Skip Navigation

European Journal of Heart Failure 2007 9(5):484-490; doi:10.1016/j.ejheart.2007.01.002
This Article
Right arrow Abstract Freely available
Right arrow FREE Full Text (PDF) Freely available
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in ISI Web of Science
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Add to My Personal Archive
Right arrow Download to citation manager
Right arrow Search for citing articles in:
ISI Web of Science (7)
Right arrowRequest Permissions
Right arrow Disclaimer
Google Scholar
Right arrow Articles by Marcassa, C.
Right arrow Articles by Giannuzzi, P.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Marcassa, C.
Right arrow Articles by Giannuzzi, P.
Social Bookmarking
Add to CiteULike   Add to Connotea   Add to Del.icio.us  
What's this?

© 2007 European Society of Cardiology

Assessment of cardiac asynchrony by radionuclide phase analysis: Correlation with ventricular function in patients with narrow or prolonged QRS interval

Claudio Marcassaa,*, R. Campinib, Edoardo Vernac, Luca Cerianid and Pantaleo Giannuzzia

a Division of Cardiology, Salvatore Maugeri Foundation IRCCS, Scientific Institute of Veruno (NO) Italy
b Nuclear Medicine Service, Salvatore Maugeri Foundation IRCCS, Scientific Institute of Veruno (NO) Italy
c Cardiology Department, Ospedale di Circolo Varese, Italy
d Nuclear Medicine Service, General Hospital Lugano (CH), Italy

* Corresponding author. Fondazione Salvatore Maugeri, IRCCS, Scientific Institute of Veruno, Cardiology Division, via Revislate 13, Veruno 28010 (No) — Italy. Tel.: +39 0322 884711; fax: +39 0322 830294. E-mail address: cmarcassa{at}fsm.it


   Abstract
Top
 Abstract
1. Introduction
 2. Methods
 3. Results
 4. Discussion
 References
 
Background: Conflicting data exist on the relation between the synchronism of cardiac contraction and ventricular function.

Aim and methods: A resting radionuclide ventriculography (RNV) was performed in 380 consecutive patients to evaluate the relationship between the synchronism of cardiac contraction and ventricular function.

Results: A significant, non-linear, relation was found between LVEF and intra-ventricular asynchrony or QRS, but not between inter-ventricular asynchrony and LVEF. A linear correlation was observed between QRS and intra-ventricular or inter-ventricular asynchrony. Intra-ventricular asynchrony was identified as the major, independent, determinant of LV function. With the increase in QRS duration, a decrease in LVEF (p<0.001), and a worsening of either intra-ventricular (p<0.001) or inter-ventricular synchronism (p<0.05), was documented. However, 48% of patients with QRS 120–150 ms had abnormal inter-ventricular and 42% abnormal intra-ventricular synchronism, while 27% of patients with QRS>150 ms had normal inter-ventricular and 25% normal intra-ventricular synchronism.

Conclusions: Intra-ventricular asynchrony was identified as the major determinant of ventricular dysfunction. A consistent proportion of patients had asynchrony despite preserved QRS duration or normal synchronism with a QRS>150 ms. Fourier phase analysis of RNV may detect asynchrony better than QRS. The role of RNV for detection of individual patients who may most benefit from resynchronization therapy requires additional investigations.

Key Words: Asynchrony • Heart failure • Phase analysis • Radionuclide ventriculography • Resynchronization • Ventricular function

Received March 27, 2006; Revised September 18, 2006; Accepted January 10, 2007


   1. Introduction
Top
 Abstract
 1. Introduction
2. Methods
 3. Results
 4. Discussion
 References
 
Asynchronous cardiac contraction is considered to be one of the substrates of heart failure, and cardiac resynchronization therapy using bi-ventricular pacing has been proposed as a treatment [1]. The presence of delayed electrical conduction or left bundle branch block, as determined by 12-lead ECG, is commonly used as an indicator of asynchronous contraction in patients with left ventricular (LV) dysfunction [2]. However, conflicting data exist on the relation between delayed activation, asynchronous cardiac contraction and ventricular function.

