scholarly journals Hypothermia elongates the contraction-relaxation cycle in explanted human failing heart decreasing the time for ventricular filling during diastole

2018 ◽  
Vol 315 (5) ◽  
pp. H1137-H1147 ◽  
Author(s):  
Halvard G. Hiis ◽  
Marie V. Cosson ◽  
Christen P. Dahl ◽  
Arnt E. Fiane ◽  
Finn Olav Levy ◽  
...  
Keyword(s):  
Heart Rate ◽  
Diastolic Dysfunction ◽  
Diastolic Function ◽  
Adrenergic Receptor ◽  
Stimulation Frequency ◽  
Targeted Temperature Management ◽  
Temperature Management ◽  
Relaxation Cycle ◽  
Resting Tension ◽  
Ventricular Filling

Targeted temperature management is part of the standardized treatment for patients in cardiac arrest. Hypothermia decreases cerebral oxygen consumption and induces bradycardia; thus, increasing the heart rate may be considered to maintain cardiac output. We hypothesized that increasing heart rate during hypothermia would impair diastolic function. Human left ventricular trabeculae obtained from explanted hearts of patients with terminal heart failure were stimulated at 0.5 Hz, and contraction-relaxation cycles were recorded. Maximal developed force (Fmax), maximal rate of development of force [(dF/d t)max], time to peak force (TPF), time to 80% relaxation (TR80), and relaxation time (RT = TR80 − TPF) were measured at 37, 33, 31, and 29°C. At these temperatures, stimulation frequency was increased from 0.5 to 1.0 and to 1.5 Hz. At 1.5 Hz, concentration-response curves for the β-adrenergic receptor (β-AR) agonist isoproterenol were performed. Fmax, TPF, and RT increased when temperature was lowered, whereas (dF/d t)max decreased. At all temperatures, increasing stimulation frequency increased Fmax and (dF/d t)max, whereas TPF and RT decreased. At 31 and 29°C, resting tension increased at 1.5 Hz, which was ameliorated by β-AR stimulation. At all temperatures, maximal β-AR stimulation increased Fmax, (dF/d t)max, and maximal systolic force, whereas resting tension decreased progressively with lowering temperature. β-AR stimulation reduced TPF and RT to the same extent at all temperatures, despite the more elongated contraction-relaxation cycle at lower temperatures. Diastolic dysfunction during hypothermia results from an elongation of the contraction-relaxation cycle, which decreases the time for ventricular filling. Hypothermic bradycardia protects the heart from diastolic dysfunction and increasing the heart rate during hypothermia should be avoided. NEW & NOTEWORTHY Decreasing temperature increases the duration of the contraction-relaxation cycle in the human ventricular myocardium, significantly reducing the time for ventricular filling during diastole. During hypothermia, increasing heart rate further reduces the time for ventricular filling and in some situations increases resting tension further impairing diastolic function. Modest β-adrenergic receptor stimulation can ameliorate these potentially detrimental changes during diastole while improving contractile force generation during targeted temperature management.

Heart Rate and Neurological Outcomes in Patients Undergoing Targeted Temperature Management

2020 ◽  
pp. 088506662098250
Author(s):  
Chad M. Conner ◽  
William H. Perucki ◽  
Andre Gabriel ◽  
David M. O’Sullivan ◽  
Antonio B. Fernandez
Keyword(s):  
Heart Rate ◽  
Positive Association ◽  
Targeted Temperature Management ◽  
Temperature Management ◽  
Neurological Outcomes ◽  
Neurologic Outcomes ◽  
Resuscitation Guidelines ◽  
The Mean ◽  
The Impact ◽  
The Relationship

