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2.
Europace ; 4(1): 91-7, 2002 Jan.
Article in English | MEDLINE | ID: mdl-11846322

ABSTRACT

We describe a case of post-incisional atrial tachycardia resembling typical atrial flutter on the surface ECG. Typical atrial flutter reentry was ruled out by the results of activation and entrainment mapping. Nevertheless, overdrive pacing from the lateral edge of the cavo-tricuspid isthmus produced tachycardia entrainment with concealed fusion associated with post-pacing and stimulus-to-P wave onset intervals exactly matching the tachycardia cycle length duration and the electrogram-to-P wave onset interval, respectively. Therefore, that site was firstly severed by sequential radiofrequency pulses. However, a transformation of the tachycardia P wave morphology and endocardial activation sequence, not associated with tachycardia termination or cycle length modification occurred. After additional mapping manoeuvres, a relatively small reentrant circuit was identified in the low and mid aspect of the lateral right atrium with the critical isthmus located between the lower border of a cannulation atriotomy and the crista terminalis, close to the inferior vena cava orifice. A single radiofrequency pulse at that site terminated the tachycardia. Both the electrocardiographic pattern and the endocardial mapping data obtained in our case might be explained by a split of the reentrant wavefront into a secondary wavelet which freely propagated through the cavo-tricuspid isthmus without completing the peritricuspid loop. In conclusion, bystander cavo-tricuspid isthmus activation during atrial tachycardia may simulate a typical atrial flutter pattern on the surface ECG. Further studies should evaluate the prevalence of this propagation pattern in post-incisional atrial reentry and atypical atrial flutters, and identify its implications for ablation strategy.


Subject(s)
Atrial Flutter/physiopathology , Bystander Effect/physiology , Catheter Ablation/adverse effects , Postoperative Complications , Tachycardia, Ectopic Atrial/etiology , Tachycardia, Ectopic Atrial/physiopathology , Atrial Flutter/diagnosis , Diagnosis, Differential , Electrocardiography , Humans , Male , Middle Aged , Tachycardia, Ectopic Atrial/diagnosis
3.
J Cardiovasc Electrophysiol ; 12(10): 1187-9, 2001 Oct.
Article in English | MEDLINE | ID: mdl-11699530

ABSTRACT

A case of iterative atrial tachycardia leading to dilated cardiomyopathy is reported. During electrophysiologic study, the tachycardia showed a markedly irregular cycle length associated with changes in atrial activation breakthrough as demonstrated by coronary sinus (CS) recordings and frequently degenerated into self-terminating atrial fibrillation. Left atrial transseptal mapping demonstrated the earliest endocardial atrial activation close to the posterolateral mitral annulus, but this was invariably later than that recorded within the CS, where low-energy radiofrequency applications eliminated the tachycardia. No acute vessel damage was observed at postablation CS angiography. In accordance with previously published experimental data, we hypothesized that the muscular sleeves surrounding the CS might be involved in the genesis of this tachycardia. During 6-month follow-up, the patient remained asymptomatic without tachycardia recurrences and with complete recovery of left ventricular function, confirming the reversible nature of the tachycardia-induced cardiomyopathy.


Subject(s)
Coronary Vessels/pathology , Coronary Vessels/surgery , Tachycardia, Ectopic Atrial/complications , Adult , Cardiomyopathy, Dilated/etiology , Cardiomyopathy, Dilated/surgery , Catheter Ablation , Electrophysiologic Techniques, Cardiac , Heart Atria/pathology , Heart Atria/surgery , Humans , Male , Muscle, Smooth, Vascular/pathology , Tachycardia, Ectopic Atrial/surgery , Ventricular Dysfunction, Left/etiology , Ventricular Dysfunction, Left/surgery
6.
Ital Heart J ; 2(2): 142-6, 2001 Feb.
Article in English | MEDLINE | ID: mdl-11256543

