Cardiac damage produced by direct current countershock applied to the heart

Doherty, Paul W.; McLaughlin, Peter R.; Billingham, Margaret E.; Kernoff, Robert S.; Goris, Michael L.; Harrison, Donald C.

doi:10.1016/s0002-9149(79)80008-9

Cited by 163 publications

(33 citation statements)

References 10 publications

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“…If an initial low-energy shock fails to defibrillate, the usual clinical practice is to repeat shocks at progressively higher energies until successful, but the combination of multiple shocks and a longer duration of ventricular fibrillation and ischemia increases the chances of myocardial damage. '13 14 If transthoracic impedance could be accurately determined in advance of defibrillation or cardioversion, inappropriately low energies could be avoided in patients with known high transthoracic impedance. This would help reduce the number of shocks required and avoid unnecessary delays in restoring sinus rhythm.…”

mentioning

confidence: 99%

Advance prediction of transthoracic impedance in human defibrillation and cardioversion: importance of impedance in determining the success of low-energy shocks.

Kerber¹,

Kouba²,

Martins³

et al. 1984

Circulation

120

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The purposes of this study were to evaluate a method that predicts transthoracic impedance in advance of defibrillating shocks in humans and to assess the importance of transthoracic impedance in low-energy defibrillation. Via defibrillator electrodes we applied 31 kHz current to the chest during the defibrillator charge cycle, before the defibrillating shock was actually delivered. The current flow was limited by transthoracic impedance; a microprocessor monitored the predischarge current flow and determined the predischarge impedance by calibration against known resistance values. Actual impedance to the defibrillating shock was also determined and compared with the predicted impedance. With this approach we predicted impedance in 19 patients who received 66 shocks for ventricular and atrial arrhythmias. Predicted impedance (y) correlated very well with actual impedance (x): y = .90x + 11.3; r = .97. To determine the importance of impedance in defibrillation and cardioversion, we prospectively gathered data from 96 patients who received shocks of various energies for ventricular or atrial arrhythmias. In patients with high transthoracic impedance (> 97 Q), low-energy shocks (. 100 J) for ventricular defibrillation had only a 20% success rate as opposed to a 70% success rate for low-energy shocks in patients with low or average impedance (p < .05). We conclude that transthoracic impedance can be accurately predicted in advance of defibrillation and cardioversion. This method permits the preshock identification of patients with high impedance in whom attempts to defibrillate with low-energy shocks are inappropriate. Circulation 70, No. 2, 303-308, 1984. ATRIAL and ventricular arrhythmias can be terminated by a damped sinusoidal electrical shock. The operator selects the shock energy (joules), but defibrillation or cardioversion is achieved by passage of current (amperes) MethodsThe study was approved by the University of Iowa HumanResearch Committee. Data were collected prospectively from a total of 96 patients receiving shocks for ventricular fibrillation ("defibrillation") and for ventricular tachycardia, atrial fibrillation, or atrial flutter ("cardioversion"). We defined defibrillation as the conversion of ventricular fibrillation to an organized rhythm, usually sinus rhythm. We defined cardioversion as the conversion of ventricular tachycardia to a supraventricular rhythm or the conversion of atrial fibrillation or atrial flutter to sinus rhythm. The patients underwent defibrillation or cardioversion in the coronary care unit, emergency room, electrophysiology laboratory, or inpatient wards. For the initial portion of this study (impedance prediction) the electrodes used were either standard hand-held electrode paddles or self-adhesive electrode pads; the two types of electrodes are equally effective. In the second phase of the study (relationship of shock success to transthoracic impedance) we analyzed data from an ongoing, prospective study of self-adhesive, monitor-defibrillator pads for d...

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mentioning

confidence: 99%

Advance prediction of transthoracic impedance in human defibrillation and cardioversion: importance of impedance in determining the success of low-energy shocks.

