Elective Cardiac Arrest

SUMMARY To assess the effects of moderate potassium cardioplegia (37 mEq/l KCI) on the severity of myocardial ischemia during arrest and on post arrest ventricular function, 32 isolated, isovolumic feline hearts were studied before, during and I hour after ischemic arrest. Normothermia (37°C) was maintained in 16 hearts, eight without KCI and eight with KCI. Hypothermia (27°C) was maintained in the remaining 16 hearts, eight with KCI and eight without KCI. Myocardial oxygen (PmO,) and carbon dioxide tensions (PmCO,) were measured by mass spectrometry. Maximum developed intraventricular pressure (max DP) and max dP/dt were used as indices of performance. Compared with normothermic or hypothermic arrest alone, the addition of potassium cardioplegia resulted in a significant reduction in the peak PmCO2 measured during the arrest period. Hypothermia alone resulted in morphologic evidence of improved myocardial preservation and a significant reduction in peak PmCO, compared with normothermia. Post arrest ventricular function was best with the combination of hypothermic arrest and potassium cardioplegia (max DP = 96 ± 6% of control and max dP/dt = 99 ± 5% of control). These data suggest that the beneficial effects of potassium cardioplegia and 27°hypothermia are additive, and that reduction in myocardial ischemia as evidenced by a reduction in peak PmCO, correlated with improvement in ventricular performance in the post arrest period and with preservation of myocardial structure.ISCHEMIC CARDIAC ARREST during open heart surgery provides a tranquil operative field and thereby facilitates valve replacement, direct coronary artery revascularization procedures and the definitive correction of complex congenital anomalies. Once cardiopulmonary bypass is instituted, aortic cross-clamping totally interrupts coronary flow, resulting in fibrillation. Although observable mechanical activity soon stops, electrocardiographic evidence of energyconsuming fibrillation continues until energy substrates are depleted. By reducing metabolic activity, myocardial cooling can prolong the safe period of ischemia. [1][2][3] In addition, various studies suggest that hyperkalemic arrest at the time of aortic crossclamping preserves myocardial function after the ischemic period by quickly inducing electromechanical arrest and thereby reducing substrate utilization.2' 4-7 Early experience with hypertonic potassium citrate arrest was unfavorable due to structural evidence of myocardial damage directly related to the cardioplegic solution.8' 9More recent reports have advocated use of a moderately hyperkalemic, isosmotic solution as an adjunct to hypothermia during ischemic arrest.10 Utilizing such a solution, this study was designed to determine the effect of potassium cardioplegia on development of myocardial ischemia during cardiac arrest at normothermia and at 270 C hypothermia. Furthermore, the protocol allowed for examination of the relationship between severity of ischemia as assessed by myocardial gas tension changes during the arrest peri...

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“…However, 5 Hg, a value which was significantly lower (P < 0.005) than the PmCO2 in the group with hypothermia alone.…”

Section: Myocardial Metabolismmentioning

confidence: 69%

Effect of potassium cardioplegia on myocardial ischemia and post arrest ventricular function.

Schaff¹,

Dombroff²,

Flaherty³

et al. 1978

Circulation

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“…A major factor in the success of this group was lack of cardiac ischemia (as aorta was not clamped) and quality of their oxygenator (which was a human adult). The first use of "elective cardiac arrest" was by Melrose in 1955, who also coined the term "cardioplegia" for the technique [5]. Gott et al used retrograde perfusion of the heart via the coronary sinus using warm blood with Melrose solution [6].…”

Section: Historical Aspectsmentioning

confidence: 99%

Myocardial Protection in Neonates and Infants: What have we Learnt? Where do we Go?

SachinTalwar¹

2015

J Heart Circ

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Myocardial protection in neonates and infants during heart surgery is still a matter of considerable debate. Multiple centers around the world have devised their own methods. Despite multiple claims of superiority of one method over another, there is no firm evidence in favor of one method over another and considerable research work is required in this field. This review summarizes the past, present and future of myocardial protection in children.

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“…The use of cardioplegic solutions started in the 1950s, when Melrose et al [1] used potassium citrate to induce heart arrest. This technique was abandoned in view of the poor outcomes, especially the myocardial necrosis.…”

Section: Introductionmentioning

confidence: 99%

Análise ultra-estrutural do miocárdio usando solução cardioplégica cristalóide com e sem procaína em pacientes submetidos à troca valvar aórtica

Dussin¹,

Moura²,

Gib³

et al. 2008

Rev Bras Cir Cardiovasc

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Análise ultra-estrutural do miocárdio usando solução cardioplégica cristalóide com e sem procaína em pacientes submetidos à troca valvar aórtica Ultrastructural study of the myocardium using cardioplegic crystalloid solution with and without procaine in patients undergoing aortic valve replacement Abstract Objective: The aim of this study was to assess whether the presence of procaine in crystalloid cardioplegic solution increases myocardial protection at the ultra structural level.Methods: Eighteen patients that underwent aortic valve replacement in the Hospital de Clínicas de Porto Alegre over a 10-month period were studied. They were randomly allocated into two groups: group A -eight patients receiving cardioplegia without procaine; group B -ten patients receiving cardioplegia with procaine. Myocardial biopsies were performed in three different periods: 1st -before ischemic arrest, 2nd -at the end of ischemic arrest, and 3rd -15 minutes after reperfusion.Results: The ultra structural analysis comparing the groups in the three moments did not show any statistically significant difference. The mean score in group A at moment I, II and III was 0.1 ± 0.2; 0.4 ± 0.3; 0.4 ± 0.4, and group B 0.2 ± 0.2; 0.4 ± 0.3; 0.7 ± 0.2. Comparative analysis of CK-MB was similar. The spontaneous return to sinus rhythm after aortic declamping in group B occurred in 70% and in group A 12.5% (p=0.024).Conclusion: Both cardioplegic solutions tested were equally effective in myocardial preservation, and we could not demonstrate at the ultrastructural level any benefit when procaine was added. The spontaneous return to sinus rhythm after aortic declamping was significantly greater when procaine was added. 390DUSSIN, LH ET AL -Ultrastructural study of the myocardium using cardioplegic crystalloid solution with and without procaine in patients undergoing aortic valve replacement Bras Cir Cardiovasc 2008; 23(3): 389-395 Rev

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Elective Cardiac Arrest

Cited by 494 publications

References 4 publications

Effect of potassium cardioplegia on myocardial ischemia and post arrest ventricular function.

Effect of potassium cardioplegia on myocardial ischemia and post arrest ventricular function.

Myocardial Protection in Neonates and Infants: What have we Learnt? Where do we Go?

Análise ultra-estrutural do miocárdio usando solução cardioplégica cristalóide com e sem procaína em pacientes submetidos à troca valvar aórtica

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