A variety of echocardiographic methods have been proposed to measure asynchrony and to evaluate serial changes over time; however, the limited reproducibility and operator dependency of these measurements of ventricular asynchrony have been recognized [3,4]. Magnetic resonance imaging (MRI) has also been used to assess ventricular asynchrony and its response to pacing therapy [5,6]. However, due to the complexity and limited availability of MRI there is insufficient data to define its role in clinical practice. Moreover, since MRI cannot be used in patients with pace-makers, its feasibility in follow-up studies is limited.

Many of these issues do not apply to radionuclide ventriculography (RNV), a reliable, non-invasive, method which provides quantitative, operator-independent and reproducible indexes of cardiac function. RNV has been used to assess synchrony of contraction in patients with conduction abnormalities, including left bundle branch block, pre-excitation syndrome, pace-makers or ventricular arrhythmias [7-14]. A few studies have focused on the role of RNV in candidates for cardiac resynchronization therapy [15-17]. However, there is little data on the relation between synchronism of cardiac contraction, QRS and functional parameters, and prognosis [18,19].

The aim of this study was therefore to correlate indexes of cardiac synchronism of contraction obtained by RNV with ventricular function, in a large group of patients with different degrees of cardiac function and a wide range of QRS duration.


   2. Methods
Top
 Abstract
 1. Introduction
 2. Methods
3. Results
 4. Discussion
 References
 
2.1. Study population
The study cohort consisted of 380 patients (mean age 61+8 y, 72% male) consecutively undergoing RNV for the evaluation of ventricular function. Ischaemic heart disease, defined as a documented previous myocardial infarction, a history of typical chest-pain, or evidence of coronary artery stenoses (>50% lumen reduction) in at least one major vessel, was documented in 194 (61%) patients; 130 patients (34%), were considered to have dilated cardiomyopathy, according to the definition of World Health Organization [20]. The remaining 56 (15%) patients, underwent RNV screening prior to chemotherapy, all had a negative cardiovascular history, a normal electrocardiogram, a normal general examination, and normal echocardiography, and were considered as a control group. All patients were in sinus rhythm; patients with atrial fibrillation or pace-maker induced rhythm were not included in this study. The study protocol was approved by the local Ethics Committee on Human Research; and informed consent was obtained from all patients.

2.2. Radionuclide ventriculography acquisition and analysis
All patients underwent RNV at rest, after in vivo red blood cell labelling (600 to 1110 MBq of 99 mTc). Acquisitions were performed in supine position, in the left anterior oblique projection that best displayed the inter-ventricular septum ("best septal" view), with a large field of view camera (Apex-409 or SP6, GE), equipped with a high resolution collimator. Data acquisition consisted of 32 frames acquired in a 64x64 array; elimination of extrasystolic and post-extrasystolic beats was obtained applying a 10% acceptance window around the mean RR interval during acquisition. A total of 5.0 to 7.0x106 counts were collected for each study.

Ejection fractions (EF) were calculated by the analysis of the LV and RV background-corrected time-activity curves, which were constructed by a semi-automated edge-detection method with variable regions of interest. The background time-activity curve was derived using a fixed region of interest designed on the end-diastolic frame [21].

To assess the ventricular synchronism of contraction, quantitative phase analysis was performed, using the first component of Fourier harmonics to fit a cosine curve to the time-activity curve of each LV and RV pixel. Phase and amplitude images were thus obtained; regions-of-interest were separately placed over the RV and LV phase image, and from the relative count-distribution histogram of phase values, the RV and LV standard deviations (SD) were obtained, as an index of intra-ventricular synchronism of contraction. Inter-ventricular asynchrony was calculated as the difference between the mean values of the RV and LV histograms (Fig. 1). Results were first expressed in angles (degrees) and then as time (milliseconds; [(average cardiac cycle during acquisition)/(360°)] times the phase angle), to take into account the duration of the cardiac cycle.


