Optimization of transthoracic ventricular defibrillation-biphasic and triphasic shocks, waveform rounding, and synchronized shock delivery

BJ Kidwai, A McIntyre, JMCC Anderson, AAJ Adgey

    Research output: Contribution to journalArticle

    13 Citations (Scopus)

    Abstract

    The aim of this study is to optimize the truncated exponential waveform for transthoracic ventricular defibrillation. Discharge of a capacitor gives a fast-rising waveform with a spike; rounding of the waveform slows the rate of rise and removes the spike. Defibrillation thresholds for electrically induced VF were determined for rounded and conventional biphasic and triphasic waveforms (apex-anterior paddles; 130 microF capacitor; 3-10 ms phase duration), and for the Lown waveform in 29 anesthetized pigs. Rounding of the leading edge of the biphasic waveform reduced the threshold voltage and current for defibrillation at 3 + 3 ms and 6 + 6 ms phase duration, relative to the conventional unrounded biphasic or the Lown waveforms. The threshold delivered energy was lower for rounded truncated exponential biphasic shocks at 3 + 3 ms (55.3 +/- 2.5 J) than at 6 + 6 ms (67.6 +/- 2.9 J; reduction 15.9 +/- 3.8%; P <.001; n = 29) phase duration. Triphasic shocks (total duration 6-12 ms) showed no advantages over biphasic shocks in this model. The rounded waveform (6 + 6 ms phase duration) had a reduced delivered energy at threshold (9%) with transthoracic shock delivery synchronized to peak (71.1 +/- 4.2 J) or trough (71.5 +/- 4.9 J) of the high amplitude body surface electrocardiogram signal in ventricular fibrillation, compared with unsynchronized shocks (78.7 +/- 4.7 J; P <.05). In this study a biphasic, rounded waveform of total duration 6 or 12 ms, was optimal for the correction of electrically-induced ventricular fibrillation. Synchronization to the peak or trough of the high amplitude electrocardiogram signal gave a further reduction in the energy to defibrillate.
    LanguageEnglish
    Pages235-244
    JournalJournal of Electrocardiology
    Volume35
    Issue number3
    Publication statusPublished - 2002

    Fingerprint

    Shock
    Ventricular Fibrillation
    Electrocardiography
    Swine

    Keywords

    • Animals
    • Electric Countershock: methods
    • Electrocardiography
    • Female
    • Male
    • Swine

    Cite this

    @article{eba85860d1ef4cd5a106d2e8df830155,
    title = "Optimization of transthoracic ventricular defibrillation-biphasic and triphasic shocks, waveform rounding, and synchronized shock delivery",
    abstract = "The aim of this study is to optimize the truncated exponential waveform for transthoracic ventricular defibrillation. Discharge of a capacitor gives a fast-rising waveform with a spike; rounding of the waveform slows the rate of rise and removes the spike. Defibrillation thresholds for electrically induced VF were determined for rounded and conventional biphasic and triphasic waveforms (apex-anterior paddles; 130 microF capacitor; 3-10 ms phase duration), and for the Lown waveform in 29 anesthetized pigs. Rounding of the leading edge of the biphasic waveform reduced the threshold voltage and current for defibrillation at 3 + 3 ms and 6 + 6 ms phase duration, relative to the conventional unrounded biphasic or the Lown waveforms. The threshold delivered energy was lower for rounded truncated exponential biphasic shocks at 3 + 3 ms (55.3 +/- 2.5 J) than at 6 + 6 ms (67.6 +/- 2.9 J; reduction 15.9 +/- 3.8{\%}; P <.001; n = 29) phase duration. Triphasic shocks (total duration 6-12 ms) showed no advantages over biphasic shocks in this model. The rounded waveform (6 + 6 ms phase duration) had a reduced delivered energy at threshold (9{\%}) with transthoracic shock delivery synchronized to peak (71.1 +/- 4.2 J) or trough (71.5 +/- 4.9 J) of the high amplitude body surface electrocardiogram signal in ventricular fibrillation, compared with unsynchronized shocks (78.7 +/- 4.7 J; P <.05). In this study a biphasic, rounded waveform of total duration 6 or 12 ms, was optimal for the correction of electrically-induced ventricular fibrillation. Synchronization to the peak or trough of the high amplitude electrocardiogram signal gave a further reduction in the energy to defibrillate.",
    keywords = "Animals, Electric Countershock: methods, Electrocardiography, Female, Male, Swine",
    author = "BJ Kidwai and A McIntyre and JMCC Anderson and AAJ Adgey",
    note = "LR: 20091111RX: 850816 (on Jul 22, 2011)",
    year = "2002",
    language = "English",
    volume = "35",
    pages = "235--244",
    journal = "Journal of Electrocardiology",
    issn = "0022-0736",
    publisher = "Elsevier",
    number = "3",

    }

    Optimization of transthoracic ventricular defibrillation-biphasic and triphasic shocks, waveform rounding, and synchronized shock delivery. / Kidwai, BJ; McIntyre, A; Anderson, JMCC; Adgey, AAJ.

