Jason H. Anderson

Prevalence and spectrum of electroencephalogram-identified epileptiform activity among patients with long QT syndrome

BACKGROUND Congenital long QT syndrome (LQTS) is a heritable cardiac disease whereby patients are at an increased risk for LQTS-triggered syncope, seizures, and sudden cardiac arrest. Seizure episodes are common in LQTS and most often seen in patients with type 2 LQTS (LQT2). OBJECTIVE To determine the prevalence of electroencephalogram (EEG)-identified epileptiform activity among patients with LQTS. METHODS A retrospective electronic medical record review of 610 patients with LQTS (250 [41%] men), evaluated between 2000 and 2012, was performed to identify (1) all patients with LQTS who presented with seizures/seizure-like episodes, (2) patients with LQTS who underwent a subsequent neurologic evaluation and EEG study, and (3) patients with LQTS and abnormal EEG recordings that showed epileptiform activity during sinus rhythm, confirming a seizure independent from cardiac arrhythmia. RESULTS Overall, seizures/seizure-like episodes were recorded in 68 of 610 (11%) patients with LQTS. Ten patients were diagnosed with a seizure disorder by an epileptologist on the basis of the clinical findings and EEG studies, giving a prevalence of 10 of 610 (1.6%; 95% confidence interval 0.8%-3%) among patients with LQTS. A diagnosis of epilepsy was overrepresented in patients with LQT2 (7 of 190 [3.7%]) in comparison to all other LQT subgroups (3 of 420 [0.7%]; P = .0126). CONCLUSIONS While the overall prevalence of epilepsy among patients with LQTS is low, 10 of 68 (15%) of the patients who presented with seizures/seizure-like episodes had EEG-identified epileptiform activity. Confirming earlier observational reports, epilepsy is more common in patients with LQT2, further supporting the shared pathogenetic link hypothesis of this KCNH2-encoded potassium channel that is expressed in both the heart and the brain.

Whole-Exome Molecular Autopsy After Exertion-Related Sudden Unexplained Death in the Young

Background— Targeted postmortem genetic testing of the 4 major channelopathy-susceptibility genes (KCNQ1, KCNH2, SCN5A, and RYR2) have yielded putative pathogenic mutations in ⩽30% of autopsy-negative sudden unexplained death in the young (SUDY) cases with highest yields derived from the subset of exertion-related SUDY. Here, we evaluate the role of whole-exome sequencing in exertion-related SUDY cases. Methods and Results— From 1998 to 2010, 32 cases of exertion-related SUDY were referred by Medical Examiners for a cardiac channel molecular autopsy. A mutational analysis of the major long-QT syndrome–susceptibility genes (KCNQ1, KCNH2, and SCN5A) and catecholaminergic polymorphic ventricular tachycardia–susceptibility gene (RYR2) identified a putative pathogenic mutation in 11 cases. Whole-exome sequencing was performed on the remaining 21 targeted gene–negative SUDY cases. After whole-exome sequencing, a gene-specific surveillance of all genes (N=100) implicated in sudden death was performed to identify putative pathogenic mutation(s). Three of these 21 decedents had a clinically actionable, pathogenic mutation (CALM2-F90L, CALM2-N98S, and PKP2-N634fs). Of the 18 remaining cases, 7 hosted at least 1 variant of unknown significance with a minor allele frequency <1:20 000. The overall yield of pathogenic mutations was higher among decedents aged 1 to 10 years (10/11, 91%) than those aged 11 to 19 years (4/21, 19%, P=0.0001). Conclusions— Molecular screening in this clinical scenario is appropriate with a pathogenic mutation detection rate of 44% using direct DNA sequencing followed by whole-exome sequencing. Only 5 of the 100 interrogated sudden death genes hosted actionable pathogenic mutations for more than one third of these exertion-related, autopsy-negative SUDY cases.

