Ioan Liuba | Lund - Academia.edu (original) (raw)

Papers by Ioan Liuba

Research paper thumbnail of The effect of the method for determining activation time during electroanatomic mapping of focal atrial tachycardia

The effect of the method for determining activation time during electroanatomic mapping of focal ... more The effect of the method for determining activation time during electroanatomic mapping of focal atrial tachycardia.

Research paper thumbnail of Arrhythmia symptoms with and without arrhythmias in patients monitored with transtelephonic ECG after AF-ablation

Research paper thumbnail of Case Report Figure8 Tachycardia Confined to the Anterior Wall of the Left Atrium

Incisional atrial tachycardias have been described most frequently in patients with previous corr... more Incisional atrial tachycardias have been described most frequently in patients with previous corrective surgery for congenital heart defects and mitral valve disease. Less information is available on atrial tachycardias appearing late after isolated aortic valve surgery. We report the case of a patient who developed a left figure-8 tachycardia after undergoing aortic valve replacement. During electrophysiologic study the entire cycle length of the tachycardia was mapped within a low voltage area confined to the left anterior atrial wall. However, during ablation a transmural lesion could not be attained. The mapping and ablation strategy along with the mechanism of the tachycardia are discussed.

Research paper thumbnail of 3-dimensional CT segmentation of the pericardiac right phrenic nerve for determining the virtual electrode size during pace-mapping in the setting of atrial fibrillation ablation

Research paper thumbnail of Figure-8 tachycardia confined to the anterior wall of the left atrium

Indian pacing and electrophysiology journal, 2004

Incisional atrial tachycardias have been described most frequently in patients with previous corr... more Incisional atrial tachycardias have been described most frequently in patients with previous corrective surgery for congenital heart defects and mitral valve disease. Less information is available on atrial tachycardias appearing late after isolated aortic valve surgery. We report the case of a patient who developed a left figure-8 tachycardia after undergoing aortic valve replacement. During electrophysiologic study the entire cycle length of the tachycardia was mapped within a low voltage area confined to the left anterior atrial wall. However, during ablation a transmural lesion could not be attained. The mapping and ablation strategy along with the mechanism of the tachycardia are discussed.

Research paper thumbnail of Loss of Local Capture of the Pulmonary Vein Myocardium After Antral Isolation: Prevalence and Clinical Significance

Journal of Cardiovascular Electrophysiology, 2014

Loss of Pulmonary Vein Capture After Isolation. Introduction: Capture of the myocardial sleeves o... more Loss of Pulmonary Vein Capture After Isolation. Introduction: Capture of the myocardial sleeves of the pulmonary veins (PV) during PV pacing is mandatory for assessing exit block after PV isolation (PVI). However, previous studies reported that a significant proportion of PVs failed to demonstrate local capture after PVI. We designed this study to evaluate the prevalence and the clinical significance of loss of PV capture after PVI. Methods and Results: Thirty patients (14 redo) undergoing antral PVI were included. Before and after PVI, local PV capture was assessed during circumferential pacing (10 mA/2 milliseconds) with a circular multipolar catheter (CMC), using EGM analysis from each dipole of the CMC and from the ablation catheter placed in ipsilateral PV. Pacing output was varied to optimize identification of sleeve capture. All PVs demonstrated sleeve capture before PVI, but only 81% and 40% after first time and redo PVI, respectively (P < 0.001 vs. before PVI). In multivariate analysis, absence of spontaneous PV depolarizations after PVI and previous PVI procedures were associated with less PV sleeve capture after PVI (40% sleeve capture, P < 0.001 for both). Loss of PV local capture by design was coincident with the development of PV entrance block and importantly predicted absence of acute reconnection during adenosine challenge with 96% positive predictive value (23% negative predictive value). Conclusion: Loss of PV local capture is common after antral PVI resulting in entrance block, and may be used as a specific alternate endpoint for PV electrical isolation. Additionally, loss of PV local capture may identify PVs at very low risk of acute reconnection during adenosine challenge.