Figure 01
View larger version (26K):
[in this window]
[in a new window]
[Download PowerPoint slide]
  		Fig. 1 Schematic representation of the assessment of intra-ventricular and inter-ventricular asynchrony. From a representative cardiac cycle, composed of a 32 frame-bin (frame f=1 to f=32), the parametric phase image is obtained (A). From the right ventricular (RV) and left ventricular (LV) regions of interest the relative count-distribution histogram of phase values are obtained (B, C). The standard deviation of each histogram is calculated, as an index of intra-ventricular asynchrony. The inter-ventricular asynchrony is calculated as the difference between the mean values of the RV and LV histograms (dotted lines).

 
According to the upper reference limit (mean+2SD) obtained in the control group, inter-ventricular asynchrony was defined by a LV-RV delay ≥40 ms, and abnormal intra-ventricular synchronism was defined by the presence of SD value ≥18°.

2.3. ECG analysis
The QRS duration was automatically calculated from a standard 12-lead ECG recorded immediately before RNV acquisitions. Patients were then divided according to QRS duration into normal (G1, QRS<120 ms), intermediate (G2, QRS from 120 to 150 ms) or wide (G3, QRS>150 ms) QRS duration.

2.4. Statistical analysis
Normality of the data was verified by the Kolgomorow-Smirnov test. Data are reported as mean±SD. In 50 randomly selected patients, phase analysis was performed by the same operator, in duplicate, by repeating image processing after 2 weeks, in order to assess intra-observer variability. The inter-observer variability was calculated in 50 patients by comparing the analysis performed by two operators blinded to the patients' data. The repeatability of the parameters was tested in 22 patients, by repeating the acquisition after a 120 min interval, with the same machine and acquisitions parameters as the first acquisition. The intra-observer and inter-observer variability of the Fourier Phase analysis were assessed by linear regression. Repeatability was analyzed according to the method of Bland and Altman [22]. Linear and nonlinear regressions were used to identify the best relation between phase indexes and LVEF, RVEF, and QRS. ANOVA was used to assess differences between groups. A stepwise regression analysis was performed to describe the contribution of electrical and mechanical asynchrony to global ventricular function. A p value <0.05 (two tailed) was considered significant.


   3. Results
Top
 Abstract
 1. Introduction
 2. Methods
 3. Results
4. Discussion
 References
 
The clinical characteristics and RNV data for the control group and the patients are reported in Table 1.


View this table:
[in this window]
[in a new window]

  		Table 1 Clinical, electrocardiographic and radionuclide ventriculographic data in the patients' group and in controls

 
3.1. Intra-observer and inter-observer variability
A very low intra-observer variability was documented for the LV and RV mean phase (R2=0.921 and R2=0.876, respectively) and SD values (R2=0.74 and R2=0.72, respectively). A very high correlation between repeated measures was also documented for inter-ventricular asynchrony (R2=0.867).

A significant agreement between operators was also documented for LV and RV mean phase (R2=0.82 and R2=0.80, respectively) and SD values (R2=0.68 and R2=0.63, respectively), as well as for inter-ventricular asynchrony (R2=0.79). From the repeatability analysis, coefficients of repeatability of 3.8, 3.2, and 2.5 for LV mean phase values, SD, and inter-ventricular asynchrony, respectively, were documented.

3.2. Synchronism of contraction and ventricular function
A significant linear relation was documented between LVSD and LVEF (r=0.68, p<0.0001). However, the data were best fitted by a non linear function (LVEF=101.2-20.1*ln(SD); p≤.0001), with no differences between patients with or without ischaemic artery disease (Fig. 2). A significant non-linear relation was also found between RVSD and RVEF (RVEF=63.3-9.2*ln(SD); r=0.49; p<0.001), although the data are more scattered than for the LV. No correlation was observed between the inter-ventricular delay and either LVEF or RVEF.


Figure 02
View larger version (14K):
[in this window]
[in a new window]
[Download PowerPoint slide]
  		Fig. 2 Correlation between LV standard deviation (SD) and ejection fraction (LVEF) in patients with (full circles) and without (open circles) ischaemic heart disease (IHD). Control patients are shown as black triangles.

