Swallowing-induced Atrial Tachycardia with a Thymic Cyst.

We herein report a 34-year-old man who presented with recurrent palpitations that occurred while swallowing solid food. Holter monitoring revealed atrial tachycardia (AT) while eating. In addition, chest computed tomography (CT) showed a small nodule in the front of the ascending aorta. Thoracoscopic surgery was performed to remove the nodule; a pathological examination revealed that the nodule was a thymic cyst. The AT disappeared postoperatively. This case demonstrates that a mediastinal nodule can cause swallowing-induced AT.

Speech-induced Atrial Tachycardia with Presyncope.

Speech-induced atrial tachycardia (AT) with presyncope is extremely rare. A 52-year-old woman employed at a supermarket reported recurrent presyncope while speaking out loud at her job. Holter electrocardiography revealed AT while swallowing without presyncope. The patient's blood pressure decreased during AT, and she experienced presyncope while saying "IRASSHAIMASE" loudly during a tilt table test. Accordingly, bisoprolol 1.25 mg was prescribed, and the patient did not experience episodes of presyncope with recurrence of AT for 2 years. This case suggests that provocation of arrhythmia in the tilting position may be useful for demonstrating a relationship between arrhythmia and presyncope and/or syncope.

[Vasovagal Syncope: Mechanisms and Treatments].

Syncope is defined as the transient loss of consciousness due to cerebral hypoperfusion. Reflex syncope (neurally mediated syncope) is among all syncope, vasovagal syncope is among reflex syncope in addition. We frequently treated several patients with vasovagal syncope in our clinical situation. We report here the mechanisms and treatments of vasovagal syncope. Although this syncope has a low risk, the diagnosis and the treatments are complicated. Therefore, invasive treatments are necessary in selected patients. This article discusses the management procedures of syncope according to the guidelines and our clinical experience.

Monomorphic ventricular tachycardia induced by tilt table testing in a patient with syncope and normal heart.

Ventricular tachycardia induced by tilt table testing.

Polymorphic Ventricular Tachycardia with QT Interval Prolongation Due to a Brain Tumor.

We herein report the case of a 20-year-old man with a history of epilepsy who presented with frequent transient loss of consciousness (T-LOC) and polymorphic ventricular tachycardia (VT) with QT interval prolongation. Blood investigations revealed panhypopituitarism. Following a biopsy, he was diagnosed with brain germinoma. During the biopsy, he had an episode of polymorphous VT with QT prolongation. There was no recurrence of T-LOC following chemotherapy and hormone replacement therapy. This case indicates the importance of checking the QT interval in patients with T-LOC, including those with seizures and brain tumors, to ensure appropriate treatment.

An autopsy case of pulmonary artery intimal sarcoma: detailed observation of tumor and its related lesions in pulmonary arteries.

We report an autopsy-proven case of a 33-year-old man who died of intimal sarcoma of the pulmonary artery. A large mass (5×4 cm) occluded the main and bilateral pulmonary arteries. Tumor cell morphology was consistent with that of undifferentiated pleomorphic sarcoma. Comprehensive histological observation of 18 pulmonary arteries from proximal to distal revealed continuous extension of the tumor from the main to the subsegmental arteries along the intima, forming an arteriosclerosis-like intimal thickening. Distal small arteries were also affected by eccentric intimal thickening or recanalization. Lung parenchyma was not involved, although there were two wedge-shaped small pulmonary infarctions caused by tumorous obstruction of the associated arteries. Histological results indicated that the intimal sarcoma in the pulmonary artery, which appeared occlusive with growth limited to the proximal artery, had in fact already spread more peripherally than expected. Both the proximal lesions and the distal small arteries were affected by peripheral tumor emboli or by pulmonary hypertension induced by the proximal tumor. However, as seen in this case, most of the occlusive tumor was located locally and intraluminally, in the proximal artery, and removing the proximal tumor by pulmonary endarterectomy was considered effective for symptomatic improvement.

Novel Device-Based Algorithm Provides Optimal Hemodynamics During Exercise in Patients With Cardiac Resynchronization Therapy.