Research paper thumbnail of Electrical connection between ipsilateral pulmonary veins: Prevalence and implications for ablation and adenosine testing

Heart Rhythm, 2015

Anatomic studies have reported the presence of shared myocardial fibers between approximately hal... more Anatomic studies have reported the presence of shared myocardial fibers between approximately half of ipsilateral pulmonary veins (IPVs). The purpose of this study was to assess the prevalence of electrical connection between IPVs and the impact of antral isolation with or without carina ablation on IPV connection. Thirty consecutive patients undergoing atrial fibrillation (AF) ablation (14 redo) were included. Wide antral pulmonary vein isolation (PVI) was performed with or without carina lesions. For each PV set, IPV electrical connection was assessed before and after PVI by pacing and recording from the ostium of both IPVs using a circular mapping catheter and the ablation catheter. Adenosine was given after PVI to assess for acute PV reconnection. Before PVI without preceding AF ablation procedure, all the PVs had ipsilateral connection albeit frequently via the left atrium. After PVI, 65.6% of the IPVs were connected without carina ablation vs 17.7% if prior carina ablation (P = .001). Left vs right IPVs were connected in 57.1% and 72.2% of the cases without carina ablation, respectively, vs 30% and 0% of cases with carina ablation (P = .19 and P = .001). When transient PV reconnection was demonstrated during adenosine challenge, connected IPVs uniformly demonstrated simultaneous reconnection. Electrical connection between IPVs is uniformly demonstrated before any ablation. Two-thirds of the IPVs are connected after antral PVI, and carina ablation decreases IPV connection. Connected IPVs consistently show the same response to adenosine challenge; therefore, a single catheter positioned in either of the IPVs with electrical connection is sufficient to confirm reconnection in both veins.

Research paper thumbnail of Activation mapping of focal atrial tachycardia: the impact of the method for estimating activation time

Journal of Interventional Cardiac Electrophysiology, 2009

Different methods can be used to estimate activation time during the mapping of focal atrial tach... more Different methods can be used to estimate activation time during the mapping of focal atrial tachycardia. The present study aimed to compare activation maps generated by three widely used methods of determining activation time. Fourteen patients (mean age 48 +/- 17 years) with focal atrial tachycardia were investigated. Mapping was performed with the CARTO system. All patients underwent successful ablation. Local activation time was successively defined as the peak amplitude (Bi-peak), the steepest downslope (Bi-dslope), and the onset (Bi-on) of the bipolar electrograms. The three methods of activation time determination were highly correlated with one another but generated foci with different locations. The distances between the foci generated by the different methods were 4.36 +/- 4.91 mm (Bi-peak-Bi-dslope), 7.21 +/- 5.11 mm (Bi-peak-Bi-on), and 7.21 +/- 5.87 mm (Bi-dslope-Bi-on) (p = 0.26). Also, the three methods generated foci with different diameters: 3.13 +/- 2.17 mm for Bi-peak, 2.81 +/- 0.78 for Bi-dslope, and 2.54 +/- 0.14 mm for Bi-on (p = 0.60). However, the foci tended to cluster within relatively wide regions of low-amplitude fractionated electrograms. The surface of these regions was 3.81 +/- 2.34 cm(2) (Bi-peak), 3.38 +/- 2.12 cm(2) (Bi-dslope), and 4.76 +/- 3.01 cm(2) (Bi-on) (p = 0.34). The three methods of activation time determination, although highly correlated with one another, may generate foci of different sizes and in different locations. However, the foci tend to cluster within relatively large areas of low-amplitude fractionated electrograms. These findings suggest a sizeable atrial region with particular electrophysiological proprieties and raise the possibility of an anatomical substrate of the tachycardia. During mapping, this region can be roughly delineated by all three methods of activation time estimation. However, details concerning the activation pattern within the region and the location of the focus vary among the methods.

Research paper thumbnail of Scar progression in patients with nonischemic cardiomyopathy and ventricular arrhythmias

Heart Rhythm, 2014

BACKGROUND Disease progression in patients with nonischemic cardiomyopathy (NICM) is poorly under... more BACKGROUND Disease progression in patients with nonischemic cardiomyopathy (NICM) is poorly understood.

Research paper thumbnail of Inflammatory markers in patients with paroxysmal atrial fibrillation

Heart Rhythm, 2005

No abstract is available. To read the body of this article, please view the Full Text online. ...... more No abstract is available. To read the body of this article, please view the Full Text online. ... © 2005 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved. ... Visit SciVerse ScienceDirect to see if you have access via your institution. ... Advertisements on this site do not ...