 
3.3. QRS, mechanical synchronization and ventricular function
In the whole study cohort, the ECG conduction pattern was normal in 96 (25%) patients; a left bundle branch block was documented in 134 (35%), an aspecific intra-ventricular conduction delay (defined as a prolonged QRS not associated with the typical axis and patterns of bundle branch blocks) in 121 (32%), and a right bundle branch block in 29 (8%) patients, respectively (Table 1).

A significant non-linear relation was observed between QRS duration and LVEF (r=0.66, p<0.001, Fig. 3). A weak linear correlation was also observed between QRS duration and LVSD (r=0.51, p<0.01) or inter-ventricular asynchrony (r=0.37, p<0.05, Fig. 4). However, no correlation was observed between QRS duration and RVEF or RVSD.


Figure 03
View larger version (18K):
[in this window]
[in a new window]
[Download PowerPoint slide]
  		Fig. 3 Correlation between QRS and left ventricular ejection fraction (LVEF). Control patients are shown as black triangles.

 


Figure 04
View larger version (21K):
[in this window]
[in a new window]
[Download PowerPoint slide]
  		Fig. 4 Correlation between QRS and inter-ventricular delay. Control patients are shown as black triangles.

 
When QRS duration, LVSD and inter-ventricular asynchrony were introduced in a stepwise regression analysis, LVSD emerged as the best independent variable correlated to LVEF (F=40.9).

When patients were divided according to QRS duration, a progressive decrease in LVEF with increasing QRS duration was observed (G1: 58±5%; G2: 37±17%; G3 :27±7%; p<0.001). A progressive worsening of either intra-(G1: 9.4±3.7°; G2: 19.6±9.8°; G3: 29.8±18.5°; p<0.001) or inter-ventricular synchronism (G1:11±7 ms; G2: 28±20 ms; G3: 40±26 ms; p<0.05) was also documented. No significant differences were observed between groups for RVEF or RVSD (Table 2).


View this table:
[in this window]
[in a new window]

  		Table 2 Radionuclide ventriculographic functional data, intra-ventricular and inter-ventricular synchronism of contraction, in patients with normal, intermediate, or prolonged QRS duration

 
Interestingly, inter-ventricular synchronism was normal in 48% of G2 patients and abnormal in 27% of G3 patients; moreover, intra-ventricular synchronism was abnormal in 42% of G2 patients and normal in 25% of G3 patients. Finally, in patients with a normal QRS duration, 12% showed an abnormal inter-ventricular and 35% and abnormal intra-ventricular synchronism of contraction. The percentage of patients with normal or abnormal inter-ventricular or intra-ventricular synchronism of contraction, in the whole study group and in the 222 (58%) patients with a LVEF <35% are reported in Fig. 5.


Figure 05
View larger version (15K):
[in this window]
[in a new window]
[Download PowerPoint slide]
  		Fig. 5 Frequency of inter-ventricular (white boxes) and intra-ventricular (black boxes) asynchrony in the whole patient group (A) and in patients with left ventricular ejection fraction <35% (B), according to QRS duration.

 

   4. Discussion
Top
 Abstract
 1. Introduction
 2. Methods
 3. Results
 4. Discussion
References
 
With the increasing interest in cardiac resynchronization therapy for the management of patients with failing hearts, several methods have been proposed to assess asynchrony of contraction and the effect of resynchronization [3-6]. Echocardiography (M-mode, 2D, TDI, strain, strain rate, tissue tracking and three-dimensional), is widely available to cardiologists for the assessment of asynchrony. However, most of these methods are limited by the use of a single imaging plane and by operator dependency, which affect the reproducibility of the measurements obtained, particularly those related to intra-ventricular asynchrony. In addition, it is unclear which parameters actually identify patients who may respond to resynchronization therapy. Magnetic resonance imaging has high spatial and temporal resolution, but is not widely available; moreover, it cannot be used in patients with pace-makers, thus limiting its role in serial measurements and follow-up after implantation.

Image acquisition and analysis of RNV data are simple to perform, not time-consuming, rarely subject to artefacts, and highly reproducible. Quantitative Fourier Phase analysis has been previously used to study the pattern of ventricular conduction and synchrony of contraction [7-14]. A few studies have validated the accuracy of the method [10,14] and reported on the relation between synchronism of cardiac contraction and the indexes of delayed conduction and cardiac function [8,9,18].

