Experiences in the use of direct current countershock in the treatment of cardiac arrhythmias.
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An 84-year-old woman was admitted to our hospital because of left heart failure of acute onset. Transthoracic echocardiography showed diffuse hypertrophy of the normal sized hyperkinetic left ventricle and chordae-like fluttering echoes attached to the mitral valve with severe mitral regurgitation signals. Mosaic flow signals were seen at the left ventricular outflow tract, but the velocity could not be measured. Emergent transesophageal echocardiography detected no obvious mitral valve prolapse. Cardiac catheterization showed greater than 100 mmHg pressure gradient between the left ventricle and femoral artery. Pressures in the femoral artery and pulmonary capillary wedge changed reciprocally in the intensive care unit; a bisferient narrow pulse pressure of the femoral artery was associated with increased v wave of the pulmonary capillary wedge pressure, and a wide pulse pressure of the femoral artery with absent v wave of the pulmonary capillary wedge pressure. Pressure monitoring in the intensive care unit, catheterization laboratory and transesophageal echocardiography were useful to understand the pathophysiology of the patient.
OBJECTIVE: In children with congenital heart diseases who have undergone surgical interventions, postoperative arrhythmias frequently complicate the clinical course. "Incisional" atrial tachycardia or flutter is one of the most common forms of postoperative arrhythmias in these patients and can lead to significant morbidity and even mortality. The aim of this study was to investigate how to use antiarrhythmic drugs and the CARTO system to treat these cases. METHODS: There were 12 patients with "incisional" atrial tachycardia or flutter complicating surgery for congenital heart diseases in this study (3 patients with correction of tetrology of Fallot, 3 with atrial septal defect repair, 2 with ventricular septal defect repair, 1 with switch, 1 with repair of Ebstein's anomaly, 1 with total anomalous pulmonary venous drainage, and 1 with atrial septal closure with the Amplatzer septal occlusion). Patients whose body weight was less than 10 kg or those who did not wish to accept ablation were treated with antiarrhythmic drugs, including digitoxin, propranolol, metoprolol and cordarone. CARTO system was used to map 6 patients whose body weight was more than 10 kg and who agreed with accepting ablation for atrial tachycardia and flutter. Radio-frequency ablation was performed in these 6 cases including two cases of "incisional" atrial tachycardia and 4 of atrial flutter. RESULTS: (1) The antiarrhythmic drug was successful in 6 patients with "incisional" atrial tachycardia. (2) Six patients including 2 children with "incisional" atrial tachycardia and 4 children with atrial flutter were successfully ablated. But one case of "incisional" atrial tachycardia relapsed after 3 months of ablation. This case, however, was successfully ablated again later. No further relapse was observed during the 2 - 24 months of follow-up. CONCLUSION: Ablation of "incisional" atrial tachycardia and flutter is the first choice to treat the patients whose body weight is more than 10 kg and those who agree with accepting ablation by CARTO system. Drug therapy of "incisional" atrial tachycardia and flutter is palliative and it is the only selection to treat the patients whose body weight is less than 10 kg or those who do not wish to accept ablation procedure.
The incidence of sustained atrial, pacemaker-mediated and ventricular rhythm disturbances was studied retrospectively in a consecutive series of 112 patients without a history of preexisting atrial tachyarrhythmias, receiving an atrial or dual-chamber pacemaker. Early atrial fibrillation (during the first week) was recorded twice. Late atrial fibrillation was seen in seven patients, flutter in one, yielding a total incidence of 8.9% for 22 months. There were no significant differences with respect to age, aetiology, electrocardiographic diagnosis, pacing history, or the measured intracardiac P wave between the group with and the group without atrial fibrillation. Treatment with digoxin reverted three patients to sinus rhythm, association of digoxin and amiodarone, six patients. One patient with congestive heart failure remained in atrial fibrillation. Pacemaker-mediated tachycardia was not a major problem. One patient of a subgroup with known ventricular arrhythmia had a non-sustained ventricular tachycardia during programming at follow-up; sustained ventricular tachycardia was not recorded. Reprogramming to VDD, DVI or VVI was done in 6/100 patients. The incidence of atrial fibrillation or flutter in highly selected patients with dual-chamber or atrial pacing is moderately low. It is not possible to identify patients with a high risk for development of atrial fibrillation; when it occurs, it is easily controlled with drugs. DDD pacing seems to be safe in patients with a history of serious ventricular arrhythmias, treated with appropriate drugs.
