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At least 37 records · Page 2Linked to original sources

Fast fluid-attenuated inversion recovery (FLAIR) magnetic resonance imaging of the brain: a comparison of multi-shot echo-planar and fast spin-echo techniques.

PURPOSE: To evaluate fast spin-echo and multi-shot echo-planar fluid-attenuated inversion recovery (FLAIR) sequences in paediatric brain imaging. MATERIALS AND METHODS: Matched images from 32 patients with suspected tumour or white matter disease were independently evaluated by two paediatric neuroradiologists. The observer preferences for image quality and lesion detection were analysed for differences between fast spin-echo FLAIR and multi-shot echo-planar FLAIR. Diagnostic quality was compared with that of fast spin-echo T2-weighted images. RESULTS: Images of a diagnostic quality equivalent to that of fast spin-echo T2-weighted images were achieved with both FLAIR techniques. Grey and white matter differentiation and cerebrospinal fluid (CSF) nulling were significantly better on fast spin-echo FLAIR sequences. CSF flow artefact was reduced on multi-shot echo-planar FLAIR. There was no difference in lesion detection. Fast spin-echo FLAIR images were visually preferred at the expense of longer imaging time. CONCLUSION: Fast FLAIR techniques are complementary to fast spin-echo T2-weighted sequences in imaging of the paediatric brain. We find that the fast spin-echo FLAIR sequence is preferable to the multi-shot echo-planar technique.

Brain↗

T2-weighted MR imaging of the uterus: comparison of optimized fast spin-echo and HASTE sequences with conventional fast spin-echo sequences.

OBJECTIVE: Our objective was to compare the value of a half-Fourier acquisition single-shot turbo spin-echo (HASTE) sequence with optimized fast spin-echo and conventional fast spin-echo techniques in evaluation of the uterus. SUBJECTS AND METHODS: Optimized fast spin-echo imaging was compared with fast spin-echo and HASTE imaging, for both image quality and ability to assess the zonal anatomy of the uterus, in 40 volunteers. In optimized fast spin-echo imaging, the imaging time was reduced using partial-Fourier reconstruction, reducing the echo spacing, and increasing the echo train length. RESULTS: HASTE imaging offered the least motion artifact of all techniques. On optimized fast spin-echo imaging, motion artifacts were moderate to severe in 10% of patients. On fast spin-echo imaging, motion artifacts were moderate to severe in 40% of patients. Optimized fast spin-echo imaging was superior to the other two techniques in terms of anatomic sharpness and overall image quality. CONCLUSION: Although HASTE imaging offers the unique feature of providing images free of motion artifacts, optimized fast spin-echo imaging appears to be the preferred technique for T2-weighted imaging of the uterus.

Adolescent↗

Fast fluid-attenuated inversion recovery (FAST-FLAIR) of ischemic lesions in the brain: comparison with T2-weighted turbo SE.

PURPOSE: We compared fast fluid-attenuated inversion recovery (FAST-FLAIR) images with Turbo SE T2-weighted images to evaluate the detectability of small ischemic lesions in the brain. MATERIALS AND METHODS: Thirty-six cases of multiple cerebral ischemic lesions were examined with FAST-FLAIR and Turbo SE imaging. The detectability of lesions, ability to discriminate lesions from the cortex, visualization of perivascular space, and visualization of brainstem lesions were compared between the two sequences. RESULTS: The total number of lesions detected on both sequences was 534 in 36 cases. Six lesions in three cases were detected only on FAST-FLAIR, and one lesion in one case was detected only on the Turbo SE. All the 52 lesions located close to the cortex could be discriminated from the cortex on the FAST-FLAIR images, while 23 of these lesions could not be discriminated on the Turbo SE. Perivascular spaces were not visualized as areas of high signal on the FAST-FLAIR images. Pontine lesions that were visualized in four cases were clearer on the Turbo SE images than on the FAST-FLAIR images. CONCLUSION: The FAST-FLAIR images were shown to be useful in the detection of ischemic lesions and in distinguishing them from the surrounding normal structures. The FAST-FLAIR sequence is expected to become a new additional routine sequence.

Aged↗

A preliminary fast may potentiate response to a subsequent low-salt, low-fat vegan diet in the management of hypertension - fasting as a strategy for breaking metabolic vicious cycles.

