Operative Myocardial protection in patients with Left Ventricular Hypertrophy: The Role of systemic Hypothermia

Objectives Myocardial hypertrophy represents a great challenge in cardiac surgery. Several strategies have been described to protect the hypertrophied myocardium during cardiopulmonary bypass, and aortic clamping, yet the ideal strategy has not been identified. This study investigates the use of moderate systemic hypothermia (MSH) as an adjuvant method to protect the hypertrophied myocardium in patients undergoing aortic valve replacement (AVR). Methods Twenty eight patients undergoing AVR were divided into two groups, (Group I) received continuous cold 5–8 °C retrograde blood cardioplegia (CRBC) and their body temperature was cooled down to 23–26 °C. (Group II) also received CRBC but their body temperature was kept at 32–34 °C. Results No operative morality (30 days) was noted in both groups. Postoperative reduction in ejection fraction (EF) was seen in nine patients of group I and in twelve patients of group II ( P < 0.05). The need for multiple inotropes was more in group II (eight patients) than in group I (two patients) ( P < 0.001). IABP was needed in three patients of group II and non in group I ( P < 0.01). Conclusion Moderate systemic hypothermia might have a role in protecting hypertrophied myocardium in patients undergoing AVR.

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Altered β-adrenergic signal transduction in nonfailing hypertrophied myocytes from Dahl salt-sensitive rats

AJP Heart and Circulatory Physiology ◽

10.1152/ajpheart.2000.279.5.h2502 ◽

2000 ◽

Vol 279 (5) ◽

pp. H2502-H2508 ◽

Cited By ~ 13

Author(s):

Kohzo Nagata ◽

Catherine Communal ◽

Chee C. Lim ◽

Mohit Jain ◽

Thomas M. Suter ◽

...

Keyword(s):

Ventricular Hypertrophy ◽

Physiological Role ◽

Cellular Level ◽

Left Ventricular ◽

Cell Shortening ◽

Hypertrophied Myocardium ◽

Intracellular Ca ◽

Myocyte Contractility ◽

Dose Dependent

Desensitization of the β-adrenergic receptor (β-AR) response is well documented in hypertrophied hearts. We investigated whether β-AR desensitization is also present at the cellular level in hypertrophied myocardium, as well as the physiological role of inhibitory G (Gi) proteins and the L-type Ca2+channel in mediating β-AR desensitization. Left ventricular (LV) myocytes were isolated from hypertrophied hearts of hypertensive Dahl salt-sensitive (DS) rats and nonhypertrophied hearts of normotensive salt-resistant (DR) rats. Cells were paced at a rate of 300 beats/min at 37°C, and myocyte contractility and intracellular Ca2+concentration ([Ca2+]i) were simultaneously measured. In response to increasing concentrations of isoproterenol, DR myocytes displayed a dose-dependent augmentation of cell shortening and the [Ca2+]i transient amplitude, whereas hypertrophied DS myocytes had a blunted response of both cell shortening and the [Ca2+]i transient amplitude. Interestingly, inhibition of Gi proteins did not restore β-AR desensitization in DS myocytes. The responses to increases in extracellular Ca2+ and an L-type Ca2+ channel agonist were also similar in both DS and DR myocytes. Isoproterenol-stimulated adenylyl cyclase activity, however, was blunted in hypertrophied myocytes. We concluded that compensated ventricular hypertrophy results in a blunted contractile response to β-AR stimulation, which is present at the cellular level and independent of alterations in inhibitory G proteins and the L-type Ca2+ channel.

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P1833 Ultrasonic imaging of radial artery reactive response in patients with hypertension with and without left ventricular hypertrophy

European Heart Journal - Cardiovascular Imaging ◽

10.1093/ehjci/jez319.1176 ◽

2020 ◽

Vol 21 (Supplement_1) ◽

Author(s):

M A Parol ◽

K Majka ◽

Z Trawinski ◽

B Gambin ◽

A Krupienicz ◽

...