ABSTRACT

Selective radiofrequency catheter ablation of the slow atrioventricular nodal pathway is currently considered the first-line therapy for patients suffering from recurrent symptomatic atrioventricular nodal reentry tachycardia. In most cases slow pathway conduction may be selectively eliminated or modified by the application of radiofrequency current at the posterior portion of Koch's triangle. The ablation site is usually targeted by careful mapping of this area performed using an ablation catheter advanced via the inferior vena cava approach. In this report we describe 2 cases in which the conventional approach to the target site was either impossible owing to the presence of an atresic inferior vena cava (case 1), or contraindicated in view of a history of common femoral vein thrombosis, subsequently extended up to the inferior vena cava (case 2). In both patients a superior vena cava approach was utilized and the slow pathway was successfully ablated. In case of arrhythmias necessitating slow pathway mapping and ablation, such an approach may be considered as a feasible and safe alternative whenever, owing to the presence of anomalies and/or diseases of the inferior vena cava, the conventional approach cannot be employed.


Subject(s)
Catheter Ablation/methods , Tachycardia, Atrioventricular Nodal Reentry/surgery , Adult , Aged , Electrocardiography , Female , Heart Conduction System , Humans , Vena Cava, Superior
8.
G Ital Cardiol ; 29(9): 1030-3, 1999 Sep.
Article in English | MEDLINE | ID: mdl-10514962

ABSTRACT

The incidence of dual atrioventricular nodal physiology in patients with Wolff-Parkinson-White syndrome is quite frequent, but arrhythmia related to an accessory pathway and atrioventricular nodal reentrant tachycardia (AVNRT) in a single patient is less common. Two of our cases (patients aged 24 and 19 yrs) presented the rare evidence of both typical and atypical AVNRTs, associated in the first case with two other atrioventricular reentrant tachycardias (AVRTs), and in the second case with a single AVRT. Both underwent radiofrequency catheter ablation of the slow nodal pathway and of the accessory pathways in a single session, without any complications. After a 3-month follow-up, they were free from symptoms suggestive of tachycardia, without any antiarrhythmic treatment.


Subject(s)
Catheter Ablation , Tachycardia, Atrioventricular Nodal Reentry/surgery , Adult , Catheter Ablation/methods , Electrocardiography , Female , Follow-Up Studies , Humans , Male , Tachycardia, Atrioventricular Nodal Reentry/diagnosis , Tachycardia, Atrioventricular Nodal Reentry/physiopathology , Time Factors
10.
Eur Heart J ; 19(6): 943-50, 1998 Jun.
Article in English | MEDLINE | ID: mdl-9651720

ABSTRACT

AIM: This study reports on the results and safety of a simplified method of trans-septal catheterization for radiofrequency catheter ablation of cardiac arrhythmias. METHODS AND RESULTS: Over 5 years, 411 patients underwent trans-septal catheterization for radiofrequency catheter ablation: 388 patients had a left-sided accessory pathway, 19 a left-sided focal atrial tachycardia, two atrial fibrillation and two post-infarction ventricular tachycardia. All but one patient with ventricular tachycardia underwent elective trans-septal catheterization. In the absence of a patent foramen ovale, puncture of the atrial septum was performed by using an 8F Mullins sheath and a Brockenbrough needle, according to the simplified method described in this paper. Trans-septal catheterization was accomplished in 383/388 patients (98.7%); in 41 patients a second trans-septal catheterization and radiofrequency catheter ablation was performed for initial failure or recurrence. Radiofrequency catheter ablation was successful in 96% of accessory pathway patients, 90% of atrial tachycardia patients, in both patients with atrial fibrillation and in both patients with ventricular tachycardia. No complication related to trans-septal catheterization was observed. CONCLUSION: In experienced hands and according to the method described in this paper, the elective use of transseptal catheterization for radiofrequency catheter ablation in a large cohort of patients with cardiac arrhythmias is feasible, safe and allows successful ablation in the vast majority of the patients.