Research paper thumbnail of Source of inflammatory markers in patients with atrial fibrillation

Europace, 2008

Aims Elevated levels of C-reactive protein and other inflammatory markers have been reported in s... more Aims Elevated levels of C-reactive protein and other inflammatory markers have been reported in some patients with atrial fibrillation (AF). Whether this finding is related to AF per se or to other conditions remains unclear. In addition, the source of inflammatory markers is unknown. Therefore, in the present study, we sought to assess the extent and the source of inflammation in patients with AF and no other concomitant heart or inflammatory conditions. Methods and results The study group consisted of 29 patients referred for radiofrequency catheter ablation: 10 patients with paroxysmal AF, 8 patients with permanent AF, and 10 control patients with Wolf-Parkinson-White (WPW) syndrome and no evidence of AF (mean age 54 + 11 vs. 57 + 13 vs. 43 + 16). No patient had structural heart diseases or inflammatory conditions. High-sensitive C-reactive protein, interleukin-6 (IL-6), and interleukin-8 (IL-8) were assessed in blood samples from the femoral vein, right atrium, coronary sinus, and the left and right upper pulmonary veins. All samples were collected before ablation. Compared with controls and patients with paroxysmal AF, patients with permanent AF had higher plasma levels of IL-8 in the samples from the femoral vein, right atrium, and coronary sinus, but not in the samples from the pulmonary veins (median values in the femoral vein: 2.58 vs. 2.97 vs. 4.66 pg/mL, P ¼ 0.003; right atrium: 2.30 vs. 3.06 vs. 3.93 pg/mL, P ¼ 0.013; coronary sinus: 2.85 vs. 3.15 vs. 4.07, P ¼ 0.016). A high-degree correlation existed between the IL-8 levels in these samples (correlation coefficient between 0.929 and 0.976, P , 0.05). No differences in the C-reactive protein and IL-6 levels were noted between the three groups of patients. Conclusion The normal levels of C-reactive protein and IL-6, along with the elevated levels of IL-8 in patients with permanent AF but not in those with paroxysmal AF, suggest a link between a low-grade inflammatory reaction and long-lasting AF. The elevated IL-8 levels in the peripheral blood, right atrium, and coronary sinus but not in the pulmonary veins suggest a possible source of inflammation in the systemic circulation.

Research paper thumbnail of Focal atrial tachycardia: increased electrogram fractionation in the vicinity of the earliest activation site

Europace, 2008

Fractionated electrograms are often noted during mapping of focal atrial tachycardia (FAT). This ... more Fractionated electrograms are often noted during mapping of focal atrial tachycardia (FAT). This finding suggests poor cell-to-cell coupling, which is thought to be an important prerequisite in the process of ectopic impulse initiation and propagation. The purpose of the present study was to assess the electrogram fractionation in the vicinity of the earliest activation site and in the remaining atrium in these patients. Thirteen patients with FAT (age 48 +/- 17 years) who underwent catheter ablation were investigated. Mapping was performed with the CARTO system. Electrogram fractionation was assessed on the basis of the number of negative deflections, both in the region surrounding the earliest activation site and in the remaining atrium. Unipolar and bipolar peak-to-peak voltage and bipolar electrogram duration were also studied. All patients underwent successful radiofrequency ablation. A higher degree of electrogram fractionation existed in the region surrounding the earliest activation site and activated within the first 15 ms when compared with the remaining atrium (incidence of bipolar electrograms with multiple negative deflections: 88 vs. 79%, P &amp;amp;amp;amp;amp;amp;lt; 0.0001; incidence of unipolar electrograms with multiple negative deflections: 56 vs. 43%, P = 0.0001). The peak-to-peak voltage in the region activated within the first 15 ms was less than that in the remaining atrium (bipolar voltage: 1.33 +/- 0.99 vs. 1.61 +/- 1.11 mV, P &amp;amp;amp;amp;amp;amp;lt; 0.001; unipolar voltage: 1.75 +/- 0.92 vs. 1.95 +/- 1.11 mV, P = 0.0188). There were no significant differences in bipolar electrogram duration. Within the region activated during the first 15 ms, from the periphery to the earliest activation site, there was a gradual increase in electrogram fractionation (incidence of bipolar electrograms with multiple negative deflections gradually increasing from 82 to 100% and incidence of unipolar electrograms with multiple negative deflections increasing from 56 to 90%), as well as a gradual decrease in peak-to-peak voltage (bipolar voltage gradually decreasing from 1.47 +/- 1.06 to 0.89 +/- 0.54 mV, P &amp;amp;amp;amp;amp;amp;lt; 0.0001; unipolar voltage gradually decreasing from 1.89 +/- 0.94 to 1.30 +/- 0.63 mV, P &amp;amp;amp;amp;amp;amp;lt; 0.0001). Irregular, closely spaced isochrones were also noted in the region activated during the first 15 ms. The area of this region was 4.88 +/- 3.59 cm(2). Increased electrogram fractionation exists within a relatively wide region around the tachycardia origin when compared with the remaining atrium. Moreover, this region is electrically heterogeneous, as suggested by the fact that the degree of electrogram fractionation increases gradually whereas the electrogram voltage decreases gradually towards the earliest activation site. These findings suggest that a non-discrete atrial region with gradually changing electrophysiological properties may underlie the substrate of FAT.