BACKGROUND: An adaptive cardiac resynchronization therapy (aCRT) algorithm has been described for synchronized left ventricular (LV) pacing and continuous optimization of cardiac resynchronization therapy (CRT). However, there are few algorithmic data on the effect of changes during exercise.Methods and Results:We enrolled 27 patients with availability of the aCRT algorithm. Eligible patients were manually programmed to optimal atrioventricular (AV) and interventricular (VV) delays by using echocardiograms at rest or during 2 stages of supine bicycle exercise. We compared the maximum cardiac output between manual echo-optimization and aCRT-on during each phase. After initiating exercise, the optimal AV delay progressively shortened (P<0.05) with incremental exercise levels. The manual-optimized settings and aCRT resulted in similar cardiac performance, as demonstrated by a high concordance correlation coefficient between the LV outflow tract velocity time integral (LVOT-VTI) during each exercise stage (Ex.1: r=0.94 P<0.0008, Ex.2: r=0.88 P<0.001, respectively). Synchronized LV-only pacing in patients with normal AV conduction could provide a higher LVOT-VTI as compared with manual-optimized conventional biventricular pacing at peak exercise (P<0.05). CONCLUSIONS: The aCRT algorithm was physiologically sound during exercise by patients.

Role of head-up tilt table testing in patients with syncope or transient loss of consciousness.

The tilt table test (TTT) is a useful method for the management of reflex syncope. However, the TTT is incomplete and has several problems. The indications for this test are established using guidelines. The TTT is not suitable for all syncopal patients. It is currently unclear (1) When should the TTT be used, (2) for which types of patients TTT should be performed, and (3) does the TTT provide useful information to guide indication for pacing therapy for reflex syncope. The answers to these questions appear in recent reports from two guidelines published by the European Society of Cardiology and the Japan Circulation Society. The indications for TTT do not apply to all syncopal patients, but selected patients. For patients with low risks and rare syncopal events, the TTT is not necessary, even when diagnoses are unconfirmed. The TTT is used not only for diagnosis of reflex syncope, but also for many clinical management of several conditions (i.e., exclusion of cardiac syncope). Positive TTT results cannot predict the effects of pacing therapy for reflex syncope. The decision to use pacing therapy should be based on documented electrocardiograms and other findings, including TTT results.

Influence of aortic valve leaflet calcification on dynamic aortic valve motion assessed by cardiac computed tomography.

BACKGROUND: Computed tomography is the best noninvasive imaging modality for evaluating valve leaflet calcification. OBJECTIVE: To evaluate the association of aortic valve leaflet calcification with instantaneous valve opening and closing using dynamic multidetector computed tomography (MDCT). METHODS: We retrospectively evaluated 58 consecutive patients who underwent dynamic MDCT imaging. Aortic valve calcification (AVC) was quantified using the Agatston method. The aortic valve area (AVA) tracking curves were derived by planimetry during the cardiac cycle using all 20 phases (5% reconstruction). da/dt in cm2/s was calculated as the rate of change of AVA during opening (positive) or closing (negative). Patients were divided into 3 three groups according to Agatston score quartile: no AVC (Q2, Score 0, n = 18), mild AVC (Q3, Score 1-2254, n = 24), and severe AVC (Q4 Score >2254, n = 14). RESULTS: In multivariable linear regression, compared to the non AVC group, the mild and severe AVC groups had lower maximum AVA (by -1.71 cm2 and -2.25 cm2, respectively), lower peak positive da/dt (by -21.88 cm2/s and -26.65 cm2/s, respectively), and higher peak negative da/dt (by 13.78 cm2/s and 18.11 cm2/s, respectively) (p < 0.05 for all comparisons). CONCLUSIONS: AVA and its opening and closing were influenced by leaflet calcification. The present study demonstrates the ability of dynamic MDCT imaging to assess quantitative aortic valve motion in a clinical setting.

Additional diagnostic value of very prolonged observation by implantable loop recorder in patients with unexplained syncope.