Although a salted diet appears to be a sine qua non for the development of essential hypertension, low-salt diets often have a modest or even negligible impact on the blood pressure of hypertensives; this suggests that salt, perhaps often acting in concert with other aspects of a modern, rich diet, may set in place certain metabolic vicious cycles that sustain blood pressure elevation even when dietary salt is eliminated. Therapeutic fasting is known to lower elevated blood pressure - presumably in large part because it minimizes insulin secretion - and may have the potential to break some of these vicious cycles. Goldhamer has recently reported that a regimen comprised of a water-only fast of moderate duration, followed by a transition to a low-fat, low-salt, whole-food vegan diet, achieves dramatic reductions in the blood pressure of hypertensives, such that the large majority of patients can be restored to normotensive status, in the absence of any drug therapy. Although long-term follow-up of these subjects has been sporadic, the available data suggest that these large reductions is blood pressure can be conserved in patients who remain compliant with the follow-up diet - in other words, a 'cure' for hypertension may be feasible. If a protein-sparing modified fast can be shown to be virtually as effective as a total fast for achieving these benefits, it may be possible to implement this regimen safely on an outpatient basis. The ability of therapeutic fasts to break metabolic vicious cycles may also contribute to the efficacy of fasting in the treatment of type 2 diabetes and autoimmune disorders. As a general principle, if a metabolic disorder is susceptible to prevention - but not reversal - by a specific diet, and therapeutic fasting has a temporary favorable impact on this disorder, then a more definitive therapy may consist of a therapeutic fast, followed up by the protective diet as a maintenance regimen.

Diet, Vegetarian↗

Adaptation to fasting in baboon. II. Regulation of lipolysis early and late in fasting.

Regulation of lipolysis by the sympathetic nervous system, basal insulin, and glucagon was studied in fasted baboons. Beta-Adrenergic mechanisms were evaluated by blockade with propranolol after 24, 40, and 65 h of fasting. Inhibition of lipolysis decreased with increasing duration of fasting. Insulin concentrations were markedly reduced by propranolol at all stages of fasting, whereas glucose and glucagon concentrations were unchanged. The roles of insulin and glucagon were evaluated by a 2-h infusion of somatostatin after 18 and 65 h of fasting. At both times, insulin and glucagon concentrations were markedly reduced. At 18 h of fasting but not at 65 h, lipolysis doubled. At both times the plasma glucose concentration fell 15-30%. At 18 h, preventing the decrease in glucose with glucose infusion prevented the increase in lipolysis. These data suggest that a beta-adrenergic mechanism is largely responsible for regulation of lipolysis early in fasting and that insulin, glucagon, and beta-adrenergic mechanisms play no major part in the maintenance of the accelerated lipolysis later in fasting.

Animals↗

Glucose-induced alkalosis in fasting subjects. Relationship to renal bicarbonate reabsorption during fasting and refeeding.

This study documents the development of alkalosis in patients returning to caloric intake after a period of starvation and investigates the mechanisms responsible for this metabolic alteration. We studied the acid-base status, bicarbonate reabsorption, acid excretion, and sodium metabolism during fasting and glucose refeeding in 19 patients receiving sodium supplements. Metabolic alkalosis developed promptly in all of the subjects who terminated an 18 day fast with 300 g of glucose daily for 4 days. Tubular maximum reabsorptive capacity for bicarbonate and renal bicarbonate threshold determinations were performed at varying intervals in six and seven subjects, respectively, who had fasted for 3-18 days. The results demonstrated that bicarbonate reabsorptive capacity was normal or low during early fasting, markedly elevated during the 2nd wk; and moderately elevated during the 3rd wk of fasting. Glucose administration at all stages of fasting caused a further increase in bicarbonate threshold. Sodium balance during fasting with sodium supplements was found to follow a triphasic pattern, with the occurrence of a natriuresis during the 1st wk followed by a period of sodium retention after which neutral daily sodium balance was reestablished. Correlation of bicarbonate reabsorption with sodium homeostasis indicated a slight decrease in renal bicarbonate threshold during the natriuretic phase, a marked increase in bicarbonate reabsorption during the period of sodium retention, and a continued moderate elevation of threshold after sodium balance was reestablished. This relationship was interpreted to indicate that changes in bicarbonate reabsorption during fasting and refeeding may be secondary to alterations in the renal reabsorption of sodium.