Research paper thumbnail of The Substrate and Ablation of Ventricular Tachycardia in Patients With Nonischemic Cardiomyopathy

Circulation Journal, 2013

The term "nonischemic cardiomyopathy" (NICM) designates a myocardial disease characterized by mec... more The term "nonischemic cardiomyopathy" (NICM) designates a myocardial disease characterized by mechanical and/ or electrical dysfunction in the absence of significant coronary artery disease, valvular heart disease, hypertension, or congenital heart disease. Although sustained ventricular tachycardia (VT) occurs in only 5% of patients with NICM, it is an important cause of sudden cardiac death. In this review we summarize the current understanding of the anatomic and electrophysiologic substrates of VT in the different types of NICM. In addition, we discuss recent progress and experience with catheter ablation of VT in these patients.

Research paper thumbnail of Gender-Related Differences in Patients With Atrioventricular Nodal Reentry Tachycardia

The American Journal of Cardiology, 2006

The present study sought to assess the extent of gender differences in electrophysiologic paramet... more The present study sought to assess the extent of gender differences in electrophysiologic parameters in patients with atrioventricular nodal reentrant tachycardia (AVNRT). The study population consisted of 203 patients (women/men ratio 2:1) who underwent slow pathway ablation. Patients with associated heart disease experienced the first episode of tachycardia at a significantly older age than patients with lone AVNRT (women 50 +/- 18 vs 29 +/- 15 years, p &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.0001; men 45 +/- 20 vs 31 +/- 17 years, p = 0.01). Sinus cycle length (797 +/- 142 vs 870 +/- 161 ms, p = 0.0001), HV interval (41 +/- 7 vs 45 +/- 8 ms, p = 0.0001), atrioventricular (AV) block cycle length (348 +/- 53 vs 371 +/- 75 ms, p = 0.01), slow pathway effective refractory period (ERP) (258 +/- 46 vs 287 +/- 62 ms, p = 0.006), and tachycardia cycle length (354 +/- 58 vs 383 +/- 60 ms, p = 0.001) were shorter in women. No gender differences were noted in fast pathway ERP and ventriculoatrial (VA) block cycle length. In women, an AV block cycle length &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt;350 ms along with a VA block cycle length &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt;400 ms predicted tachycardia induction without the need for autonomic intervention, with a positive predictive value of 93% (sensitivity 71%, specificity 82%). No such cut-off values could be found in men. The acute success rate (100% vs 98%) and the recurrence rate (3% vs 6%) were similar for the 2 genders. In conclusion, in patients with lone AVNRT, the onset of symptoms occurred at a younger age than in patients with concomitant heart disease. Women had shorter slow pathway refractory periods, AV block cycle lengths, and tachycardia cycle lengths. No gender differences were noted in the fast pathway ERP. Therefore, women have a wider &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;quot;tachycardia window&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;quot; (i.e., the difference between the fast and slow pathway refractory periods), a finding that may explain their greater incidence of AVNRT.