INTRODUCTION: In the literature, the average diagnostic yield of the implantable loop recorder (ILR) is reported to be 35% over an observation period generally less than 18 months. The aim of this study was to evaluate the diagnostic value of ILR during very prolonged observation. METHODS AND RESULTS: Consecutive patients who had received one or more (in the case of battery exhaustion before diagnosis) ILR (Reveal/plus/DX, Medtronic Inc.) from 2001 to 2010 were included. The diagnostic ECG was classified according to the ISSUE classification. We analyzed 157 patients (87 males, 69 ± 14 years): 70 of these were followed up for ≥18 months. The estimated cumulative diagnostic rates were 30%, 43%, 52%, and 80% at 1, 2, 3, and 4 years, respectively; 26% of diagnoses were made after 18 months. The diagnostic yield was independent of structural heart disease, bundle branch block, number of syncopes, age, and gender; the median time to diagnosis of ISSUE type 1 patients was shorter than that of the others (4 [2;10] vs. 16 [6;23] months; P = 0.003). During the observation period, 3 patients (1.9%) died and none suffered arrhythmic death. CONCLUSIONS: Prolonging observation up to 4 years increased the diagnostic value of ILR in syncopal patients and was safe. A quarter of patients diagnosed needed more than 18 months of follow-up. As consequence, when a strategy of prolonging monitoring is chosen, monitoring should be maintained even for several years until diagnosis is established.

Electrochemical stability of self-assembled monolayers on nanoporous Au.

Desorption of thiolate self-assembled monolayers (SAMs) seriously limits the fabrication of thiol-based devices. Here we demonstrate that nanoporous Au produced by dealloying Au-Ag alloys exhibits high electrochemical stability against thiolate desorption. Nanoporous Au has many defective sites, lattice strain and residual Ag on the ligament surface. First-principles calculations indicate that these surface aspects increase the binding energy between a SAM and the surface of nanoporous Au.

Effect of clinical triggers on positive responses to tilt-table testing potentiated with nitroglycerin or clomipramine.

The effect of clinical triggers on tilt-table testing (TTT) responses has not been systematically evaluated. In the present study, we evaluated the effect of clinical triggers on positive responses to TTT potentiated with nitroglycerin (which acts mainly through peripheral dilation) or clomipramine (which acts mainly through a central serotoninergic mechanism). We enrolled 380 consecutive adult patients. In 66 patients, syncope was triggered by emotional distress (central trigger), in 161 by specific situations or prolonged standing (peripheral trigger), and in 153 syncope occurred in the absence of any detectable trigger. Nitroglycerin TTT, performed in 252 patients, consisted of a passive phase of 20 minutes followed, if negative, by sublingual administration of 400 µg nitroglycerin spray and continuation of tilting for 15 minutes. Clomipramine TTT, performed in 128 patients, consisted of 20 minutes of tilting with intravenous administration of 5 mg clomipramine during the first 5 minutes. The positivity of nitroglycerin TTT was greater in patients with clinical triggers (71% central and 75% peripheral) than in those without (36%). With clomipramine TTT, the positivity rate was greater in patients with central triggers (92%) than in those with peripheral triggers (45%) or no triggers (30%). The cardioinhibitory form was more frequent in patients with a central trigger than in the other 2 groups (34% vs 12% and 7%) and with clomipramine TTT than with nitroglycerin TTT (19% vs 11%, respectively). In contrast, mixed or vasodepressor forms were more frequently induced by nitroglycerin TTT (41% vs 24%). In conclusion, the presence of clinical triggers increased the positivity of TTT and influenced the type of response. We found some specificity of nitroglycerin and clomipramine for peripheral and central mechanisms.

Effectiveness of remote monitoring in the management of syncope and palpitations.

