Abstract
BACKGROUND--The mechanism responsible for the reported high incidence of ventricular arrhythmias in mitral valve prolapse is not clear. Electrocardiographic studies show an increased occurrence of repolarisation abnormalities on the 12 lead surface electrocardiogram, indicating regional differences in ventricular recovery. The purpose of this study was to investigate whether dispersion of refractoriness was an arrhythmogenic mechanism. METHODS--QT dispersion was measured in 32 patients with echocardiographically documented mitral valve prolapse and ventricular arrhythmias on 24 hour Holter recordings. QT dispersion was defined as the difference between the maximum and minimum average QT interval in any of the 12 leads of the surface electrocardiogram. QT dispersion corrected for heart rate was calculated by Bazett's formula. The results were compared with the data from 32 matched controls without a history of cardiac disease. Patients taking drugs that influence the QT interval and patients with a QRS duration > 120 ms were excluded. RESULTS--QT dispersion was greater in patients with mitral valve prolapse than in matched controls (60 (20) v 39 (11 ms) respectively, P < or = 0.001) as was corrected QT (64 (20 ms) v 43 (12 ms) respectively, P < or = 0.001). There was no significant difference in minimum or maximum QT intervals between the two groups. CONCLUSIONS--QT dispersion on the 12 lead surface electrocardiogram was greater in patients with mitral valve prolapse with ventricular arrhythmias than in normal controls, but the maximum QT interval was not increased. The results accord with the hypothesis that regional shortening and lengthening of repolarisation times in patients with mitral valve prolapse may account for the increased dispersion of refractoriness.
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- Alpert M. A. Mitral valve prolapse. BMJ. 1993 Apr 10;306(6883):943–944. doi: 10.1136/bmj.306.6883.943. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Bhutto Z. R., Barron J. T., Liebson P. R., Uretz E. F., Parrillo J. E. Electrocardiographic abnormalities in mitral valve prolapse. Am J Cardiol. 1992 Jul 15;70(2):265–266. doi: 10.1016/0002-9149(92)91287-e. [DOI] [PubMed] [Google Scholar]
- Campbell R. W., Godman M. G., Fiddler G. I., Marquis R. M., Julian D. G. Ventricular arrhythmias in syndrome of balloon deformity of mitral valve. Definition of possible high risk group. Br Heart J. 1976 Oct;38(10):1053–1057. doi: 10.1136/hrt.38.10.1053. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Cowan J. C., Yusoff K., Moore M., Amos P. A., Gold A. E., Bourke J. P., Tansuphaswadikul S., Campbell R. W. Importance of lead selection in QT interval measurement. Am J Cardiol. 1988 Jan 1;61(1):83–87. doi: 10.1016/0002-9149(88)91309-4. [DOI] [PubMed] [Google Scholar]
- Cowan M. D., Fye W. B. Prevalence of QTc prolongation in women with mitral valve prolapse. Am J Cardiol. 1989 Jan 1;63(1):133–134. doi: 10.1016/0002-9149(89)91100-4. [DOI] [PubMed] [Google Scholar]
- Day C. P., McComb J. M., Campbell R. W. QT dispersion in sinus beats and ventricular extrasystoles in normal hearts. Br Heart J. 1992 Jan;67(1):39–41. doi: 10.1136/hrt.67.1.39. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Day C. P., McComb J. M., Campbell R. W. QT dispersion: an indication of arrhythmia risk in patients with long QT intervals. Br Heart J. 1990 Jun;63(6):342–344. doi: 10.1136/hrt.63.6.342. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Dean J. W., Lab M. J. Arrhythmia in heart failure: role of mechanically induced changes in electrophysiology. Lancet. 1989 Jun 10;1(8650):1309–1312. doi: 10.1016/s0140-6736(89)92697-4. [DOI] [PubMed] [Google Scholar]
- Gardin J. M., Isner J. M., Ronan J. A., Jr, Fox S. M., 3rd Pseudoischemic "false positive" S-T segment changes induced by hyperventilation in patients with mitral valve prolapse. Am J Cardiol. 1980 May;45(5):952–958. doi: 10.1016/0002-9149(80)90162-9. [DOI] [PubMed] [Google Scholar]
- Gooch A. S., Vicencio F., Maranhao V., Goldberg H. Arrhythmias and left ventricular asynergy in the prolapsing mitral leaflet syndrome. Am J Cardiol. 1972 May;29(5):611–620. doi: 10.1016/0002-9149(72)90161-0. [DOI] [PubMed] [Google Scholar]
