Effects of postextrasystolic potentiation on systolic time intervals

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      The changes in systolic time intervals associated with postextrasystolic potentiation were studied in 48 patients whose left ventricular function was categorized angiographlcally into four groups—normal function (I) and mlld (II), moderate (III) and severe (IV) left ventricular dysfunction. Postectopic potentiation in all groups caused a decrease in preejection period/left ventricular ejection time (PEP/LVET) ratio. The greatest potentiation and decreases in PEP/LVET ratio were noted in beats where the difference in compensatory pause and coupling interval (both expressed as percent of basic cycle length [CP percent — CI percent]) exceeded 40. The decrease in the ratio was least in the normal subjects (Group I) and maximal in Group IV patients. The pattern of response of the rate-corrected left ventricular ejection time and preejectlon period was also different at the four levels of ventricular function. Marked shortening of ejection time with minimal shortening of preejection period occurred in Group I, but in Group IV patients there was marked shortening of preejection period and minimal shortening of ejection time. An intermediate response was seen in Group II and III patients. The amount of shortening of ejection time exceeded that of preejection period in Group II patients; the reverse was true in Group III patients. The group responses differed with a significance of 2P <0.001 except when Group II was compared with Group III, when the significance was 2P <0.025. Thus, measurement of changes in systolic time intervals associated with postextrasystolic potentiation is of value as a noninvasive means of assessing resting left ventricular function.
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        • Hamby RI
        • Aintablian A
        • Wisoff BG
        • et al.
        Response of the left ventricle in coronary artery disease to postextrasystolic potentiation.
        Circulation. 1975; 51: 428-435
        • Dyke SH
        • Cohn PF
        • Gorlin R
        • et al.
        Detection of residual myocardial function in coronary artery disease using post-extrasystolic potentiation.
        Circulation. 1974; 50: 694-699
        • Dyke SH
        • Urschel CW
        • Sonnenblick EH
        • et al.
        Detection of latent function in acutely ischemic myocardium in the dog: comparison of pharmacologic inotropic stimulation and post-extrasystolic potentiation.
        Circ Res. 1975; 36: 490-497
        • Weissler AM
        • Harris WS
        • Schoenfeld CD
        Bedside technics for the evaluation of ventricular function in man.
        Am J Cardiol. 1969; 23: 577-583
        • Braunwald E
        • Ross J
        • Frommer PL
        • et al.
        Clinical observations on paired electrical stimulation of the heart: effects on ventricular performance and heart rate.
        Am J Med. 1964; 37: 700-711
        • White CW
        • Zimmerman TJ
        Prolonged left ventricular ejection time in the post-premature beat: a sensitive sign of idiopathic hypertrophic subaortic stenosis.
        Circulation. 1975; 52: 306-312
        • Bazett HC
        An analysis of the time relations of the electrocardiogram.
        Heart. 1920; 7: 353-370
        • Weissler AM
        • Harris WS
        • Schoenfeld CD
        Systolic time intervals in heart failure in man.
        Circulation. 1968; 37: 149-159
        • Woodworth RS
        Maximal contraction “staircase” contraction refractory period and compensatory pause of the heart.
        Am J Physiol. 1902–1903; 8: 213-249
        • Ranganathan N
        • Silver MD
        • Robinson TI
        • et al.
        Idiopathic prolapsed mitral leaflet syndrome Angiographic-clinical correlations.
        Circulation. 1976; 54: 707-716
        • Scampardonis G
        • Yang SS
        • Maranhao V
        • et al.
        Left ventricular abnormalities in prolapsed mitral leaflet syndrome.
        Circulation. 1973; 48: 287-297
        • Langendorff O
        Ueber elektrische Reizung des Herzens.
        in: Arch Physiol (Arch Anat Physiol, Phys Abt). 1885: 284-287
        • Langendorff O
        Untersuchungen am uberlebenden Saugethierherzen 111. Abhandlung. Vorubergehende Unregelmassigkeiten des Herzschlages und ihre Ausgleichung.
        Pfluegers Arch. 1898; 70: 473-486
        • Gley E
        Sur la loi de l'inexcitabilité periodique de coeur chez les mammifères.
        Arch Physiol Norm Path, ser 5. 1888; 1: 499-507
        • Macwilliam JA
        On the rhythm of the mammalian heart.
        J Physiol. 1888; 9: 167-198
        • Bottazzi F
        Sullo sviluppo embrionale del la fuzione motoria negli organi a cellule muscolari.
        in: G. Carnesecchi e Firgli, Firenze1897: 120
        • Hoffman BF
        • Blndter E
        • Suckling EE
        Post-extrasystolic potentiation of contraction in cardiac muscle.
        Am J Physiol. 1956; 185: 95-102
        • Rihl J
        Zur Erklarung der Vergrosserang der post-extra-systolischen Systole des Saugethierherzens.
        Z Exp Pathol Ther. 1906; 3: 1-18
        • Bornstein A
        Die Postextrasystole.
        Zentralbl Physiol. 1906; 20: 588-590
        • Hoffman BF
        • Kelly JJ
        Effects of rate and rhythm on contraction of rat papillary muscle.
        Am J Physiol. 1959; 197: 1199-1204
        • Siebens AA
        • Hoffman BF
        • Cranefield PF
        Ventricular excitability and contractility (abstr).
        Am J Physiol. 1955; 183: 662
        • Siebens AA
        • Hoffman BF
        • Cranefield PF
        • et al.
        Regulation of contractile force during ventricular arrhythmias.
        Am J Physiol. 1959; 197: 971-977
        • Lendrum B
        • Feinberg H
        • Boyd E
        • et al.
        Rhythm effects on contractility of the beating isovolumic left ventricle.
        Am J Physiol. 1960; 199: 1115-1120
        • Cranefield PF
        • Scherlag BJ
        • Yeh BK
        • et al.
        Treatment of acute cardiac failure by maintained post-extrasystolic potentiation.
        Bull NY Acad Med. 1964; 40: 903-913
        • Braunwald NS
        • Gay WA
        • Morrow AG
        • et al.
        Sustained paired electrical stimuli. Slowing of the ventricular rate and augmentation of the contractile force.
        Am J Cardiol. 1964; 14: 385-393
        • Frommer PL
        • Robinson BF
        • Braunwald E
        Paired electrical stimulation A comparison of the effects on performance of the failing and nonfailing heart.
        Am J Cardiol. 1966; 18: 738-744
        • Hoffman BF
        • Bartlestone HJ
        • Scherlag BJ
        • et al.
        Effects of postextrasystolic potentiation on normal and failing hearts.
        Bull NY Acad Med. 1965; 41: 498-534
        • Ross Jr, J
        • Sonnenblick EH
        • Kaiser GA
        • et al.
        Electroaugmentation of ventricular performance and oxygen consumption by repetitive application of paired electrical stimuli.
        Circ Res. 1965; 16: 332-342
        • Beck W
        • Chesler E
        • Schrire V
        Post-extrasystolic ventricular pressure responses.
        Circulation. 1971; 44: 523-533
        • Zoll PM
        • Belgard AH
        • Weintraub MJ
        • et al.
        External mechanical cardiac stimulation.
        N Engl J Med. 1976; 294: 1274-1277
        • Lown B
        • Fakhro AM
        • Hood Jr, WB
        • et al.
        The coronary care unit. New perspectives and directions.
        JAMA. 1967; 199: 188-198