Electrophysiologic properties and ventricular fibrillation in normal and myopathic hearts

1999 ◽  
Vol 77 (7) ◽  
pp. 510-519 ◽  
Author(s):  
Katherine M Kavanagh ◽  
Patricia A Guerrero ◽  
Bodh I Jugdutt ◽  
Francis X Witkowski ◽  
Jeffrey E Saffitz

This study tests the hypothesis that moderate myocardial dysfunction is associated with altered myocardial anisotropic properties and structurally altered ventricular fibrillation (VF). Mongrel dogs were randomized to either a control group or a group that was rapidly paced at 250 beats/min until the left ventricular ejection fraction was [Formula: see text] 40%. Changes in anisotropic properties and the electrical characteristics of VF associated with the development of moderate myocardial dysfunction were assessed by microminiature epicardial mapping studies. In vivo conduction, refractory periods, and repolarization times were prolonged in both longitudinal and transverse directions in myopathic animals versus controls. VF was different in myopathic versus control animals. There were significantly more conducted deflections during VF in normal hearts compared with myopathic hearts. Propagated deflection-to-deflection intervals during VF were significantly longer in myopathic hearts compared with controls (125.5 ± 49.06 versus 103.4 ± 32.9 ms, p = 0.009). There were no abnormalities in cell size, cell shape, or the number of intercellular gap junctions and there was no detectable change in the expression of the gap junction proteins Cx43 and Cx45. Moderate myocardial dysfunction is associated with significant electrophysiological abnormalities in the absence of changes in myocardial cell morphology or intercellular connections, suggesting a functional abnormality in cell-to-cell communication.Key words: cardiomyopathy, anisotropy, fibrillation, defibrillation.

2014 ◽  
Vol 115 (suppl_1) ◽  
Author(s):  
Chao Chi ◽  
Bo Xiang ◽  
Jixian Deng ◽  
Fei Wang ◽  
Kanmani Natarajan ◽  
...  

Background: Adipose stem cells (ASC) from subcutaneous and visceral adipose tissues have been studied individually. However, it is unclear whether ASC from the two sources have different biological properties and, more importantly, whether one sub-type of ASC is more effective in treatment of CHF. This study was designed to address these concerns. Methods: Morphology, yield, proliferation, surface markers, and cytokine secretion of rat subcutaneous ASC (S-ASC) and visceral ASC (V-ASC) were analyzed. A rat model of myocardial infarction (MI) was established by occlusion of the LAD. 7 days after MI, S-ASC (n = 11), V-ASC (n = 11), and cell culture medium (Control, n = 7) were injected into the infarct rim, respectively. Cardiac function of the infarcted hearts was monitored with MRI for 6 months. Results: Both S-ASC and V-ASC exhibited a fibroblast-like morphology and expressed stromal cell markers (CD29, CD90 and CD105). No significant expression of hematopoietic markers (CD11b, CD34 and CD45) was found. Under appropriate conditions, both cells could differentiate to adipocyte- and osteocyte-like cells. Both of them expressed a significant level of HGF, IGF-1 and VEGF. As to their differences, V-ASC had approximately 3-times greater cell yield and a lower colony-formation rate (9.8±1.0% vs.13.5±2.6%) relative to S-ASC. In contrast, S-ASC showed a significantly greater growth rate (Doubling Time: 17.9 h vs. 26.0 h) relative to V-ASC. Both S-ASC and V-ASC-treated hearts showed a significantly greater left ventricular ejection fraction (LVEF, 58.3% and 56.7%) than the control group (LVEF, 47.2%) at end of 6 months. LVEF between the two ASC-treated groups was not significantly different. Finally, the implanted stem cells were readily detected in vivo with MRI for at least 6 months. Myocardial tissue sections showed existence of ASC and their locations matched with MRI signals. Conclusions: S-ASC and V-ASC share several biological characteristics. Both provide comparable significant improvement on cardiac function. Moreover, these implanted cells can be reliably tracked for at least 6 months using MRI. We conclude that the S-ASC and V-ASC are equally effective for treatment of heart failure.


