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Intra-ventricular dyssynchrony under pharmacological stress: Does QRS duration matter?
Poster 2
S149
P2-46 THE RELATIONSHIP BETWEEN SUDDEN CARDIAC DEATH AND RIGHT VENTRICULAR FUNCTION IN PATIENTS WITH IDIOPATIC DILATED CARDIOMYOPATHY: A LONG TERM STUDY E. Moro, MD, F. Caprioglio, MD, G. Berton, MD, P. Degan, MD, C. Marcon, MD and Pietro Delise, MD. Conegliano General Hospital, Conegliano Veneto, Italy. Background: Reduced left ventricular ejection fraction (LVEF) is associated with a poor prognosis in patients (pts) with idiopatic dilated cardiomyopathy (IDCM) but it does not predict arrhythmic death. Also the relationship between the modality of cardiac death and right ventricular function is still unclear and not well defined in pts with IDCM. Aim: Investigate the independent role of right ventricular function to predict arrhythmic death in pts with IDCM. Methods: We studied 82 pts with IDCM (46M, 36F, age 67⫾6 years) in sinus rhythm. At twodimensional echo, measurements included dimensions of left ventricle in systole and diastole; LVEF; right ventricular fractional shortening area (RVFSA). From Doppler early (E) and atrial (A) mitral flow pattern, E/A ratio, E deceleration time (EDT) were measured. Subsequently we selected 59 pts with LVEF⬍35% and among these we considered four groups on the basis of RVFSA and mitral flow pattern. Group I: normal RVFSA (⬎30%) and E/A⬍1, EDT⬎115ms; Group II: normal RVFSA and E/A⬎1, EDT⬍115ms; Group III: reduced RVFSA (⬍30%) and E/A⬍1, EDT⬎115ms; Group IV: reduced RVFSA and E/A⬎1, EDT⬍115ms. Results: After 6 years follow-up in Group I all pts were alive; in Group II 3 pts underwent cardiac transplantation and 1 died suddenly; in Group III 7 pts had sudden death; in Group IV 11 pts died only for congestive heart failure. At multivariate analysis reduced RVFSA associated with normal mitral filling pattern was the strongest predictor of sudden death (chi-square⫽10.2; p⫽0.001). The Kaplan Meier curve demonstrated significant difference between Group II and III for survival free of sudden death (log-rank: p⫽0.001). Conclusion: Anatomical remodelling associated with dysfuction of right ventricle can represent a marker for arrhythmic substrate. Clinically the integrated evaluation of RVFSA and Doppler trasmitral flow pattern identifies high risk pts for sudden death and can be utilized in daily clinical practice for arrhythmic stratification of pts with IDCM.
Intraventricular systolic dyssynchrony increases with pharmacological stress irrespective of the QRS duration though the increase may be higher in the NQRS patients. Thus pharmacological stress may have a role in assessment of dyssynchrony in this group of patients.
P2-48 “AF NESTS” ELECTRICAL RESONANCE. IS IT A NEW ATRIAL FIBRILLATION PHYSIOPATHOLOGY? Jose C. Pachon M, MD, Enrique I. Pachon M, MD, Juan C. Pachon M, MD, Tasso J. Lobo, MD, M. Zelia C. Pachon, MD, Remy N. A. Vargas, MD, Dariana V. A. Penteado, MD, M. Liduina Ferreira, MD and Adib D. Jatene, MD, PhD. Sao Paulo Heart Hospital and Dante Pazzanese Cardiology Institute, Sa˜o Paulo, Brazil.
INTRA-VENTRICULAR DYSSYNCHRONY UNDER PHARMACOLOGICAL STRESS: DOES QRS DURATION MATTER? Sudipta Chattopadhyay, M. F. Alamgir, N. P. Nikitin, A. L. Clark and J. G. F. Cleland. University of Hull, Hull East Yorkshire England, United Kingdom.
