Frequency and long term follow up of valvar insufficiency caused by retrograde aortic radiofrequency catheter ablation procedures. (1/442)

OBJECTIVE: To assess the frequency of valvar complications caused by left sided radiofrequency catheter ablation using the retrograde aortic technique. METHODS: 179 patients (118 male) with a mean (SD) age of 43 (17) years underwent 216 procedures at one centre. The target of the ablation was an accessory atrioventricular pathway in 144 patients, the atrioventricular junction in 29 patients, and a ventricular tachycardia in six patients. In 25 patients structural heart disease was identified before the procedure (ischaemic heart disease 10, cardiomyopathy nine, valvar three, other three). Echo/Doppler examinations were performed the day before the procedure and within 24 hours postablation; the investigations were all reviewed by the same investigator. Patients with identified valvar injury caused by the procedure were followed for 42 (7) months. RESULTS: Valvar injury caused by the ablation procedure was identified in four young (age 30 (8) years), otherwise healthy patients with left lateral atrioventricular accessory pathways. Mild mitral insufficiency with a central regurgitation jet was detected in two patients and remained unchanged at follow up. Mild aortic insufficiency was detected in another two patients. In one of these the regurgitation jet was central and remained unchanged at follow up. In one patient the regurgitation jet was located between the non-coronary and left cusps in relation to a loosely attached structure. Both the structure and the valvar regurgitation disappeared during follow up. No clinical complications occurred in any of the patients during follow up. CONCLUSION: In this study, the frequency of valvar complications after left sided radiofrequency catheter ablation using the retrograde aortic technique was 1.9%.  (+info)

Tachyarrhythmias triggered by swallowing and belching. (2/442)

Three cases with supraventricular tachyarrhythmias related to oesophageal transit are reported. A 61 year old man had episodes of atrial tachycardia on each swallow of food but not liquid; this has been reported only rarely. A 55 year old man had atrial fibrillation initiated by drinking ice cold beverages; this has not been described previously although atrial tachycardia triggered by drinking ice cold beverages has been described once. A 68 year old man had supraventricular tachycardia initiated by belching; this has not been described previously. These cases illustrate the diversity of atrial tachyarrhythmias that can be precipitated by oesophageal stimulation and suggest that what is regarded as a very rare phenomenon may be found more commonly when sought.  (+info)

Electrophysiologic effects of adenosine in patients with supraventricular tachycardia. (3/442)

BACKGROUND: We correlated the electrophysiologic (EP) effects of adenosine with tachycardia mechanisms in patients with supraventricular tachycardias (SVT). METHODS AND RESULTS: Adenosine was administered to 229 patients with SVTs during EP study: atrioventricular (AV) reentry (AVRT; n=59), typical atrioventricular node reentry (AVNRT; n=82), atypical AVNRT (n=13), permanent junctional reciprocating tachycardia (PJRT; n=12), atrial tachycardia (AT; n=53), and inappropriate sinus tachycardia (IST; n=10). There was no difference in incidence of tachycardia termination at the AV node in AVRT (85%) versus AVNRT (86%) after adenosine, but patients with AVRT showed increases in the ventriculoatrial (VA) intervals (13%) compared with typical AVNRT (0%), P<0.005. Changes in atrial, AV, or VA intervals after adenosine did not predict the mode of termination of long R-P tachycardias. For patients with AT, there was no correlation with location of the atrial focus and adenosine response. AV block after adenosine was only observed in AT patients (27%) or IST (30%). Patients with IST showed atrial cycle length increases after adenosine (P<0.05) with little change in activation sequence. The incidence of atrial fibrillation after adenosine was higher for those with AVRT (15%) compared with typical AVNRT (0%) P<0.001, or atypical AVNRT (0%) but similar to those with AT (11%) and PJRT (17%). CONCLUSIONS: The EP response to adenosine proved of limited value to identify the location of AT or SVT mechanisms. Features favoring AT were the presence of AV block or marked shortening of atrial cycle length before tachycardia suppression. Atrial fibrillation was more common after adenosine in patients with AVRT, PJRT, or AT. Patients with IST showed increases in cycle length with little change in atrial activation sequence after adenosine.  (+info)

