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. 2000 Sep;84(3):272–276. doi: 10.1136/heart.84.3.272

Different effects of abnormal activation and myocardial disease on left ventricular ejection and filling times

Q Zhou 1, M Henein 1, A Coats 1, D Gibson 1
PMCID: PMC1760964  PMID: 10956289

Abstract

BACKGROUND—Ventricular activation is often abnormal in patients with dilated cardiomyopathy, but its specific effects on timing remain undetermined.
OBJECTIVE—To investigate the use of the ratio of the sum of left ventricular ejection and filling times to the total RR interval (Z ratio) to dissociate the effects of abnormal activation from those of cavity dilatation.
METHODS—Subjects were 20 normal individuals, 11 patients with isolated left bundle branch block (LBBB, QRS duration > 120 ms), 17 with dilated cardiomyopathy and normal activation, and 23 with dilated cardiomyopathy and LBBB. An additional 30 patients (nine with normal ventricular systolic function and 21 with dilated cardiomyopathy) were studied before and after right ventricular pacing. Left ventricular ejection and filling times were measured by pulsed wave Doppler and cavity size by M mode echocardiography.
RESULTS—Z ratio was independent of RR interval in all groups. Mean (SD) Z ratio was 82 (10)% for normal subjects, 66 (10)% for isolated LBBB (p < 0.01 v normal), 77 (7)% for dilated cardiomyopathy without LBBB (NS v normal), and 61 (7)% for dilated cardiomyopathy with LBBB (p < 0.01 v normal). In the nine patients with normal left ventricular size and QRS duration, Z ratio fell from 88 (6)% in sinus rhythm to 77 (10)% with right ventricular pacing (p = 0.26). In the 21 patients with dilated cardiomyopathy and LBBB, Z ratio rose from 59 (10)% in sinus rhythm to 74 (9)% with right ventricular DDD pacing (p < 0.001).
CONCLUSIONS—Z ratio dissociates the effects of abnormal ventricular activation and systolic disease. It also clearly differentiates right ventricular pacing from LBBB. It may thus be useful in comparing the haemodynamic effects of different pacing modes in patients with or without left ventricular disease.


Keywords: dilated cardiomyopathy; pacemaker; left bundle branch block; echocardiography.

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Figure 1  .

Figure 1  

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Individual values of Z ratio in normal subjects, patients with isolated left ventricular bundle branch block, patients with dilated cardiomyopathy (DCM) without left bundle branch block (LBBB), and patients with dilated cardiomyopathy with left bundle branch block. The effects of left bundle branch block appear independent of those of left ventricular size.

Figure 2  .

Figure 2  

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Changes of Z ratio in individual patients with normal ventricular size and in patients with dilated cardiomyopathy (DCM) and right ventricular pacing. Right ventricular pacing did not affect Z ratio in patients with normal cavity size and activation, but consistently increased it in patients with dilated cardiomyopathy and left bundle branch block.

Selected References

These references are in PubMed. This may not be the complete list of references from this article.