Research paper thumbnail of The effect of the method for determining activation time during electroanatomic mapping of focal atrial tachycardia

The effect of the method for determining activation time during electroanatomic mapping of focal ... more The effect of the method for determining activation time during electroanatomic mapping of focal atrial tachycardia.

Research paper thumbnail of Arrhythmia symptoms with and without arrhythmias in patients monitored with transtelephonic ECG after AF-ablation

Research paper thumbnail of Case Report Figure8 Tachycardia Confined to the Anterior Wall of the Left Atrium

Incisional atrial tachycardias have been described most frequently in patients with previous corr... more Incisional atrial tachycardias have been described most frequently in patients with previous corrective surgery for congenital heart defects and mitral valve disease. Less information is available on atrial tachycardias appearing late after isolated aortic valve surgery. We report the case of a patient who developed a left figure-8 tachycardia after undergoing aortic valve replacement. During electrophysiologic study the entire cycle length of the tachycardia was mapped within a low voltage area confined to the left anterior atrial wall. However, during ablation a transmural lesion could not be attained. The mapping and ablation strategy along with the mechanism of the tachycardia are discussed.

Research paper thumbnail of 3-dimensional CT segmentation of the pericardiac right phrenic nerve for determining the virtual electrode size during pace-mapping in the setting of atrial fibrillation ablation

Research paper thumbnail of Figure-8 tachycardia confined to the anterior wall of the left atrium

Indian pacing and electrophysiology journal, 2004

Incisional atrial tachycardias have been described most frequently in patients with previous corr... more Incisional atrial tachycardias have been described most frequently in patients with previous corrective surgery for congenital heart defects and mitral valve disease. Less information is available on atrial tachycardias appearing late after isolated aortic valve surgery. We report the case of a patient who developed a left figure-8 tachycardia after undergoing aortic valve replacement. During electrophysiologic study the entire cycle length of the tachycardia was mapped within a low voltage area confined to the left anterior atrial wall. However, during ablation a transmural lesion could not be attained. The mapping and ablation strategy along with the mechanism of the tachycardia are discussed.

Research paper thumbnail of Loss of Local Capture of the Pulmonary Vein Myocardium After Antral Isolation: Prevalence and Clinical Significance

Journal of Cardiovascular Electrophysiology, 2014

Loss of Pulmonary Vein Capture After Isolation. Introduction: Capture of the myocardial sleeves o... more Loss of Pulmonary Vein Capture After Isolation. Introduction: Capture of the myocardial sleeves of the pulmonary veins (PV) during PV pacing is mandatory for assessing exit block after PV isolation (PVI). However, previous studies reported that a significant proportion of PVs failed to demonstrate local capture after PVI. We designed this study to evaluate the prevalence and the clinical significance of loss of PV capture after PVI. Methods and Results: Thirty patients (14 redo) undergoing antral PVI were included. Before and after PVI, local PV capture was assessed during circumferential pacing (10 mA/2 milliseconds) with a circular multipolar catheter (CMC), using EGM analysis from each dipole of the CMC and from the ablation catheter placed in ipsilateral PV. Pacing output was varied to optimize identification of sleeve capture. All PVs demonstrated sleeve capture before PVI, but only 81% and 40% after first time and redo PVI, respectively (P < 0.001 vs. before PVI). In multivariate analysis, absence of spontaneous PV depolarizations after PVI and previous PVI procedures were associated with less PV sleeve capture after PVI (40% sleeve capture, P < 0.001 for both). Loss of PV local capture by design was coincident with the development of PV entrance block and importantly predicted absence of acute reconnection during adenosine challenge with 96% positive predictive value (23% negative predictive value). Conclusion: Loss of PV local capture is common after antral PVI resulting in entrance block, and may be used as a specific alternate endpoint for PV electrical isolation. Additionally, loss of PV local capture may identify PVs at very low risk of acute reconnection during adenosine challenge.