Ventriculo-atrial time interval measured on M mode echocardiography: a determining element in diagnosis, treatment, and prognosis of fetal supraventricular tachycardia. (4/442)

OBJECTIVE: To determine whether M mode echocardiography can differentiate fetal supraventricular tachycardia according to the ventriculo-atrial (VA) time interval, and if the resulting division into short and long VA intervals holds any relation with clinical presentation, management, and fetal outcome. DESIGN: Retrospective case series. SUBJECTS: 23 fetuses with supraventricular tachycardia. MAIN OUTCOME MEASURES: A systematic review of the M mode echocardiograms (for VA and atrioventricular (AV) interval measurements), clinical profile, and final outcome. RESULTS: 19 fetuses (82.6%) had supraventricular tachycardia of the short VA type (mean (SD) VA/AV ratio 0.34 (0.16); heart rate 231 (29) beats/min). Tachycardia was sustained in six and intermittent in 13. Hydrops was present in three (15.7%). Digoxin, the first drug given in 14, failed to control tachycardia in five. Three of these then received sotalol and converted to sinus rhythm. All fetuses of this group survived. Postnatally, supraventricular tachycardia recurred in three, two having Wolff-Parkinson-White syndrome. Four fetuses (17.4%) had long VA tachycardia (VA/AV ratio 3.89 (0.82); heart rate 226 (10) beats/min). Initial treatment with digoxin was ineffective in all, but sotalol was effective in two. Heart failure caused fetal death in one and premature delivery in one. All three surviving fetuses had recurrences of supraventricular tachycardia after birth: two had the permanent form of junctional reciprocating tachycardia and one had atrial ectopic tachycardia. CONCLUSIONS: Careful measurement of ventriculo-atrial intervals on fetal M mode echocardiography can be used to distinguish short from long VA supraventricular tachycardia and may be helpful in optimising management. Digoxin, when indicated, may remain the drug of choice in the short VA type but appears ineffective in the long VA type.  (+info)

Recovery pattern of left ventricular dysfunction following radiofrequency ablation of incessant supraventricular tachycardia in infants and children. (5/442)

OBJECTIVE: To assess recovery pattern of left ventricular function secondary to incessant tachycardia after radiofrequency ablation in a group of infants and children. DESIGN AND SETTING: A combined prospective and retrospective echocardiographic study carried out in a tertiary paediatric cardiac centre. PATIENTS: Echocardiographic evaluation of left ventricular size and function in nine children with incessant tachycardia, before and after successful radiofrequency ablation. Age at ablation ranged from 2 months to 12.5 years (mean 4.1 years). Recovery of left ventricular function was analysed in relation to age at ablation (group I < 18 months, group II > 18 months). MAIN OUTCOME MEASURE: Ventricular recovery pattern. RESULTS: Seven of the nine children had left ventricular dysfunction; six of these also had left ventricular dilatation. All children with left ventricular dysfunction had normalisation of ejection fraction and fractional shortening; left ventricular dilatation also improved, but the improvement occurred after recovery of function. There was a shorter recovery time for left ventricular function in younger (group I) than in older children (group II) (mean (SD) 5.7 (7.2) months v 31.3 (5.2) (p < 0.002). CONCLUSIONS: Tachycardia induced cardiomyopathy is reversible following curative treatment with radiofrequency. Recovery of left ventricular systolic function precedes recovery of left ventricular dilatation. Time course to recovery is shorter in younger children.  (+info)

Conduction disturbances and increased atrial vulnerability in Connexin40-deficient mice analyzed by transesophageal stimulation. (6/442)