Background: To study the AF physiopathology we have used the atrial potentials spectral mapping by FFT in sinus rhythm (SR) finding 2 kinds of very different myocardium: the Compact(CM) having very well connected cells and low frequency(F) leftward non-segmented spectrum and the Fibrillar(FM) with loose cells and rightward high frequency segmented spectrum usually found in small clusters named “AF-Nests”. Hypothesis: For having different spectrum with low resonance the CM is only bystander, while the FM having high resonance is the active element (resonant) refeeding the AF. Methods: 36p without significant cardiopathy (25M, 44.7⫾10y) with very frequent refractory AF 28(A) or controls without AF 8(B) were submitted to: L⫹R atrial endocardial mapping in SR and post-AF induction using time domain and frequency domain mapping (spectral by FFT); Catheter RF-ablation [EPT 4mm-60o/30J/30s] of the AF-Nests in SR or AF outside pulmonary veins shifting the FM spectrum into the CM or stopping AF (group A); AF inducibility by atrial pacing;
Intraventricular systolic dyssynchrony is prevalent in patients with left ventricular systolic dysfunction (LVSD) at rest. Ischaemia increases conduction delay. Hypothesis: ischaemia, under pharmacological stress, would increase dyssynchrony indices [SD of the time to peak systolic velocities from the onset of the QRS (Ts-SD) and difference between the maximum and minimum Ts (Tsdiff)] more in patients with wide QRS (WQRS) than those with narrow QRS (NQRS). 77 patients with LVSD [47 with QRSd⬍120ms(NQRS), 30 with QRSd⬎120ms(WQRS)]had DSE using a standard protocol in tissue Doppler mode after clinical and echocardiographic examination. Standard views at rest and peak stress were analysed off-line. Ts at 12 nonapical LVsegments were measured and corrected for heart rate using the Bazett’s formula (Tscor). Ts-SD,Tscor-SD,Tsdiff and Tscorrdiff were computed. The t test was used to compare means within and across the groups. P⬍0.05 was considered significant. Both groups were clinically and echocardiographically well matched. All the indices were higher in WQRS group than NQRS at rest and peak stress. Ts-SD and Tsdiff did not change in either group with stress. The indices corrected for heart rate increased significantly with stress in both groups, more so in the NQRS group.
Results: SR Spectrum: CM shows one main F⫽59.6⫾11Hz and the FM shows a mean of 3.6⫾0.8 main F up to 253Hz. AF Mean Rate: FM⫽32.8⫾8Hz; CM⫽6.3⫾1.5Hz; AF/Control AF-Nest number ratio⫽13.7; AF induction: only 1/B-12.5% having 6 AF-Nests and in 28/A100% having 53⫾15 AF-Nests. AF was not reinduced in controls having ⬍3 AF-Nests 7/B and in those having all AF-Nests ablated 25/A-89% ( p⬍0.01). In 19/A-67.8% AF reverted during AF-Nests ablation. Conclusion: The atrial wall is heterogeneous having compact and fibrillar myocardium; FM has high resonance having resonant or active role during AF. CM has low resonance being bystander during AF. It was impossible AF induction in p without AF-Nests post-RF or controls. This suggests that AF occurs only in those atria with critical amount of FM; AF-Nests seems to be the AF-cell and the key to convert the atrial tachycardia into AF.
P2-47
S149
P2-46 THE RELATIONSHIP BETWEEN SUDDEN CARDIAC DEATH AND RIGHT VENTRICULAR FUNCTION IN PATIENTS WITH IDIOPATIC DILATED CARDIOMYOPATHY: A LONG TERM STUDY E. Moro, MD, F. Caprioglio, MD, G. Berton, MD, P. Degan, MD, C. Marcon, MD and Pietro Delise, MD. Conegliano General Hospital, Conegliano Veneto, Italy. Background: Reduced left ventricular ejection fraction (LVEF) is associated with a poor prognosis in patients (pts) with idiopatic dilated cardiomyopathy (IDCM) but it does not predict arrhythmic death. Also the relationship between the modality of cardiac death and right ventricular function is still unclear and not well defined in pts with IDCM. Aim: Investigate the independent role of right ventricular function to predict arrhythmic death in pts with IDCM. Methods: We studied 82 pts with IDCM (46M, 36F, age 67⫾6 years) in sinus rhythm. At twodimensional echo, measurements included dimensions of left ventricle in systole and diastole; LVEF; right ventricular fractional shortening area (RVFSA). From Doppler early (E) and atrial (A) mitral flow pattern, E/A ratio, E deceleration time (EDT) were measured. Subsequently we selected 59 pts with LVEF⬍35% and among these we considered four groups on the basis of RVFSA and mitral flow pattern. Group I: normal RVFSA (⬎30%) and E/A⬍1, EDT⬎115ms; Group II: normal RVFSA and E/A⬎1, EDT⬍115ms; Group III: reduced RVFSA (⬍30%) and E/A⬍1, EDT⬎115ms; Group IV: reduced RVFSA and E/A⬎1, EDT⬍115ms. Results: After 6 years follow-up in Group I all pts were alive; in Group II 3 pts underwent cardiac transplantation and 1 died suddenly; in Group III 7 pts had sudden death; in Group IV 11 pts died only for congestive heart failure. At multivariate analysis reduced RVFSA associated with normal mitral filling pattern was the strongest predictor of sudden death (chi-square⫽10.2; p⫽0.001). The Kaplan Meier curve demonstrated significant difference between Group II and III for survival free of sudden death (log-rank: p⫽0.001). Conclusion: Anatomical remodelling associated with dysfuction of right ventricle can represent a marker for arrhythmic substrate. Clinically the integrated evaluation of RVFSA and Doppler trasmitral flow pattern identifies high risk pts for sudden death and can be utilized in daily clinical practice for arrhythmic stratification of pts with IDCM.
