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European Journal of Heart Failure 2006 8(3):275-277; doi:10.1016/j.ejheart.2005.10.001
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© 2005 European Society of Cardiology

Relationship between QRS duration, left ventricular volumes and prevalence of nonviability in patients with coronary artery disease and severe left ventricular dysfunction

Olivier De Wintera,*, Nico Van de Veireb, Frederic Van Heuverswijnb, Geert Van Pottelbergeb, Thierry C. Gillebertb and Johan De Sutterb

a Nuclear Medicine Division, Ghent University Hospital De Pintelaan 185, 9000 Ghent, Belgium
b Department of Cardiovascular Diseases, Ghent University Hospital Ghent, Belgium

* Corresponding author. Tel.: +32 9 240 30 28; fax: +32 9 240 38 07. E-mail address: olivier.dewinter{at}UGent.be (O. De Winter).


   Abstract
Top
 Abstract
1. Background
 2. Aims
 3. Methods
 4. Results
 5. Conclusion
 References
 
Background: Patients with coronary artery disease (CAD), a QRS duration ≥120 ms and left ventricular ejection fraction (LVEF) ≤30% are potential candidates for cardiac resynchronization therapy (CRT). Our aim was to investigate the relationship between QRS duration, left ventricular volumes and prevalence of nonviable tissue in this patient population.

Methods: We studied 132 patients (118 men, age 68±5 years) with CAD and LVEF ≤30% (mean LVEF 24±6%). LV volumes and myocardial viability were determined by gated myocardial perfusion imaging.

Results: A QRS duration ≥120 ms was present in 91 patients (69%). Although there were no differences in LVEF, patients with longer QRS durations had significant larger end-diastolic and end-systolic volumes (p<0.01). Substantial nonviable tissue in the inferior or lateral wall was present in 29% of patients with a QRS duration ≥120 ms versus 7% of those with a QRS duration <<120 ms (p<0.01).

Conclusions: An increased QRS duration is associated with more advanced remodeling in patients with CAD and poor LV function. Almost one third of these patients with a prolonged QRS duration have no viable tissue in the inferolateral wall, an area that is usually stimulated with CRT.

Key Words: QRS duration • Left ventricular ejection fraction • Cardiac resynchronization therapy

Received March 3, 2005; Revised July 19, 2005; Accepted October 3, 2005


   1. Background
Top
 Abstract
 1. Background
2. Aims
 3. Methods
 4. Results
 5. Conclusion
 References
 
Cardiac resynchronization therapy (CRT) is considered as a potential therapeutic option in patients with heart failure, reduced left ventricular ejection fraction (LVEF) and an increased QRS duration. Although functional improvements and effects on morbidity and mortality have been reported, up to 30% of CRT patients do not respond to this therapy and this percentage could be even higher in patients with underlying coronary artery disease (CAD) [1-3]. One of the reasons could be the presence of nonviable tissue in the inferolateral wall which is usually paced when the LV lead is placed transvenously via the coronary sinus.


   2. Aims
Top
 Abstract
 1. Background
 2. Aims
3. Methods
 4. Results
 5. Conclusion
 References
 
Our study aims were to assess the relationship between QRS duration on the surface ECG, left ventricular volumes and the prevalence of nonviable tissue in patients with CAD and poor LV function.


   3. Methods
Top
 Abstract
 1. Background
 2. Aims
 3. Methods
4. Results
 5. Conclusion
 References
 
We studied 132 consecutive patients with CAD and a resting LVEF ≤30%. The diagnosis of CAD was based on a history of myocardial infarction, coronary revascularization or angiographic significant CAD (at least one vessel with ≥75% stenosis). All patients were studied more than 3 months after myocardial infarction or revascularization and patients with ventricular pacing on the resting ECG were excluded. QRS duration was measured on a 12-lead surface ECG, at a speed of 25 mm/s, from the resting ECG.

All patients underwent a resting gated myocardial perfusion SPECT study using technetium-99m tetrofosmin as described previously [4]. Quantified Gated SPECT software (QGS®, Cedars-Sinai, Los Angeles, CA, USA) was used to obtain resting LV ejection fraction and volumes. For viability scoring, the myocardium was divided in 5 regions: anterior wall, lateral wall, inferior wall, septal wall and apex. The anterior, lateral, inferior and septal wall were subdivided in 3 regions (apical, mid and basal region), the apex was subdivided in 2 regions [5]. A myocardial wall was considered to contain substantial nonviable tissue if none of the segments had a mean myocardial uptake higher than 55% of the maximum uptake in the myocardium on the resting perfusion images [6].

Statistical analyses were performed using SPSS 11.0.1 statistical software (SPSS Inc., Chicago, USA). Spearman rank correlations, Mann-Whitney U and Kruskall-Wallis testing were used to investigate relations between QRS duration and LV volumes and prevalences of nonviable according to QRS duration.

The study was approved by the local Ethics Committee of the Ghent University Hospital.


   4. Results
Top
 Abstract
 1. Background
 2. Aims
 3. Methods
 4. Results
5. Conclusion
 References
 
Mean age of the 132 patients was 68±5 years and mean LVEF was 24±6%. Previous myocardial infarction was present in 86 (65%) and previous coronary revascularization in 63 (48%) patients. According to the SPECT findings, the anterior wall was infarcted in 21 (16%), the septal wall in 19 (14%) and the inferolateral in 73 (55%) patients. Patients were treated with ACE-inhibitors or AT-2 receptor blockers (n=98, 74%), beta-blockers (n=59, 45%) and diuretics (n=48, 36%). Mean QRS duration was 131±32 ms and a QRS duration ≥120 ms was present in 91 patients (69%). For the whole group, QRS duration correlated significantly with LV enddiastolic volumes (r=0.31, p<0.001) and LV endsystolic volumes (r=0.30, p<0.001). As compared to patients with small QRS, patients with QRS duration >120 ms had significantly higher LV enddiastolic volumes (248±77 vs. 205±73 ml, p<0.01) and LV endsystolic volumes (193±68 vs. 159±60 ml, p<0.01). Fig. 1 shows the mean LV enddiastolic and endsystolic volumes according to four classes of QRS duration. No significant relation was found between LVEF and QRS duration.


