Calmodulin mutations associated with recurrent cardiac arrest in infants.

Background: Life-threatening disorders of heart rhythm may arise during infancy and can result in the sudden and tragic death of a child. We performed exome sequencing on 2 unrelated infants presenting with recurrent cardiac arrest to discover a genetic cause.

Methods And Results: We ascertained 2 unrelated infants (probands) with recurrent cardiac arrest and dramatically prolonged QTc interval who were both born to healthy parents.

The potential utility of (123)I-mIBG in atrial fibrillation and in the electrophysiology laboratory.

A novel indication for (123)I-mIBG has recently been proposed to risk stratify patients with atrial fibrillation. This review puts into perspective the utility and importance of such a risk stratification modality, in the setting of the epidemic of atrial fibrillation, which also relates to the prevalence of heart failure, obesity, hypertension, and stroke. The authors argue that the epic cost of care for patients with paroxysmal and more advanced forms of atrial fibrillation-including catheter ablation, heart failure, and stroke management-coupled with the poor efficacy of all treatment modalities in advanced atrial fibrillation, make necessary a paradigm shift where only paroxysmal atrial fibrillation that demonstrably will turn into permanent fibrillation should be targeted aggressively.

Investigation of near ohmic behavior for poly(3,4-ethylenedioxythiophene): a model consistent with systematic variations in polymerization conditions.

The impedance behavior of semiconducting polymer film electrodes based on poly(3,4-ethylenedioxythiophene) (PEDOT) in combination with a series of anionic dopants has been investigated using electrochemical impedance spectroscopy (EIS) over the frequency range from 0.1 Hz to 100 kHz. Films were electrodeposited on gold-coated Pt wire electrodes from a nonaqueous solution containing 3,4-ethylenedioxythiophene (EDOT).

A management strategy for fetal immune-mediated atrioventricular block.

Introduction: The purpose of this study is to describe an in utero management strategy for fetuses with immune-mediated 2° or 3° atrioventricular (AV) block.

Methods And Results: The management strategy as applied to 29 fetuses consisted of three parts. First, using fetal echocardiography and obstetrical ultrasound, we assessed fetal heart rate (FHR), heart failure, growth and a modified biophysical profile score (BPS) assessing fetal movement, breathing and tone.

An expanded phenotype of maternal SSA/SSB antibody-associated fetal cardiac disease.

Objectives: Conventional manifestations of fetal Sjogren's antibodies (SSA/SSB) associated cardiac disease include atrioventricular block (AVB), transient sinus bradycardia, endocardial fibroelastosis (EFE) and dilated cardiomyopathy. We describe other manifestations of cardiac disease.

Methods: We describe three fetuses with unique myocardial and conduction system disease.

Atrial and ventricular rate response and patterns of heart rate acceleration during maternal-fetal terbutaline treatment of fetal complete heart block.

Terbutaline is used to treat fetal bradycardia in the setting of complete heart block (CHB); however, little is known of its effects on atrial and ventricular beat rates or patterns of heart rate (HR) acceleration. Fetal atrial and ventricular beat rates were compared before and after transplacental terbutaline treatment (10 to 30 mg/day) by fetal echocardiography in 17 fetuses with CHB caused by immune-mediated damage to a normal conduction system (isoimmune, n = 8) or a congenitally malformed conduction system associated with left atrial isomerism (LAI, n = 9). While receiving terbutaline, 9 of the 17 fetuses underwent fetal magnetocardiography (fMCG) to assess maternal HR and rhythm, patterns of fetal HR acceleration, and correlation between fetal atrial and ventricular accelerations (i.

Conduction system disease in fetuses evaluated for irregular cardiac rhythm.

Objectives: To determine the prevalence of 1st and 2nd degree AV block in fetuses with an irregular cardiac rhythm, and to summarize outcome of these pregnancies.

Background: The diagnosis of irregular cardiac rhythm or 'skipped beats' includes isolated ectopy that resolves spontaneously. Recently, Doppler measurements of the 'mechanical' PR interval have been shown to identify AV conduction disease prenatally.

Ultrasonic biophysical measurements in the normal human fetus for optimal design of the monolithic fetal pacemaker.

Ultrasound measurements, including xiphoid-to-pericardial distance and deployment angle, were made on human fetuses as a function of gestational age for the purpose of assessing the likelihood of 3 failure modes of a monolithic fetal pacemaker, including primary positioning failure due to device length and secondary dislodgement failure due to somatic growth. The small variation of the measurements over the gestational age range relevant to device implantation for the major indications of the device (for complete heart block complicated by hydrops and for bradycardia risk after fetal surgery or intrauterine intervention) predicts a small likelihood of these failure modes.

Defibrillator for primary prevention in congenital heart disease.

A 21-year-old patient with repaired double-outlet right ventricle and normal ventricular function underwent internal cardioverter defibrillator implantation for primary prevention of sudden death. First occurrence of spontaneous ventricular tachycardia resulted in hemodynamic collapse and syncope but the internal cardioverter defibrillator rescued the patient. ICD implantation for primary prevention may be an appropriate goal in adults with repaired congenital heart disease, even in the setting or normal ventricular function.

The monolithic fetal pacemaker: prototype lead design for closed thorax deployment.

Prenatal sudden cardiac death and hydrops fetalis are often due to complete heart block. However, no pacing modality exists for intrauterine application for fetal bradycardia. A prototype lead for a novel fetal pacemaker has been developed and used in a direct pacing model.

Chronic fatigue syndrome and eating disorders: concurrence or coincidence?

In this report we present four patients who were found to have both an eating disorder and the chronic fatigue syndrome (CFS). Two of the patients presented for evaluation of an eating disorder and also had CFS, while two of the patients presented for evaluation of CFS and also had an eating disorder. In all four patients the eating disorder preceded the CFS.

In vivo CH3(CH2)11SAu SAM electrodes in the beating heart: in situ analytical studies relevant to pacemakers and interstitial biosensors.

To study in vivo modification of the SAM equivalent circuit when a highly ordered SAM is used as a bioelectrode, dodecanethiolate SAM-Au intramuscular electrodes were studied in living rat heart in a challenging in situ perfused rat model by impedance spectroscopy, cyclic voltammetry, and neutron activation analysis (NAA). The SAM layer experienced disintegration in vivo biological system, as NAA detected the presence of Au atoms that had leached into the surrounding living tissue. Therefore, the underlying Au surface became exposed during biological implant.

Determination of standard electrode potential E(o) for chronic platinum and gold electrodes in rat muscle: implications for biosensors and the "anode" of bipolar pacing.

Pacemaker electrode surface modification by organosilane and organic self-assembled monolayer strategies creates a possible new variable in pacemaker electrode behavior. Because all of these chemical surface coatings are unstable at extremes of potential, the potential to which the electrode relaxes (between pacing pulses) becomes extremely important. The authors measured this potential for platinum (Pt) and gold (Au) relevant for their use as anode (or cathode) in a bipolar pacing system and from this potential the standard electrode potential, E(o) was determined.