Keyword(s):

Left Ventricular Hypertrophy ◽

Radial Artery ◽

Ventricular Hypertrophy ◽

Transient Flow ◽

Normal Subjects ◽

Left Ventricular ◽

Group I ◽

Group Ii ◽

Artery Disease ◽

Flow Stimulation

Abstract Background Endothelium plays an important role in anti-inflammatory process and regulating vascular tone. It has been shown in numerous studies that increase of vessel dilation after several minutes hyperemia, was induced by mechanical transient flow stimulation of the endothelium. Most of the reported research experiments were conducted on the brachial artery. We proposed to measure the flow-mediated dilation in the radial artery (FMDr) in patients with hypertension (HT). In order to improve the axial resolution affecting the precision of FMDr determination, radial artery imaging was performed using a high frequency 20 MHz ultrasound. Aim The aim of the study was assessment of FMDr in patients with HT using 20 MHz probe. Methods: Our studies involved two groups group I consisted of 76 pts. 35 men and 41 women (71 ± 5.6 yr. old); with documented HT and group II consisted of 16 healthy volunteers, 12 men and 4 women (51.4 ± 9.4 yr. old). We divided patients with HT in to three subgroups: IA - 25 pts. with HT and left ventricular hypertrophy (VH), IB - 26 pts. with HT without VH, and IC patients with HT without VH but with coexisting coronary artery disease (CAD). Results Statistically significant differences in FMDr between the two groups were confirmed by a Wilcoxon-Mann-Whitney test. In group II FMDr was 11.9 ± 4.8%, and in group I FMDr was significantly less at 5.1% ± 4%. We have not observed any statistical differences in FMDr between groups: IA and IB ( 5.05%, 5.55%) respectively. We calculated FMDr for IC 4.21% (p = 0.018). Fig. 1. Conclusion The results confirm the usefulness of the proposed measurements of radial artery FMDr to differentiation of normal subjects from those with documented HT. There are no significant differences between males and females in all considered groups of subjects. We did not find the differences in FMDr between patients with and without VH. Patients with HT, without VH and with coexisting CAD had the lowest reactive response of FMDr. Abstract P1833 Figure. Fig. 1

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Role of Aldosterone in Left Ventricular Hypertrophy in Hypertension

Yearbook of Endocrinology ◽

10.1016/s0084-3741(08)70177-x ◽

2007 ◽

Vol 2007 ◽

pp. 366-369 ◽

Cited By ~ 1

Author(s):

D.E. Schteingart

Keyword(s):

Left Ventricular Hypertrophy ◽

Ventricular Hypertrophy ◽

Left Ventricular

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Effects of Rest and Exercise on Cardiac Blood Volume Determinations

Nuklearmedizin ◽

10.1055/s-0038-1629844 ◽

1997 ◽

Vol 36 (08) ◽

pp. 259-264

Author(s):

N. Topuzović

Keyword(s):

Radionuclide Ventriculography ◽

Left Ventricular ◽

Peak Exercise ◽

Volume Determination ◽

Group I ◽

Lv Volumes ◽

Group Ii ◽

Lv Volume

Summary Aim: The purpose of this study was to investigate the changes in blood activity during rest, exercise and recovery, and to assess its influence on left ventricular (LV) volume determination using the count-based method requiring blood sampling. Methods: Forty-four patients underwent rest-stress radionuclide ventriculography; Tc-99m-human serum albumin was used in 13 patients (Group I), red blood cells was labeled using Tc-99m in 17 patients (Group II) in vivo, and in 14 patients (Group III) by modified in vivo/in vitro method. LV volumes were determined by a count-based method using corrected count rate in blood samples obtained during rest, peak exercise and after recovery. Results: In group I at stress, the blood activity decreased by 12.6 ± 5.4%, p <0.05, as compared to the rest level, and increased by 25.1 ± 6.4%, p <0.001, and 12.8 ± 4.5%, p <0.05, above the resting level in group II and III, respectively. This had profound effects on LV volume determinations if only one rest blood aliquot was used: during exercise, the LV volumes significantly decreased by 22.1 ± 9.6%, p <0.05, in group I, whereas in groups II and III it was significantly overestimated by 32.1 ± 10.3%, p <0.001, and 10.7 ± 6.4%, p <0.05, respectively. The changes in blood activity between stress and recovery were not significantly different for any of the groups. Conclusion: The use of only a single blood sample as volume aliquot at rest in rest-stress studies leads to erroneous estimation of cardiac volumes due to significant changes in blood radioactivity during exercise and recovery.

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Oxygen Fraction Adjustment According to Body Surface Area during Extracorporeal Circulation

The Heart Surgery Forum ◽

10.1532/hsf.1325 ◽

2015 ◽

Vol 18 (3) ◽

pp. 098

Author(s):

Cem Arıtürk ◽

Serpil Ustalar Özgen ◽

Behiç Danışan ◽

Hasan Karabulut ◽

Fevzi Toraman

Keyword(s):