  1. Baduini G., Calcaterra G., Rossi P. Changes of left ventricular contractility in alternating left bundle branch block. Eur J Cardiol. 1981;12(3-4):207–213. [PubMed] [Google Scholar]
  2. Bland J. M., Altman D. G. Statistical methods for assessing agreement between two methods of clinical measurement. Lancet. 1986 Feb 8;1(8476):307–310. [PubMed] [Google Scholar]
  3. Grines C. L., Bashore T. M., Boudoulas H., Olson S., Shafer P., Wooley C. F. Functional abnormalities in isolated left bundle branch block. The effect of interventricular asynchrony. Circulation. 1989 Apr;79(4):845–853. doi: 10.1161/01.cir.79.4.845. [DOI] [PubMed] [Google Scholar]
  4. Leclercq C., Cazeau S., Le Breton H., Ritter P., Mabo P., Gras D., Pavin D., Lazarus A., Daubert J. C. Acute hemodynamic effects of biventricular DDD pacing in patients with end-stage heart failure. J Am Coll Cardiol. 1998 Dec;32(7):1825–1831. doi: 10.1016/s0735-1097(98)00492-6. [DOI] [PubMed] [Google Scholar]
  5. Lee C. H., Vancheri F., Josen M. S., Gibson D. G. Discrepancies in the measurement of isovolumic relaxation time: a study comparing M mode and Doppler echocardiography. Br Heart J. 1990 Sep;64(3):214–218. doi: 10.1136/hrt.64.3.214. [DOI] [PMC free article] [PubMed] [Google Scholar]
  6. Mattheos M., Shapiro E., Oldershaw P. J., Sacchetti R., Gibson D. G. Non-invasive assessment of changes in left ventricular relaxation by combined phono-, echo-, and mechanocardiography. Br Heart J. 1982 Mar;47(3):253–260. doi: 10.1136/hrt.47.3.253. [DOI] [PMC free article] [PubMed] [Google Scholar]
  7. Panidis I. P., Ross J., Munley B., Nestico P., Mintz G. S. Diastolic mitral regurgitation in patients with atrioventricular conduction abnormalities: a common finding by Doppler echocardiography. J Am Coll Cardiol. 1986 Apr;7(4):768–774. doi: 10.1016/s0735-1097(86)80335-7. [DOI] [PubMed] [Google Scholar]
  8. Sahn D. J., DeMaria A., Kisslo J., Weyman A. Recommendations regarding quantitation in M-mode echocardiography: results of a survey of echocardiographic measurements. Circulation. 1978 Dec;58(6):1072–1083. doi: 10.1161/01.cir.58.6.1072. [DOI] [PubMed] [Google Scholar]
  9. Schnittger I., Appleton C. P., Hatle L. K., Popp R. L. Diastolic mitral and tricuspid regurgitation by Doppler echocardiography in patients with atrioventricular block: new insight into the mechanism of atrioventricular valve closure. J Am Coll Cardiol. 1988 Jan;11(1):83–88. doi: 10.1016/0735-1097(88)90170-2. [DOI] [PubMed] [Google Scholar]
  10. Wilensky R. L., Yudelman P., Cohen A. I., Fletcher R. D., Atkinson J., Virmani R., Roberts W. C. Serial electrocardiographic changes in idiopathic dilated cardiomyopathy confirmed at necropsy. Am J Cardiol. 1988 Aug 1;62(4):276–283. doi: 10.1016/0002-9149(88)90225-1. [DOI] [PubMed] [Google Scholar]
  11. Xiao H. B., Brecker S. J., Gibson D. G. Differing effects of right ventricular pacing and left bundle branch block on left ventricular function. Br Heart J. 1993 Feb;69(2):166–173. doi: 10.1136/hrt.69.2.166. [DOI] [PMC free article] [PubMed] [Google Scholar]
  12. Xiao H. B., Lee C. H., Gibson D. G. Effect of left bundle branch block on diastolic function in dilated cardiomyopathy. Br Heart J. 1991 Dec;66(6):443–447. doi: 10.1136/hrt.66.6.443. [DOI] [PMC free article] [PubMed] [Google Scholar]
  13. Xiao H. B., Roy C., Gibson D. G. Nature of ventricular activation in patients with dilated cardiomyopathy: evidence for bilateral bundle branch block. Br Heart J. 1994 Aug;72(2):167–174. doi: 10.1136/hrt.72.2.167. [DOI] [PMC free article] [PubMed] [Google Scholar]
  14. von Bibra H., Wirtzfeld A., Hall R., Ulm K., Blömer H. Mitral valve closure and left ventricular filling time in patients with VDD pacemakers. Assessment of the onset of left ventricular systole and the end of diastole. Br Heart J. 1986 Apr;55(4):355–363. doi: 10.1136/hrt.55.4.355. [DOI] [PMC free article] [PubMed] [Google Scholar]

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