Introduction: There is a paucity of data evaluating the impact of heart rate (HR) during Targeted Temperature Management (TTM) and neurologic outcomes. Current resuscitation guidelines do not specify a HR goal during TTM. We sought to determine the relationship between HR and neurologic outcomes in a single-center registry dataset. Methods: We retrospectively studied 432 consecutive patients who completed TTM (33°C) after cardiac arrest from 2008 to 2017. We evaluated the relationship between neurologic outcomes and HR during TTM. Pittsburgh Cerebral Performance Categories (CPC) at discharge were used to determine neurological recovery. Statistical analysis included chi square, Student’s t-test and Mann-Whitney U. A logistic regression model was created to evaluate the strength of contribution of selected variables on the outcome of interest. Results: Approximately 94,000 HR data points from 432 patients were retrospectively analyzed; the mean HR was 82.17 bpm over the duration of TTM. Favorable neurological outcomes were seen in 160 (37%) patients. The mean HR in the patients with a favorable outcome was lower than the mean HR of those with an unfavorable outcome (79.98 bpm vs 85.67 bpm p < 0.001). Patients with an average HR of 60-91 bpm were 2.4 times more likely to have a favorable neurological outcome compared to than HR’s < 60 or > 91 (odds ratio [OR] = 2.36, 95% confidence interval [CI] 1.61-3.46, p < 0.001). Specifically, mean HR’s in the 73-82 bpm range had the greatest rate of favorable outcomes (OR 3.56, 95% CI 1.95-6.50), p < 0.001. Administration of epinephrine, a history of diabetes mellitus and hypertension all were associated with worse neurological outcomes independent of HR. Conclusion: During TTM, mean HRs between 60-91 showed a positive association with favorable outcomes. It is unclear whether a specific HR should be targeted during TTM or if heart rates between 60-91 bpm might be a sign of less neurological damage.

Interpretation and implication of diastolic dysfunction in critically ill patients

2017 ◽  
Author(s):  
Claire Colebourn ◽  
Jim Newton
Keyword(s):  
Diastolic Dysfunction ◽  
Diastolic Function ◽  
Critically Ill ◽  
Critically Ill Patients ◽  
Left Ventricular ◽  
Left Ventricular Filling ◽  
Critically Ill Patient ◽  
Severe Illness ◽  
Ventricular Relaxation ◽  
Ventricular Filling

This chapter looks at the interpretation of parameters of diastolic function in the critically ill patient. It provides a guide to interpretation and how to avoid misinterpretation of these parameters in the context of severe illness. The assessment of left ventricular relaxation and left ventricular filling pressures are described in detail.

P6383Cardiac output during targeted temperature management and renal function after out-of-hospital cardiac arrest

2019 ◽  
Vol 40 (Supplement_1) ◽  
Author(s):  
J Grand ◽  
C Hassager ◽  
J Bro-Jeppesen ◽  
M Wanscher ◽  
J Kjaergaard
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Acute Kidney Injury ◽  
Cardiac Index ◽  
Renal Injury ◽  
Kidney Injury ◽  
Targeted Temperature Management ◽  
Temperature Management ◽  
Research Fund ◽  
Hospital Cardiac Arrest

Abstract Background After resuscitation from out-of-hospital cardiac arrest (OHCA), renal injury and hemodynamic instability are common. Low blood pressure during targeted temperature management (TTM) is associated with acute renal injury (AKI). The aim of this study is to test the hypothesis, that low cardiac output during TTM is associated with acute kidney injury after OHCA. Methods Single-center substudy of 171 patients included in the prospective, randomized TTM-trial. Hemodynamic evaluation was performed with serial measurements by pulmonary artery catheter. Mean arterial pressure ≥65 mmHg and central venous pressure of 10 to 15 mmHg were hemodynamic treatment goals. Acute kidney injury (AKI) was the primary endpoint and was defined according to the KDIGO-criteria. Differences between groups were tested by repeated measurements mixed models. Measurements and main results Of 152 patients with available hemodynamic data, 49 (32%) had AKI and 21 (14%) had AKI with need for renal replacement therapy (RRT) in the first three days. At admission, cardiac index was higher in the AKI-group (mean (confidence interval): 2.6 (2.2–3.0) L/min/m2 versus 2.2 (2.0–2.3) L/min/m2, p=0.003). During 24 hours of targeted temperature management, patients with AKI had increased heart rate (11 beats/min, pgroup<0.0001) and increased lactate (1 mmol/L, pgroup<0.0001) compared to patients without AKI. However, there was no overall difference in cardiac index (pgroup = 0.25) (Figure). In multivariate models, adjusting for potential confounders including targeted temperature, mean arterial pressure (odds ratio: 0.69 (0.50–0.96) per 5 mmHg increase, p=0.03), heart rate (1.04 (1.01–1.08) per beat/min increase, p=0.01) and lactate (1.59 (1.14–2.2) per mmol/L increase, p=0.006) were independently associated with AKI, but cardiac index remained unrelated with AKI. Figure 1 Conclusions Blood pressure, heart rate and lactate, but not cardiac output, during 24 hours of targeted temperature management were associated with renal injury in comatose OHCA-patients. Acknowledgement/Funding The research fund Gangstedfonden and the Research fund of Rigshospitalet has supported this study with unrestricted salary in Dr. Grand's PhD project.