INTRODUCTION: A major drawback of therapy with an implantable defibrillator is the nonspecificity of detection. Theoretically, adding atrial sensing information to a decision algorithm could improve specificity of detection. METHODS AND RESULTS: This open-label nonrandomized study compares the detection algorithm of the Ventak AV and the Ventak Mini implantable defibrillators. The Ventak AV (n = 39) uses dual chamber detection as opposed to single chamber detection (with rate stability) in the Ventak Mini (n = 55). Programmed zone configurations, rate thresholds, and stability criteria were identical in all patients. In the Ventak AV group, 235 ventricular tachyarrhythmias were adequately detected and treated by the device. In the Mini group, 699 episodes of ventricular fibrillation/tachycardia occurred. All but six of the latter episodes were correctly identified and treated: one patient with incessant ventricular tachycardia had five episodes not terminated by the device, another episode occurred in a patient with a device/lead defect. In the Ventak AV group, 33 episodes of sinus tachycardia and 166 episodes of atrial fibrillation/flutter activated the device; inappropriate therapy was applied to 41% of atrial fibrillation/flutter episodes. In the Ventak Mini group, 226 supraventricular tachyarrhythmias activated the device, eight of which were sinus tachycardia and 218 were atrial fibrillation or flutter; of the atrial fibrillation/ flutter episodes 24% were treated inappropriately (fewer vs Ventak AV, P < 0.001). CONCLUSION: The new detection algorithm incorporated in the Ventak AV did not inadvertently withhold therapy for ventricular tachyarrhythmias, but at the same time the number of inappropriate therapies for atrial fibrillation was not decreased in comparison to a single chamber device.
During the past decade, a variety of innovative procedures and devices for non-pharmacological treatment of tachyarrhythmias have been proposed. Recent improvements in the implantable cardioverter/defibrillators and transcatheter ablative techniques have resulted in a revolution of the therapeutic approach in ventricular and supraventricular tachyarrhythmias, respectively, providing a valuable alternative to conventional antiarrhythmic surgery. Indeed, the selection criteria for surgery for tachyarrhythmias have been revised, and this therapeutic option is considered appropriate only for selected patients with postinfarction ventricular tachycardia. Ther implantable cardioverter/defibrillator has proved effective in conversion of life-threatening tachyarrhythmias, leading a dramatic decrease in the incidence of sudden death in high risk subjects. Thus, with further refinements, a wide use of this therapeutic modality can be anticipated. Transcatheter ablation has become the first-line option in the most common forms of supraventricular tachycardias, such as accessory pathway-mediated tachycardia and AV nodal reentry. More recently, encouraging results of this technique in common atrial flutter and ectopic atrial tachycardia have been reported, although confirmation with larger series and longer follow-up is needed. In general, results of catheter ablation in ventricular tachycardia have been disappointing, with the exception of bundle branch reentry and idiopathic ventricular tachycardia, in which a high success rate is reported. An increasingly important role of these therapeutic modalities is expected. In the meanwhile, due to their evolutional character and the specific competence required for their use, such procedures should be performed exclusively in well trained centers.