4.1. Association of synchrony of contraction to ventricular function
Ventricular synchrony and function are closely correlated. In normal subjects, ventricular phase histograms consist of a single narrow peak, and the mean global RV phase occurs slightly earlier than the mean global LV phase. In patients with right bundle branch block the RV mean phase occurs after the LV one, but the delay between ventricles is generally not as large as that seen in left bundle branch block, were the LV mean phase occurs much later than the RV mean phase. In patients with normal volumes and function however, the presence of a bundle branch block "per se", reflected by an increased inter-ventricular delay, does not necessarily imply the occurrence of intra-ventricular asynchrony. Myocardial ischaemia, fibrosis, or conduction disturbances, which broaden the phase histogram and are reflected in a higher SD, may be implicated in the delayed contraction.

An inverse relation between LV ejection fraction and SD was reported in 1981 by Mena et al., in a small group of patients with various cardiovascular diseases [23]. Schwaiger et al. confirmed an inverse linear correlation between SD and LV ejection fraction in patients with ischaemic heart disease, but not in those with cardiomyopathy, where the data were best fitted by a curvilinear relation [24]. An inverse curvilinear relationship between LV ejection fraction and SD was also documented in a group of 56 patients with various heart diseases by Ratib et al. [25]. More recently, an inverse linear relation between SD and LV ejection fraction was also reported, mainly in patients with non-ischaemic disease [16-19].

To the best of our knowledge, the present study is the largest to correlate the synchronism of contraction, assessed by RNV phase analysis, with ventricular functional data, in patients with ischaemic heart disease or dilated cardiomyopathy. Our results confirm that global ventricular systolic function, expressed as EF, is significantly related to the intra-ventricular synchronism of contraction and demonstrate that the relation is best described by a non-linear function, both for the LV and RV. This relationship suggests that the synchronicity of wall motion can be maintained despite moderately impaired global function; in severe dysfunction, however, SD markedly increases.

Comparable results were documented in patients with or without ischaemic heart disease. In ischaemic heart disease regional asynergy due to an ischaemic event could play a major role in determining intra-ventricular asynchrony. In patients with dilated cardiomyopathy this finding could be ascribed to the abnormal geometry of severely dilated ventricles, with regional differences in wall stress causing asynchronous wall motion, as well as the presence of scattered fibrosis. Thus, phase delays may be the result of activation abnormalities, contraction abnormalities, or a combination of both. In patients with severe LV dysfunction, both factors are probably involved and although it is difficult to differentiate the two mechanisms, the ultimate result is a loss of synchrony of wall motion.

The relationship between inter-ventricular asynchrony and ventricular function was addressed only recently, and discordant results have been reported. In patients with dilated cardiomyopathy a significant negative correlation was observed between LV ejection fraction and inter-ventricular asynchrony [17-19]. However, in a group of patients with heart failure due to different cardiovascular aetiologies, a less convincing correlation was reported [14,16]. In our study, in patients with or without ischaemic heart disease, no significant correlation between inter-ventricular asynchrony and LVEF was found.

4.2. QRS duration, mechanical synchrony and ventricular function
In our study, a significant non-linear relation was observed between QRS duration and LVEF. However, no correlation was observed between QRS duration and RVEF or RVSD. A significant linear correlation was observed between QRS and either LVSD or inter-ventricular asynchrony; these results are comparable to those obtained by Toussaint et al. and by Fauchier et al., who also reported similar regression coefficients [14,16,18].

Patients with heart failure who are considered for cardiac resynchronization therapy (CRT) are usually selected on the basis of QRS duration on surface ECG [1,2]. A few studies have also included direct measurements of mechanical asynchrony as an additional selection criterion, mainly by using simple echocardiographic measurements [3,4].

