1/39. Malignant pheochromocytoma lacking clinical features of catecholamine excess until the late stage.A malignant pheochromocytoma is described in a 71-year-old man. Osseous metastases became manifest 12 years after successful removal of the primary tumor which originated in paraganglionic tissue near the right adrenal gland. Although the patient had no symptoms of catecholamine excess initially, hypertension, tachycardia and excessive sweating appeared several months before his death, concomitantly with a sharp increase in noradrenaline secretion due to an accelerated growth of metastatic tumors. Since there is no histologic criterion of malignancy in this neoplasm, it would be prudent to consider every case of pheochromocytoma as potentially malignant and to follow-up carefully for a long time after removal of the primary tumor.- - - - - - - - - - ranking = 1keywords = near (Clic here for more details about this article) |
2/39. Dissimilar atrial rhythms: coexistence of reentrant atrial tachycardia, atrioventricular nodal reentrant tachycardia and interatrial conduction block.We report a patient in whom mapping of the right atrium with multipolar catheters and electroanatomic mapping revealed the presence of three dissimilar rhythms: a reentrant atrial tachycardia in the antero-lateral wall of the right atrium and an atrioventricular nodal reentrant tachycardia (AVNRT) isolated from each other and a conduction disturbance at the interatrial septum resulting in a rate-related interatrial block and a slow left atrial rhythm. The AVNRT was stopped with intravenous adenosine (6 mg) and induced repeatedly by atrial extrastimuli associated with a critical atrioventricular delay and dual atrioventricular nodal pathways. Electroanatomic mapping disclosed extensive fibrosis isolating viable myocardium of the antero-lateral wall from the rest of the right atrium. The viable myocardium in the antero-lateral wall was activated by a reentrant rhythm circulating around an islet of fibrosis located in the middle of the viable tissue. The AVNRT was ablated by a standard approach and the reentrant atrial tachycardia by producing a linear lesion bridging the central islet of fibrosis with the anterior tricuspid annulus. This case highlights the complicated nature of some dissimilar atrial rhythms and the power of electroanatomic mapping tools to reveal the exact mechanism and guide radiofrequency ablation.- - - - - - - - - - ranking = 1keywords = near (Clic here for more details about this article) |
3/39. Myopotential interference with a unipolar VDD pacemaker presenting with tachycardia and transient ventricular asystole.Interference between myopotentials and pacemakers is well recognized, especially in a unipolar pacing system. This case report describes myopotential interference with an atrial synchronous ventricular inhibited (VDD) unipolar pacemaker in a 54-year-old woman. The interference caused both repetitive ventricular upper rate pacing and sometimes ventricular channel inhibition, resulting in palpitation and near syncope. Provocative tests elicited the myopotential interference reproducibly. The problem was partially corrected by further sensitivity adjustment.- - - - - - - - - - ranking = 1keywords = near (Clic here for more details about this article) |
4/39. Primary cardiac T-cell lymphoma.Primary cardiac lymphoma (PCL), defined as a lymphoma clinically mimicking cardiac disease, with the bulk of the tumor located intrapericardially, is extremely rare in immunocompetent patients. Clinical manifestations vary depending on sites of involvement in the heart and include chest pain, arrhythmias, pericardial effusion, and heart failure. diagnosis is often difficult and may require invasive procedures; in some cases, diagnosis is not made until autopsy. Histologically, nearly all cases of PCL reported thus far have been of B-cell origin. In this report, we describe a case of PCL of T-cell origin in an adult immunocompetent patient, the second reported in the literature to the best of our knowledge, and provide a brief overview of the features of previously published PCL cases.- - - - - - - - - - ranking = 1keywords = near (Clic here for more details about this article) |
5/39. Persistent tachycardia with a 2:1 exit block within an isolated pulmonary vein.We describe a patient with drug-resistant, paroxysmal atrial fibrillation who underwent segmental pulmonary vein (PV) isolation. After complete isolation of the right superior PV, a persistent regular tachycardia was recorded within the vein. A tachycardia focus with a cycle length of 114 ms was found 2.5 cm away from the ostium of the PV. The cycle lengths of the PV tachycardia near the ostium and near the focus were 400 ms and 200 ms, respectively, which indicates the presence of a 2:1 exit block within the vein. This PV tachycardia was completely eliminated with the application of radiofrequency energy at the focus.- - - - - - - - - - ranking = 2keywords = near (Clic here for more details about this article) |