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OBJECTIVE: Since the 1990's radiofrequency ablation radiofrequency ablation of atrial flutter has evolved in its methods and results. We have reviewed the long term outcome in 62 patients with typical (common) or reversed (clockwise) flutter undergoing radiofrequency ablation between 1990 and 1997. PATIENTS AND METHODS: Fifty men and 12 women, aged 22-78 years (57 +/- 12) with flutter recurring after cardioversion and antiarrhythmic drugs make this series. Flutter was typical in 59 cases and reversed in 3. There was no heart disease in 14, bronchopulmonary disease in 10, coronary disease in 9, cardiomyopathies in 6 and other processes in the remainder. In 5 cases with previous surgery for atrial or ventricular septal defect, Ebstein's anomaly or myxoma, we treated also a macro-reentry tachycardia around the atriotomy in the right atrium. Radiofrequency ablation was directed to the inferior vena cava-tricuspid isthmus in typical and reversed flutter, and to the isthmus between the inferior end of the atriotomy and the inferior vena cava, in the lateral right atrium, in the atriotomy tachycardias. We subdivided our patients in Group 1 (24 patients), treated until the end of 1994, and Group 2 (38 patients) treated since 1995 using specially designed catheters and trying to produce isthmus block as the endpoint of the procedure. RESULTS: Radiofrequency ablation interrupted flutter in 61 of 62 cases (98.4%), and the atriotomy tachycardia in all 5. The number of application in Group 1 was 18.6 +/- 10.1 vs 12 +/- 10 in Group 2 (p < 0.05). Follow-up was 40 +/- 24 months in Group 1 vs 16 +/- 9.5 in Group 2. Flutter recurred in 58% of Group 1 and 13% of Group 2 patients (p < 0.001), usually 1-3 months after radiofrequency ablation and they were successfully treated by new radiofrequency ablation with a small number of applications. There was no recurrence of atriotomy tachycardia. Atrial fibrillation occurred in 14 patients (23%) (11 paroxysmal, 3 persistent), with equal incidence in both groups. At the end of follow-up 85% of the patients were in sinus rhythm, although 6 needed pacemakers for sinus node dysfunction (3) or AV ablation (3). Antiarrhythmic drugs were used by 46% of patients in Group 1 and 26% in Group 2 (p = NS) for atrial arrhythmias or recurrent flutter. CONCLUSIONS: Radiofrequency ablation is an effective treatment for flutter and macro-reentry atriotomy tachycardia. Progress in methods have improved results significantly. Atrial fibrillation can still be a problem in 20-25% of the patients after flutter control.
Currently d,l-sotalol is widely used to prevent recurrence of atrial fibrillation and/or atrial flutter, although a randomized dose-response study has not previously been conducted to guide therapy for this indication. This study summarizes findings of a double-blind, placebo-controlled, multicenter, randomized trial evaluating the efficacy, safety, and dose-response relation of 3 fixed doses of d,l-sotalol (80, 120, and 160 mg twice daily) for the maintenance of sinus rhythm in 253 patients with atrial fibrillation and/or atrial flutter. All patients were in sinus rhythm at randomization. Treatment (69 patients on placebo, 59 on 80 mg, 63 on 120 mg, and 62 on 160 mg given twice daily) was continued for 12 months or until documented recurrence of symptomatic atrial fibrillation and/or flutter. Transtelephonic electrocardiographic monitoring was used to detect symptomatic recurrences. Demographic characteristics were not different in the 4 groups. Structural heart disease was present in 57% of patients. Patients with a history of heart failure were excluded. The time from randomization to symptomatic arrhythmia recurrence was significantly longer in the 2 higher d,l-sotalol dose groups than in the placebo group. The median times to recurrence were 27, 106, 229, and 175 days for the placebo, 80, 120, and 160 mg groups, respectively. There were no deaths or cases of torsade de pointes, sustained ventricular tachycardia, or ventricular fibrillation reported. Thus, d,l-sotalol appeared to be both safe and effective in maintaining sinus rhythm in patients with symptomatic atrial fibrillation and/or flutter. Further, the 120-mg twice daily dose appeared to provide the most favorable benefit and/or risk.