Subject(s)
Atrial Fibrillation/surgery , Cardiac Catheterization/instrumentation , Catheter Ablation/instrumentation , Heart Septum/surgery , Tachycardia, Ectopic Atrial/surgery , Tachycardia, Ventricular/surgery , Adolescent , Adult , Aged , Atrial Fibrillation/physiopathology , Child , Child, Preschool , Feasibility Studies , Female , Heart Conduction System/physiopathology , Heart Conduction System/surgery , Heart Septum/physiopathology , Humans , Infant , Infant, Newborn , Male , Middle Aged , Recurrence , Reoperation , Tachycardia, Ectopic Atrial/physiopathology , Tachycardia, Ventricular/physiopathology , Treatment Failure
12.
Int J Cardiol ; 56(3): 263-7, 1996 Oct 25.
Article in English | MEDLINE | ID: mdl-8910071

ABSTRACT

A safe approach to radiofrequency catheter ablation is still unclear and not well defined in patients with AV nodal reentrant tachycardia and prolonged PR interval. In our study, a patient with iterative AV nodal reentrant tachycardia and prolonged PR interval underwent fast pathway radiofrequency catheter ablation. By mapping Koch's triangle, the earliest retrograde atrial activation area was localized. Radiofrequency energy was delivered here with the interruption of tachycardia with no complications.


Subject(s)
Catheter Ablation/methods , Tachycardia, Atrioventricular Nodal Reentry/surgery , Aged , Body Surface Potential Mapping , Female , Heart Block/prevention & control , Humans
13.
Cardiologia ; 41(4): 369-74, 1996 Apr.
Article in Italian | MEDLINE | ID: mdl-8674106

ABSTRACT

Two patients with branch to branch ventricular tachycardia (BBVT) are reported: successful radiofrequency catheter ablation of BBVT was performed in both, delivering energy distally to the point where the maximum amplitude of His deflection occurred, so that a wide ventricular deflection was obtained without any atrial electrogram. No significant conduction delay appeared but a right bundle branch block. HV intervals during BBVT resulted equal or longer than in sinus rhythm: whether this was secondary to anatomical or functional variations or to the possibility that the His bundle may be "bystander" in BBVT, is discussed.


Subject(s)
Cardiomyopathy, Dilated , Catheter Ablation , Tachycardia, Atrioventricular Nodal Reentry/surgery , Adult , Cardiomyopathy, Dilated/complications , Cardiomyopathy, Dilated/diagnostic imaging , Cardiomyopathy, Dilated/surgery , Echocardiography , Electrocardiography , Female , Humans , Hypertension/complications , Male , Middle Aged , Tachycardia, Atrioventricular Nodal Reentry/diagnostic imaging
14.
J Interv Cardiol ; 8(6 Suppl): 793-805, 1995 Dec.
Article in English | MEDLINE | ID: mdl-10159771

ABSTRACT

The first experiences of nonpharmacological treatment of ectopic atrial tachycardia (EAT), common atrial flutter (AFl), and atrial fibrillation (AF) were performed by surgical techniques. Many studies reported a very high success rate on the use of catheter ablation with radiofrequency current for the treatment of supraventricular arrhythmias; and recently, various preliminary reports are dedicated to the treatment of EAT, AFl, and AF with that source of energy. To our knowledge 108 cases of EAT treated by catheter ablation of the ectopic focus are reported in the literature with a success rate superior to 90%. On the basis of our personal experience regarding 11 cases (4 of right atrium EAT and 7 of left) we discuss here the essential role of unipolar leads derived from the mapping catheter to select the target for radiofrequency applications. Two hundred and one cases of AFl tested by catheter ablation were previously reported. The majority of them (> 80%) were successfully treated with radiofrequency. Some working groups performed the procedure as the basis of electrophysiological findings, while others preferred an anatomical approach applying radiofrequency energy at the isthmus lying between the coronary sinus ostium and the tricuspid ring, near the vena cava orifice. On the basis of these assumptions, we obtained 83% of final success in 12 cases of AFl treated by radiofrequency. Finally, we discuss the problem related to the modulation of atrioventricular (AV) nodal conduction during AF. In our laboratory, five cases with chronic AF and very fast ventricular response were treated with radiofrequency with a posterior septal approach. In all patients, we obtained very encouraging results with a constant decrease of ventricular rate (from 137 +/- 33 to 69 +/- 14 beats per minute). All cases treated by modulation of AV nodal conduction demonstrated an appropriate chronotropic response to the variations of the functional state that persists during the follow-up. More experience with longer follow-up and accurate pre- and postprocedure evaluations are needed to finalize the most appropriate technique of radiofrequency applications in these cases.


