves. Tetralogy of Fallot is an abnormal embryologic development in which an unequal conotruncal division results in a small pulmonary artery and a large aortic artery. We report a case of prenatal diagnosis of a complete atrioventricular canal defect associated with tetralogy of Fallot.     

Clinical assessment of arrhythmias in tetralogy of Fallot

As a major success story of an early surgical era, corrective surgery transformed the prognosis of patients born with tetralogy of Fallot. With lifelong care, healthy survival well into adulthood is now the norm, albeit somewhat blemished by long-term sequelae. Arrhythmias are an important source of morbidity and a leading cause of mortality. This succinct review provides a contemporary summary of the prevalence and types of arrhythmias encountered in tetralogy of Fallot, including conduction disorders, atrial and ventricular tachyarrhythmias, and sudden death. Current prognostic markers and existing diagnostic tools are discussed, and available therapeutic options are elaborated.     

小于6个月法乐四联征患儿根治术后远期疗效观察

目的观察小于6个月的法乐四联征患儿行根治性手术治疗的远期效果。方法56例法乐四联征1～6个月患儿均采用右心房、右心室纵切1=7,补片修补室间隔缺损,15例仅行右心室流出道加宽补片,41例行跨环补片。结果术后早期无死亡;发绀均消失,血氧饱和度均在96％以上;随访3～62个月,1例死亡,2例需行二次手术,1例左肺动脉狭窄,1例右心室流出道残余梗阻;NYHA心功能I级或Ⅱ级。结论小于6个月的法乐四联征患儿行根治手术安全、有效,远期效果良好。