Compared to control subjects, patients eligible for CRT represent a broad spectrum of underlying conduction abnormalities with variable inter- and intra-ventricular delays. There is no simple correlation between QRS prolongation and ventricular dyssynchrony. In our study the majority of patients with a narrow QRS interval (G1) did not exhibit dyssynchrony; however, some did show significant dyssynchrony, either interventricular or intraventricular. Whether these patients would benefit from CRT requires further studies. Moreover, a number of patients with prolonged QRS did not present with abnormalities of either inter-ventricular or intra-ventricular synchronism, as assessed by Fourier phase analysis. In these patients, it is uncertain whether a significant improvement in cardiac function after biventricular pacing could be expected. An imaging technique is required to demonstrate that mechanical dyssynchrony is present beyond QRS duration and that resynchronization is effectively achieved after pace-maker implantation.

Our results were obtained both in patients with ischaemic and non-ischaemic heart disease, and are comparable to that of Fauchier et al., who evaluated 103 patients with idiopathic dilated cardiomyopathy by RNV [18]. They found that intra-ventricular asynchrony was absent in 54% of patients with complete left bundle branch block; in addition, asynchrony was present in 41% of patients with "normal" QRS [18]. Moreover, Ghio et al., using echocardiography and tissue Doppler imaging, documented that intra-ventricular asynchrony was present in 29% of patients with a narrow QRS and absent in 29% of patients with a QRS duration ≥150 ms [26].

When QRS, intra-ventricular, and inter-ventricular asynchrony were introduced in a stepwise regression analysis, intra-ventricular asynchrony emerged as the major, independent determinant of global systolic LV function. This suggests that intra-ventricular asynchrony might be more important than inter-ventricular asynchrony in determining LV function and the subsequent prognosis, and should therefore be the target of resynchronization therapy. Interestingly, in the study by Fauchier et al., LV intra-ventricular asynchrony was, with pulmonary capillary wedge pressure, the only multivariate predictor of major events, and prognosis was related to this parameter rather than to inter-ventricular asynchrony. In addition, RV asynchrony was also a predictor of events, at univariate analysis. Thus, RNV which has high accuracy and reproducibility in the assessment of intra-ventricular asynchrony may be useful in the assessment of patients with heart failure who are potential candidates for resynchronization therapy [27]. Moreover, RNV is the only non-invasive, quantitative, validated technique able to assess RV intra-ventricular asynchrony.

4.3. Limitations of the study
RNV was only performed in patients in sinus rhythm. Therefore, our results do not necessarily apply to patients with rhythm disturbances such as atrial fibrillation or with a right-side pace-maker.

4.4. Conclusions
RNV is a non-invasive, highly reproducible technique, for the objective measurement of ventricular function and synchronism of contraction. In a large, unselected population of patients with various heart diseases and different degrees of delayed conduction or LV dysfunction, intra-ventricular asynchrony emerged as the major determinant of ventricular dysfunction. Fourier phase analysis of RNV may detect asynchrony of contraction better than QRS. Mechanical inter-ventricular or intra-ventricular asynchrony may be present in subjects with preserved QRS duration, and absent in patients with a wide QRS. However, further studies are needed to define the role of RNV for the identification of patients who may benefit from resynchronization therapy.


   References
Top
 Abstract
 1. Introduction
 2. Methods
 3. Results
 4. Discussion
 References
 

