Clinical impact of repolarization changes in supine versus upright body position

Background: The impact of postural changes on various electrocardiography (ECG) characteristics has only been assessed in a few small studies. This large prospective trial was conducted to confirm or refute preliminary data and add important results with immediate impact on daily clinical practice. Methods: ECGs in supine and upright position from 1028 patients were analyzed. Evaluation was made according to changes in T-wave vector and direction, ST-segment deviation, heart rate, QT interval and QTc interval was performed. Findings were correlated with the medical history of patients. Results: Positional change from supine to upright resulted in a significantly increased heart rate (8.05 ± 7.71 bpm) and a significantly increased QTc interval after Bazetts (18 ± 23.45 ms) and Fridericas (8.84 ± 17.30) formula. In the upright position significantly more T-waves turned negative (14.7%) than positive (5.7%). ST elevation was recorded in only 0.4% and ST depression in not more than 0.2% of all patients. Conclusions: The majority of the patients do not show significant morphological changes in their ECG by changing the body position from supine to upright. Changes of QTc time instead, are significant and the interval might be overestimated in upright. Therefore assessment of the QTc interval should strictly be done in a supine position

Narrow QRS complex tachycardia with long RP-interval: what is the mechanism?

No anstrac

Mechanistic assessment and ablation of left ventricular assist device related ventricular tachycardia in patients with severe heart failure

Aims: Left-ventricular-assist-devices (lvad) are an established treatment for patients with severe heart failure with reduced ejection fraction (HF) and reduce mortality. However, HF patients have significant substrate for ventricular tachycardia (VT) and the lvad itself might be pro-arrhythmogenic. We investigated the mechanism of VT in lvad-patients in relation to the underlying etiology and provide in silico and ex-vivo data for ablation in these HF patients.Methods and Results: We retrospectively analyzed invasive electrophysiological (EP) studies of 17 patients with VT and lvad. The mechanism of VT was determined using electroanatomical, entrainment and activation time mapping. Ischemic cardiomyopathy was present in 70% of patients. VT originated from the lvad region in >30%. 1/6 patients with VT originating from the lvad region had episodes before lvad implantation, while 7/11 patients with VT originating from other regions had episodes before implantation. Number and time of radiofrequency (RF)-ablation lesions were not different between VTs originating from the lvad or other regions. Long-term freedom from VT was 50% upon ablation in patients with VT originating from the lvad region and 64% if ablation was conducted in other regions. To potentially preemptively mitigate lvad related VT in patients undergoing lvad implantation, we obtained in silico derived data and performed ex-vivo experiments targeting ventricular myocardium. Of the tested settings, application of 25 W for 30 s was safe and associated with optimal lesion characteristics.Conclusion: A significant percentage of patients with lvad undergoing VT ablation exhibit arrhythmia originating in close vicinity to the device and recurrence rates are high. Based on in silico and ex-vivo data, we propose individualized RF-ablation in selected patients at risk for/with lvad related VT

Clinical outcomes of cryoballoon ablation for pulmonary vein isolation: Impact of intraprocedural heart rhythm

Background: The current study sought to assess the impact of the intraprocedural heart rhythm (sinus rhythm [SR] vs. atrial fibrillation [AF]) on acute procedural characteristics, durability of pulmonary vein isolation (PVI) and long-term clinical outcomes of cryoballoon (CB) ablation. Methods: A total of 195 patients with symptomatic paroxysmal (n = 136) or persistent AF (n = 59) underwent CB-based PVI. Ablation procedures were either performed in SR (SR group; n = 147) or during AF (AF group; n = 48). Persistent AF was more frequent in the AF group than in the SR group (62% vs. 20%). All other patient baseline characteristics did not differ between the two groups. Results: The nadir temperature during the CB applications was significantly lower in the AF group than in patients in the SR group (–49 [interquartile range, –44; –54]°C vs. –47 [-42; –52]°C, p = 0.002). Median procedure and fluoroscopy times as well as the rate of real-time recordings were not different between the two groups. Repeat ablation for the treatment of atrial arrhythmia recurrence was performed in 60 patients (SR: 44 [30%] patients; AF: 16 [33%] patients), with a trend towards a lower rate of PV reconnections in the AF group (p = 0.07). There was no difference in 3-year arrhythmia-free survival (p = 0.8). Conclusions: Cryoballoon-based PVI during AF results in lower nadir balloon temperatures and a trend towards a higher durability of PVI as compared to procedures performed in SR. The rate of real-time PVI recordings was not affected by the intraprocedural heart rhythm

