A peculiar form of focal atrial tachycardia mimicking atypical atrial flutter

What is the mechanism of this post ablation atrial flutter "recurrence"?

We present the case of a patient with typical atrial flutter treated with radiofrequency ablation of the cavo-tricuspid isthmus, which presented 5 days later with an ECG suggesting an atrial flutter recurrence. However, careful analysis of this ECG demonstrated a potentially different mechanism of the arrhythmia, underlying the importance of a pragmatic approach to ECG interpretation of arrhythmias. A secondary electrophysiological study was performed diagnosing a focal atrial tachycardia with origin at the coronary sinus ostium, in the presence of a blocked cavotricuspid isthmus. RF ablation successfully suppressed the arrhythmia.

Interatrial mechanical dyssynchrony shown by tissue doppler imaging during atrial flutter

Although regular supraventricular tachycardia is traditionally classified on the basis of P-wave morphology, diagnostic accuracy is limited to information obtained from surface electrocardiography. Intracardiac electrophysiology is a conclusive although invasive diagnostic method. We report a case of regular supraventricular tachycardia with a heart rate of 162 bpm. M-mode echocardiography of the interatrial septum clarified both the atrial rate and the ventricular response ratio. Tissue Doppler M-mode imaging demonstrated the delay between the posterior wall motion of the left and right atrium. Although it deserves further study, transthoracic echocardiography may provide useful information in addition to electrocardiography.

The 12-lead electrocardiogram in supraventricular tachycardia

The 12-lead electrocardiogram (ECG) is an invaluable tool for the diagnosis of supraventricular tachycardia (SVT). Most forms of SVT can be distinguished with a high degree of certainty based on specific ECG characteristics by using a systematic, stepwise approach. This article provides a general framework with which to approach an ECG during SVT by describing the salient characteristics, ECG findings, and underlying electroanatomical relationships of each specific type of SVT encountered in adults. It concludes by providing a systematic algorithm for diagnosing SVT based on the findings of the 12-lead ECG.

Ablation of Nonautomatic Focal Atrial Tachycardia in Children and Adults with Congenital Heart Disease

INTRODUCTION

Nonautomatic focal atrial tachycardia (NAFAT) has been characterized in adults with structurally normal hearts. This article characterizes NAFAT in a population of patients with complex congenital heart disease.

METHODS AND RESULTS

Electrophysiologic and electroanatomic mapping data and acute outcomes were reviewed in patients undergoing mapping and ablative procedures for atrial tachycardia at Children's Hospital, Boston, between January 1999 and December 2003. Twenty-two NAFAT foci were identified in 17 patients out of 216 patients studied. Fourteen of these 17 patients had congenital heart disease. The average age of the patients with a NAFAT mechanism was 27 years and there was no gender predilection. The presumptive diagnosis based on clinical grounds and surface ECG assessment in 11 of 17 patients with NAFAT was atrial flutter. None of the 17 patients were suspected of having a NAFAT mechanism by noninvasive assessment. Four of the 10 patients had both NAFAT and macroreentrant atrial tachycardias. NAFAT cycle lengths varied widely (200-680 ms) between patients. Sixteen of the 22 NAFAT foci were mapped to the anatomic right atrium (RA). Acute ablative success was achieved in 17 out of 22 foci (77%).

CONCLUSION

NAFAT is relatively uncommon in a pediatric tertiary care setting, and in that setting occurs most often in adults with congenital heart disease. NAFAT is indistinguishable from other forms of atrial tachycardia by noninvasive means and can mimic other forms of atrial tachycardia on electrocardiogram. The foci were predominantly found in the RA and were, in most cases, acutely amenable to catheter ablation therapy.

Mechanisms of Organized Left Atrial Tachycardias Occurring After Pulmonary Vein Isolation

BACKGROUND

A proarrhythmic consequence of pulmonary vein (PV) isolation can be a recurrent organized left atrial (LA) tachycardia after ablation. This arrhythmia is frequently referred to as "left atrial flutter," but the mechanism and best ablation strategy have not been determined.

METHODS AND RESULTS

Isolation of arrhythmogenic PVs was initially performed by segmental ostial PV ablation guided by a circular mapping catheter in 341 patients. Patients whose predominant recurrent arrhythmia was a persistent organized tachycardia returned for mapping and ablation. Recurrent organized LA tachycardias (cycle length 253+/-33 ms, range 213 to 328 ms) occurred in 10 (2.9%) of 341 patients (age 59+/-9 years, 1 woman). Mapping was consistent with a focal origin in 8 patients and with macroreentry in 1 patient and was unclear in 1 patient owing to degeneration to atrial fibrillation. Focal tachycardias originated from reconnected segments of prior isolated PVs (6 patients), the posterior LA (1 patient), or the superior septum (1 patient). Focal atrial tachycardias were ablated with point lesions that targeted the earliest activation. All reconnected PVs were also reisolated. Reentrant LA flutter occurred around the left PVs in 1 patient. After 6.7+/-2.3 months of follow-up, 9 (90%) of 10 patients were arrhythmia free (4 of whom were taking antiarrhythmic drug therapy), and one was having recurrent atrial fibrillation.

CONCLUSIONS

Recurrent organized LA tachycardia after PV isolation is uncommon and typically has a focal origin from reconnected PV ostia. Reisolation of the PV and ablation of non-PV foci are sufficient to treat this proarrhythmia. Linear lesions are only required when a macroreentrant mechanism is present.

An atypical atrial flutter of focal origin: a study using a noncontact mapping system

We report a case of focal atrial tachycardia with appearance suggestive of atypical atrial flutter in a 57-year-old man. Based on ECG criteria, tachycardia was misclassified as atypical atrial flutter. The electrophysiological study using a noncontact mapping system revealed a focal activity within the left upper pulmonary vein ostium. This case highlights the limitations of standard electrocardiographic and electrophysiological classifications of regular atrial tachycardia. This report also shows the relevance of new mapping techniques in the successful mapping and ablation of these arrhythmias, even those arising within the left atrium.