Subject(s)
Atrial Fibrillation/surgery , Atrial Flutter/surgery , Catheter Ablation , Tachycardia, Ectopic Atrial/surgery , Adult , Atrial Fibrillation/physiopathology , Atrial Flutter/physiopathology , Electrocardiography , Female , Humans , Male , Middle Aged , Tachycardia, Ectopic Atrial/physiopathology
16.
J Cardiovasc Electrophysiol ; 5(9): 777-81, 1994 Sep.
Article in English | MEDLINE | ID: mdl-7827717

ABSTRACT

Three patients in whom permanent AV reentrant tachycardia became the clinical manifestation of Wolff-Parkinson-White syndrome are described. The substrate for the arrhythmia was created by coexistence of a concealed left-sided accessory pathway and an ipsilateral bundle branch block. Pharmacologic therapy in all three patients failed to control the tachycardia, which in two cases led to severe left ventricular failure. After successful radiofrequency ablation of the accessory pathway (in two) or AV junction (in one), left ventricular function gradually returned to normal.


Subject(s)
Bundle-Branch Block/physiopathology , Tachycardia, Atrioventricular Nodal Reentry/physiopathology , Bundle-Branch Block/complications , Catheter Ablation , Electrocardiography , Female , Humans , Male , Middle Aged , Tachycardia, Atrioventricular Nodal Reentry/etiology , Tachycardia, Atrioventricular Nodal Reentry/surgery , Wolff-Parkinson-White Syndrome/complications
17.
G Ital Cardiol ; 24(6): 707-21, 1994 Jun.
Article in Italian | MEDLINE | ID: mdl-8088470

ABSTRACT

BACKGROUND: Among patients (pts) with atrioventricular accessory pathway (AP), some cases show wide complex arrhythmias with different QRS morphology. In a subset of these pts, an atrioventricular reentrant tachycardia with left bundle branch block morphology (LBBBM-AVRT) is observed. The aim of this study is: 1) to identify the substrate and the reentrant mechanism underlying the LBBBM-AVRT in pts undergoing radiofrequency catheter ablation (RFCA) of AP; 2) to report the results achieved by RFCA of the identified substrate. METHODS: From May 1991 to April 1993, among the 168 pts who underwent RFCA for arrhythmias related to an AP, 12 (7.1%) (8M, 4F, mean age 35 +/- 21 yrs, range 8-65) showed LBBBM-AVRT, alone or associated with other arrhythmias. Pts, in whom LBBBM was rate-related during orthodromic AVRT, were excluded from this study. During sinus rhythm, QRS complex was normal in 1 pt, while ventricular preexcitation due to a right-sided Kent bundle (KB) was present in 4 pts; among the other pts without preexcitation, 3 showed left bundle branch block (LBBB) and 4 right bundle branch block. In 2 pts, an Ebstein disease was present, while dilated cardiomyopathy was observed in another. The LBBBM-AVRT was iterative in 3 pts and in 6 pts it was the only arrhythmia observed; the mean tachycardia cycle length was 341 +/- 49 msec (range 250-428). In 1 pt, the LBBBM-AVRT was induced only after successful RFCA of a right-sided AP, responsible for orthodromic AVRT. All pts underwent diagnostic electrophysiologic study and RFCA during the same session. RESULTS: In 6/12 pts one or more KBs were observed, while in the remaining 6 an atrioventricular or atriofascicular "Mahaim like" bundle (MB) was present; the patient population was divided into 4 groups on the basis of the substrate and the reentrant mechanism responsible for LBBBM-AVRT. In Group 1, 3 pts were included: the LBBBM-AVRT was an orthodromic AVRT involving the nodal conduction antegradely (showing LBBB also during sinus rhythm) and a left-sided unidirectional KB, retrogradely. In all the 3 pts, the LBBBM-AVRT was iterative and not controlled by antiarrhythmic agents and RFCA of the KB abolished the arrhythmia. Two further pts were included in Group 2: in these pts with multiple bilateral KBs, the LBBBM-AVRT involved a right-sided KB antegradely and a left-sided one, retrogradely. In these 2 pts both KBs were successfully ablated. In 1 pt, considered in Group 3, the LBBBM-AVRT was sustained by an antidromic circuit involving a right-sided KB antegradely and the nodal conduction retrogradely; in this pt the KB was completely interrupted after two RFCA procedures. The remaining 6 pts with MB were included in Group 4: at least one associated electrophysiologic abnormality was present in all (dual A-V nodal pathway in 4/6 and a right-sided KB in 4/6); Ebstein disease was also observed in 2 of them. In 4/6 pts the LBBBM-AVRT was an antidromic tachycardia involving the nodal conduction retrogradely and the MB antegradely; in 3/4 pts the MB was ablated (along with a nodal reentrant tachycardia in 1 pt), while in the remaining pt in whom the non-sustained LBBBM-AVRT, inducible only after RFCA of a right-sided KB, had not been clinically observed, no further ablation was mandatory. In the remaining 2 pts in Group 4, the LBBBM-AVRT was due to the involvement of MB in other arrhythmias such as an AVRT due to a right-sided KB and a "slow-slow" nodal reentrant tachycardia, respectively; the LBBBM-AVRT were abolished by RFCA of these two underlying arrhythmias. All pts are asymptomatic during a 7.9 +/- 6.9 months follow-up. CONCLUSIONS: The LBBBM-AVRT is observed in a minority (7.1%) of the cases referred for RFCA of AP. (ABSTRACT TRUNCATED)


