1/47. DDD-pacing-induced cardiomyopathy following AV node ablation for persistent atrial tachycardia.Ventricular rate control by catheter ablation of the AV node and pacing in patients with persistent atrial tachycardia has been reported to improve left ventricular function. However, this approach requires careful selection of the pacing mode. We report a patient who underwent AV node ablation for persistent multiple atrial tachycardias, and who then had a non-mode-switching pacemaker implanted. Because of an inappropriately programmed relatively high upper rate limit, the patient developed left ventricular dysfunction after 6 years. This resolved after programming the pacemaker to VVI at 70 bpm.- - - - - - - - - - ranking = 1keywords = ventricular dysfunction, dysfunction (Clic here for more details about this article) |
2/47. Hormonal and cardiovascular reflex assessment in a female patient with pure autonomic failure.We report the case of a 72-year-old female with pure autonomic failure, a rare entity, whose diagnosis of autonomic dysfunction was determined with a series of complementary tests. For approximately 2 years, the patient has been experiencing dizziness and a tendency to fall, a significant weight loss, generalized weakness, dysphagia, intestinal constipation, blurred vision, dry mouth, and changes in her voice. She underwent clinical assessment and laboratory tests (biochemical tests, chest X-ray, digestive endoscopy, colonoscopy, chest computed tomography, abdomen and pelvis computed tomography, abdominal ultrasound, and ambulatory blood pressure monitoring). Measurements of catecholamine and plasmatic renin activity were performed at rest and after physical exercise. Finally the patient underwent physiological and pharmacological autonomic tests that better diagnosed dysautonomia.- - - - - - - - - - ranking = 0.01054122712393keywords = dysfunction (Clic here for more details about this article) |
3/47. tachycardia-induced cardiomyopathy secondary to thyrotoxicosis: a young man with previously unrecognized Graves' disease.A young man with previously unrecognized Graves' disease presented with atrial fibrillation and severe low-output heart failure due to dilated cardiomyopathy. The patient's cardiomyopathy resolved and cardiac function recovered shortly after hyperthyroidism and tachycardia were treated during hospitalization. The temporal relationship between heart rate and cardiac function during the recovery period suggests that chronic tachycardia may have been an important cause of his cardiac dysfunction. thyrotoxicosis seemed to be directly responsible for the development of sustained supraventricular tachycardia in this patient, which then led to tachycardia-induced cardiomyopathy causing severe low-output heart failure. Although relatively infrequent, this etiology should not be overlooked in patients thyrotoxicosis and heart failure. This is the first case in which the time course and the temporal relationship between the control of heart rate and the recovery of cardiac function are illustrated in a thyrotoxic patient.- - - - - - - - - - ranking = 0.01054122712393keywords = dysfunction (Clic here for more details about this article) |
4/47. atrioventricular block after reciprocating atrioventricular junctional tachycardia.Short runs of symptomatic atrioventricular (A-V) block occurred after spontaneous cessation of reciprocating A-V junctional tachycardia in a patient with right bundle branch block, normal H-V interval and sinus nodal dysfunction. These episodes were characterized by long (more than 1 sec) P-P intervals during which the A deflections were not followed by His bundle electrograms. Three possible explanations are: (1) a posttachycardia-induced period of abnormally prolonged A-V nodal refractoriness; (2) pseudo-A-V block produced by concealed A-V junctional tachycardia, or (3) bradycardia-dependent (phase 4) A-V block at the "upper" His bundle, above the site from which the H deflection was recorded.- - - - - - - - - - ranking = 0.01054122712393keywords = dysfunction (Clic here for more details about this article) |
5/47. Neurovesical dysfunction in postural tachycardia syndrome (POTS).This is the first report of neurovesical dysfunction in a woman with postural tachycardia syndrome (POTS). The patient had both symptoms and urodynamic findings diagnostic of detrusor hyperreflexia. Management consisted of anticholinergic medication and timed voiding. Lower urinary tract dysfunction may be underrecognized in POTS.- - - - - - - - - - ranking = 0.063247362743578keywords = dysfunction (Clic here for more details about this article) |
6/47. Compound heterozygosity for mutations (W156X and R225W) in SCN5A associated with severe cardiac conduction disturbances and degenerative changes in the conduction system.Cardiac conduction defects associate with mutations in SCN5A, the gene encoding the cardiac Na channel. In the present study, we characterized a family in which the proband was born in severe distress with irregular wide complex tachycardia. His older sister died at 1 year of age from severe conduction disease with similarly widened QRS-complexes. Mutational analysis of SCN5A in the proband demonstrated compound heterozygosity for a nonsense mutation (W156X), inherited from the father, and a missense mutation (R225W), inherited from the mother. Genotyping on dna extracted from tissue from the deceased sibling revealed the same SCN5A genotype. Injection of cRNA encoding the W156X mutation in xenopus oocytes did not produce any current. The R225W substitution neutralizes the third Arg residue within the voltage-sensing segment of domain I. Expression studies showed that this mutation leads to a severe reduction in I(Na) and is also associated with gating changes. Histological examination of the heart from the deceased sibling revealed changes consistent with a dilated type of cardiomyopathy and severe degenerative abnormalities of the specialized conduction system. The occurrence of compound heterozygosity for these two mutations implies that the proband carries solely severely dysfunctional cardiac Na channels. This explains his severe phenotype and that of his deceased sister who had been a carrier of the same genotype. The morphological changes within the heart of the deceased sibling may have occurred secondary to the Na channel abnormality and contributed to the severity of the disorder in this individual.