Clinical impact of repolarization changes in supine versus upright body position

BACKGROUND The impact of postural changes on various electrocardiography (ECG) characteristics has only been assessed in a few small studies. This large prospective trial was conducted to confirm or refute preliminary data and add important results with immediate impact on daily clinical practice. METHODS ECGs in supine and upright position from 1028 patients were analyzed. Evaluation was made according to changes in T-wave vector and direction, ST-segment deviation, heart rate, QT interval and QTc interval was performed. Findings were correlated with the medical history of patients. RESULTS Positional change from supine to upright resulted in a significantly increased heart rate (8.05 ± 7.71 bpm) and a significantly increased QTc interval after Bazetts (18 ± 23.45 ms) and Fridericas (8.84 ± 17.30) formula. In the upright position significantly more T-waves turned negative (14.7%) than positive (5.7%). ST elevation was recorded in only 0.4% and ST depression in not more than 0.2% of all patients. CONCLUSIONS The majority of the patients do not show significant morphological changes in their ECG by changing the body position from supine to upright. Changes of QTc time instead, are significant and the interval might be overestimated in upright. Therefore assessment of the QTc interval should strictly be done in a supine position

Radiofrequency ablation in children and adolescents: results in 154 consecutive patients

AIMS: The experience of using radiofrequency ablation (RFA) for the treatment of arrhythmias in children and adolescents is still limited. This study aimed to review the most recent results of RF ablation in children and adolescents in a highly experienced centre with access to both conventional techniques and non-fluoroscopic electroanatomic mapping (CARTO). METHODS AND RESULTS: A total of 154 consecutive patients younger than 19 years treated with RFA during the period 2000-04 were included. Numbers (%) or median (quartiles) are reported. Age was 15 (12-17) years, 70 (45%) were males. Five patients (3%) had congenital heart disease. RFA was successful in 147/154 patients (95%). Arrhythmia recurrence occurred in 11 patients (7%). Procedure time was 55 (35-90) min and fluoroscopy time was 8.8 (4-19) min. Number of RF applications was 4 (2-10) and number of RF applications >20 s was 2 (1-7). One patient (0.7%) had complicating high-grade atrioventricular block. CARTO was used in 18 RF ablation procedures (11%) performed in 15 patients. CONCLUSION: RF ablation can be undertaken in children and adolescents with a high success rate, few recurrences and complications, very short procedure times, and acceptable fluoroscopy times. Non-fluoroscopic electroanatomic mapping is helpful in selected patients

Perception of atrial fibrillation before and after radiofrequency catheter ablation: relevance of asymptomatic arrhythmia recurrence.

BACKGROUND The objective of this study was to assess the incidence and impact of asymptomatic arrhythmia in patients with highly symptomatic atrial fibrillation (AF) who qualified for radiofrequency (RF) catheter ablation. METHODS AND RESULTS In this prospective study, 114 patients with at least 3 documented AF episodes together with corresponding symptoms and an ineffective trial of at least 1 antiarrhythmic drug were selected for RF ablation. With the use of CARTO, circumferential lesions around the pulmonary veins and linear lesions at the roof of the left atrium and along the left atrial isthmus were placed. A continuous, 7-day, Holter session was recorded before ablation, right after ablation, and after 3, 6, and 12 months of follow-up. During each 7-day Holter monitoring, the patients recorded quality and duration of any complaints by using a detailed symptom log. More than 70,000 hours of ECG recording were analyzed. In the 7-day Holter records before ablation, 92 of 114 patients (81%) had documented AF episodes. All episodes were symptomatic in 35 patients (38%). In 52 patients (57%), both symptomatic and asymptomatic episodes were recorded, whereas in 5 patients (5%), all documented AF episodes were asymptomatic. After ablation, the percentage of patients with only asymptomatic AF recurrences increased to 37% (P<0.05) at the 6-month follow-up. An analysis of patient characteristics and arrhythmia patterns failed to identify a specific subset who were at high risk for the development of asymptomatic AF. CONCLUSIONS Even in patients presenting with highly symptomatic AF, asymptomatic episodes may occur and significantly increase after catheter ablation. A symptom-only-based follow-up would substantially overestimate the success rate. Objective measures such as long-term Holter monitoring are needed to identify asymptomatic AF recurrences after ablation

Late recurrent arrhythmias after ablation of atrial fibrillation: incidence, mechanisms, and treatment.

