Ablation of focal atrial tachycardia from the non-coronary aortic cusp: case series and review of the literature.

AIMS: Focal atrial tachycardia successfully ablated from the non-coronary cusp (NCC) is rare. Our aim was to describe the characteristics of mapping and ablation therapy of NCC focal atrial tachycardias and to provide a comprehensive review of the literature. METHODS AND RESULTS: Seven patients (age 40 ± 9 years) with symptomatic, drug-refractory atrial tachycardia were referred for electrophysiological study. Extensive right and left atrial mapping revealed atrial tachycardia near His in all patients but either failed to identify a successful ablation site or radiofrequency applications only resulted in temporary termination of the tachycardia. Mapping and ablation of the NCC were performed retrogradely via the right femoral artery. Mapping of the NCC demonstrated earliest atrial activation during atrial tachycardia 38 ± 14 ms (ranging 17-56 ms) before the onset of the P-wave. Earliest atrial activation in the NCC was earlier than earliest activation in the right atrium and left atrium in all patients. The P-wave morphology was predominantly negative in the inferior leads and biphasic in leads V1 and V2. The tachycardia was successfully terminated by radiofrequency application in 10 ± 6 s (2-16 s), without complications. All patients were free of symptoms during a follow-up of 19 ± 9 months. Literature search revealed 18 reports (91 patients) describing NCC focal atrial tachycardia, with 99% long-term ablation success with a 1% complication rate. CONCLUSION: Symptomatic focal atrial tachycardia near His may originate from the NCC and can be treated safely and effectively with radiofrequency ablation.

Arrhythmias in heart transplant recipients.

The suture between the recipient and donor atrium in a heart transplant patient usually gives complete electric isolation. In this case report, we describe two transplant patients with an atrial tachycardia in the recipient atrium. In the first patient there was no conduction to the donor atrium, whereas the second patient had a breakthrough with 2-to-1 conduction.

Cerebral Seizures in an Adolescent with Jervell and Lange-Nielsen Syndrome: It May Not Be Epilepsy.

A 13-year-old girl with Jervell and Lange-Nielsen syndrome associated congenital long QT syndrome (LQTS) and central deafness was admitted for generalized seizures. LQTS had been diagnosed after birth and confirmed at genetic testing. ß-blocker treatment was immediately started. Despite this, since the age of 12 months, recurrent cerebral seizures occurred leading to the diagnosis of epilepsy. Anti-convulsive therapy was initiated but without success. At the last admission, nadolol dosage seemed infratherapeutic. Considering malignant ventricular arrhythmias as the cause of seizures, the ß-blocker dosage was adjusted to weight and levels of magnesium and potassium optimized. Furthermore, the patient received an implantable Medtronic Reveal LINQ Recorder®. Since then, the adolescent has been asymptomatic with no arrhythmia documented. LQTS is due to one or more mutations of genes coding for ion channels. It may induce malignant ventricular arrhythmias and is a major cause of sudden cardiac death in children. Generalized cerebral seizures are extra-cardiac manifestations caused by decreased cerebral perfusion during ventricular arrhythmia. They are commonly misinterpreted as manifestations of epilepsy. For any patient with known or unknown LQTS who presents seizures with resistance to anti-convulsive therapy, a cardiac electrophysiological investigation should be performed promptly to ensure etiological diagnosis and optimize treatment.

Efficacy of radiofrequency catheter ablation in athletes with atrial fibrillation.

AIMS: Endurance sports activities have been associated with the development of atrial fibrillation (AF). Pulmonary vein isolation (PVI) by means of radiofrequency catheter ablation has been established as an effective treatment for AF. The aim of the present study was to analyse the efficacy of AF ablation in athletes. METHODS AND RESULTS: We compared procedural outcome and median term follow-up in 94 consecutive athletes (>3 h of sports/week for ≥ 10 years or ≥ 1500 h lifetime) who underwent PVI (94% men, 51 ± 8 years, 87% paroxysmal AF, left atrial (LA) diameter 40 ± 8 mm, mean follow-up 41 months), and 41 contemporary controls. Sixty-three per cent of athletes performed endurance sports (running, cycling, swimming, and rowing). Documented focal induction of AF and failed treatment with ≥ 1 anti-arrhythmic drug were pre-requisites for selection of ablation treatment. Patients with long-standing persistent or permanent AF or an LA diameter ≥ 55 mm were not considered for ablation. Median lifetime cumulative hours of sports was 8638 (4175-13 688) in athletes vs. 450 (280-600) in controls (P < 0.001). Other baseline characteristics except for gender (94 vs. 66% men, respectively, P < 0.001) were comparable between both groups, as was the total number of ablation procedures per patient (1.2 ± 0.5, P = 0.62). Survival analysis showed similar AF recurrence rate after a first ablation for controls and endurance athletes, though non-endurance athletes had a significantly higher AF recurrence rate (48 vs. 46 vs. 34% freedom from AF at 3 year follow-up after a single ablation, P= 0.04). Final outcome after all ablations was similar (87 vs. 84 vs. 85% freedom from AF at 3-year follow-up, P = 0.88). No other independent predictor for AF recurrence was identified. CONCLUSION: In patients with documented focal induction of non-permanent AF and absence of structural heart disease, PVI is as effective in endurance athletes as in other patients.