Body Temperature ◽

Surface Area ◽

Body Surface Area ◽

Body Surface ◽

Extracorporeal Circulation ◽

Group Iii ◽

Oxygen Fraction ◽

Arterial Blood ◽

Group I ◽

Group Ii

Background: The inspiratory oxygen fraction (FiO2) is usually set between 60% and 100% during conventional extracorporeal circulation (ECC). However, this strategy causes partial oxygen pressure (PaO2) to reach hyperoxemic levels (>180 mmHg). During anesthetic management of cardiothoracic surgery it is important to keep PaO2 levels between 80-180 mmHg. The aim of this study was to assess whether adjusting FiO2 levels in accordance with body temperature and body surface area (BSA) during ECC is an effective method for maintaining normoxemic PaO2 during cardiac surgery.Methods: After approval from the Ethics Committee of the University of Acıbadem, informed consent was given from 60 patients. FiO2 adjustment strategies applied to the patients in the groups were as follows: FiO2 levels were set as 0.21 × BSA during hypothermia and 0.21 × BSA + 10 during rewarming in Group I; 0.18 × BSA during hypothermia and 0.18 × BSA + 15 during rewarming in Group II; and 0.18 × BSA during hypothermia and variable with body temperature during rewarming in Group III. Arterial blood gas values and hemodynamic parameters were recorded before ECC (T1); at the 10th minute of cross clamp (T2); when the esophageal temperature (OT) reached 34°C (T3); when OT reached 36°C (T4); and just before the cessation of ECC (T5).Results: Mean PaO2 was significantly higher in Group I than in Group II at T2 and T3 (P = .0001 and P = .0001, respectively); in Group I than in Group III at T1 (P = .02); and in Group II than in Group III at T2, T3, and T4 (P = .0001 for all). Conclusion: Adjustment of FiO2 according to BSA rather than keeping it at a constant level is more appropriate for keeping PaO2 between safe level limits. However, since oxygen consumption of cells vary with body temperature, it would be appropriate to set FiO2 levels in concordance with the body temperature in the rewarming period.

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Genoprotective role of vitamin E and selenium in rabbits anaesthetized with sevoflurane

Human & Experimental Toxicology ◽

10.1191/0960327104ht463oa ◽

2004 ◽

Vol 23 (8) ◽

pp. 413-419 ◽

Cited By ~ 9

Author(s):

Cetin Kaymak ◽

Ela Kadioglu ◽

Hulya Basar ◽

Semra Sardas

Keyword(s):

Dna Damage ◽

Vitamin E ◽

Comet Assay ◽

Antioxidant Supplementation ◽

Group Iii ◽

Sevoflurane Anaesthesia ◽

Group I ◽

The Mean ◽

Group Ii

In this study, genotoxic effects of repeated sevoflurane anaesthesia were investigated in rabbits with or without antioxidant supplementation. Twenty-one New Zealand male rabbits were included in the study and randomized into three groups as: placebo treated (Group I), vitamin E supplemented (Group II) and selenium supplemented (Group III). Vitamin E and selenium were given intraperitoneally for 15 days before anaesthesia treatment. Anaesthesia was administered using 3% sevoflurane in 4 L/min oxygen for a 3-hour period and continued for 3 days. Blood samples were collected before anaesthesia (Sample 1), after the first, second and third days of sevoflurane administration (Sample 2, Sample 3 and Sample 4 respectively) and the last samples were taken 5 days after the last sevoflurane administration (Sample 5). Genotoxic damage was examined using the comet assay. The degree of damage is assessed by grading the cells into three categories of no migration (NM), low migration (LM) and high migration (HM) depending on the fraction of DNA pulled out into the tail under the influence of the electric field. The number of comets in each sample was calculated (1 × number of comets in category NM + 2 × number of comets in category LM + 3 ×number of comets in category HM) and expressed as the total comet score (TCS), which summarizes the damage frequencies. In Group I, a significant increase in the mean TCSs was observed for Samples 3 and 4 as compared with Sample 1. However, there were no significant differences between Samples 1, 2 and 5. The mean TCS of Sample 4 was significantly higher than Sample 1, 2 and 3 in Group II. Group III demonstrated no significant mean TCSs for any experimental conditions. Statistical differences were also observed between the groups with significant P values. This experimental study points out the presence of DNA damage with repeated sevoflurane anaesthesia and the genoprotective role of antioxidant supplementation on DNA damage in mononuclear leukocytes of rabbits by highly sensitive comet assay.

