Negative Impact of Acute Reloading after Mechanical Left Ventricular Unloading

Mazurek, Renata; Kariya, Taro; Sakata, Tomoki; Mavropoulos, Spyros A.; Ravichandran, Anjali J; Romeo, Francisco; Yamada, Kelly P.; Ishikawa, Kiyotake

doi:10.1007/s12265-023-10371-z

Cited by 4 publications

(3 citation statements)

References 15 publications

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“…The LV was sliced into five to six cross‐sectional slices from apex to base and separately weighed. Slices were incubated in 2% triphenyltetrazolium chloride solution, and superior and inferior surfaces of each slice were photographed for planimetry analysis to determine percentage infarct size as previously described (Mazurek et al., 2024).…”

Section: Methodsmentioning

confidence: 99%

Reduction of left ventricular diastolic pressure as a key regulator of infarct coronary flow under mechanical left ventricular support

Sakata,

Mavropoulos,

Mazurek

et al. 2024

The Journal of Physiology

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Restoring ischaemic myocardial tissue perfusion is crucial for minimizing infarct size. Acute mechanical left ventricular (LV) support has been suggested to improve infarct tissue perfusion. However, its regulatory mechanism remains unclear. We investigated the physiological mechanisms in six Yorkshire pigs, which were subjected to 90‐min balloon occlusion of the left anterior descending artery. During the acute reperfusion phase, LV support using an Impella heart pump was initiated. LV pressure, coronary flow and pressure of the infarct artery were simultaneously recorded to evaluate the impact of LV support on coronary physiology. Coronary wave intensity was calculated to understand the forces regulating coronary flow. Significant increases in coronary flow velocity and its area under the curve were found after mechanical LV support. Among the coronary flow‐regulating factors, coronary pressure was increased mainly during the late diastolic phase with less pulsatility. Meanwhile, LV pressure was reduced throughout diastole resulting in significant and consistent elevation of coronary driving pressure. Interestingly, the duration of diastole was prolonged with LV support. In the wave intensity analysis, the duration between backward suction and pushing waves was extended, indicating that earlier myocardial relaxation and delayed contraction contributed to the extension of diastole. In conclusion, mechanical LV support increases infarct coronary flow by extending diastole and augmenting coronary driving pressure. These changes were mainly driven by reduced LV diastolic pressure, indicating that the key regulator of coronary flow under mechanical LV support is downstream of the coronary artery, rather than upstream. Our study highlights the importance of LV diastolic pressure in infarct coronary flow regulation. imageKey points Restoring ischaemic myocardial tissue perfusion is crucial for minimizing infarct size. Although mechanical left ventricular (LV) support has been suggested to improve infarct coronary flow, its specific mechanism remains to be clarified. LV support reduced LV pressure, and elevated coronary pressure during the late diastolic phase, resulting in high coronary driving pressure. This study demonstrated for the first time that mechanical LV support extends diastolic phase, leading to increased infarct coronary flow. Future studies should evaluate the correlation between improved infarct coronary flow and resulting infarct size.

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Section: Methodsmentioning

confidence: 99%

Reduction of left ventricular diastolic pressure as a key regulator of infarct coronary flow under mechanical left ventricular support

Sakata,

Mavropoulos,

Mazurek

et al. 2024

The Journal of Physiology

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“…While several studies have established the cardioprotective physiological basis of left-ventricular unloading, 20 , 21 a more recent investigation indicates the detrimental effects of rapid reloading by abruptly increased LV end-diastolic wall stress resulting in cardiomyocyte stretch-induced injury and/or microvascular flow impairment. 22 …”

Section: Weaningmentioning

confidence: 99%

Differential utilization of Impella devices, extracorporeal membrane oxygenation, and combined therapies as escalation and de-escalation strategies

Bernhardt,

Potapov,

Vandenbriele

et al. 2023

European Heart Journal Supplements

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Cardiogenic shock (CS) is a life-threatening condition characterized by a state of inadequate systemic tissue perfusion caused by cardiac dysfunction. When to implement, change, or remove the use of a temporary mechanical circulatory support (tMCS) in patients with CS is dependent on the aetiology and severity. Here, patient scenarios underlying the need to escalate, de-escalate, wean, or bridge from tMCS devices are taken into consideration by interdisciplinary heart failure and CS teams. This includes a comprehensive review of and focus on the rationale for specific device escalation and de-escalation strategies, device selection, and general management.

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“…Currently, controversy exists regarding optimal regulation of PVA when the heart is recovering from acute injury. Mazurek et al [ 37 ] reported that acute reloading induces cardiac apoptosis. On the other hand, Diakos et al [ 38 ] showed that cardiac reloading through an LV assist device normalizes metabolism.…”

Section: Characteristics and Hemodynamic Effects Of Temporary Mechani...mentioning

confidence: 99%

Mechanical circulatory support in cardiogenic shock

Nakata,

Yamamoto,

Saku

et al. 2023

j intensive care

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Cardiogenic shock is a complex and diverse pathological condition characterized by reduced myocardial contractility. The goal of treatment of cardiogenic shock is to improve abnormal hemodynamics and maintain adequate tissue perfusion in organs. If hypotension and insufficient tissue perfusion persist despite initial therapy, temporary mechanical circulatory support (t-MCS) should be initiated. This decade sees the beginning of a new era of cardiogenic shock management using t-MCS through the accumulated experience with use of intra-aortic balloon pump (IABP) and venoarterial extracorporeal membrane oxygenation (VA-ECMO), as well as new revolutionary devices or systems such as transvalvular axial flow pump (Impella) and a combination of VA-ECMO and Impella (ECPELLA) based on the knowledge of circulatory physiology. In this transitional period, we outline the approach to the management of cardiogenic shock by t-MCS. The management strategy involves carefully selecting one or a combination of the t-MCS devices, taking into account the characteristics of each device and the specific pathological condition. This selection is guided by monitoring of hemodynamics, classification of shock stage, risk stratification, and coordinated management by the multidisciplinary shock team.

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Negative Impact of Acute Reloading after Mechanical Left Ventricular Unloading

Cited by 4 publications

References 15 publications

Reduction of left ventricular diastolic pressure as a key regulator of infarct coronary flow under mechanical left ventricular support

Reduction of left ventricular diastolic pressure as a key regulator of infarct coronary flow under mechanical left ventricular support

Differential utilization of Impella devices, extracorporeal membrane oxygenation, and combined therapies as escalation and de-escalation strategies

Mechanical circulatory support in cardiogenic shock

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