  1. Swedberg K., Cleland J., Dargie H., et al. Guidelines for the diagnosis and treatment of chronic heart failure: executive summary (update 2005); the Task Force for the Diagnosis and treatment of chronic heart failure of the European Society of Cardiology. Eur Heart J (2005) 26:1115–1140.[Free Full Text]
  2. Kashani A., Barold S.S. Significance of QRS complex duration in patients with heart failure. J Am Coll Cardiol (2005) 46:2153–2167.[Abstract/Free Full Text]
  3. Lane R.E., Chow A.W., Chin D., Mayet J. Selection and optimization of biventricular pacing: the role of echocardiography. Heart (2004) 90(suppl_VI):vi10–vi16.[Abstract/Free Full Text]
  4. Bax J.J., Abraham T., Barold S.S., et al. Cardiac resynchronization therapy, I: issues before device implantation. J Am Coll Cardiol (2005) 46:2153–2167.[Abstract/Free Full Text]
  5. Wyman B.T., Hunter W.C., Prinzen F.W., et al. Mapping propagation of mechanical activation in paced heart with MRI tagging. Am J Physiol (1999) 276:H881–H891.[Web of Science][Medline]
  6. Zwanenburg J.J., Gotte M.J., Kuijer J.P., Heethaar R.M., van Rossum A.C., Marcus J.T. Timing of contraction in humans mapped by high-temporal-resolution MRI tagging: early onset and late peak of shortening in lateral wall. Am J Physiol Heart Circ Physiol (2004) 286:H1872–H1880.[Abstract/Free Full Text]
  7. Alcan K.E., Robeson W., Graham M.C., Palestro C., Oliver F.H., Benua R.S. Combined Fourier amplitude and phase imaging in patients with coronary artery disease. Clin Nucl Med (Dec 1984) 9(12):693–701.[CrossRef][Web of Science][Medline]
  8. Alfano B., Betocchi S., Pace L., Perrone-Filardi P., Chiariello M., Salvatore M. Quantitation of left ventricular asynchrony on radionuclide angiography phase images. Eur J Nucl Med (1990) 16(11):801–806.[CrossRef][Web of Science][Medline]
  9. Bonow R.O., Vitale D.F., Bacharach S.L., Frederick T.M., Kent K.M., Green M.V. Asynchronous left ventricular regional function and impaired global diastolic filling in patients with coronary artery disease: reversal after coronary angioplasty. Circulation (Feb 1985) 71(2):297–307.[Abstract/Free Full Text]
  10. Dormehl I., Burow R., Hugo N., Maree M., Van Zandwijk C., Van Vuuren C., et al. Phase mapping from left ventricular radionuclide ventriculograms: interobserver reliability and accuracy of the programme. Nucl Med Commun (Oct 1987) 8(10):805–813.[Web of Science][Medline]
  11. Itti R., Casset D., Philippe L., Fauchier J.P., Cosnay P., Huguet R. Characterization of right or left ventricular contraction heterogeneity using Fourier phase analysis. Application to a group of patients with severe ventricular arrhythmias. Eur J Nucl Med (1988) 14(4):196–202.[Web of Science][Medline]
  12. Rolfe S.J., Rasor T., Shaffer P.A., Sanitate P.A., Bashore T.M. Relation between premature ventricular contraction site of origin (defined by radionuclide phase analysis) and subsequent left ventricular function. Am J Cardiol (Apr 1 1984) 53(8):1028–1033.[CrossRef]
  13. Santomauro M., Fazio S., Ferraro S., Maddalena G., Papaccioli G., Pappone C., et al. Fourier analysis in patients with different pacing modes. Pacing Clin Electrophysiol (Sep 1991) 14(9):1351–1358.[CrossRef][Medline]
  14. Toussaint J.F., Peix A., Lavergne T., Vicente F.P., Froissart M., Alonso C., et al. Reproducibility of the ventricular synchronization parameters assessed by multiharmonic phase analysis of radionuclide angiography in the normal heart. Int J Cardiovasc Imaging (Jun 2002) 18(3):187–194.[CrossRef][Web of Science][Medline]
  15. Aernout Somsen G., Verberne H.J., Burri H., Ratib O., Righetti A. Ventricular mechanical dyssynchrony and resynchronization therapy in heart failure: a new indication for Fourier analysis of gated blood-pool radionuclide ventriculography. Nucl Med Commun (Feb 2006) 27(2):105–112.[CrossRef][Web of Science][Medline]
  16. Toussaint J.F., Lavergne T., Ollitraut J., Hignette C., Darondel J.M., De Dieuleveult B., et al. Biventricular pacing in severe heart failure patients reverses electromechanical dyssynchronization from apex to base. Pacing Clin Electrophysiol (Nov 2000) 23(11 Pt 2):1731–1734.[Medline]
  17. Kerwin W.F., Botvinick E.H., O'Connel W., et al. Ventricular contraction abnormalities in dilated cardiomyopathy: effect of biventricular pacing to correct interventricular dyssynchrony. J Am Coll Cardiol (2000) 35:1221–1227.[Abstract/Free Full Text]
  18. Fauchier L., Marie O., Casset-Senon D., Babuty D., Cosnay P., Fauchier J.P. Interventricular and intraventricular dyssynchrony in idiopathic dilated cardiomyopathy: a prognostic study with Fourier phase analysis of radionuclide angioscintigraphy. J Am Coll Cardiol (Dec 4 2002) 40(11):2022–2030.[CrossRef]
  19. Fauchier L., Marie O., Casset-Senon D., Babuty D., Cosnay P., Fauchier J.P. Ventricular dyssynchrony and risk markers of ventricular arrhythmias in nonischemic dilated cardiomyopathy: a study with phase analysis of angioscintigraphy. Pacing Clin Electrophysiol (Jan 2003) 26:352–356.[CrossRef][Medline]
  20. Richardson P., McKenna W., Bristow M., et al. Report of the 1995 World Health Organization/International Society and Federation of Cardiology Task Force on the definition and classification of cardiomyopathies. Circulation (1996) 93:841–842.[Free Full Text]
  21. Marcassa C., Galli M., Campini R., Marzullo P., Giannuzzi P. Differential systolic and diastolic effects of β-adrenergic stimulation in patients with severe left ventricular dysfunction: a radionuclide ventriculographic study. J Nucl Cardiol (2003) 10:46–50.[CrossRef][Web of Science][Medline]
  22. Bland J.M., Altman D.G. Statistical method for assessing agreement between two methods of clinical measurement. Lancet (1986) 8:307–310.
  23. Mena I., Carmody J., Chelsey S., Fan J. Usefulness of phase analysis in nuclear medicine. J Nucl Med (1981) 22:83.
  24. Schwaiger M., Ratib O., Henze E., Schelbert H.R. Limitations of quantitative phase analysis of radionuclide angiograms for detecting coronary artery disease in patients with impaired left ventricular function. Am Heart J (1984) 108:942–949.[CrossRef][Web of Science][Medline]
  25. Ratib O., Henze E., Schon H. Phase analysis of radionuclide ventriculograms for the detection of coronary artery disease. Am Heart J (1982) 104:1–12.[CrossRef][Web of Science][Medline]
  26. Ghio S, Constantin C, Klersy C, et al. Interventricular and intraventricular dyssynchrony are common in heart failure patients, regardless of QRS duration. Eur Heart J. 204(25):751–8.
  27. Botvinick E.H. Scintigraphic blood pool and phase image analysis. The optimal tool for the evaluation of resynchronization therapy. J Nucl Cardiol (2003) 10:424–428.[CrossRef][Web of Science][Medline]