6/39. Dual antegrade response tachycardia induced cardiomyopathy.We report a rare case of tachycardia induced cardiomyopathy resulting from nearly incessant dual antegrade response tachycardia. Criteria necessary for sustaining dual antegrade responses are discussed, including: (1) sufficient antegrade dissociation of the AV node; (2) absence of retrograde conduction over each AV nodal pathway following antegrade conduction over its counterpart; (3) difference between fast and slow pathway conduction times exceeding His-Purkinje refractoriness; and (4) critical timing of sinus impulses relative to preceding AV nodal conduction. Both the arrhythmia and cardiomyopathy were successfully treated by slow pathway ablation.- - - - - - - - - - ranking = 1keywords = near (Clic here for more details about this article) |
7/39. Asymptomatic brugada syndrome associated with postural orthostatic tachycardia syndrome: Does autonomic disorder increase propensity for future arrhythmic events?Autonomic imbalance may work as a modifying factor for initiating lethal arrhythmia in patients with brugada syndrome. A 26-year-old man with episodes of near syncope was given a diagnosis of an autonomic disorder, postural orthostatic tachycardia syndrome (POTS). The patient spontaneously showed typical Brugada-type ECG, and ventricular fibrillation was induced by programmed electrical stimulation, which allowed the further diagnosis of brugada syndrome. Although it seems that brugada syndrome is asymptomatic, its uncommon association of POTS may increase the risk for future arrhythmic events in this patient.- - - - - - - - - - ranking = 1keywords = near (Clic here for more details about this article) |
8/39. Atrial tachycardia ablation in a patient with double outlet right ventricle corrected by surgery.The development of surgical and percutaneous techniques for treatment or palliation of congenital heart disease has prolonged survival in these patients and has increased late complications, particularly arrhythmias. Such arrhythmias are more frequently refractory to medical therapy, requiring percutaneous ablation. We present the clinical case of a 14-year-old child with complex congenital heart disease (double outlet right ventricle) who underwent two corrective surgeries (Rastelli operation and subsequent replacement of the homograft in the conduit connecting the right ventricle to the pulmonary artery; ventricular septal defect closure and tricuspid valve repair). After the second surgery the patient presented with wide complex syncopal tachycardia, refractory to medical therapy. Electrophysiologic study (EPS) identified an isthmus-dependent atrial flutter that was successfully treated by radiofrequency (RF) ablation (a linear block was created along the cavo-tricuspid isthmus). Three months later a new episode of tachycardia occurred, but without syncope. The second EPS revealed an atrial tachycardia originating from the lateral wall of the right atrium, which was treated by ablation with focal application of RF energy. Four months after the last EPS the child remains free of arrhythmic symptoms, under no anti-arrhythmic therapy.- - - - - - - - - - ranking = 1keywords = near (Clic here for more details about this article) |
9/39. The permanent form of junctional reciprocating tachycardia: further elucidation of the underlying mechanism.A case of the permanent form of junctional reciprocating tachycardia studied by endocardial and epicardial mapping is presented. The ability of the retrograde impulse to penetrate the atrium in 2 different areas, one near the region of the recorded His potential and the other near the orifice of the coronary sinus, is demonstrated. Retrograde conduction persisted after the surgical creation of complete antegrade heart block suggesting the existence of an accessory ventriculo-atrial connection. The decremental properties of retrograde conduction observed suggest that an accessory ventriculo-artrial nodal structure may be the underlying substrate of this arrhythmia.- - - - - - - - - - ranking = 2keywords = near (Clic here for more details about this article) |
10/39. Signal-averaged electrocardiographic detection of terminal QRS deflection suggesting late potentials.A terminal QRS deflection on a 12-lead electrocardiogram (previously described as peri-infarction block) most likely represents slowed conduction in a large area of myocardium near the infarct zone. We have described a patient with peri-infarction block, abnormal findings on signal-averaged electrocardiogram, and reentrant ventricular tachyarrhythmias. Our observation underscores the need to recognize the importance of terminal QRS deflections in the appropriate clinical situation.- - - - - - - - - - ranking = 1keywords = near (Clic here for more details about this article) |
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