AIMS: Recently, the remote transmission of data detected by implantable loop recorders (ILRs) has become available. The aim of this study was to evaluate effectiveness and acceptance of remote monitoring in the clinical management of syncope and palpitations in patients with ILR. METHODS AND RESULTS: Consecutive patients implanted with ILR (Reveal DX/XT Medtronic, Inc.) and followed up by means of remote monitoring (CareLink(®)) were included. The patients were requested to transmit the data stored in the ILR every week, via the CareLink system, or more frequently during the first period. Patient acceptance of ILR was evaluated by means of a questionnaire concerning physical and mental components. Forty-seven patients (27 males, average age 64 ± 19 years) were enrolled and followed up for 20 ± 13 weeks. Thirty-two patients (68%) had at least one ECG recording of a true relevant event. The mean time from ILR implantation to the first true relevant ECG was 28 ± 49 days, which was 71 ± 17 days less than in the clinical practice of 3-monthly in-office follow-up examinations. Thirty-eight patients (81%) had at least one false arrhythmic event, mainly false asystole and false fast ventricular tachycardia. In the absence of Carelink transmission, at least one episode of memory saturation of ILR would have occurred in 21 patients (45%) that would have limited the diagnostic yield. Patient compliance was good even though one-fifth had some minor psychological concern regarding the ILR implant. CareLink was well accepted and judged easy to use. CONCLUSION: Remote monitoring enhances the diagnostic effectiveness of Reveal, limiting the risk of memory saturation due to the high number of false detections and reducing the time to diagnosis. Both ILR and CareLink were well accepted and well tolerated by the patients, as they were considered useful.

Utility of distinctive local electrogram pattern and aortographic anatomical position in catheter manipulation at coronary cusps.

BACKGROUND: The coronary cusps have recently become target sites for radiofrequency catheter ablation of both outflow tract ventricular arrhythmias originating near the coronary cusps (CC-VA) and atrial tachyarrhythmias such as focal atrial tachycardia originating near the noncoronary cusp (NCC-AT). However, the relation between local electrograms recorded at each CC during sinus rhythm and their anatomical position as assessed by aortography has not yet been systematically described. METHODS AND RESULTS: In 28 patients undergoing RFCA for CC-VA or NCC-AT, amplitudes of the atrial and ventricular potentials at the CCs were measured during sinus rhythm, and the atrial/ventricular (A/V) potential ratio was computed. Relative positions of the CCs were assessed by aortography in 2 X-ray projections. In the right (RCC) and left coronary cusps (LCC), amplitudes of the ventricular potential were larger than those of the atrial potential, leading to an A/V ratio <1 in all patients (0.08 ± 0.10, 0.32 ± 0.21, respectively). In contrast, in the NCC, the amplitude of the atrial potential was larger than the ventricular potential, leading to a higher A/V ratio relative to the CCs (5.7 ± 2.6, P < 0.0001). Aortography demonstrated the rightward and anterior location of the RCC, the leftward and superior location of the LCC, and the inferior and posterior location of the NCC. CONCLUSIONS: Awareness of the distinctive local electrogram pattern of each CC and their positions on aortography should lead to safer and more effective catheter ablation at the CCs.

Non-invasive continuous blood pressure monitoring of tachycardic episodes during interventional electrophysiology.

AIMS: We thought to evaluate feasibility of continuous non-invasive blood pressure monitoring during procedures of interventional electrophysiology. METHODS AND RESULTS: We evaluated continuous non-invasive finger blood pressure (BP) monitoring by means of the Nexfin device in 22 patients (mean age 70 ± 24 years), undergoing procedures of interventional electrophysiology, in critical situations of hypotension caused by tachyarrhythmias or by intermittent incremental ventricular temporary pacing till to the maximum tolerated systolic BP fall (mean 61 ± 14 mmHg per patient at a rate of 195 ± 37 bpm). In all patients, Nexfin was able to detect immediately, at the onset of tachyarrythmia, the changes in BP and recorded reliable waveforms. The quality of the signal was arbitrarily classified as excellent in 11 cases, good in 10 cases, and sufficient in 1 case. In basal conditions, calibrations of the signal occurred every 49.2 ± 24.3 s and accounted for 4% of total monitoring time; during tachyarrhythmias their frequency increased to one every 12.7 s and accounted for 19% of total recording duration. A linear correlation for a range of BP values from 41 to 190 mmHg was found between non-invasive and intra-arterial BP among a total of 1055 beats from three patients who underwent simultaneous recordings with both methods (coefficient of correlation of 0.81, P < 0.0001). CONCLUSION: In conclusion, continuous non-invasive BP monitoring is feasible in the clinical practise of an interventional electrophysiology laboratory without the need of utilization of an intra-arterial BP line.

Influence of autonomic stimulation on the genesis of atrial fibrillation in remodeled canine atria not the same as in normal atria.