    In: Journal of Electrocardiology, Vol. 35, No. 3, 2002, p. 235-244.

    Research output: Contribution to journalArticle

    TY - JOUR

    T1 - Optimization of transthoracic ventricular defibrillation-biphasic and triphasic shocks, waveform rounding, and synchronized shock delivery

    AU - Kidwai, BJ

    AU - McIntyre, A

    AU - Anderson, JMCC

    AU - Adgey, AAJ

    N1 - LR: 20091111RX: 850816 (on Jul 22, 2011)

    PY - 2002

    Y1 - 2002

    N2 - The aim of this study is to optimize the truncated exponential waveform for transthoracic ventricular defibrillation. Discharge of a capacitor gives a fast-rising waveform with a spike; rounding of the waveform slows the rate of rise and removes the spike. Defibrillation thresholds for electrically induced VF were determined for rounded and conventional biphasic and triphasic waveforms (apex-anterior paddles; 130 microF capacitor; 3-10 ms phase duration), and for the Lown waveform in 29 anesthetized pigs. Rounding of the leading edge of the biphasic waveform reduced the threshold voltage and current for defibrillation at 3 + 3 ms and 6 + 6 ms phase duration, relative to the conventional unrounded biphasic or the Lown waveforms. The threshold delivered energy was lower for rounded truncated exponential biphasic shocks at 3 + 3 ms (55.3 +/- 2.5 J) than at 6 + 6 ms (67.6 +/- 2.9 J; reduction 15.9 +/- 3.8%; P <.001; n = 29) phase duration. Triphasic shocks (total duration 6-12 ms) showed no advantages over biphasic shocks in this model. The rounded waveform (6 + 6 ms phase duration) had a reduced delivered energy at threshold (9%) with transthoracic shock delivery synchronized to peak (71.1 +/- 4.2 J) or trough (71.5 +/- 4.9 J) of the high amplitude body surface electrocardiogram signal in ventricular fibrillation, compared with unsynchronized shocks (78.7 +/- 4.7 J; P <.05). In this study a biphasic, rounded waveform of total duration 6 or 12 ms, was optimal for the correction of electrically-induced ventricular fibrillation. Synchronization to the peak or trough of the high amplitude electrocardiogram signal gave a further reduction in the energy to defibrillate.

    AB - The aim of this study is to optimize the truncated exponential waveform for transthoracic ventricular defibrillation. Discharge of a capacitor gives a fast-rising waveform with a spike; rounding of the waveform slows the rate of rise and removes the spike. Defibrillation thresholds for electrically induced VF were determined for rounded and conventional biphasic and triphasic waveforms (apex-anterior paddles; 130 microF capacitor; 3-10 ms phase duration), and for the Lown waveform in 29 anesthetized pigs. Rounding of the leading edge of the biphasic waveform reduced the threshold voltage and current for defibrillation at 3 + 3 ms and 6 + 6 ms phase duration, relative to the conventional unrounded biphasic or the Lown waveforms. The threshold delivered energy was lower for rounded truncated exponential biphasic shocks at 3 + 3 ms (55.3 +/- 2.5 J) than at 6 + 6 ms (67.6 +/- 2.9 J; reduction 15.9 +/- 3.8%; P <.001; n = 29) phase duration. Triphasic shocks (total duration 6-12 ms) showed no advantages over biphasic shocks in this model. The rounded waveform (6 + 6 ms phase duration) had a reduced delivered energy at threshold (9%) with transthoracic shock delivery synchronized to peak (71.1 +/- 4.2 J) or trough (71.5 +/- 4.9 J) of the high amplitude body surface electrocardiogram signal in ventricular fibrillation, compared with unsynchronized shocks (78.7 +/- 4.7 J; P <.05). In this study a biphasic, rounded waveform of total duration 6 or 12 ms, was optimal for the correction of electrically-induced ventricular fibrillation. Synchronization to the peak or trough of the high amplitude electrocardiogram signal gave a further reduction in the energy to defibrillate.

    KW - Animals

    KW - Electric Countershock: methods

    KW - Electrocardiography

    KW - Female

    KW - Male

    KW - Swine

    M3 - Article

    VL - 35

    SP - 235

    EP - 244

    JO - Journal of Electrocardiology

    T2 - Journal of Electrocardiology

    JF - Journal of Electrocardiology

    SN - 0022-0736

    IS - 3

    ER -