Subject(s)
Bundle-Branch Block/surgery , Catheter Ablation , Tachycardia, Atrioventricular Nodal Reentry/surgery , Adolescent , Adult , Aged , Bundle-Branch Block/physiopathology , Child , Electrocardiography , Electrophysiology , Female , Humans , Male , Middle Aged , Tachycardia, Atrioventricular Nodal Reentry/physiopathology , Wolff-Parkinson-White Syndrome/physiopathology , Wolff-Parkinson-White Syndrome/surgery
18.
Cardiologia ; 39(3): 169-80, 1994 Mar.
Article in Italian | MEDLINE | ID: mdl-8039195

ABSTRACT

In some cases undergoing radiofrequency catheter ablation (RFCA) of accessory pathway (AP), a Mahaim-like right-sided atrioventricular AP (M-AP) showing slow and decremental conduction is observed. Among 200 consecutive patients referred to our Institution up to September 1993 for arrhythmias related to an AP and undergoing RFCA, 8 patients (6 males, 2 females; mean age 24 +/- 8 years, range 8-35) showed a M-AP. Seven out of 8 patients have been complaining episodes of palpitation for 13 +/- 7 years (range 1-20), while 1 subject was an asymptomatic young athlete. In 2/8 patients an Ebstein disease (Eb) was present and they had previously undergone right-sided Kent bundle (Kb) ablation elsewhere. During sinus rhythm, QRS was normal in 1 patient, while it showed ventricular preexcitation due to right-sided Kb in 3 patients and right bundle branch block in another 4 patients. A left bundle branch block morphology (LBBBM) reentrant tachycardia (RT) was observed in 7 patients (in 1, only after RFCA of a right-sided Kb); 3 showed also orthodromic RT. In the asymptomatic young athlete, a preexcitation atrial fibrillation with very rapid ventricular response was inducible. All patients underwent diagnostic electrophysiologic (EP) study and RFCA in the same session. In 2/8 patients M-AP was manifest only after right-sided Kb RFCA. In all patients, associated EP abnormalities were noted: in 5/8 patients a dual A-V node pathway was present and in 5/8 patients 6 right-sided Kbs were associated. Patients have been divided in 3 groups, according to the mechanism involving the M-AP in the RT. In the 2 Group I patients showing also Eb, antidromic LBBBM RT and orthodromic RT involving the M-AP anterogradely and retrogradely, respectively, were observed; both arrhythmias were abolished by ablating the M-AP. The 3 Group II patients showed only antidromic LBBBM RT, involving a fast A-V node pathway retrogradely; also in these patients, the M-AP was the target of RFCA. This was performed only in 1 patient, in whom A-V node RT was also observed and ablated after RFCA of M-AP; as to the other 2 patients, in 1 the ablation of M-AP was not considered mandatory, since it was responsible for inducible not sustained LBBBM RT observed only after RFCA of a Kb in the same EP session, while in the other it was not possible because of a prolonged traumatic conduction block through the M-AP.(ABSTRACT TRUNCATED AT 400 WORDS)