- - - - - - - - - - ranking = 0.01054122712393keywords = dysfunction (Clic here for more details about this article) |
7/47. Permanent form of junctional reciprocating tachycardia and tachycardia-induced cardiomyopathy treated by catheter ablation: a case report.The permanent form of junctional reciprocating tachycardia (PJRT) is usually refractory to drug therapy, and these patients are at risk of developing tachycardia-induced cardiomyopathy. The electrocardiogram insribes inverted P waves in leads 2, 3, aVF as well as left lateral leads, along with a P-R interval shorter than R-P interval during the tachycardia. This report describes a three-year-old male patient with PJRT who underwent successful radiofrequency catheter ablation (RFA) of accessory pathway. On transthoracic echocardiography of patient, decreased ventricular systolic function was observed. RFA was performed by applying radiofrequency pulses. Echocardiograms of the patient, two months after catheter ablation, demonstrated progressive improvement of ventricular function. Transcatheter radiofrequency ablation of accessory pathways in patients with PJRT is an effective, and possibly preferable, form of treatment, especially in cases of tachycardia refractory to multiple pharmacologic treatments or when left ventricular dysfunction is present.- - - - - - - - - - ranking = 1keywords = ventricular dysfunction, dysfunction (Clic here for more details about this article) |
8/47. Use of DDDRP pacing device in prevention and treatment of tachy-brady syndrome after Mustard procedure.A 13-year-old male patient, who underwent Mustard operation for a very complex congenital heart disease (CHD), after palliation presented a decrease of the sinus node function, developing a tachy-brady syndrome and a mild dysfunction of atrioventricular (AV) conduction. He was successfully treated using a DDDRP pacemaker, which ensured a suitable atrial rhythm and was able to interrupt supraventricular tachycardia episodes. Until now, hospitalization related to episodes of heart failure or symptomatic arrhythmia, has not been necessary.- - - - - - - - - - ranking = 0.01054122712393keywords = dysfunction (Clic here for more details about this article) |
9/47. McLeod syndrome: a distinct form of neuroacanthocytosis. Report of two cases and literature review with emphasis on neuromuscular manifestations.McLeod syndrome was originally described on the basis of a specific blood group phenotype with weak expression of Kell antigens. This erythrocyte abnormality also causes acanthocytosis. The haematological findings are associated with abnormalities in other organ systems, including neuromuscular manifestations. A 51-year-old patient was followed up for 11 years. He presented with persistent muscle creatine kinase elevation and progressive heart disease and later developed a slowly progressive neuropathy and choreic movements. His younger brother presented with grand mal seizures, involuntary movements and high muscle creatine kinase when aged 43 years. Clinical myopathy was absent in both, yet muscle biopsy showed mild myopathic changes. The presence of a motor axonopathy was supported by electrophysiological findings. One brother also showed sensory axonopathy. The movement disorder suggested accompanying basal ganglia dysfunction. Earlier reports of McLeod syndrome are reviewed with respect to neuromuscular involvement. Absence of the Kx membrane protein seems to be the cause of this multi-system disorder.- - - - - - - - - - ranking = 0.01054122712393keywords = dysfunction (Clic here for more details about this article) |
10/47. encainide dosing in patients with severe renal dysfunction: report of a case and literature review.Dosage of encainide for patients with lethal ventricular arrhythmias is based on pharmacodynamic effects and efficacy of arrhythmia suppression, coupled with metabolizer phenotype and extent of renal and hepatic dysfunction. Decreased clearance in patients with renal dysfunction necessitates a reduction in dosage to avoid toxic and dose-related proarrhythmic effects. This case represents a patient with severe renal dysfunction and sustained ventricular tachycardia who achieved electrophysiologically guided suppression of induced ventricular tachycardia at a steady-state encainide dose of only 25 mg daily, significantly lower than package insert or compendial recommendations for initial dosage in patients with renal insufficiency. Documented "therapeutic" metabolite concentrations correlated to electrophysiologic response. literature review illustrates the complexity of encainide dosage in such individuals and underscores the need for therapeutic drug monitoring to individualize dosage.- - - - - - - - - - ranking = 0.073788589867508keywords = dysfunction (Clic here for more details about this article) |
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