Cardiac resynchronization implantable cardioverter defibrillator: normal or abnormal behaviour?

Cardiac resynchronization permits atrial-synchronized simultaneous pacing of both left and right ventricles in order to optimize mechanical contraction. In case of an atrial tachycardia, a VVI-'ventricular sense'-tracking modus can be programmed to maintain biventricular pacing. In this case report, we describe the use of this modus.

Cause of recurrent syncope revealed.

Implantable loop recorders (ILRs) allow long-time rhythm monitoring in order to correlate unexplained symptoms with possible arrhythmias. In this case report, we describe a patient with unexplained syncope in which the ILR revealed the cause.

Undersensing of ventricular fibrillation due to interference between a pacemaker and defibrillator in the same patient.

Sensing in pacemakers (PMs) and implantable cardioverter defibrillators (ICDs) is crucial to normal device behaviour. Since both devices treat different arrhythmias, the technical approach to signal detection is also completely different. A PM has a fixed threshold of sensing, above which events are sensed and therapy of the device withheld. On the other hand, the defibrillator has a variable threshold of sensing to detect tachyarrhythmias, with sometimes very small and changing electrogram amplitudes. In this case report, we describe interference between a PM and an ICD caused by these differences in the detection of cardiac events, leading to undersensing of ventricular fibrillation at defibrillation threshold testing.

The Impact of Function-Flow Interaction on Left Ventricular Efficiency in Patients with Conduction Abnormalities: A Particle Image Velocimetry and Tissue Doppler Study.

BACKGROUND: The aims of this study were to assess the influence of left bundle branch block (LBBB)-like conduction abnormalities on left ventricular (LV) blood flow patterns and to characterize their potential impact on LV efficiency by measuring the changes in vortex formation and energy dissipation in the left ventricle using echocardiographic particle image velocimetry. METHODS: Thirty-six subjects were prospectively studied, including 20 patients with pacemakers, six patients with LBBB, and 10 healthy control subjects, all of whom had normal ejection fractions (>50%). In patients with pacemakers, data were acquired in both DDD and AAI modes. Standard grayscale, tissue Doppler myocardial imaging, and contrast-enhanced echocardiographic particle image velocimetric data were acquired, and LV flow patterns were analyzed using dedicated software. Dyssynchrony was quantified by measuring apical transverse motion. RESULTS: Apical transverse motion was significantly higher in patients with LBBB compared with normal control subjects (mean, 4.9 ± 1.9 vs 1.0 ± 0.7 mm; P < .001). Quantitative measures of vortex energy dissipation (relative strength, vortex relative strength, and vortex pulsation correlation) were significantly higher in patients with LBBB (2.05 ± 0.54, 0.53 ± 0.13, and 0.87 ± 0.47, respectively) compared with control subjects (1.48 ± 0.28, 0.33 ± 0.05, and 0.24 ± 0.51, respectively) (P < .02 for all). Vortex duration time in relation to the entire cardiac cycle was shorter in patients with LBBB than in control subjects (28% vs 44%). All findings in both groups were comparable with DDD and AAI. CONCLUSION: LV flow pattern analysis by echocardiographic particle image velocimetry reveals that conduction delay due to LBBB or pacemaker stimulation in the right ventricle (DDD) disturbs the transfer of kinetic energy during the cardiac cycle and causes less efficient LV function. These data contribute to a better understanding of hemodynamic consequences of conduction delays and may help in the optimization of therapeutic approaches.

Cytomegalovirus colitis in an apparently immunecompetent host after biliopancreatic diversion for obesity.

CMV colitis in an immunocompetent host is a rare occurrence. We report a case of CMV colitis after biliopancreatic diversion surgery. The diagnosis of primary CMV infection with CMV colitis was based on histological examination of tissues biopsies obtained at colonoscopy, serology positive for CMV-IgM and CMV-IgG antibodies and a good response to systemic gancyclovir treatment. Malnutrition and colonic mucosal damage, both consequences of biliopancreatic diversion surgery, were thought to be predisposing factors. To our knowledge this is the first report in the English language literature of an association between CMV colitis and status following biliopancreatic diversion surgery.