OBJECTIVES The aim of the study was to determine the incidence of atrial flutter and other arrhythmia recurrences (other than atrial fibrillation [AF]) during long-term follow-up after left atrial substrate modification by percutaneous radiofrequency (RF) ablation of AF. BACKGROUND RF ablation is an effective treatment for patients with AF. However, late recurrent arrhythmias may complicate the patient's course. METHODS One hundred fifty consecutive patients with paroxysmal or persistent AF were included in this prospective study. The incidence of arrhythmia recurrences after AF ablation was analyzed during long-term follow-up using repetitive 7-day ECG recording. RESULTS In 28 of 150 patients (18.7%), stable regular arrhythmias other than AF were detected during follow-up. Left atrial flutter observed in 10 patients (6.7%) was treated by recompletion of the ablation lines in all 10 patients. Left atrial flutter was associated with recurrence of AF in all 10 patients. Nine of 10 patients (90%) were free from atrial flutter and 6 of 10 patients were free from AF after the second intervention. Typical right atrial flutter occurred in 10 patients (6.7%) and was treated successfully by percutaneous RF ablation without recurrence in all patients. Additionally, atrial flutter was documented during follow-up in 7 patients (4.7%); however, invasive electrophysiologic evaluation was not performed due to various reasons. CONCLUSIONS Left atrial flutter is a relevant complication after RF catheter ablation of AF and was always associated with AF recurrence in our study population. Prevention of left atrial flutter can be achieved by induction of ablation lines as continuous and transmural as possible. However, left atrial flutter that does occur late after ablation is amenable to interventional treatment with good prospects of success

Stable secondary arrhythmias late after intraoperative radiofrequency ablation of atrial fibrillation: incidence, mechanism, and treatment.

INTRODUCTION Intraoperative radiofrequency (RF) ablation is an effective treatment of atrial fibrillation (AF). However, secondary arrhythmias late after ablation may complicate the patient's course. We report on the incidence, mechanisms, and treatment of gap-related atrial flutter and other secondary arrhythmias during long-term follow-up. METHODS AND RESULTS In 129 patients who underwent intraoperative RF ablation with placement of left atrial linear lesions using minimally invasive surgical techniques, secondary arrhythmias were analyzed during long-term follow-up (20 +/- 6 months). Transient atrial arrhythmias during the first 3 postoperative months were excluded. In 8 (6.2%) of 129 patients, sustained stable secondary arrhythmias were documented. Left atrial, gap-related atrial flutter was observed in 4 patients (3.1%). The flutter was treated by percutaneous RF ablation in 3 patients (2.3%) and with drugs in 1 patient (0.8%). In 2 patients (1.6%), right atrial isthmus-dependent atrial flutter occurred and was treated successfully by percutaneous RF ablation. In 2 patients (1.6%), ectopic right atrial tachycardias occurred and were treated with percutaneous RF ablation. CONCLUSION Late after intraoperative RF ablation of atrial fibrillation, three types of stable secondary arrhythmias were observed in 6% of patients: left atrial gap-related atrial flutter, right atrial isthmus-dependent atrial flutter, and ectopic atrial tachycardia. Gaps after intraoperative RF ablation due to noncontinuous or nontransmural linear lesions may lead to stable left atrial macroreentrant tachycardias, requiring new interventional therapy

Outflow tract tachycardia with R/S transition in lead V3: six different anatomic approaches for successful ablation.

OBJECTIVES The aim of this study was to analyze different anatomic mapping approaches for successful ablation of outflow tract tachycardia with R/S transition in lead V(3). BACKGROUND Idiopathic ventricular tachycardia can originate from different areas in the outflow tract, including the right and left ventricular endocardium, the epicardium, the pulmonary artery, and the aortic sinus of Valsalva. Although electrocardiographic criteria may be helpful in predicting the area of origin, sometimes the focus is complex to determine, especially when QRS transition in precordial leads is in V(3). METHODS We analyzed surface electrocardiograms of 33 successfully ablated patients with outflow tract tachycardia: 20 from the right ventricular outflow tract (RVOT) and 13 from different sites. The R/S transition was determined, and the different anatomic approaches needed for successful catheter ablation were studied. RESULTS Overall, R/S transition in lead V(3) was present in 19 (58%) of all patients. In these patients, mapping was started and successfully completed in the RVOT in 11 of 19 (58%) patients. The remaining eight patients with R/S transition in lead V(3) needed five additional anatomic accesses for successful ablation: from the left ventricular outflow tract (n = 3), aortic sinus of Valsalva (n = 2), coronary sinus (n = 1), the epicardium via pericardial puncture (n = 1), and the trunk of the pulmonary artery (n = 1), respectively. CONCLUSIONS A R/S transition in lead V(3) is common. In patients with outflow tract tachycardia with R/S transition in lead V(3), a stepwise endocardial and epicardial mapping through up to six anatomic approaches can lead to successful radiofrequency catheter ablation