- HAN J., MOE G. K. NONUNIFORM RECOVERY OF EXCITABILITY IN VENTRICULAR MUSCLE. Circ Res. 1964 Jan;14:44–60. doi: 10.1161/01.res.14.1.44. [DOI] [PubMed] [Google Scholar]
- Hii J. T., Wyse D. G., Gillis A. M., Duff H. J., Solylo M. A., Mitchell L. B. Precordial QT interval dispersion as a marker of torsade de pointes. Disparate effects of class Ia antiarrhythmic drugs and amiodarone. Circulation. 1992 Nov;86(5):1376–1382. doi: 10.1161/01.cir.86.5.1376. [DOI] [PubMed] [Google Scholar]
- Jackman W. M., Friday K. J., Anderson J. L., Aliot E. M., Clark M., Lazzara R. The long QT syndromes: a critical review, new clinical observations and a unifying hypothesis. Prog Cardiovasc Dis. 1988 Sep-Oct;31(2):115–172. doi: 10.1016/0033-0620(88)90014-x. [DOI] [PubMed] [Google Scholar]
- Jeresaty R. M. Sudden death in the mitral valve prolapse-click syndrome. Am J Cardiol. 1976 Feb;37(2):317–318. doi: 10.1016/0002-9149(76)90328-3. [DOI] [PubMed] [Google Scholar]
- Kligfield P., Levy D., Devereux R. B., Savage D. D. Arrhythmias and sudden death in mitral valve prolapse. Am Heart J. 1987 May;113(5):1298–1307. doi: 10.1016/0002-8703(87)90958-6. [DOI] [PubMed] [Google Scholar]
- Kuo C. S., Munakata K., Reddy C. P., Surawicz B. Characteristics and possible mechanism of ventricular arrhythmia dependent on the dispersion of action potential durations. Circulation. 1983 Jun;67(6):1356–1367. doi: 10.1161/01.cir.67.6.1356. [DOI] [PubMed] [Google Scholar]
- Lab M. J. Contraction-excitation feedback in myocardium. Physiological basis and clinical relevance. Circ Res. 1982 Jun;50(6):757–766. doi: 10.1161/01.res.50.6.757. [DOI] [PubMed] [Google Scholar]
- Lobstein H. P., Horwitz L. D., Curry G. C., Mullins C. B. Electrocardiographic abnormalities and coronary arteriograms in the mitral click-murmur syndrome. N Engl J Med. 1973 Jul 19;289(3):127–131. doi: 10.1056/NEJM197307192890304. [DOI] [PubMed] [Google Scholar]
- Meyers D. G., Vallone N. L., Engel T. R. Repolarization abnormalities in mitral valve prolapse. Am Heart J. 1987 Jun;113(6):1414–1416. doi: 10.1016/0002-8703(87)90656-9. [DOI] [PubMed] [Google Scholar]
- Nishimura R. A., McGoon M. D., Shub C., Miller F. A., Jr, Ilstrup D. M., Tajik A. J. Echocardiographically documented mitral-valve prolapse. Long-term follow-up of 237 patients. N Engl J Med. 1985 Nov 21;313(21):1305–1309. doi: 10.1056/NEJM198511213132101. [DOI] [PubMed] [Google Scholar]
- Pocock W. A., Bosman C. K., Chesler E., Barlow J. B., Edwards J. E. Sudden death in primary mitral valve prolapse. Am Heart J. 1984 Feb;107(2):378–382. doi: 10.1016/0002-8703(84)90389-2. [DOI] [PubMed] [Google Scholar]
- Savage D. D., Levy D., Garrison R. J., Castelli W. P., Kligfield P., Devereux R. B., Anderson S. J., Kannel W. B., Feinleib M. Mitral valve prolapse in the general population. 3. Dysrhythmias: the Framingham Study. Am Heart J. 1983 Sep;106(3):582–586. doi: 10.1016/0002-8703(83)90706-8. [DOI] [PubMed] [Google Scholar]
- Shenoy M. M., Hariman R. J., Balla S., Punatar H. K. Triggered activity as a possible mechanism of ventricular tachycardia in mitral valve prolapse. Am Heart J. 1986 Dec;112(6):1339–1342. doi: 10.1016/0002-8703(86)90377-7. [DOI] [PubMed] [Google Scholar]
- Wei J. Y., Bulkley B. H., Schaeffer A. H., Greene H. L., Reid P. R. Mitral-valve prolapse syndrome and recurrent ventricular tachyarrhythmias: a malignant variant refractory to conventional drug therapy. Ann Intern Med. 1978 Jul;89(1):6–9. doi: 10.7326/0003-4819-89-1-6. [DOI] [PubMed] [Google Scholar]
- Winkle R. A., Lopes M. G., Fitzgerald J. W., Goodman D. J., Schroeder J. S., Harrison D. C. Arrhythmias in patients with mitral valve prolapse. Circulation. 1975 Jul;52(1):73–81. doi: 10.1161/01.cir.52.1.73. [DOI] [PubMed] [Google Scholar]
- Winkle R. A., Lopes M. G., Popp R. L., Hancock E. W. Life-threatening arrhythmias in the mitral valve prolapse syndrome. Am J Med. 1976 Jun;60(7):961–967. doi: 10.1016/0002-9343(76)90567-2. [DOI] [PubMed] [Google Scholar]
- Wit A. L., Fenoglio J. J., Jr, Hordof A. J., Reemtsma K. Ultrastructure and transmembrane potentials of cardiac muscle in the human anterior mitral valve leaflet. Circulation. 1979 Jun;59(6):1284–1292. doi: 10.1161/01.cir.59.6.1284. [DOI] [PubMed] [Google Scholar]