scholarly journals Echocardiographic Evaluation of Diastolic Function in Asymptomatic Type 2 Diabetes

2009 ◽  
Vol 48 (173) ◽  
Author(s):  
Nikesh Raj Shrestha ◽  
SK Sharma ◽  
P Karki ◽  
NK Shrestha ◽  
P Acharya
Keyword(s):  
Type 2 Diabetes ◽  
Diastolic Dysfunction ◽  
Diastolic Function ◽  
Valsalva Maneuver ◽  
Systolic Function ◽  
Left Ventricular ◽  
High Risk Population ◽  
Asymptomatic Patients ◽  
Ventricular Filling

INTRODUCTION:Diabetes mellitus is an established risk factor for congestive cardiac failure in which the diastolic function is impaired earlier than the systolic function and majority of these patients maybe asymptomatic without signs of overt heart failure.METHODS:A cross sectional hospital based study was done which included 100 asymptomatic patients with type 2 diabetes without evidence of coronary artery disease, congestive heart failure, thyroid or overt renal disease. LVDD was evaluated by Doppler echocardiography, which included the valsalva maneuver to unmask the pseudonormal pattern of left ventricular filling. The prevalence of LVDD and the associated risk factors were assessed.RESULTS:LVDD was found in 71 subjects (71%), of whom 60 had impaired relaxation and 11 had a pseudonormal pattern of ventricular filling. Systolic function was normal in all subjects, and there was no correlation between LVDD and indexes of metabolic control. It was also found that age > or =45 years was associated with an almost three times higher risk for the development of diastolic dysfunction in type 2 diabetes. Females were at a two times higher risk of developing diastolic dysfunction than when compared to men. Duration of diabetes > or = two years was associated with a two times higher risk for developing diastolic dysfunction.CONCLUSIONS:LVDD is much more common than previously reported in subjects with well-controlled type 2 diabetes who are free of clinically detectable heart disease. The high prevalence of this phenomenon in this high-risk population suggests that screening for LVDD in type 2 diabetes should include procedures such as the valsalva maneuver to unmask a pseudonormal pattern of ventricular filling.Keywords:diabetes mellitus, diastolic dysfunction, echocardiography, impaired relaxation, pseudonormal

scholarly journals HEART RATE AND NEUROLOGICAL OUTCOMES IN PATIENTS UNDERGOING TARGETED TEMPERATURE MANAGEMENT

CHEST Journal ◽  
2020 ◽  
Vol 158 (4) ◽  
pp. A116
Author(s):  
Chad Conner ◽  
William Perucki ◽  
Andre Gabriel ◽  
David O’Sullivan ◽  
Antonio Fernandez
Keyword(s):  
Heart Rate ◽  
Targeted Temperature Management ◽  
Temperature Management ◽  
Neurological Outcomes

scholarly journals Haemodynamics and vasopressor support during prolonged targeted temperature management for 48 hours after out-of-hospital cardiac arrest: a post hoc substudy of a randomised clinical trial

2020 ◽  
pp. 204887262093430
Author(s):  
Johannes Grand ◽  
Christian Hassager ◽  
Markus B Skrifvars ◽  
Marjaana Tiainen ◽  
Anders M Grejs ◽  
...  
Keyword(s):  
Clinical Trial ◽  
Heart Rate ◽  
Cardiac Arrest ◽  
Mean Arterial Pressure ◽  
Arterial Pressure ◽  
Randomised Clinical Trial ◽  
Hazard Ratio ◽  
Targeted Temperature Management ◽  
Temperature Management ◽  
Hospital Cardiac Arrest