Absorption↗

Sero-epidemiological assessment and diagnosis of visceral leishmaniasis in an endemic locality using Fast Agglutination Screening Test (FAST).

The Fast Agglutination Screening Test (FAST) was employed on sera obtained from an endemic area of visceral leishmaniasis in southwestern Ethiopia, in February 2000. The study involved (i) active case detection among 1575 residents of two villages; and (ii) passive case detection in an outpatient clinic. Sera of 1587 individuals, including 143 sera of previously treated VL patients, were tested. Based on the size of agglutination mat, the FAST results were read qualitatively as non-reactive (-), weakly reactive (1+), moderately reactive (2+) and highly reactive (3+). All FAST reactive sera were re-tested with the Direct Agglutination Test (DAT). After clinical screening of 1625 individuals, 61 individuals with signs and symptoms of early or late VL were found; 26 sera were FAST positive. Twenty-two of these suspected VL cases were subjected to parasitological examination using lymph node aspirates. Eighteen (81.8%) were confirmed either by demonstration of amastigotes in smears or promastigotes in NNN cultures. FAST reactive anti-leishmanial antibodies were detected in 4.5% of untreated and 70.6% of previously treated patients. Forty-five sera of 1390 previously untreated asymptomatic individuals (3.2%) were found to be FAST positive. This report demonstrates that FAST is a rapid and cost-effective screening test for the diagnosis and sero-epidemiological surveillance of visceral leishmaniasis.

Adolescent↗

Development of a fast agglutination screening test (FAST) for the detection of anti-Leishmania antibodies in dogs.

A fast agglutination screening test (FAST) for the detection of anti-Leishmania antibodies in serum samples from dogs with visceral leishmaniosis was developed. The test is based on the direct agglutination test (DAT), but combines a higher parasite concentration with a smaller test volume. In contrast to the DAT, the FAST makes use of only one serum dilution and the results can be read within 3 h as opposed to 18-20 h for the DAT. The FAST was evaluated using serum samples of confirmed cases of the disease and healthy controls collected in the most important endemic regions of canine visceral leishmaniosis, import cases of canine leishmaniosis in a non-endemic country, from non-endemic healthy controls and from dogs with other diseases. The performance of the FAST was compared with standard DAT. In the present study, the FAST had a sensitivity of 93.6% and a specificity of 89.0%. The DAT had a sensitivity of 88.6% and a specificity of 96.7%. Furthermore, using a large panel of serum samples of previously examined DAT positive or negative dogs it was shown that degree of agreement between the two tests was high (95.7%; kappa value = 0.91). The FAST offers the advantages of the DAT based on freeze-dried antigen with respect to stability of the antigen, sensitivity and specificity. Moreover, the FAST allows the rapid screening of a large number of samples, which makes the test very useful for epidemiological screening of large populations of dogs.

Agglutination Tests↗

Spike-wave complexes and fast components of cortically generated seizures. IV. Paroxysmal fast runs in cortical and thalamic neurons.

In the preceding papers of this series, we have analyzed the cellular patterns and synchronization of neocortical seizures occurring spontaneously or induced by electrical stimulation or cortical infusion of bicuculline under a variety of experimental conditions, including natural states of vigilance in behaving animals and acute preparations under different anesthetics. The seizures consisted of two distinct components: spike-wave (SW) or polyspike-wave (PSW) at 2-3 Hz and fast runs at 10-15 Hz. Because the thalamus is an input source and target of cortical neurons, we investigated here the seizure behavior of thalamic reticular (RE) and thalamocortical (TC) neurons, two major cellular classes that have often been implicated in the generation of paroxysmal episodes. We performed single and dual simultaneous intracellular recordings, in conjunction with multisite field potential and extracellular unit recordings, from neocortical areas and RE and/or dorsal thalamic nuclei under ketamine-xylazine and barbiturate anesthesia. Both components of seizures were analyzed, but emphasis was placed on the fast runs because of their recent investigation at the cellular level. 1) The fast runs occurred at slightly different frequencies and, therefore, were asynchronous in various cortical neuronal pools. Consequently, dorsal thalamic nuclei, although receiving convergent inputs from different neocortical areas involved in seizure, did not express strongly synchronized fast runs. 2) Both RE and TC cells were hyperpolarized during seizure episodes with SW/PSW complexes and relatively depolarized during the fast runs. As known, hyperpolarization of thalamic neurons deinactivates a low-threshold conductance that generates high-frequency spike bursts. Accordingly, RE neurons discharged prolonged high-frequency spike bursts in close time relation with the spiky component of cortical SW/PSW complexes, whereas they fired single action potentials, spike doublets, or triplets during the fast runs. In TC cells, the cortical fast runs were reflected as excitatory postsynaptic potentials appearing after short latencies that were compatible with monosynaptic activation through corticothalamic pathways. 3) The above data suggested the cortical origin of these seizures. To further test this hypothesis, we performed experiments on completely isolated cortical slabs from suprasylvian areas 5 or 7 and demonstrated that electrical stimulation within the slab induces seizures with fast runs and SW/PSW complexes, virtually identical to those elicited in intact-brain animals. The conclusion of all papers in this series is that complex seizure patterns, resembling those described at the electroencephalogram level in different forms of clinical seizures with SW/PSW complexes and, particularly, in the Lennox-Gastaut syndrome of humans, are generated in neocortex. Thalamic neurons reflect cortical events as a function of membrane potential in RE/TC cells and degree of synchronization in cortical neuronal networks.