2019 ◽  
Vol 40 (Supplement_1) ◽  
Author(s):  
A V Osokina ◽  
V N Karetnikova ◽  
O M Polikutina ◽  
Y U S Slepynina ◽  
O V Gruzdeva ◽  
...  

Abstract Purpose To identify the peculiarities of the dynamics of fibrosis markers in patients with STEMI and preserved myocardial contractility and to determine the relationship between the studied biomarkers and EchoCG indicators characterizing the violation of left ventricular myocardium diastolic function. Material and methods The study included 120 patients with STEMI. The final analysis included 83 patients with preserved left ventricular myocardial contractility measured. The preserved ejection fraction was considered to be ≥50%. Echocardiographic examination was performed using Sonos 2500. In addition to the standard laboratory and instrumental examinations, all the patients underwent the estimation of the concentrations of PICP and PIIINP by enzyme-linked immunoassay using BCM Diagnostics laboratory kits (USA) on the 1st and the 12th days of disease. To compare the obtained values of the studied markers, a control group of healthy volunteers matched by age and gender with the main sample of the patients, was recruited, n=20 (100%). In this group the following values were obtained: PIIINP 7.2 [6.8; 7.5] ng/ml, PICP 179.2 [163.5; 194.9] ng/ml. Statistical processing of the obtained data was performed using Statistica 6.0 software. Results The mean age of the patients was 58.8 years; LVEF was 59.0% [54; 62]. According to EchoCG data, LV dysfunction at normal dimensions was registered in 59 (72%) patients, dilatation – in 22 (27%) patients and regional contractility violation – in 43 (52.4%) cases. The increased values of Tei index 0.70 [0.63; 0.76] and myocardial mass 241.0 g [206.5; 272.0] stand out. The values of serum markers concentrations obtained on the 1st day of STEMI, significantly exceeded the values of the control group and were as follows: PIIINP 26.0 (18.9; 34.9) ng/ml (p=0.047), PICP – 609.0 (583.0; 635.0) ng/ml (p=0.049). On the 12th day the concentration of PICP - 588.0 (580.0; 621.0) ng/ml, PIIINP – 24.2 (18.6; 30.3) ng/ml. No statistically significant differences were obtained in comparison of the markers' concentrations on the 1st and 12th days of the disease. As a result of the correlation analysis between the values of the studied serum markers and EchoCG indicators the following statistically significant relationships were identified: E/Em the 1st day - PICP the 12th day: r=0.55, p=0.005; E/A the 12th day - PICP the 1st day: r=−0.42, p=0.033; E/Em the 12th day - PICP the 12th day: r=0.48, p=0.015; EDV the 12th day - PIIINP the 1st day: r=0.62, p=0.001; EDI the 12th day - PIIINP the 1st day: r=0.43, p=0.034; Age - PIIINP the 1st day: r=0.558, p=0.016. Conclusion The presence of statistically significant correlations between the concentrations of PIIINP, PICP with EchoCG indicators evidence the role of fibrosis in the formation of diastolic myocardial dysfunction and reflect the potential use of procollagen to predict heart failure in long-term post-infarction period.


Circulation ◽  
2008 ◽  
Vol 118 (suppl_18) ◽  
Author(s):  
Morten Pytte ◽  
Shijie Sun ◽  
Wanchun Tang ◽  
Max H Weil