Add to CiteULike CiteULike   Add to Connotea Connotea   Add to Del.icio.us Del.icio.us    What's this?


This article has been cited by other articles:


Home page
 HeartHome page
F Leyva, P W X Foley, B Stegemann, J A Ward, L L Ng, M P Frenneaux, F Regoli, R E A Smith, and A Auricchio
Development and validation of a clinical index to predict survival after cardiac resynchronisation therapy
Heart, October 1, 2009; 95(19): 1619 - 1625.
[Abstract] [Full Text] [PDF]

Home page
 JNMHome page
S. D. Van Kriekinge, H. Nishina, M. Ohba, D. S. Berman, and G. Germano
Automatic Global and Regional Phase Analysis from Gated Myocardial Perfusion SPECT Imaging: Application to the Characterization of Ventricular Contraction in Patients with Left Bundle Branch Block
J. Nucl. Med., November 1, 2008; 49(11): 1790 - 1797.
[Abstract] [Full Text] [PDF]

This Article
Right arrow Abstract Freely available
Right arrow FREE Full Text (PDF) Freely available
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in ISI Web of Science
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Add to My Personal Archive
Right arrow Download to citation manager
Right arrow Search for citing articles in:
ISI Web of Science (7)
Right arrowRequest Permissions
Right arrow Disclaimer
Google Scholar
Right arrow Articles by Marcassa, C.
Right arrow Articles by Giannuzzi, P.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Marcassa, C.
Right arrow Articles by Giannuzzi, P.
Social Bookmarking
Add to CiteULike   Add to Connotea   Add to Del.icio.us  
What's this?