Research paper thumbnail of Electrical connection between ipsilateral pulmonary veins: Prevalence and implications for ablation and adenosine testing

Heart Rhythm, 2015

Anatomic studies have reported the presence of shared myocardial fibers between approximately hal... more Anatomic studies have reported the presence of shared myocardial fibers between approximately half of ipsilateral pulmonary veins (IPVs). The purpose of this study was to assess the prevalence of electrical connection between IPVs and the impact of antral isolation with or without carina ablation on IPV connection. Thirty consecutive patients undergoing atrial fibrillation (AF) ablation (14 redo) were included. Wide antral pulmonary vein isolation (PVI) was performed with or without carina lesions. For each PV set, IPV electrical connection was assessed before and after PVI by pacing and recording from the ostium of both IPVs using a circular mapping catheter and the ablation catheter. Adenosine was given after PVI to assess for acute PV reconnection. Before PVI without preceding AF ablation procedure, all the PVs had ipsilateral connection albeit frequently via the left atrium. After PVI, 65.6% of the IPVs were connected without carina ablation vs 17.7% if prior carina ablation (P = .001). Left vs right IPVs were connected in 57.1% and 72.2% of the cases without carina ablation, respectively, vs 30% and 0% of cases with carina ablation (P = .19 and P = .001). When transient PV reconnection was demonstrated during adenosine challenge, connected IPVs uniformly demonstrated simultaneous reconnection. Electrical connection between IPVs is uniformly demonstrated before any ablation. Two-thirds of the IPVs are connected after antral PVI, and carina ablation decreases IPV connection. Connected IPVs consistently show the same response to adenosine challenge; therefore, a single catheter positioned in either of the IPVs with electrical connection is sufficient to confirm reconnection in both veins.

Research paper thumbnail of Activation mapping of focal atrial tachycardia: the impact of the method for estimating activation time

Journal of Interventional Cardiac Electrophysiology, 2009

Different methods can be used to estimate activation time during the mapping of focal atrial tach... more Different methods can be used to estimate activation time during the mapping of focal atrial tachycardia. The present study aimed to compare activation maps generated by three widely used methods of determining activation time. Fourteen patients (mean age 48 +/- 17 years) with focal atrial tachycardia were investigated. Mapping was performed with the CARTO system. All patients underwent successful ablation. Local activation time was successively defined as the peak amplitude (Bi-peak), the steepest downslope (Bi-dslope), and the onset (Bi-on) of the bipolar electrograms. The three methods of activation time determination were highly correlated with one another but generated foci with different locations. The distances between the foci generated by the different methods were 4.36 +/- 4.91 mm (Bi-peak-Bi-dslope), 7.21 +/- 5.11 mm (Bi-peak-Bi-on), and 7.21 +/- 5.87 mm (Bi-dslope-Bi-on) (p = 0.26). Also, the three methods generated foci with different diameters: 3.13 +/- 2.17 mm for Bi-peak, 2.81 +/- 0.78 for Bi-dslope, and 2.54 +/- 0.14 mm for Bi-on (p = 0.60). However, the foci tended to cluster within relatively wide regions of low-amplitude fractionated electrograms. The surface of these regions was 3.81 +/- 2.34 cm(2) (Bi-peak), 3.38 +/- 2.12 cm(2) (Bi-dslope), and 4.76 +/- 3.01 cm(2) (Bi-on) (p = 0.34). The three methods of activation time determination, although highly correlated with one another, may generate foci of different sizes and in different locations. However, the foci tend to cluster within relatively large areas of low-amplitude fractionated electrograms. These findings suggest a sizeable atrial region with particular electrophysiological proprieties and raise the possibility of an anatomical substrate of the tachycardia. During mapping, this region can be roughly delineated by all three methods of activation time estimation. However, details concerning the activation pattern within the region and the location of the focus vary among the methods.

Research paper thumbnail of Scar progression in patients with nonischemic cardiomyopathy and ventricular arrhythmias

Heart Rhythm, 2014

BACKGROUND Disease progression in patients with nonischemic cardiomyopathy (NICM) is poorly under... more BACKGROUND Disease progression in patients with nonischemic cardiomyopathy (NICM) is poorly understood.

Research paper thumbnail of Inflammatory markers in patients with paroxysmal atrial fibrillation

Heart Rhythm, 2005

No abstract is available. To read the body of this article, please view the Full Text online. ...... more No abstract is available. To read the body of this article, please view the Full Text online. ... © 2005 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved. ... Visit SciVerse ScienceDirect to see if you have access via your institution. ... Advertisements on this site do not ...