Contrary to patients with the WPW-syndrome and AV nodal reentry in whom radiofrequency catheter ablation is the therapy of first choice for cure from these arrhythmias instead of life-long medical therapy, pharmacologic therapy of atrial fibrillation and atrial flutter remains the treatment of choice in these patients. If, however, atrial fibrillation with rapid atrioventricular conduction is medically intractable and associated with severe haemodynamic impairment, these patients may be offered catheter ablation of AV conduction by radiofrequency energy. Compared to DC ablation, this approach is associated by an acceptable complication rate. Including the left ventricular approach in cases where it is not possible to ablate AV conduction using the venous approach, the success rate to achieve third degree AV block approaches 100%. With the development of temperature-controlled radiofrequency catheter ablation, a further reduction of side effects is anticipated. A disadvantage of this approach is the need for permanent pacemaker implantation (usually rate-adaptive VVI stimulation) after induction of complete AV block. Therefore, the advantage of normalization of ventricular rate by ablation of AV conduction has to be weighed against the risk of life-long pacemaker treatment for complete AV block in every patient. Patients with medically intractable typical atrial flutter may be offered the following alternative modes of electric treatment: selective ablation of the area of slow conduction sustaining circus movement in the right atrium underlying atrial flutter, by radiofrequency energy without interrupting AV conduction, implantation of a permanent antitachycardia pacemaker with electrodes positioned in the right atrium, radiofrequency catheter ablation of AV conduction.(ABSTRACT TRUNCATED AT 250 WORDS)
AIMS: The aim of the study was to test the feasibility of the new Realtime Position Management mapping system for ablation of typical atrial flutter. METHODS AND RESULTS: The ultrasound multi-transducer catheters of the RPM Mapping System are placed in the coronary sinus and at the right ventricular apex. Position and movement of the ablation catheter can be depicted on the monitor at any time. Several guiding marks are set in the right atria and thus, define the subsequent lesion lines. A total of 15 patients were treated. In 13 patients complete bi-directional block was established after the ablation. In two patients only significant conduction delay was measured after the end of the procedure. A total of 10.2 +/- 6.3 cooled RF-applications were needed to reach the end-point of the procedure. The total energy was 18.76 +/- 13.23 J. The fluoroscopy time for ablation was 22.2 +/- 8.34 min. During a mean follow-up of 8.4 +/- 3.2 months no recurrence of atrial flutter occurred. One patient developed atypical flutter and another patient had atrial fibrillation. Both patients were treated with antiarrhythmic drugs. There was one ablation related complication, a pericardial effusion. CONCLUSION: The Realtime Position Management system is easy to manage and control. The precision of anatomical linear lesions is improved and fluoroscopic exposure time considerably reduced after learning curve.
Five patients aged between 27 and 48 years were referred for investigation of recurrent paroxysmal tachycardias. Electrophysiological studies revealed concealed ventriculoatrial accessory pathways in two patients, possible atrionodal pathways in two patients and dual intranodal pathways in one patient. During electrophysiological study, particular attention was paid to methods of terminating tachycardia by pacing techniques including single or double atrial and ventricular extrastimuli, atrial or ventricular underdrive, atrial overdrive pacing, and in two patients, rapid ventricular pacing. 'Autodecremental' atrial pacing was employed in all five patients and autodecremental ventricular pacing in two patients. This system is controlled by a microprocessor interfaced with a stimulator. When tachycardia of a cycle length less than 375 ms is sensed the system initiates pacing sequences. The initial stimulus is introduced at an interval less than the tachycardia cycle determined by a preset decremental value D. Each subsequent pacing interval is reduced by the value of D resulting in a gradual acceleration of pacing. The total duration of pacing is limited by the value of the pacing period (P). The final pacing rate is determined by P but cannot exceed 275 bpm (cycle length of 218 ms). Both P and D are operator programmable variables. Tachycardias of a cycle length less than 218 ms do not activate the pacemaker. The postpacing sensing deadtime of the system is set at 50 ms. In three patients, double atrial extrastimuli or atrial overdrive initiated atrial flutter or fibrillation. Autodecremental atrial pacing was successful in converting tachycardia to sinus rhythm in all five patients without initiation of other tachyarrhythmias. Autodecremental ventricular pacing was successful in one of the two patients in which it was used. This new modality of pacing has several theoretical advantages over conventional methods: the decremental mode may avoid stimulation in the vulnerable period and minimizes the risk of initiating other tachyarrhythmias; gradual acceleration of pacing over a short period results in stimulation at different phases of the tachycardia cycle length; and the operator variables D and P provide a flexible system which may be adjusted to suit a particular patient and tachycardia. The development of a fully implantable programmable system is made attractive by the simplicity and adaptability of this technique.