Background Comatose patients admitted after out-of-hospital cardiac arrest frequently experience haemodynamic instability and anoxic brain injury. Targeted temperature management is used for neuroprotection; however, targeted temperature management also affects patients’ haemodynamic status. This study assessed the haemodynamic status of out-of-hospital cardiac arrest survivors during prolonged (48 hours) targeted temperature management at 33°C. Methods Analysis of haemodynamic and vasopressor data from 311 patients included in a randomised, clinical trial conducted in 10 European hospitals (the TTH48 trial). Patients were randomly allocated to targeted temperature management at 33°C for 24 (TTM24) or 48 (TTM48) hours. Vasopressor and haemodynamic data were reported hourly for 72 hours after admission. Vasopressor load was calculated as norepinephrine (µg/kg/min) plus dopamine(µg/kg/min/100) plus epinephrine (µg/kg/min). Results After 24 hours, mean arterial pressure (mean±SD) was 74±9 versus 75±9 mmHg ( P=0.19), heart rate was 57±16 and 55±14 beats/min ( P=0.18), vasopressor load was 0.06 (0.03–0.15) versus 0.08 (0.03–0.15) µg/kg/min ( P=0.22) for the TTM24 and TTM48 groups, respectively. From 24 to 48 hours, there was no difference in mean arterial pressure ( Pgroup=0.32) or lactate ( Pgroup=0.20), while heart rate was significantly lower (average difference 5 (95% confidence interval 2–8) beats/min, Pgroup<0.0001) and vasopressor load was significantly higher in the TTM48 group ( Pgroup=0.005). In a univariate Cox regression model, high vasopressor load was associated with mortality in univariate analysis (hazard ratio 1.59 (1.05–2.42) P=0.03), but not in multivariate analysis (hazard ratio 0.77 (0.46–1.29) P=0.33). Conclusions In this study, prolonged targeted temperature management at 33°C for 48 hours was associated with higher vasopressor requirement but no sign of any detrimental haemodynamic effects.

A STUDY ON THE CORRELATION BETWEEN MORPHOLOGIC ANORMALIES AND LEFT VENTRICULAR DIASTOLIC FUNCTION IN DILATED CARDIO-MYOPATHY

2011 ◽  
pp. 137-144
Author(s):  
Thi Ngoc Ha Hoang ◽  
Anh Vu Nguyen ◽  
Minh Loi Hoang ◽  
Cuu Long Nguyen ◽  
Thi Thuy Hang Nguyen
Keyword(s):  
Pulmonary Artery ◽  
Dilated Cardiomyopathy ◽  
Diastolic Dysfunction ◽  
Diastolic Function ◽  
Pulmonary Arteries ◽  
Left Ventricular ◽  
University Hospital ◽  
Cross Sectional ◽  
X Ray ◽  
Key Words Dilated Cardiomyopathy

Purposes: Describe the morphological and diastolic function of left ventricular changes in the patients with dilated cardiomyopathy (DCM) on US, X-ray findings, and Evaluate the correlation between morphology and diastolic function of left ventricular. Materials and method: Cross sectional study from Dec 2009 to Aug 2010, on 39 patients with dilated cardiomyopathy were evaluated at the University Hospital of Hue College of Medical and Pharmaceutical. Results: 1. X-ray and US findings characteristics of DCM is significantly increased in diameter of L, H and mG; LVM, LVMI, LVDd and LAD. 2. The pression of pulmonary artery has been significantly increased with redistribution pulmonary arteries in 61.5% cases and 23.1% have reversed pulmonary artery distribution. 3. DCM have diastolic dysfunction in 100% patients, including severe disorders to 61.5%; the restrictive dysfunction has ratio E/A>2 and E/Em average was 23.89± 17.23. 4.The correlation between the morphology and function in DCM: the diameter of H and L on the X-ray, LAD and ratio LA/AO on US correlated with the level of diastolic dysfunction (p< 0.05). All three radiographic parameters on the radio standard (H, L, the index Cardio/Thoracic) and LVDd on US have negative correlated with EF and FS with p <0.05. Key words: dilated cardiomyopathy, diastolic dysfunction, cardiac tissue Doppler, reversed pulmonary artery distribution

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