Current criteria for the differential diagnosis between supraventricular tachycardia with aberrant conduction and ventricular tachycardia are frequently absent or suggest the wrong diagnosis. The absence of an RS complex in all precordial leads is easily recognizable and highly specific for the diagnosis of ventricular tachycardia. When an RS complex is present in one or more precordial leads, an RS interval of more than 100 msec is highly specific for ventricular tachycardia. This new stepwise approach may prevent diagnostic mistakes.
on behalf of the International Study on Syncope of Uncertain Etiology (ISSUE) Investigators* Background-Because of its episodic behavior, the correlation of spontaneous syncope with an abnormal finding can be considered a reference standard. Methods and Results-We inserted an implantable loop recorder in 111 patients with syncope, absence of significant structural heart disease, and a normal ECG; tilt-testing was negative in 82 (isolated syncope) and positive in 29 (tilt-positive). The patients had had Ն3 episodes of syncope in the previous 2 years and were followed up for 3 to 15 months. Results were similar in the isolated syncope group and the tilt-positive group: syncope recurred in 28 (34%) and 10 patients (34%), respectively, and electrocardiographic correlation was found in 24 (23%) and 8 (28%) patients, respectively. The most frequent finding, which was recorded in 46% and 62% of patients, respectively, was one or more prolonged asystolic pauses, mainly due to sinus arrest, preceded for a few minutes by progressive bradycardia or progressive tachycardia-bradycardia. Bradycardia without pauses was observed in 8% and 12% of cases, respectively. The remaining patients had normal sinus rhythm or sinus tachycardia, except for one, who had ectopic atrial tachycardia.In the tilt-positive group, an asystolic syncope was also recorded when the type of response to tilt-testing was vasodepressor or mixed. Presyncopal episodes were never characterized by asystolic pauses; normal sinus rhythm was the most frequent finding. Conclusions-Homogeneous findings were observed during syncope. In most patients, the likely cause was neurallymediated, and the most frequent mechanism was a bradycardic reflex. In the other cases, a normal sinus rhythm was frequently recorded. Presyncope was not an accurate surrogate for syncope in establishing a diagnosis. (Circulation.
This study sought to determine the long-term follow-up, safety, and efficacy of radiofrequency catheter ablation of patients with the permanent form of junctional reciprocating tachycardia (PJRT). We assessed the reversibility of tachycardia induced LV dysfunction and we detailed the location and electrophysiological characteristics of these retrograde atrioventricular decremental pathways. PJRT is an infrequent form of reciprocating tachycardia, commonly incessant, and usually drug refractory. The ECG hallmarks include an RP interval > PR with inverted P waves in leads II, III, a VF, and V3-V6. During tachycardia, retrograde VA conduction occurs over an accessory pathway with slow and decremental conduction properties, located predominantly in the posteroseptal zone. It is known that long-lasting and incessant tachycardia may result in tachycardia induced severe ventricular dysfunction. We included 36 patients (13 men, 23 women, mean +/- SD, aged 44 +/- 22 years) with the diagnosis of PJRT. Seven patients had tachycardia induced left ventricular dysfunction. Radiofrequency energy was delivered at the site of earliest retrograde atrial activation during ventricular pacing or during reciprocating tachycardia. All patients were followed at the outpatient clinic and serial echocardiograms were performed in those who presented with depressed LV function. Radiofrequency ablation was performed in 36 decremental accessory pathways. Earliest retrograde atrial activation was right posteroseptal in 32 patients (88%), right mid-septal in 2 (6%), right posterolateral in 1 (3%), and left anterolateral in 1 (3%). Thirty-five accessory pathways were successfully ablated with a mean of 5 +/- 3 applications. A mid-septal accessory pathway could not be ablated. After a mean follow-up of 21 +/- 16 months (range 1-64) 34 patients are asymptomatic. There were recurrences in 8 patients after the initial successful ablation (mean of 1.2 months), 5 were ablated in a second ablation procedure, 2 patients required a third procedure, and 1 patient required four ablation sessions. All patients with LV dysfunction experienced a remarkable improvement after ablation. Mean preablation LV ejection fraction in patients with tachycardiomyopathy was 28% +/- 6% and rose to 51% +/- 16% after ablation (P< 0.02). Our study supports the concept that radiofrequency catheter ablation is a safe and effective treatment for patients with PJRT. Radiofrequency ablation should be the treatment of choice in these patients because this arrhythmia is usually drug refractory. The majority of accessory pathways are located in the posteroseptal zone. Cessation of the arrhythmia after successful ablation results in recovery of LV dysfunction.
Aims Treatment patterns were compared between randomized groups in EAST-AFNET 4 to assess whether differences in anticoagulation, therapy of concomitant diseases, or intensity of care can explain the clinical benefit achieved with early rhythm control in EAST-AFNET 4. Methods and results Cardiovascular treatment patterns and number of visits were compared between randomized groups in EAST-AFNET 4. Oral anticoagulation was used in >90% of patients during follow-up without differences between randomized groups. There were no differences in treatment of concomitant conditions between groups. The type of rhythm control varied by country and centre. Over time, antiarrhythmic drugs were given to 1171/1395 (84%) patients in early therapy, and to 202/1394 (14%) in usual care. Atrial fibrillation (AF) ablation was performed in 340/1395 (24%) patients randomized to early therapy, and in 168/1394 (12%) patients randomized to usual care. 97% of rhythm control therapies were within class I and class III recommendations of AF guidelines. Patients randomized to early therapy transmitted 297 166 telemetric electrocardiograms (ECGs) to a core lab. In total, 97 978 abnormal ECGs were sent to study sites. The resulting difference between study visits was low (0.06 visits/patient/year), with slightly more visits in early therapy (usual care 0.39 visits/patient/year; early rhythm control 0.45 visits/patient/year, P < 0.001), mainly due to visits for symptomatic AF recurrences or recurrent AF on telemetric ECGs. Conclusion The clinical benefit of early, systematic rhythm control therapy was achieved using variable treatment patterns of antiarrhythmic drugs and AF ablation, applied within guideline recommendations.
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