Research paper thumbnail of Source of inflammatory markers in patients with atrial fibrillation

Europace, 2008

Aims Elevated levels of C-reactive protein and other inflammatory markers have been reported in s... more Aims Elevated levels of C-reactive protein and other inflammatory markers have been reported in some patients with atrial fibrillation (AF). Whether this finding is related to AF per se or to other conditions remains unclear. In addition, the source of inflammatory markers is unknown. Therefore, in the present study, we sought to assess the extent and the source of inflammation in patients with AF and no other concomitant heart or inflammatory conditions. Methods and results The study group consisted of 29 patients referred for radiofrequency catheter ablation: 10 patients with paroxysmal AF, 8 patients with permanent AF, and 10 control patients with Wolf-Parkinson-White (WPW) syndrome and no evidence of AF (mean age 54 + 11 vs. 57 + 13 vs. 43 + 16). No patient had structural heart diseases or inflammatory conditions. High-sensitive C-reactive protein, interleukin-6 (IL-6), and interleukin-8 (IL-8) were assessed in blood samples from the femoral vein, right atrium, coronary sinus, and the left and right upper pulmonary veins. All samples were collected before ablation. Compared with controls and patients with paroxysmal AF, patients with permanent AF had higher plasma levels of IL-8 in the samples from the femoral vein, right atrium, and coronary sinus, but not in the samples from the pulmonary veins (median values in the femoral vein: 2.58 vs. 2.97 vs. 4.66 pg/mL, P ¼ 0.003; right atrium: 2.30 vs. 3.06 vs. 3.93 pg/mL, P ¼ 0.013; coronary sinus: 2.85 vs. 3.15 vs. 4.07, P ¼ 0.016). A high-degree correlation existed between the IL-8 levels in these samples (correlation coefficient between 0.929 and 0.976, P , 0.05). No differences in the C-reactive protein and IL-6 levels were noted between the three groups of patients. Conclusion The normal levels of C-reactive protein and IL-6, along with the elevated levels of IL-8 in patients with permanent AF but not in those with paroxysmal AF, suggest a link between a low-grade inflammatory reaction and long-lasting AF. The elevated IL-8 levels in the peripheral blood, right atrium, and coronary sinus but not in the pulmonary veins suggest a possible source of inflammation in the systemic circulation.

Research paper thumbnail of Focal atrial tachycardia: increased electrogram fractionation in the vicinity of the earliest activation site

Europace, 2008

Fractionated electrograms are often noted during mapping of focal atrial tachycardia (FAT). This ... more Fractionated electrograms are often noted during mapping of focal atrial tachycardia (FAT). This finding suggests poor cell-to-cell coupling, which is thought to be an important prerequisite in the process of ectopic impulse initiation and propagation. The purpose of the present study was to assess the electrogram fractionation in the vicinity of the earliest activation site and in the remaining atrium in these patients. Thirteen patients with FAT (age 48 +/- 17 years) who underwent catheter ablation were investigated. Mapping was performed with the CARTO system. Electrogram fractionation was assessed on the basis of the number of negative deflections, both in the region surrounding the earliest activation site and in the remaining atrium. Unipolar and bipolar peak-to-peak voltage and bipolar electrogram duration were also studied. All patients underwent successful radiofrequency ablation. A higher degree of electrogram fractionation existed in the region surrounding the earliest activation site and activated within the first 15 ms when compared with the remaining atrium (incidence of bipolar electrograms with multiple negative deflections: 88 vs. 79%, P &amp;amp;amp;amp;amp;amp;lt; 0.0001; incidence of unipolar electrograms with multiple negative deflections: 56 vs. 43%, P = 0.0001). The peak-to-peak voltage in the region activated within the first 15 ms was less than that in the remaining atrium (bipolar voltage: 1.33 +/- 0.99 vs. 1.61 +/- 1.11 mV, P &amp;amp;amp;amp;amp;amp;lt; 0.001; unipolar voltage: 1.75 +/- 0.92 vs. 1.95 +/- 1.11 mV, P = 0.0188). There were no significant differences in bipolar electrogram duration. Within the region activated during the first 15 ms, from the periphery to the earliest activation site, there was a gradual increase in electrogram fractionation (incidence of bipolar electrograms with multiple negative deflections gradually increasing from 82 to 100% and incidence of unipolar electrograms with multiple negative deflections increasing from 56 to 90%), as well as a gradual decrease in peak-to-peak voltage (bipolar voltage gradually decreasing from 1.47 +/- 1.06 to 0.89 +/- 0.54 mV, P &amp;amp;amp;amp;amp;amp;lt; 0.0001; unipolar voltage gradually decreasing from 1.89 +/- 0.94 to 1.30 +/- 0.63 mV, P &amp;amp;amp;amp;amp;amp;lt; 0.0001). Irregular, closely spaced isochrones were also noted in the region activated during the first 15 ms. The area of this region was 4.88 +/- 3.59 cm(2). Increased electrogram fractionation exists within a relatively wide region around the tachycardia origin when compared with the remaining atrium. Moreover, this region is electrically heterogeneous, as suggested by the fact that the degree of electrogram fractionation increases gradually whereas the electrogram voltage decreases gradually towards the earliest activation site. These findings suggest that a non-discrete atrial region with gradually changing electrophysiological properties may underlie the substrate of FAT.

