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J Hluchy

Publications and source records attributed to J Hluchy.

10 recordsLinked to original sources
PubMed2000

Mahaim fibers: electrophysiologic characteristics and radiofrequency ablation.

Mahaim fibers that exhibit decremental atrioventricular (AV) node-like conduction properties are unusual, comprising < 3% of accessory pathways. They are involved in antidromic AV reciprocating (Mahaim) tachycardia with a left bundle branch block morphology. There is a frequent association of Mahaim pathways with Ebstein's anomaly, additional AV accessory pathways (Kent) and dual AV nodal pathway conduction. The majority of these pathways are long right atriofascicular pathways capable of only anterograde conduction. Radiofrequency (RF) ablation of right atriofascicular pathways guided by a distinct Mahaim potential recorded at the anterolateral-to-posterolateral tricuspid annulus or in the right ventricular free wall is safe and highly effective. True nodoventricular or nodofascicular Mahaim pathways usually also capable of only anterograde conduction appear to be rare and are associated with pre-excited tachycardia of left bundle branch block morphology not distinguishable from the preexcitation pattern of right atriofascicular pathways. In these pathways, a reliable method for mapping and safe RF ablation is lacking because no Mahaim potential could be recorded from the tricuspid annulus in the right midseptal region where ablation may result in elimination of both the slow AV nodal pathway and Mahaim conduction. Fasciculoventricular Mahaim pathways have never been reported to be involved in a tachycardia circuit. At our institution, successful RF ablation of unusual Mahaim pathways (concealed nodoventricular and nodofascicular and left anterograde atriofascicular) was performed without impairing the normal AV conduction system.

Adolescent↗
PubMed2000

Decremental conduction properties in overt and concealed atrioventricular accessory pathways.

AIM: Most atrioventricular accessory pathways (AV-APs) exhibit Kent bundle physiology characterized by fast and non-decremental conduction properties. In contrast, atriofascicular APs, which are only capable of reaching slow levels of long antegrade decremental conduction, are uncommon. The aim of this study was to describe antegrade and/or retrograde AV-APs with unusual decremental properties. METHODS AND RESULTS: Five patients with unusual decremental AV-APs underwent electrophysiological evaluation and radiofrequency catheter ablation for symptomatic tachycardias. Three were found to have structural heart disease, and three latent decremental AV-APs in the anterograde and/or retrograde direction that could not be demonstrated by routine electrophysiological testing. In Case 1, a right posteroseptal AV-AP with bidirectionally latent decremental conduction was associated with clinical antidromic circus movement tachycardia (CMT) mimicking ventricular tachycardia and orthodromic CMT, the latter inducible only with isoprenaline. In Case 2, incessant orthodromic CMT was due to a latent retrograde left posterolateral AV-AP. In both cases, double atrial responses to a single paced ventricular beat, initiating orthodromic CMT, were observed. In Case 3 with latent preexcitation unmasked by adenosine and atrial pacing, retrograde latent decremental conduction over a right posteroseptal AV-AP could be shown only with isoprenaline. This patient and the remaining two with overt preexcitation demonstrated anterograde decremental AP conduction that was discontinuous over a right posteroseptal AV-AP in Cases 3 and 4 and was continuous over a midseptal AV-AP in Case 5. In the latter case, the site of decremental conduction could be localized at the proximal AP origin. All five AV-APs were successfully ablated at the annulus level. CONCLUSION: AV-APs with unusual decremental properties that are either latent, demonstrable only during CMT or overt, exhibiting functional longitudinal dissociation are described. These APs could be identified and successfully ablated after detailed electrophysiological analysis.

Adenosine↗
PubMed2000

Electrophysiologic characteristics and radiofrequency ablation of concealed nodofascicular and left anterograde atriofascicular pathways.