Adrenergic alpha-Agonists↗

Fasting and refeeding modulate neutral amino acid transport activity in the basolateral membrane of the rat exocrine pancreatic epithelium: fasting-induced insulin insensitivity.

The effects of fasting and refeeding on amino acid transport in the perfused rat exocrine pancreas were investigated using a rapid dual tracer dilution technique. Unidirectional amino acid influx (15 s) was quantified (relative to the extracellular tracer D-mannitol) over a wide range of perfusate concentrations in pancreata isolated frm fed and 24 h, 48 h, and 72 h fasted and 72 h fasted and refed (24 h) animals. In fed animals transport of phenylalanine (1-24 mM) and L-serine (1-50 mM) was saturable and weighted non-linear regression analyses of the overall transport indicated an apparent Kt = 10 +/- 3 mM and Vmax = 7.0 +/- 1.0 mumol/min per g (n = 7) for phenylalanine and Kt = 16 +/- 3 mM and Vmax = 20.6 +/- 2.1 mumol/min per g (n = 5) for serine. Fasting animals for 24 h or 48 h did not change the kinetics of either phenylalanine or serine transport. After a 72 h fast the rate of phenylalanine transport (Vmax = 15.9 +/- 2.9 mumol/min per g, n = 5) was enhanced whereas the transport affinity (Kt = 11 +/- 3 mM) remained unaltered. L-Serine transport was essentially unaltered. When 72 h fasted animals were refed for 24 h the Vmax for phenylalanine transport was reduced to values observed in fed animals. In parallel experiments refeeding had no significant effect on serine transport. Perfusion of pancreata isolated from 72 h fasted animals with bovine insulin (1 mU/ml or 1 microU/ml) did not stimulate either phenylalanine or serine transport.(ABSTRACT TRUNCATED AT 250 WORDS)

Amino Acids↗

The effect of ten days of fasting on various aspects of carbohydrate metabolism in obese diabetic subjects with significant fasting hyperglycemia.

Patients with nonketotic diabetes mellitus, who were both obese and had significant fasting hyperglycemia (mean plasma glucose = 310 mg/100 ml), were fasted for 10 days. There was a prompt drop of plasma glucose levels as the result of the caloric deprivation with a mean fall of approximately 200 mg/dl at the end of the fast. The drop in plasma glucose level that occurred during the fast was associated with a drop in plasma insulin level. Fasting plasma glucose concentration rose immediately after food intake was resumed and stabilized within 3--4 days at levels halfway between the initial and the lowest value. At this time, the patients also seemed capable of disposing of an oral glucose load more efficiently. The apparent improvement in carbohydrate homeostasis observed after the fast could not be attributed to an increase in insulin response, but was associated with some amelioration of the insulin resistance that characterizes these patients. Unfortunately, the beneficial effects of the 10-day period of caloric deprivation were transitory and fasting plasma glucose values had returned to prefast levels in most patients within a few months.

Adult↗

Trimetazidine diminishes fasting glucose in rats with fasting hyperglycemia: a preliminary study.