Research paper thumbnail of The Substrate and Ablation of Ventricular Tachycardia in Patients With Nonischemic Cardiomyopathy

Circulation Journal, 2013

The term "nonischemic cardiomyopathy" (NICM) designates a myocardial disease characterized by mec... more The term "nonischemic cardiomyopathy" (NICM) designates a myocardial disease characterized by mechanical and/ or electrical dysfunction in the absence of significant coronary artery disease, valvular heart disease, hypertension, or congenital heart disease. Although sustained ventricular tachycardia (VT) occurs in only 5% of patients with NICM, it is an important cause of sudden cardiac death. In this review we summarize the current understanding of the anatomic and electrophysiologic substrates of VT in the different types of NICM. In addition, we discuss recent progress and experience with catheter ablation of VT in these patients.

Research paper thumbnail of Gender-Related Differences in Patients With Atrioventricular Nodal Reentry Tachycardia

The American Journal of Cardiology, 2006

The present study sought to assess the extent of gender differences in electrophysiologic paramet... more The present study sought to assess the extent of gender differences in electrophysiologic parameters in patients with atrioventricular nodal reentrant tachycardia (AVNRT). The study population consisted of 203 patients (women/men ratio 2:1) who underwent slow pathway ablation. Patients with associated heart disease experienced the first episode of tachycardia at a significantly older age than patients with lone AVNRT (women 50 +/- 18 vs 29 +/- 15 years, p &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.0001; men 45 +/- 20 vs 31 +/- 17 years, p = 0.01). Sinus cycle length (797 +/- 142 vs 870 +/- 161 ms, p = 0.0001), HV interval (41 +/- 7 vs 45 +/- 8 ms, p = 0.0001), atrioventricular (AV) block cycle length (348 +/- 53 vs 371 +/- 75 ms, p = 0.01), slow pathway effective refractory period (ERP) (258 +/- 46 vs 287 +/- 62 ms, p = 0.006), and tachycardia cycle length (354 +/- 58 vs 383 +/- 60 ms, p = 0.001) were shorter in women. No gender differences were noted in fast pathway ERP and ventriculoatrial (VA) block cycle length. In women, an AV block cycle length &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt;350 ms along with a VA block cycle length &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt;400 ms predicted tachycardia induction without the need for autonomic intervention, with a positive predictive value of 93% (sensitivity 71%, specificity 82%). No such cut-off values could be found in men. The acute success rate (100% vs 98%) and the recurrence rate (3% vs 6%) were similar for the 2 genders. In conclusion, in patients with lone AVNRT, the onset of symptoms occurred at a younger age than in patients with concomitant heart disease. Women had shorter slow pathway refractory periods, AV block cycle lengths, and tachycardia cycle lengths. No gender differences were noted in the fast pathway ERP. Therefore, women have a wider &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;quot;tachycardia window&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;quot; (i.e., the difference between the fast and slow pathway refractory periods), a finding that may explain their greater incidence of AVNRT.