INTRODUCTION: True nodoventricular or nodofascicular pathways and left-sided anterograde decremental accessory pathways (APs) are considered rare findings. METHODS AND RESULTS: Two unusual patients with paroxysmal supraventricular tachycardia were referred for radiofrequency (RF) ablation. Both patients had evidence of dual AV nodal conduction. In case 1, programmed atrial and ventricular stimulation induced regular tachycardia with a narrow QRS complex or episodes of right and left bundle branch block not altering the tachycardia cycle length and long concentric ventriculoatrial (VA) conduction. Ventricular extrastimuli elicited during His-bundle refractoriness resulted in tachycardia termination. During the tachycardia, both the ventricles and the distal right bundle were not part of the reentrant circuit. These findings were consistent with a concealed nodofascicular pathway. RF ablation in the right atrial mid-septal region with the earliest atrial activation preceded by a possible AP potential resulted in tachycardia termination and elimination of VA conduction. In case 2, antidromic reciprocating tachycardia of a right bundle branch block pattern was considered to involve an anterograde left posteroseptal atriofascicular pathway. For this pathway, decremental conduction properties as typically observed for right atriofascicular pathways could be demonstrated. During atrial stimulation and tachycardia, a discrete AP potential was recorded at the atrial and ventricular insertion sites and along the AP. Mechanical conduction block of the AP was reproducibly induced at the annular level and at the distal insertion site. Successful RF ablation was performed at the mitral annulus. CONCLUSION: This report describes two unusual cases consistent with concealed nodofascicular and left anterograde atriofascicular pathways, which were ablated successfully without impairing normal AV conduction system.

Adult↗
PubMed1999

Radiofrequency ablation of a concealed nodoventricular Mahaim fiber guided by a discrete potential.

INTRODUCTION: We present the case of a 17-year-old woman who underwent an electrophysiological study and radiofrequency (RF) ablation of supraventricular tachycardia refractory to medical treatment. Two right-sided, concealed, nondecremental atrioventricular accessory pathways (AV-APs) involved in orthodromic circus movement tachycardias were identified. After RF ablation of both AV-APs, evidence of bidirectional dual AV nodal conduction was demonstrated and regular narrow complex tachycardia was induced. METHODS AND RESULTS: During the tachycardia, retrograde slow and fast AV nodal pathway conduction with second-degree ventriculoatrial (VA) block and VA dissociation were observed. During the tachycardia with second-degree VA block, ventricular extrastimuli elicited during His-bundle refractoriness advanced the next His potential or terminated the tachycardia. Mapping the right atrial mid-septal region, a distinct high-frequency activation P potential was recorded in a discrete area, two thirds of the way from the His bundle toward the os of the coronary sinus. Detailed electrophysiologic testing with the recordable P potential demonstrated that the tachycardia utilized a concealed nodoventricular AP arising from the proximal slow AV nodal pathway. CONCLUSION: The tachycardia with slow 1:1 VA conduction could be reset by ventricular extrastimuli elicited during His-bundle refractoriness advancing the subsequent activation P potential and atrial activation. RF ablation guided by recording of the activation P potential resulted in elimination of both the slow AV nodal pathway and the nodoventricular connection with preservation of the normal AV conduction system.

Adolescent↗
PubMed1997

Atrial double potentials associated with a left-sided accessory pathway having a single ventricular and two remote atrial insertions.

This paper reports the case of a 63-year-old female patient with Wolff-Parkinson-White syndrome who underwent an electrophysiologic study (EPS) and ablation using temperature-guided radiofrequency current for atrial fibrillation with a shortest preexcited RR interval of 160 ms. Detailed EPS and mapping demonstrated an unusual, complex left-sided accessory pathway, with the two distinct branches having two remote atrial insertions and a narrow common ventricular isthmus associated with the manifestation of atrial double potentials recorded from the coronary sinus. Simple ablation at the left lateral side from the ventricular aspect completely eliminated complex accessory pathway conduction, resulting in the disappearance of atrial double potentials.

Cardiac Pacing, Artificial↗
PubMed1997

Inhibition of muscarinic K+ current in guinea-pig atrial myocytes by PD 81,723, an allosteric enhancer of adenosine binding to A1 receptors.