Three-Dimensional Rotational Angiography-Guided Stent Placement for Treatment of Acquired Supravalvar Aortic Stenosis

A 15-year–old boy with a history of d-transposition of the great arteries, status postarterial switch procedure with LeCompte maneuver, and severe neoaortic regurgitation underwent neoaortic valve replacement with an Edwards Magna 23-mm pericardial bioprosthesis, along with reconstruction of the ascending aorta with a bovine graft. At routine follow-up 8 months after surgery, he was found to have a harsh systolic ejection murmur over his midprecordium, with a prominent palpable bruit over both carotid arteries. Echocardiography demonstrated a Doppler mean gradient >50 mm Hg through the ascending aorta, but 2-dimensional imaging was unable to define the anatomic lesion because of poor acoustic windows. Left ventricular systolic function was mildly decreased. Subsequent cardiac magnetic resonance imaging documented a long stenosis of the ascending aorta with a minimum diameter of 11 mm. Given the patient history of multiple and recent cardiac operations, both surgical and transcatheter management options were discussed in a multidisciplinary setting. After presenting these options to the patient and his family, they elected to proceed with endovascular stent placement. At the time of catheterization, the peak systolic gradient from the left ventricle to the distal ascending aortic arch was 50 mm Hg. Three-dimensional rotational angiography (3DRA) using a DynaCT system (Siemens, Munich, Germany) demonstrated …

Novel delivery technique for atrial septal defect closure in young children utilizing the GORE® CARDIOFORM® septal occluder

To develop a novel delivery technique to overcome vascular size limitations for device closure of a secundum ASD in the young patient.

Ultrasound guided percutaneous common carotid artery access in piglets for intracoronary stem cell infusion

In pigs, the deep location of the common carotid artery and overlying sternomastoideus muscle in the neck has led to the recommendation for a surgical cutdown for common carotid access, as opposed to minimally invasive techniques for vascular access. We sought to determine if direct percutaneous common carotid artery access in piglets is attainable. Seventeen piglets were anesthetized and intubated. Under two-dimensional and color flow Doppler ultrasound guidance, a 21 gauge needle was utilized to access the right common carotid artery. Following arterial puncture, the Seldinger technique was applied to place a 4 or 5 French introducer. Upon completion of cardiac catheterization with intracoronary stem cell infusion the introducer was removed and manual pressure was applied to prevent hematoma development. Successful access with an introducer was achieved in all 17 piglets. The average weight was 8.5 ± 1.7 kg. One piglet developed a hematoma with hemorrhaging from the catheterization site and was euthanized. This piglet was given bivalirudin for the procedure. After this incident, subsequent piglets were not given anticoagulation and no other complications occurred. Ultrasound guided percutaneous common carotid artery access in piglets is attainable in a safe, reliable, and reproducible manner when performed by microvascular experts.

Imaging the adult with transposition of the great arteries

Purpose of review Patients with complete and congenitally corrected transposition of the great arteries commonly survive into adulthood and present with a vast array of clinical residua. Recent findings Echocardiography remains the primary imaging modality in the routine assessment of the adult with transposition of the great arteries. It provides a comprehensive anatomic and hemodynamic evaluation. Limitations to echocardiography include evaluation of the following: the systemic right ventricle, baffle patency following atrial switch procedure, coronary arteries following arterial switch procedure or Nikadoh, and multilevel right ventricular outflow tract obstruction. Summary Each form of palliation for transposition of the great arteries results in unique long-term sequelae that affect outcomes. A multimodality approach to imaging is required for a complete evaluation.

AngioJet™ thrombolysis of SVC thrombosis after orthotopic heart transplantation: A case report

SVC obstruction is a rare acute complication after bicaval cardiac transplantation and can be catastrophic for the patient. Herein, we report the case of a child who developed SVC thrombosis causing acute SVC syndrome nine days after heart transplantation. Thrombolysis was successfully performed using the AngioJet™ system and subsequent balloon angioplasty with re‐establishment of flow. This procedure allowed for revascularization without repeat sternotomy or stent implantation. The patient is well without recurrence at last follow‐up.