Introduction : Repetitive episodes of ischemia and reperfusion following regional myocardial and cerebral ischemia, representing ischemic post-conditioning (IPC), protect against ischemic injury. The possibility that such may have functional application for myocardial injury and survival in settings of cardiac arrest and resuscitation was examined. We hypothesized that repetitive cycles of ventricular fibrillation and reperfusion following resuscitation, representing IPC, would improve cardiovascular function and survival. Methods : Ventricular fibrillation (VF) was electrically induced in 10 SD rats weighing 536±15 g and left untreated for 8 minutes prior to 6 minutes of uninterrupted pre-cordial compressions followed by attempted defibrillation. Resuscitated animals were randomized to either IPC or control. IPC was induced at 5 minutes with electrical re-fibrillation lasting 30 sec followed by spontaneous reversion to a perfusing rhythm. The IPC was repeated 5 minutes later. Except for IPC, controls were identically treated. Frontal plane ECG, mean arterial blood pressure, left ventricular pressures and end tidal CO 2 were continuously recorded. Left ventricular ejection fraction (EF) and cardiac output (CO) were measured echocardiographically at hourly intervals together with blood gases for a total of four hours. Survival was documented at the end of 72 hours. Results : Baseline values did not differ between the IPC and control group. No statistically significant differences between the groups were demonstrated. A power calculation indicates that a minimum of 240 animals would be required to find a difference that would be potentially significant, accordingly the study was concluded. Table . Mean values with standard deviation. Conclusion : The potential value of ischemic post-conditioning represented by repetitive episodes of VF, under the conditions of global ischemia of cardiac arrest, failed to demonstrate a survival value.


2020 ◽  
Vol 28 (3) ◽  
pp. 290-299
Author(s):  
Kira A. Ageeva ◽  
Evgenii V. Filippov

Aim. To study the prognostic value of the results of dynamic capnography in the complex assessment of parameters of the respiratory system in 6-minute walk test in patients with chronic heart failure (CHF). Materials and Methods. 73 Patients were examined: the group of study included 48 patients with IIA or IIB stage CHF (mean age 57.94.6 years, 23 men), the control group included 25 practically healthy volunteers (mean age 47.63.5 years, 9 men). The patients were conducted complex determination of parameters of the respiratory system: clinical scaling before and after 6-minute walk test (6MWT), instrumental examinations including spirometry, capnography and pulse oximetry before, during and after physical activity. The analysis of survival was conducted on the basis of the dynamic follow-up of patients within 5 years (60 months). Results. In the analysis of parameters of dyspnea at rest, all the parameters were higher in the group of patients with CHF (р0.05). The distance walked by the patients with CHF in 6 minutes was 488.2390.84 m, which was significantly less than in the control group (815.6053.89 m, р=0.009). Dyspnea as the cause of stoppage/slowing down of walking in 6MWT, was also more often recorded in patients with CHF (93.83.0% and 48.05.1%, р=0.049). Besides, in 6MWT the patients noted: weakness in legs (50.15.0% in the group of CHF and 40.05.0% in the control group, р=0.014), palpitation (29.04.6% and 20.04.1%, respectively, р=0.004). Worsening of dyspnea parameters in 6MWT was more evident in patients with CHF than in the control group (р0.01). In the CHF group, hypocapnic type of ventilation was revealed in 6MWT, analysis of РЕТСО2 trend graphs revealed a wave-like increase in the parameters, the so called periodic breathing (PB). CO2 trend was recorded in CHF group in 58.31.0% of cases (the difference with the control group with р=0.046), the trend of heart rate in 18.80.3% of cases (р=0.027). Cox proportional hazards regression analysis of mortality in patients with CHF showed a prognostic significance of a complex model comprising the following parameters of a patient: body mass index (р=0.005), left ventricular end-diastolic dimension (р=0.034), left ventricular end-systolic dimension (р=0.002), left ventricular ejection fraction (р=0.041), 6MWT distance (р=0.004), desaturation (р=0.009), and the presence of signs of PB during 6MWT (р=0.005). Model coefficients were statistically significant at р0.0001. Conclusions. Dynamic capnography and pulse oximetry allow to identify signs of PB in patients with CHF during 6MWT which may deepen a complex assessment of parameters of the cardio-respiratory system in patients with CHF in order to determine tolerance to physical exercise as well as the effectiveness of the conducted treatment. Complex assessment of survival of patients with CHF showed prognostic significance of the following parameters of a patient: body mass index, left ventricular end-diastolic dimension, left ventricular end-systolic dimension, left ventricular ejection fraction, 6MWT distance, desaturation, PB during 6MWT.