Trimetazidine is a drug with cardioprotective properties used in coronary artery disease. Its effect has been attributed to the inhibition of the long chain fatty acids intramitochondrial transport via carnitine-palmitoyl-transferase-1. Clinical evidence supports the possibility that trimetazidine is able to improve the fasting glycemia in diabetic patients. For this reason, the objective of the present study was to determine the effect of trimetazidine on serum glucose of Sprague-Dawley rats with fasting hyperglycemia. All animals received water and food "ad libitum." Blood glucose was measured weekly to confirm fasting hyperglycemia in rats. The rats were treated for 1 month with trimetazidine (1 mg/kg), and blood samples were collected (in the fasting period) on the last day of treatment (the 30th day); and then on the 15th day posttreatment, measurements of plasma glucose were taken. Fasting plasma levels after 30 days of trimetazidine administration decreased significantly from 141.2 +/- 3.3 mg/dL (pre-drug) to 120.9 +/- 5.8 mg/dL (P<0.01). 15 days after the end of treatment, fasting plasma glucose levels (137.0 +/- 7.0 mg/dL) were close to the pretreatment levels but significantly different (P<0.05) from levels on day 30 of treatment. These data suggest that trimetazidine improved blood glucose utilization in rats with fasting hyperglycemia.

Animals↗

Prolonged fasting and cortisol reduce myostatin mRNA levels in tilapia larvae; short-term fasting elevates.

Myostatin negatively regulates muscle growth and development and has recently been characterized in several fishes. We measured fasting myostatin mRNA levels in adult tilapia skeletal muscle and in whole larvae. Although fasting reduced some growth indexes in adults, skeletal muscle myostatin mRNA levels were unaffected. By contrast, larval myostatin mRNA levels were sometimes elevated after a short-term fast and were consistently reduced with prolonged fasting. These effects were specific for myostatin, as mRNA levels of glyceraldehyde-3-phosphate dehydrogenase and glucose-6-phosphatase were unchanged. Cortisol levels were elevated in fasted larvae with reduced myostatin mRNA, whereas in addition immersion of larvae in 1 ppm (2.8 microM) cortisol reduced myostatin mRNA in a time-dependent fashion. These results suggest that larval myostatin mRNA levels may initially rise but ultimately fall during a prolonged fast. The reduction is likely mediated by fasting-induced hypercortisolemia, indicating divergent evolutionary mechanisms of glucocorticoid regulation of myostatin mRNA, since these steroids upregulate myostatin gene expression in mammals.

Adaptation, Physiological↗

Spatial variation in fast muscle function of the rainbow trout Oncorhynchus mykiss during fast-starts and sprinting.

Fish fast-starts and sprints are rapid kinematic events powered by the lateral myotomal musculature. A distinction can be made between fast-starts and sprint-swimming activity. Fast-starts are kinematic events involving rapid, asymmetrical movements. Sprints involve a series of symmetrical, high-frequency tailbeats that are kinematically similar to lower-frequency, sustained swimming. The patterns of muscle recruitment and strain associated with these swimming behaviours were determined using electromyography and sonomicrometry. Axial patterns of fast muscle recruitment during sprints were similar to those in slow muscle in that the duration of electromyograhic (EMG) activity decreased in a rostro-caudal direction. There was also an axial shift in activity relative to the strain cycle so that activity occurred relatively earlier in the caudal region. This may result in caudal muscle performing a greater proportion of negative work and acting as a power transmitter as well as a power producer. The threshold tailbeat frequency for recruitment of fast muscle differed with location in the myotome. Superficial muscle fibres were recruited at lower tailbeat frequencies and shortening velocities than those deeper in the musculature. During sprints, fast muscle strain ranged from +/- 3.4% l(0) (where l(0) is muscle resting length) at 0.35FL (where FL is fork length) to +/- 6.3% l(0) at 0.65FL. Fast-starts involved a prestretch of up to 2.5% l(0) followed by shortening of up to 11.3% l(0). Stage 1 EMG activity began simultaneously, during muscle lengthening, at all axial locations. Stage 2 EMG activity associated with the major contralateral contraction also commenced during lengthening and proceeded along the body as a wave. Onset of muscle activity during lengthening may enhance muscle power output.

Animals↗

[Pharmacokinetics of cefadroxil in rats: comparison of fasting and non-fasting (author's transl)].

