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. 2009 Feb 3;22(10):649–654. doi: 10.1002/clc.4960221011

Relation of ventricular repolarization to cardiac cycle length in normal subjects, hypertrophic cardiomyopathy, and patients with myocardial infarction

Irina Savelieva 1,✉, Yee Guan Yap 1, Gang Yi 1, Xiao Hua Guo 1, Katerina Hnatkova 1, A John Camm 1, Marek Malik 1
PMCID: PMC6655915  PMID: 10526689

Abstract

Background: Prolonged QT interval and QT dispersion have been reported to reflect an increased inhomogeneity of ventricular repolarization, which is believed to be responsible for the development of arrhythmic events in patients with long QT syndrome, coronary heart disease, and myocardial infarction, congestive heart failure, and hypertrophic cardiomyopathy (HC).

Hypothesis: This study was undertaken to determine whether an abnormal QT/RR dynamicity may reflect autonomic imbalance and may contribute to arrhythmogenesis in patients with heart disease.

Methods: The relation between QT, QTpeak (QTp), Tpeak‐Tend (TpTc) intervals and cardiac cycle length was assessed in 70 normal subjects, 37 patients with HC, and 48 survivors of myocardial infarction (MI). A set of 10 consecutive electrocardiograms was evaluated automatically in each subject using QT Guard software (Marquette Medical Systems, Milwaukee, Wisc.).

Results: In patients with HC, all intervals were significantly prolonged compared with normals (p <0.001 for QT and QTp; p <0.04 for TpTc); in survivors of MI, this was true for the maximum QT and QTp intervals (p <0.05). A strong linear correlation between QT, QTp, and RR intervals was observed in normals and in patients with MI and HC (r = 0.65–0.59, 0.82–0.77, 0.79–0.74, respectively, p <0.0001). TpTc interval only showed a weak correlation with heart rate in normals (r = 0.24, p <0.05) and was rate‐independent in both patient groups (p = NS). Compared with normals, the slopes of QT/RR and QTp/RR regression lines were significantly steeper in patients with MI and HC (0.0990–0.0883, 0.1597–0.1551, 0.1653–0.1486, respectively). Regression lines were neither parallel nor identical between normals and patients (T> 1.96, Z> 3.07). There was no difference in steepness for TpTeR/RR lines between groups (0.0110, 0.0076, 0.0163, respectively). TpTe/QTp ratio was similar in normals and in patients with MI and HC (0.30 ± 0.03, 0.31 ± 0.07, 0.30 ± 0.04, respectively), in the absence of any correlation between QTp and TpTe intervals, suggesting disproportional prolongation of both components of QT interval.

Conclusion: Compared with normals, a progressive increase in QT and QTp intervals at slower heart rates in patients with MI and HC may indicate an enhanced variability of the early ventricular repolarization and may be one of the mechanisms of arrhythmogenesis.

Keywords: ventricular repolarization, QT interval, QT/RR dynamicity, hypertrophic cardiomyopathy, myocardial infarction