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Regression of Established Left Ventricular Hypertrophy: Role of the Renin-Angiotensin System and Protein Synthesis

Clinical Science ◽

10.1042/cs086039pb ◽

1994 ◽

Vol 86 (s30) ◽

pp. 39P-39P

Author(s):

T Siddiq ◽

P J Richardson ◽

V R Preedy

Keyword(s):

Protein Synthesis ◽

Left Ventricular Hypertrophy ◽

Ventricular Hypertrophy ◽

Renin Angiotensin System ◽

Left Ventricular ◽

Angiotensin System ◽

Renin Angiotensin

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Abstract 313: STIM1 Silencing Reverses Pressure-overload Induced Cardiac Hypertrophy In Mice

Circulation Research ◽

10.1161/res.113.suppl_1.a313 ◽

2013 ◽

Vol 113 (suppl_1) ◽

Author(s):

Ludovic O Bénard ◽

Daniel S Matasic ◽

Mathilde Keck ◽

Anne-Marie Lompré ◽

Roger J Hajjar ◽

...

Keyword(s):

Ventricular Hypertrophy ◽

Contractile Function ◽

Pressure Overload ◽

Left Ventricular ◽

Aortic Banding ◽

Cross Section Area ◽

Abdominal Aortic ◽

Section Area

STromal Interaction Molecule 1 (STIM1), a membrane protein of the sarcoplasmic reticulum, has recently been proposed as a positive regulator of cardiomyocyte growth by promoting Ca2+ entry through the plasma membrane and the activation of Ca2+-mediated signaling pathways. We demonstrated that STIM1 silencing prevented the development of left ventricular hypertrophy (LVH) in rats after abdominal aortic banding. Our aim was to study the role of STIM1 during the transition from LVH to heart failure (HF). For experimental timeline, see figure. Transverse Aortic Constriction (TAC) was performed in C57Bl/6 mice. In vivo gene silencing was performed using recombinant Associated AdenoVirus 9 (AAV9). Mice were injected with saline or with AAV9 expressing shRNA control or against STIM1 (shSTIM1) (dose: 1e+11 viral genome), which decreased STIM1 cardiac expression by 70% compared to control. While cardiac parameters were similar between the TAC groups at weeks 3 and 6, shSTIM1 animals displayed a progressive and total reversion of LVH with LV walls thickness returning to values observed in sham mice at week 8. This reversion was associated with the development of significant LV dilation and severe contractile dysfunction, as assessed by echography. Hemodynamic analysis confirmed the altered contractile function and dilation of shSTIM1 animals. Immunohistochemistry showed a trend to more fibrosis. Despite hypertrophic stimuli, there was a significant reduction in cardiac myocytes cross-section area in shSTIM1-treated animals as compared to other TAC mice. This study showed that STIM1 is essential to maintain compensatory LVH and that its silencing accelerates the transition to HF.

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Evaluation of Recurrent Pediatric Syncope: Role of Tilt Table Testing

PEDIATRICS ◽

10.1542/peds.93.4.660 ◽

1994 ◽

Vol 93 (4) ◽

pp. 660-662

Author(s):

Margaret J. Strieper ◽

Debbie O. Auld ◽

J. Edward Hulse ◽

Robert M. Campbell

Keyword(s):

Pediatric Patients ◽

Neurocardiogenic Syncope ◽

Tilt Table ◽

Conversion Reaction ◽

Cell Counts ◽

Group I ◽

Tilt Table Testing ◽

Group Ii ◽

Made In

Objective. To determine the current practice and effectiveness of evaluating recurrent syncope in pediatric patients, and to establish the role of tilt table testing in the evaluation. Design. Retrospective analysis of 54 pediatric patients with the history of syncope referred to cardiologists. Group I consisted of 27 patients examined without tilt table testing group II consisted of 27 patients whose examination included tilt table testing. Results. Group I had an average of 5.4 studies and group II, 6.6 studies performed per patient. Studies included chest radiograph (16 vs 13), electrocardiogram (24 vs 27), echocardiography (21 vs 27), 24-hour electrocardiogram (14 vs 16), transtelephonic monitor (7 vs 8), electrophysiology study (1 vs 3), complete blood cell counts (11 vs 12), chemistries (10 vs 11), thyroid function test (3 vs 3), neurology consult (12 vs 6), electroencephalogram (12 vs 5), and head computed tomographic scan (5 vs 3). Of the 298 non-tilt studies, the results of only 5 (1.6%) were abnormal. Diagnoses were made in 5 (18.5%) of 27 group I patients (Wolff-Parkinson-White syndrome, 1; conversion reaction, 2; hyperventilation, 1; migraines, 1), whereas diagnosis was made in 27 (100%) of 27 group II patients (neurocardiogenic syncope, 25; conversion reaction, 2). Conclusion. An extensive workup is not routinely indicated in syncopal patients with a history consistent with neurocardiogenic syncope. Tilt table testing performed early in the evaluation will increase the probability of a diagnosis, and will often prevent the need for further extensive, expensive anxiety-producing tests.

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