A single dose 50 mg/kg of cefadroxil was administered orally to rats in fasting and non-fasting. In both fasting and non-fasting, the serum levels of cefadroxil were higher than those of cephalexin. In fasting, the biological half-life (T 1/2) of cefadroxil was longer than that of cephalexin. This indicates its prolonged durable action. Ingestion of cefadroxil with food affected the serum level less than that of cephalexin with food, and the serum levels of cefadroxil in non-fasting were same as those of cephalexin in fasting.

Administration, Oral↗

Imaging of the spinal cord and brain in multiple sclerosis: a comparative study between fast FLAIR and fast spin echo.

Recent reports have suggested that fluid attenuated inversion recovery (FLAIR) is a technique superior to conventional (CSE) or fast spin echo (FSE) T2-weighted sequences in detecting intrinsic lesions both in the brain and spinal cord. We report our experience of an inversion recovery prepared FSE, which we refer to as fast FLAIR, in a comparative study of ten patients with clinically definite multiple sclerosis (MS) who underwent cervical cord and brain imaging with both FSE and fast FLAIR. The results showed that in the cerebral hemispheres fast FLAIR detected more lesions than FSE (P < 0.001). However, FSE detected more lesions than fast FLAIR in the posterior fossa (P = 0.02) and in the cord fast FLAIR was much inferior detecting only 2 of 33 lesions seen on FSE. Estimating the T2 relaxation times of lesions in each of three areas (periventricular, posterior fossa, cervical cord) showed that the T2 value of posterior fossa and cervical cord lesions was significantly lower than that of periventricular lesions, suggesting that the lesion composition is different and consequently their imaging appearances are different. In conclusion, although fast FLAIR improves the detection of MS lesions in the cerebral hemispheres, its substantially lower sensitivity in the posterior fossa and spinal cord is a potentially important limitation to its use as a tool for the diagnosis of MS and for monitoring therapies. Further studies are needed to elucidate the mechanisms underlying the loss of sensitivity.

Brain↗

N-acetylation among HIV-positive patients and patients with AIDS: when is fast, fast and slow, slow?

BACKGROUND: The discrepancy between genotype and expressed phenotype of the polymorphic N-acetyltransferase (NAT2) has been suggested by separate genotypic and phenotypic studies in populations with human immunodeficiency virus (HIV). Only one study has examined both genotype and phenotype in the same population, and no discrepancies were observed. METHODS: In a cross-sectional study, 105 HIV-positive patients and patients with acquired immunodeficiency syndrome (AIDS) were phenotyped for NAT2 activity with use of caffeine as an in vivo probe; 50 of these patients were also genotyped by restriction mapping and allele-specific amplification. In a longitudinal study, 23 patients were phenotyped at least twice during the 2-year study. RESULTS: The distribution of the NAT2 phenotype among the 105 patients was unimodal and skewed toward slow acetylators as opposed to the bimodal distribution observed in healthy white populations. The genotype distribution was 26:24 slow:fast. There were 18 discrepancies between genotype and phenotype: 12 slow acetylators with fast genotypes and six fast acetylators with slow genotypes. No drug-related effects on NAT2 activity were apparent, but the role of disease progression was evident. Among the slow acetylators whose genotype was fast, the incidence of AIDS was higher (six of 12) than that among the fast acetylators whose genotype was fast (two of 14). Among patients phenotyped more than once (mean time between samples, 10.4 months) changes in phenotype from fast to slow were associated with progression of HIV infection. CONCLUSIONS: Disease progression in HIV infection and AIDS may alter expression of the NAT2 gene. The genotype and the phenotype are not interchangeable measurements. In the HIV population, to know the genotype is useful only if the phenotype is also known and vice versa.

Acetylation↗

Double atrial and double ventricular responses during slow-fast fast-slow atrioventricular nodal reentrant tachycardia.

A case was described with fast-slow form of atrioventricular nodal reentrant tachycardia as related with simultaneous fast and slow pathway conduction both antegrade and retrograde. Fast-slow form of tachycardia was induced by premature right atrial stimulation or incremental right ventricular pacing when the last paced beat conducted to the atria via both fast and slow pathways of the atrioventricular node causing double atrial response. Fast-slow form of tachycardia was spontaneously shifted to slow-fast form when the atrial echo, possibly through the retrograde intermediate pathway, was conducted antegradely over the fast and slow pathways simultaneously, producing double ventricular response.

Adolescent↗