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References

  • 1. Day CP, McComb JM, Campbell RWF: QT dispersion: An indication of arrhythmia risk in patients with long QT intervals. Br Heart J 1990; 63: 342–344 [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 2. Priori S, Napolitano C, Diehl L, Schwartz PJ: Dispersion of QT interval. A marker of therapeutic efficacy in the idiopathic long QT syndrome. Circulation 1994; 89: 1681–1689 [DOI] [PubMed] [Google Scholar]
  • 3. Zareba W, Moss AJ le Cessie SI: Dispersion of ventricular repolarization and arrhythmic death in coronary artery disease. Am J Cardiol 1994; 74: 550–553 [DOI] [PubMed] [Google Scholar]
  • 4. Schwartz PJ, Wolf S: QT interval prolongation as predictor of sudden death in patients with myocardial infarction. Circulation 1978; 57: 1074–1077 [DOI] [PubMed] [Google Scholar]
  • 5. Algra A, Tijssen JGP, Roelandt JRTC, Pool J, Lubsen J: QTc prolongation measured by standard 12‐lead electrocardiography is an independent risk factor for sudden death due to cardiac arrest. Circulation 1991; 83: 1888–1894 [DOI] [PubMed] [Google Scholar]
  • 6. Fu GS, Messier A, Simon R: Repolarization dispersion and sudden cardiac death in patients with impaired left ventricular function. Eur Heart J 1997; 18: 281–289 [DOI] [PubMed] [Google Scholar]
  • 7. Buja G, Miorelli M, Turrini P, Melacini P, Nava A: Comparison of QT dispersion in hypertrophic cardiomyopathy between patients with and without ventricular arrhythmias and sudden death. Am J Cardiol 1993; 72: 973–976 [DOI] [PubMed] [Google Scholar]
  • 8. Gang Yi, Elliot PM, Prasad K, Sharma S, Guo X O'Donoghue A, Camm AJ, Malik M, McKenna WJ: Computerised QT dispersion measurement and risk stratification in patients with hypertrophic cardiomyopathy. Circulation 1997; 96 (suppl): I–759 [Google Scholar]
  • 9. Lepeshkin E, Surawicz B: The measurement of the Q‐T interval of the electrocardiogram. Circulation 1952; 6: 378–388 [DOI] [PubMed] [Google Scholar]
  • 10. Merri M, Benhorin J, Alberti M, Locati E, Moss AJ: Electrocardiographic quantitation of ventricular repolarisation. Circulation 1989; 80: 1301–1308 [DOI] [PubMed] [Google Scholar]
  • 11. Emori T, Ohe T, Aihara N, Kurita T, Shimizu W, Kamakura S, Shimomura K: Dynamic relationship between Q‐aT interval and heart rate in patients with long QT syndrome during 24‐hour Holter ECG monitoring. PACE 1995; 18: 1909–1918 [DOI] [PubMed] [Google Scholar]
  • 12. Bexton RS, Vallin HO, Camm AJ: Diurnal variation of the QT interval—influence of the autonomic nervous system. Br Heart J 1986; 55: 253–258 [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 13. Chaundry II, Quamar S, Spodick DH: QT interval effects of normal QRS variation. Am J Cardiol 1994; 74: 628–629 [DOI] [PubMed] [Google Scholar]
  • 14. O'Donnel J, Knoebel SB, Lovelace DE, McHenry PL: Computer quantitation of QT and terminal T wave (aT‐eT) intervals during exercise: Methodology and results in normal men. Am J Cardiol 1981; 47: 1168–1172 [DOI] [PubMed] [Google Scholar]
  • 15. Sundqvist K, Sylven C: Cardiac repolarization properties during standardized exercise test as studied by QT, QT peak and terminated T‐wave intervals. Clin Physiol 1989; 9: 419–425 [DOI] [PubMed] [Google Scholar]
  • 16. Benhorin J, Merri M, Alberti M, Locati E, Moss AJ, Hall WJ, Cui L: Long QT syndrome: New electrocardiographic characteristics. Circulation 1990; 82: 521–527 [DOI] [PubMed] [Google Scholar]
  • 17. Bruggemann T, Eisenreich S, Behrens S, Ehlers C, Muller D, Andresen D: Continuous QT interval measurements from 24‐hour electrocardiography and risk after myocardial infarction. Ann Noninvas Electrocardiol 1997; 2: 264–273 [Google Scholar]
  • 18. Brandenburg RO, Chazov E, Cherian G, Falase AO, Grosgogeat Y, Kawai C, Loogen F, Martin Judez Y, Orinius E, Goodwin JF, Olsen EGJ, Oakley CM, Pisa Z: Report of the WHO/IFSC task force on the definition and classification of cardiomyopathies. Br Heart J 1980; 44: 672–673 [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 19. Xue Q, Reddy S: New algorithms for QT dispersion analysis. IEEE Comput Cardiol 1996: 293–296
  • 20. Savelieva I, Gang Yi, Guo X, Hnatkova K, Malik M: Agreement and reproducibility of automatic versus manual measurement of QT interval and QT dispersion. Am J Cardiol 1998; 81: 471–477 [DOI] [PubMed] [Google Scholar]
  • 21. Copie X, Alonso C, Lavergne T, Iliou MC, Guize L, Le Heuzey JY: Reproducibility of QT interval measurements obtained from 24‐hour digitized ambulatory three‐lead electrocardiograms in patients with acute myocardial infarction and healthy subjects. Ann Noninvas Electrocardiol 1998; 3: 38–45 [Google Scholar]
  • 22. Dritsas A, Sbarouni E, Gilligan D, Nihoyannopoulos P, Oakley CM: QT‐interval abnormalities in hypertrophic cardiomyopathy. Clin Cardiol 1992; 15: 739–742 [DOI] [PubMed] [Google Scholar]
  • 23. Higham PD, Furiss SS, Campbell RWF: QT dispersion and components of the QT interval in ischaemia and infarction. Br Heart J 1995; 73: 32–36 [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 24. Greenberg PS, Friscia DA, Ellestad MH: Predictive accuracy of Q‐X/Q‐T ratio, Q‐Tc interval, S‐T depression and R wave amplitude during stress testing. Am J Cardiol 1979; 44: 18–23 [DOI] [PubMed] [Google Scholar]
  • 25. Viitasalo M, Karjalainen J: QT intervals at heart rates from 50 to 120 beats per minute during 24‐hour electrocardiographic recordings in 100 healthy men: Effects of atenolol. Circulation 1992; 86: 1439–1442 [DOI] [PubMed] [Google Scholar]
  • 26. Merri M, Moss AJ, Benhorin J, Locati EH, Alberti M, Badilini F: Relation between ventricular repolarisation duration and cardiac cycle length during 24‐hour Holter recordings: Findings in normal patients and patients with long QT syndrome. Circulation 1992; 85: 1816–1821 [DOI] [PubMed] [Google Scholar]
  • 27. Kluge P, Walter T, Neugebauer A: Comparison of QT/RR relationship using two algorithms of QT interval analysis for identification of high risk patients for life‐threatening ventricular arrhythmias. Ann Noninvas Electrocardiol 1997; 2: 3–8 [Google Scholar]
  • 28. Extramiana F, Huikuri HV, Neyroad N, Koistenen JM, Coumel P, Maison‐Blanche P: QT rate adaptation: A new index to discriminate patients with and without ventricular arrhythmias following myocardial infarction? Circulation 1997; 96 (suppl 1): I‐716 [Google Scholar]
  • 29. Singh JP, Johnston J, Sleight P, Bird R, Ryder K, Hart J: Left ventricular hypertrophy in hypertensive patients is associated with abnormal rate adaptation of QT interval. J Am Coll Cardiol 1997; 29: 778–784 [DOI] [PubMed] [Google Scholar]
  • 30. Kurita T, Ohe T, Marui N, Aihara N, Takaki H, Kamakura S, Matsuhisa M, Shimomura K: Bradycardia‐induced abnormal QT prolongation in patient with complete atrioventricular block with torsades de pointes. Am J Cardiol 1992; 69: 628–633 [DOI] [PubMed] [Google Scholar]

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