Figure 1
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  		Fig. 1 Relationship between QRS duration and left ventricular volumes. A significant increase in LV endiastolic (EDV) and endsystolic (ESV) volumes is noted according to QRS duration.

 
The inferior or lateral wall was nonviable in 26 patients with a QRS duration ≥120 ms (29%). This frequency was significantly higher than in patients with QRS duration <120 ms (29% vs. 7%, p<0.01). Prevalences of nonviable tissue in different regions for patients with QRS<120 ms and QRS≥120 ms are shown in Fig. 2.


Figure 2
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  		Fig. 2 Prevalence of nonviable tissue in different myocardial regions in patients with QRS duration <120 ms and patients with QRS duration ≥120 ms. A significantly higher prevalence of nonviable tissue in the inferolateral wall is noted in patients with QRS duration ≥120 ms.

 

   5. Conclusion
Top
 Abstract
 1. Background
 2. Aims
 3. Methods
 4. Results
 5. Conclusion
References
 
Our results indicate that a prolonged QRS duration (≥120 ms) is frequent in patients with CAD and LVEF ≤30% with a prevalence of almost 70%. Similar to previous studies in patients with idiopathic dilated cardiomyopathy [7-9], this increase in QRS duration is clearly related to an increase in LV enddiastolic and endsystolic volumes, indicating more advanced remodeling in these patients. More importantly, absence of viable tissue in the inferolateral wall in CAD patients with poor LV function is frequent, with a prevalence of 29% when QRS duration is increased as compared to only 7% when QRS duration is <120 ms. This implicates that almost 30% of potential candidates for CRT with CAD have nonviable tissue in the inferolateral wall. Since nonviable tissue is electromechanically nonfunctional [10], placement of the lead in the inferolateral region could lead to ineffective pacing in these patients [11]. This could therefore be one of the explanations why CRT is ineffective in a substantial number of patients with CAD. Further studies are however needed to determine whether viability assessment can help in the selection of candidates for CRT and in the determination of optimal lead localization.


   References
Top
 Abstract
 1. Background
 2. Aims
 3. Methods
 4. Results
 5. Conclusion
 References
 

  1. Abraham W.T., Fisher W.G., Smith A.L., et al. Cardiac resynchronization in chronic heart failure. N Engl J Med (2002) 346:1845–1853.[Abstract/Free Full Text]
  2. Leclercq C., Hare J.M. Ventricular resynchronization. Current state of the art. Circulation (2004) 109:296–299.[Free Full Text]
  3. Bax J.J., Ansalone G., Breithardt O.A., et al. Echocardiographic evaluation of cardiac resynchronization therapy: ready for routine clinical use? A critical appraisal. J Am Coll Cardiol (2004) 44:1–9.[Abstract/Free Full Text]
  4. De Winter O., De Bondt P., Van de Wiele C., De Backer G., Dierckx R.A., De Sutter J. Day-to-day variability of global left ventricular functional and perfusional measurements by quantitative gated SPECT using Tc-99m tetrofosmin in patients with heart failure due to coronary artery disease. J Nucl Cardiol (2004) 11:47–52.[CrossRef][Web of Science][Medline]
  5. Berman D., Germano G. An approach to the interpretation and reporting of gated myocardial perfusion SPECT. In: Clinical Gated Cardiac SPECT—Germano G., Berman D., eds. (1999) New York: Futura Publishing Company, Inc. 147–182.
  6. Acampa W., Cuocolo A., Petretta M., et al. Tetrofosmin imaging in the detection of myocardial viability in patients with previous myocardial infarction: comparison with sestamibi and Tl-201 scintigraphy. J Nucl Cardiol (2002) 9:33–40.[CrossRef][Web of Science][Medline]
  7. Koga Y., Wada T., Toshima H., Akazawa K., Nose Y. Prognostic significance of electrocardiographic findings in patients with dilated cardiomyopathy. Heart Vessels (1993) 8:37–41.[CrossRef][Medline]
  8. Wilensky R.L., Yudelman P., Cohen A.I., et al. Serial electrocardiographic changes in idiopathic dilated cardiomyopathy confirmed at necropsy. Am J Cardiol (1988) 62:276–283.[CrossRef][Web of Science][Medline]
  9. Xiao H.B., Roy C., Fujimoto S., Gibson D.G. Natural history of abnormal conduction and its relation to prognosis in patients with dilated cardiomyopathy. Int J Cardiol (1996) 53:163–170.[CrossRef][Web of Science][Medline]
  10. Lambiase P.D., Rinaldi A., Hauck J., et al. Non-contact left ventricular endocardial mapping in cardiac resynchronisation therapy. Heart (2004) 90:44–51.[Abstract/Free Full Text]
  11. Sciagra R., Giaccardi M., Porciani M.C., et al. Myocardial perfusion imaging using gated SPECT in heart failure patients undergoing cardiac resynchronization therapy. J Nucl Med (2004) 45:164–168.[Abstract/Free Full Text]

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