Intraventricular systolic dyssynchrony increases with pharmacological stress irrespective of the QRS duration though the increase may be higher in the NQRS patients. Thus pharmacological stress may have a role in assessment of dyssynchrony in this group of patients.
P2-48 “AF NESTS” ELECTRICAL RESONANCE. IS IT A NEW ATRIAL FIBRILLATION PHYSIOPATHOLOGY? Jose C. Pachon M, MD, Enrique I. Pachon M, MD, Juan C. Pachon M, MD, Tasso J. Lobo, MD, M. Zelia C. Pachon, MD, Remy N. A. Vargas, MD, Dariana V. A. Penteado, MD, M. Liduina Ferreira, MD and Adib D. Jatene, MD, PhD. Sao Paulo Heart Hospital and Dante Pazzanese Cardiology Institute, Sa˜o Paulo, Brazil.
INTRA-VENTRICULAR DYSSYNCHRONY UNDER PHARMACOLOGICAL STRESS: DOES QRS DURATION MATTER? Sudipta Chattopadhyay, M. F. Alamgir, N. P. Nikitin, A. L. Clark and J. G. F. Cleland. University of Hull, Hull East Yorkshire England, United Kingdom.
Background: To study the AF physiopathology we have used the atrial potentials spectral mapping by FFT in sinus rhythm (SR) finding 2 kinds of very different myocardium: the Compact(CM) having very well connected cells and low frequency(F) leftward non-segmented spectrum and the Fibrillar(FM) with loose cells and rightward high frequency segmented spectrum usually found in small clusters named “AF-Nests”. Hypothesis: For having different spectrum with low resonance the CM is only bystander, while the FM having high resonance is the active element (resonant) refeeding the AF. Methods: 36p without significant cardiopathy (25M, 44.7⫾10y) with very frequent refractory AF 28(A) or controls without AF 8(B) were submitted to: L⫹R atrial endocardial mapping in SR and post-AF induction using time domain and frequency domain mapping (spectral by FFT); Catheter RF-ablation [EPT 4mm-60o/30J/30s] of the AF-Nests in SR or AF outside pulmonary veins shifting the FM spectrum into the CM or stopping AF (group A); AF inducibility by atrial pacing;
Intraventricular systolic dyssynchrony is prevalent in patients with left ventricular systolic dysfunction (LVSD) at rest. Ischaemia increases conduction delay. Hypothesis: ischaemia, under pharmacological stress, would increase dyssynchrony indices [SD of the time to peak systolic velocities from the onset of the QRS (Ts-SD) and difference between the maximum and minimum Ts (Tsdiff)] more in patients with wide QRS (WQRS) than those with narrow QRS (NQRS). 77 patients with LVSD [47 with QRSd⬍120ms(NQRS), 30 with QRSd⬎120ms(WQRS)]had DSE using a standard protocol in tissue Doppler mode after clinical and echocardiographic examination. Standard views at rest and peak stress were analysed off-line. Ts at 12 nonapical LVsegments were measured and corrected for heart rate using the Bazett’s formula (Tscor). Ts-SD,Tscor-SD,Tsdiff and Tscorrdiff were computed. The t test was used to compare means within and across the groups. P⬍0.05 was considered significant. Both groups were clinically and echocardiographically well matched. All the indices were higher in WQRS group than NQRS at rest and peak stress. Ts-SD and Tsdiff did not change in either group with stress. The indices corrected for heart rate increased significantly with stress in both groups, more so in the NQRS group.
Results: SR Spectrum: CM shows one main F⫽59.6⫾11Hz and the FM shows a mean of 3.6⫾0.8 main F up to 253Hz. AF Mean Rate: FM⫽32.8⫾8Hz; CM⫽6.3⫾1.5Hz; AF/Control AF-Nest number ratio⫽13.7; AF induction: only 1/B-12.5% having 6 AF-Nests and in 28/A100% having 53⫾15 AF-Nests. AF was not reinduced in controls having ⬍3 AF-Nests 7/B and in those having all AF-Nests ablated 25/A-89% ( p⬍0.01). In 19/A-67.8% AF reverted during AF-Nests ablation. Conclusion: The atrial wall is heterogeneous having compact and fibrillar myocardium; FM has high resonance having resonant or active role during AF. CM has low resonance being bystander during AF. It was impossible AF induction in p without AF-Nests post-RF or controls. This suggests that AF occurs only in those atria with critical amount of FM; AF-Nests seems to be the AF-cell and the key to convert the atrial tachycardia into AF.
P2-47