INTRODUCTION: Atrial flutter is a common sustained atrial tachyarrhythmia for which frequency increases with age. Ibutilide is a novel class III antiarrhythmic agent used for the rapid cardioversion of atrial fibrillation or atrial flutter. AIM: The aim of our study was to assess the use of ibutilide in a selected population of very elderly patients (octogenarians) with recent-onset atrial flutter. METHOD: Twenty-nine consecutive elderly patients (11 male, 18 female; mean age 83 +/- 3 years; interquartile range of 10) with recent-onset atrial flutter were included in the study; none of them had signs or symptoms of severe heart failure, angina or impaired renal or hepatic function. All patients underwent a 10-minute intravenous infusion of ibutilide (0.87 mg in 10 ml). RESULTS: The rate of successful arrhythmia termination was 75.9% within a mean time of 31 +/- 20 minutes. No clinical variables were shown to be associated with successful cardioversion, although there was a tendency towards higher efficacy in patients with a shorter duration of arrhythmia. Two female patients (6.9%) developed torsade de pointes, requiring direct current cardioversion under general anaesthesia. Episodes of nonsustained ventricular tachycardia occurred in two other patients. CONCLUSION: Ibutilide appears to be an effective and well tolerated drug for rapid conversion of recent-onset atrial flutter in octogenarian patients, and may represent a valid approach in the acute management of atrial flutter in this particular set of patients.
Radiofrequency catheter ablation has been established as a first-line treatment of various paroxysmal tachycardias, and its developments are still ongoing. As recent advances of radiofrequency catheter ablation, we can point out the following issues: 1) transaortic approach for idiopathic ventricular tachycardia(VT) of LBBB-form with inferior axis, 2) new approach guided by mid-diastolic potential for verapamil-sensitive VT, 3) pulmonary vein(PV) isolation technique guided by PV ostial circular electrogram mapping for paroxysmal atrial fibrillation, 4) new ablation strategies for macro-reentry tachycardia such as incisional atrial tachycardia and VT post old myocardial infarction guided by electro-anatomical mapping, and 5) cooled-tip ablation technique for atrial flutter and VT resistant to conventional system.
In patients with drug-refractory atrial fibrillation, left-atrial catheter ablation represents a new curative therapeutic option. Segmental ostial or circumferential pulmonary vein isolation can achieve stable sinus rhythm in some 70% of patients with paroxysmal atrial fibrillation but no severe structural heart disease. In patients with chronic atrial fibrillation, complex left-atrial linear, or substrate-oriented ablation strategies may additionally be applied. In patients with cardiac insufficiency or more severe systolic left-ventricular dysfunction, restoration of a stable sinus rhythm through the use of left-atrial catheter ablation can improve the left-ventricular ejection fraction and reduce the severity of cardiac failure. Potential complications of ablation include, in particular, pulmonary veins stenosis, iatrogenic left-atrial tachycardia, thromboembolic events and fatal atrio-esophageal fistulas.