Subject(s)
Arrhythmias, Cardiac/surgery , Catheter Ablation , Pre-Excitation, Mahaim-Type/surgery , Adolescent , Adult , Arrhythmias, Cardiac/physiopathology , Bundle-Branch Block/physiopathology , Bundle-Branch Block/surgery , Child , Ebstein Anomaly/complications , Ebstein Anomaly/physiopathology , Electrocardiography , Electrophysiology , Female , Heart Conduction System/physiopathology , Humans , Male , Pre-Excitation, Mahaim-Type/physiopathology , Tachycardia, Atrioventricular Nodal Reentry/physiopathology , Tachycardia, Atrioventricular Nodal Reentry/surgery
19.
Cardiologia ; 38(12 Suppl 1): 199-206, 1993 Dec.
Article in Italian | MEDLINE | ID: mdl-8020018

ABSTRACT

The first experiences on non-pharmacological treatment of ectopic atrial tachycardia (EAT) and common atrial flutter (AFl) were performed by surgical techniques. The surgical abolition of EAT comprised the isolation, the excision or the cryoablation of the ectopic atrial foci using electromapping guide. The AFl was treated by extensive cryoablation of the slow conduction area responsible for the macroreentrant process located in the infero-posterior part of the right atrium (RA). Transcatheter ablation with DC-shock for the treatment of EAT was proposed in 1985 but the technique did not gain wide acceptance due to its risks. The same method was utilized for the treatment of AFl since 1987. Many preliminary studies reported on the use of transcatheter ablation with radiofrequency (RF) current as an energy source since 1992 and no major complications were encountered. According with our knowledge, 81 cases of permanent or iterative EAT were treated by RF in the world with a primary success rate superior than 90%. The low rates of recurrence are reported very early (within 24-48 hours) after the procedure; recurrencies are very easy to recognise and they are successfully ablated in a second session. Cases of EAT due to an ectopic focus localized in the RA are ablated from the superior or inferior vena cava approaches and cases of EAT related to a left atrial (LA) ectopic focus by a trans-septal approach (persistent foramen ovale or atrial septum puncture). On the basis of our personal experience regarding 7 cases (4 LA and 3 RA foci) the role of unipolar leads derived from the mapping catheter appears essential to select the target for RF applications.(ABSTRACT TRUNCATED AT 250 WORDS)


Subject(s)
Atrial Flutter/surgery , Catheter Ablation , Tachycardia, Ectopic Atrial/surgery , Adult , Atrial Flutter/physiopathology , Electrophysiology , Female , Humans , Male , Middle Aged , Tachycardia, Ectopic Atrial/physiopathology
20.
G Ital Cardiol ; 23(9): 905-10, 1993 Sep.
Article in Italian | MEDLINE | ID: mdl-8119519

ABSTRACT

Two patients underwent surgical treatment of ventricular tachycardia after repair of tetralogy of Fallot. Both patients had right bundle branch block, moderate pulmonary valve incompetence and right ventricular dilatation, and were refractory to electrophysiologically guided drug therapy. Both patients underwent intraoperative epicardial mapping, which located the arrhythmogenic focus on the right ventricular outflow tract, on the border of the previous ventriculotomy. In one patient removal of the previous scar and endocardial cryoablation was successful in ablating the arrhythmia. In the other, the same procedure was only temporarily effective. VT recurred and was subsequently identified at the superior border of the closed ventricular septal defect. It was ablated by means of transcatheter radiofrequency. While VT from foci located on the right ventricular free wall can be easily detected and ablated, septal origin of VT requires extensive preoperative and intraoperative electrophysiological evaluation and may necessitate combined surgical and transcatheter procedures.


Subject(s)
Postoperative Complications/etiology , Tachycardia, Ventricular/etiology , Tetralogy of Fallot/complications , Adolescent , Adult , Cardiac Pacing, Artificial , Cryosurgery , Female , Humans , Intraoperative Care , Postoperative Complications/diagnosis , Postoperative Complications/surgery , Tachycardia, Ventricular/diagnosis , Tachycardia, Ventricular/surgery , Tetralogy of Fallot/surgery
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