BACKGROUND: The role of autonomic effects in the occurrence and maintenance of atrial fibrillation (AF) has undergone little investigation in the remodeling heart. METHODS AND RESULTS: In the present study, 2 groups were studied: those with complete atrioventricular block (AVB) produced by radiofrequency current application (AVB dogs, n=17) and those not undergoing AVB (sham dogs, n=5). Eight weeks after creation of AVB, electrophysiologic study, including pulmonary vein (PV) pacing for AF induction, was performed under vagal nerve stimulation (VNS) and sympathetic stimulation (SS) in both groups. After 8 weeks, atrial dimensions and the percentage of fibrosis in the atria were significantly greater in the AVB dogs. In AVB dogs, atrial and PV effective refractory periods were shorter (P<0.01), and atrial conduction velocity increased (P=0.01) during SS, but not during VNS. Inducibility of AF increased only during SS in the AVB dogs (sustained AF: control 7%, SS 60%; P=0.005), whereas it increased only during VNS in the sham dogs. CONCLUSIONS: In the remodeled atria, sympathetic stimulation was crucial for the genesis of AF, which is completely different from the condition in normal atria.

Clinical and electrophysiological characteristics of patients having atrial flutter with 1:1 atrioventricular conduction.

AIMS: The purpose of this retrospective study was to assess characteristics of patients who had suffered atrial flutter (AFL) with 1:1 atrioventricular (AV) conduction (1:1 AFL). METHODS AND RESULTS: Subjects were 8 patients (61 +/- 14 years) with documented 1:1 AFL, and 101 AFL patients without a history of 1:1 AFL (control patients). 1:1 AFL occurred during physical activity with a ventricular rate of 218 +/- 18 bpm. Antiarrhythmic agents were administered to all eight 1:1 AFL patients, whereas AV nodal conduction-suppressing agents were administered to four. The maximum ventricular rate at which 1:1 AV conduction occurred was significantly lower than when spontaneous 1:1 AFL occurred (164 vs. 218 bpm, P < 0.05). The 1:1 AFL patients had a significantly longer AFL cycle length (CL) (292 vs. 258 ms, P < 0.05) and more rapid AV nodal conduction time (maximum 1:1 AV conduction: 375 vs. 464 ms, P < 0.05) than did control. Arrhythmia had occurred in patients with an AFL CL > or = 250 ms and a CL of maximum 1:1 AV conduction < or = 400 ms. CONCLUSION: Clinicians should be aware of the potential for 1:1 AV conduction in AFL patients, especially in those with remarkable prolongation of the CL in addition to enhanced AV conduction.

Mechanism of the conversion of a pulmonary vein tachycardia to atrial fibrillation in normal canine hearts: role of autonomic nerve stimulation.

INTRODUCTION: The role of the autonomic nervous system in inducing pulmonary vein (PV)-triggered atrial fibrillation (AF) and the termination mechanism of the AF are unknown. The purpose of this study was to elucidate the mechanism of the conversion of a tachycardia within a PV into AF under autonomic stimulation and the termination mechanism of the AF in normal canine hearts. METHODS AND RESULTS: In open-chest dogs, the electrophysiologic parameters were measured under vagal stimulation (VS) or an isoproterenol administration. The effects of the VS or isoproterenol on the PV tachycardias (PVTs), which were created by burst pacing from a PV or the application of aconitine onto the PV, were evaluated. Pilsicainide, a Na channel blocker, was administered during the induced AF. VS and isoproterenol shortened the atrial and PV effective refractory periods. In the pacing model, the VS converted the PV rapid activations into sustained AF in 9 of 12 dogs during pacing cycle lengths < or = 120 msec, but the isoproterenol did not cause any sustained AF. In the aconitine model, the VS increased the rate of the aconitine-induced PVTs and transformed them into sustained AF in all 14 dogs, whereas the isoproterenol did not induce AF, and decreased the PVT rate. In all 14 dogs the sustained AF was terminated by pilsicainide, which had suppressive effects on the PVT as well as atria and PV-atrial junction. CONCLUSIONS: These findings indicate that the vagal effects affecting the PVT and atria facilitate the onset and maintenance of PV-triggered AF in normal canine hearts.