Kerber¹,

Kouba²,

Martins³

et al. 1984

Circulation

120

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“…The incidence of post-operative ventricular arrhythmias may range from 1.8% -13% (14). Ventricular fibrillation status and attempts for treatment by DC shock may injure the myocardium during reperfusion (15). Although there several anti-arrhythmic agents can be used to prevent postoperative arrhythmia after aortic declamping, there are reports that show amiodarone may be more effective in preventing post-operative arrhythmias (16).…”

Section: Discussionmentioning

confidence: 99%

Impact of Procaine Hydrochloride Versus Lidocaine in Cardioplegic Solution, on Reperfusion Arrhythmia During Coronary Artery Bypass Graft Surgery

Sadeghi

Austin

Totonchi

et al. 2018

Multidiscip Cardio Annal

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Background: The best way to reduce the occurrence of arrhythmias that generally occur after an open heart surgery is to improve the quality of myocardial protection against reperfusion damage during the cross-clamp time. In this regard, different cardioplegic solutions play a key role. Differences in the types and contents of cardioplegic solutions may lead to different results of effective protection of the myocardium. The purpose of this study was to compare the effects of the newly introduced procaine hydrochloride (PHC) containing cardioplegic solution (Shahid Ghazi Pharmaceutical Co. Tabriz, Iran) and lidocaine (L) in cardioplegic solution on post aortic clamp arrhythmia in coronary artery bypass graft surgery.

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“…Transient ECG changes consistent with myocyte damage have been reported after transthoracic countershocks 12 and appear to be corroborated by the release of myocardium-specific enzymes 13 and ultrastructural damage to cardiac myocytes. 10 These indirect markers of countershock-induced injury, however, have proven difficult to correlate with surprisingly variable effects on myocardial function.…”

Section: Countershock-induced Contractile Dysfunctionmentioning

confidence: 99%

Resuscitation After Prolonged Ventricular Fibrillation With Use of Monophasic and Biphasic Waveform Pulses for External Defibrillation

et al. 2000

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Background-Survival after prolonged ventricular fibrillation (VF) appears severely limited by 2 major factors: (1) low defibrillation success rates and (2) persistent post-countershock myocardial dysfunction. Biphasic (BP) waveforms may prove capable of favorably modifying these limitations. However, they have not been rigorously tested against monophasic (MP) waveforms in clinical models of external defibrillation, particularly where rescue from prolonged VF is the general rule. Methods and Results-We randomized 26 dogs to external countershocks with either MP or BP waveforms.Hemodynamics were assessed after shocks applied during sinus rhythm, after brief VF (Ͼ10 seconds), and after resuscitation from prolonged VF (Ͼ10 minutes). Short-term differences in percent change in left ventricular ϩdP/dt max (MP Ϫ16Ϯ28%, BP ϩ9.1Ϯ24%; Pϭ0.03) and left ventricular ϪdP/dt max (MP Ϫ37Ϯ26%, BP Ϫ18Ϯ20%; Pϭ0.05) were present after rescue from brief VF, with BP animals exhibiting less countershock-induced dysfunction. After prolonged VF, the BP group had lower mean defibrillation thresholds (107Ϯ57 versus 172Ϯ88 J for MP, Pϭ0.04) and significantly shorter resuscitation times (397Ϯ73.7 versus 488Ϯ74.3 seconds for MP, Pϭ0.03). Conclusions-External defibrillation is more efficacious with BP countershocks than with MP countershocks. The lower defibrillation thresholds and shorter resuscitation times associated with BP waveform defibrillation may improve survival after prolonged VF arrest.

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Cardiac damage produced by direct current countershock applied to the heart

Cited by 163 publications

References 10 publications

Advance prediction of transthoracic impedance in human defibrillation and cardioversion: importance of impedance in determining the success of low-energy shocks.

Advance prediction of transthoracic impedance in human defibrillation and cardioversion: importance of impedance in determining the success of low-energy shocks.

Impact of Procaine Hydrochloride Versus Lidocaine in Cardioplegic Solution, on Reperfusion Arrhythmia During Coronary Artery Bypass Graft Surgery

Resuscitation After Prolonged Ventricular Fibrillation With Use of Monophasic and Biphasic Waveform Pulses for External Defibrillation

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