1. PD 81,723 has been shown to enhance binding of adenosine to A1 receptors by stabilizing G protein-receptor coupling ('allosteric enhancement'). Evidence has been provided that in the perfused hearts and isolated atria PD 81,723 causes a sensitization to adenosine via this mechanism. 2. We have studied the effect of PD 81,723 in guinea-pig isolated atrial myocytes by use of whole-cell measurement of the muscarinic K+ current (I[K(ACh)]) activated by different Gi-coupled receptors (A1, M2, sphingolipid). PD 81,273 caused inhibition of I[K(ACh)] (IC50 approximately 5 microM) activated by either of the three receptors. Receptor-independent I[K(ACh)] in cells loaded with GTP-gamma-S and background I[K(ACh)], which contributes to the resting conductance of atrial myocytes, were equally sensitive to PD 81,723. At no combination of concentrations of adenosine and PD 81,723 could an enhancing effect be detected. 3. The compound was active from the outside only. Loading of the cells with PD 81,723 (50 microM) via the patch pipette did not affect either I[K(ACh)] or its sensitivity to adenosine. We suggest that PD 81,723 acts as an inhibitor of inward rectifying K+ channels; this is supported by the finding that ventricular I(K1), which shares a large degree of homology with the proteins (GIRK1/GIRK4) forming I[K(ACh)] but is not G protein-gated, was also blocked by this compound. 4. It is concluded that the functional effects of PD 81,723 described in the literature are not mediated by the A1 adenosine receptor-Gi-I[K(ACh)] pathway.

Adenosine↗
PubMed1996

Radiofrequency catheter ablation of a right atriofascicular (Mahaim) and two atrioventricular (Kent) accessory pathways in a single session.

This report describes the case of a 19-year-old patient with Ebstein's anomaly, who had an unusual combination of a right atriofascicular (Mahaim) and two ipsilateral right atrioventricular (Kent) accessory pathways participating in three types of antidromic and orthodromic reciprocating tachycardias in the absence of retrograde conduction over the bundle of His-atrioventricular node axis. All three pathways were ablated in a single session using temperature-guided radiofrequency current.

Adult↗
PubMed1993

[Is Helicobacter pylori gastritis a macroscopic diagnosis?].

In a prospective study, gastroscopy and biopsies from the gastric antrum and body were undertaken in 100 consecutive patients (67 women, 33 men; mean age 58.6 [11-90] years) with unknown Helicobacter pylori status. None had been on any bacteria-suppressing drugs. Main indications for gastroscopy were upper abdominal pain, dyspepsia, emesis and anaemia of unknown cause. The macroscopic criteria for the diagnosis of H. pylori gastritis were the presence of at least one of the following signs: (1) chronic antral erosions; (2) goose-pimple-like appearance of the antral mucosa; (3) spotty erythema in the antrum; (4) complex changes of the antral mucosa with both bizarre reddening and pale areas; and (5) increased areolar markings and diffuse or fine-spotty erythema in the mucosa of the body of the stomach. Four biopsies each from the antrum and body were examined with the urease quick-test, microscopically as smears, specific culture and histology as reference methods. 60 patients had H. pylori gastritis, recognized macroscopically in 59 (sensitivity 98.3%). A false-positive diagnosis was made in 10 of 40 H. pylori-negative patients (specificity 75%). The positive predictive value of macroscopic diagnosis was 85.5%, the negative predictive value 96.8%.

Adolescent↗
PubMed1993

Areas of slow conduction in atrial re-entrant tachycardia: a case report and review of the literature.

An electrophysiologic study of atrial tachycardia is presented. During tachycardia, transient entrainment and sinus rhythm, two patterns of persistent double potentials in the high right atrium and fragmented activity in the low atrial septum were observed. No activity was recorded from multiple areas of the right atrium with endocardial mapping during sinus rhythm. The observations suggest that persistent fragmented activity represents slow conduction within the circuit which could be orthodromically entrained. Persistent double potentials probably represent slow conduction orthodromically and/or antidromically activated outside the circuit. However, a wave front from pacing impulses travelling through this area could entrain the circuit.

Aged↗