BACKGROUND: Recently, it has been reported that connexin40 (Cx40) deficiency in targeted mouse mutants is associated with a prolongation of P-wave and QRS complex duration on surface electrograms. The specific effects of Cx40 deficiency on sinus node function, sinoatrial, and atrioventricular conduction properties as well as on atrial vulnerability have not yet been investigated systematically by electrophysiological analysis. METHODS AND RESULTS: Fifty-two mice (18 Cx40(+/+), 15 Cx40(+/-), and 19 Cx40(-/-) mice) were subjected to rapid atrial transesophageal stimulation after anesthesia with avertin. A significant prolongation of sinus node recovery time was noticed in Cx40(-/-) mice compared with Cx40(+/-) and Cx40(+/+) mice (287.8+/-109.0 vs 211.1+/-61.8 vs 204.4+/-60.9 ms; P<0.05). In addition, Wenckebach periodicity occurred at significantly longer atrial pacing cycle lengths in Cx40(-/-) mice than in Cx40(+/-) or Cx40(+/+) mice (93. 3+/-11.8 vs 83.9+/-9.7 vs 82.8+/-8.0 ms, P<0.05). Analysis of 27 Cx40(-/-) mice showed a significant increase in intra-atrial conduction time and atrioventricular conduction time compared with 52 Cx40(+/-) and 31 wild-type (Cx40(+/+)) mice. Furthermore, in Cx40(-/-) mice, atrial tachyarrhythmias could be induced frequently by atrial burst pacing, whereas no atrial arrhythmias were inducible in heterozygous or wild-type mice. CONCLUSIONS: This study demonstrates that Cx40 deficiency is associated with sinoatrial, intra-atrial, and atrioventricular conduction disturbances. In atrial myocardium of the mouse, Cx40 deficiency results in increased atrial vulnerability and might contribute to arrhythmogenesis.  (+info)

Neurological morbidity after fetal supraventricular tachyarrhythmia. (7/442)

BACKGROUND: Fetal tachyarrhythmia is a well-documented entity which, in the absence of pharmacological intervention, may lead to congestive heart failure, fetal hydrops and eventually fetal demise. The success rate of the implemented treatment is generally measured by survival and achievement of control of the arrhythmia. We report on the occurrence of associated cerebral damage in three patients with fetal tachycardia. METHODS: We describe three patients with a history of fetal supraventricular tachyarrhythmia who developed cerebral complications in utero. RESULTS: Two patients had cerebral hypoxic-ischemic lesions and one had hemorrhagic lesions present at birth. They had developed severe congestive heart failure and fetal hydrops secondary to fetal tachyarrhythmia, and there were no other obvious causes for the cerebral pathology. Two of these patients were referred to us antenatally. Therapy was instituted and resulted in control of the tachycardia and resolution of hydrops. The third patient was referred to our clinic shortly after birth because of severe circulatory problems secondary to fetal tachyarrhythmia. CONCLUSION: From these observations, we believe that a fetus with tachyarrhythmia and subsequent hydrops is at increased risk for the development of cerebral complications, due to the circulatory disturbances and sudden changes in heart rate which may lead to fluctuations in cerebral perfusion. This would imply that it is of the utmost importance to aim at immediate and complete control of the heart rate in the treatment of fetal tachyarrhythmia.  (+info)

Clinical experience with a novel multielectrode basket catheter in right atrial tachycardias. (8/442)

BACKGROUND: The complexity of atrial tachycardias (ATs) makes the electroanatomic characterization of the arrhythmogenic substrate difficult with conventional mapping techniques. The aim of our study was to evaluate possible advantages of a novel multielectrode basket catheter (MBC) in patients with AT. METHODS AND RESULTS: In 31 patients with AT, an MBC composed of 64 electrodes was deployed in the right atrium (RA). The possibility of deployment, spatial relations between MBC and RA, MBC recording and pacing capabilities, mapping performance, and MBC-guided ablation were assessed. MBC deployment was possible in all 31 patients. The MBC was left in the RA for 175+/-44 minutes. Stable bipolar electrograms were recorded in 88+/-4% of electrodes. Pacing from bipoles was possible in 64+/-5% of electrode pairs. The earliest activity intervals, in relation to P-wave onset, measured from the MBC and standard roving catheters were 41+/-9 and 46+/-6 ms, respectively (P=0.21). Radiofrequency ablation was successful in 15 (94%) of 16 patients in whom it was attempted, including 2 patients with polymorphic right atrial tachycardia (RAT), 2 with RAT-atrial flutter combination, 1 with macroreentrant AT, and 1 with focal origin of atrial fibrillation. CONCLUSIONS: These data demonstrate that MBC can be used safely in patients with right atrial arrhythmias. The simultaneous multielectrode mapping aids in the rapid identification of sites of origin of the AT and facilitates radiofrequency ablation procedures. The technique is especially effective for complex atrial arrhythmias.  (+info)