2011 ◽  
pp. 36-42
Author(s):  
Hung Viet Bui ◽  
Thi Cu Nguyen

Objective: In Vietnam, obesity is increasing particularly in many large cities. Adult cardiovascular diseases are often derived from cardiovascular disorders during the children period. The implementation of early measures to prevent atherosclerosis, such as weight control, better lipid control will reduce the cardiovascular complications, such as hypertension (HTA), coronary heart diseases and some other diseases. Materials and Methods: Overweight - obese children from 5 to 15 years old who visited the Children's Hospital in Can Tho from May 2009 to May 2010. Total number of patients were chosen as 50 children. Method: Descriptive cross-sectional. Children in the study underwent Doppler ultrasound exam to evaluate cardiac morphology and cardiac function. Results: There were increases in left ventricular systolic diameter, left ventricular diastolic diameter, LV mass in overweight-obese children in the study compared with controls at all ages (p <0.05 ). Left ventricular ejection fraction in overweight-obese children in the study was lower than the control group at all ages (p> 0.05). The average rate of left ventricular shortening of overweight-obese children in the study was 34.8 ± 4.5(%). There was no difference in the rate of shortening of the left ventricle in overweight-obese children in the study compared with controls (p>0.05). There was no relationship between variation in morphology and left ventricular function with the degree of overweight-obesity in this study. Conclusion: The study showed that disturbances in morphology and left ventricular function in overweight-obese children but did not find a strong association with the disorder degree of overweight-obesity.


Open Heart ◽  
2021 ◽  
Vol 8 (2) ◽  
pp. e001716
Author(s):  
Luke Byrne ◽  
Roisin Gardiner ◽  
Patrick Devitt ◽  
Caleb Powell ◽  
Richard Armstrong ◽  
...  

IntroductionThe COVID-19 pandemic has seen the introduction of important public health measures to minimise the spread of the virus. We aim to identify the impact government restrictions and hospital-based infection control procedures on ST elevation myocardial infarction (STEMI) care during the COVID-19 pandemic.MethodsPatients meeting ST elevation criteria and undergoing primary percutaneous coronary intervention from 27 March 2020, the day initial national lockdown measures were announced in Ireland, were included in the study. Patients presenting after the lockdown period, from 18 May to 31 June 2020, were also examined. Time from symptom onset to first medical contact (FMC), transfer time and time of wire cross was noted. Additionally, patient characteristics, left ventricular ejection fraction, mortality and biochemical parameters were documented. Outcomes and characteristics were compared against a control group of patients meeting ST elevation criteria during the month of January.ResultsA total of 42 patients presented with STEMI during the lockdown period. A significant increase in total ischaemic time (TIT) was noted versus controls (8.81 hours (±16.4) vs 2.99 hours (±1.39), p=0.03), with increases driven largely by delays in seeking FMC (7.13 hours (±16.4) vs 1.98 hours (±1.46), p=0.049). TIT remained significantly elevated during the postlockdown period (6.1 hours (±5.3), p=0.05), however, an improvement in patient delays was seen versus the control group (3.99 hours (±4.5), p=0.06). There was no difference seen in transfer times and door to wire cross time during lockdown, however, a significant increase in transfer times was seen postlockdown versus controls (1.81 hours (±1.0) vs 1.1 hours (±0.87), p=0.004).ConclusionA significant increase in TIT was seen during the lockdown period driven mainly by patient factors highlighting the significance of public health messages on public perception. Additionally, a significant delay in transfer times to our centre was seen postlockdown.


Author(s):  
Radosław Pietrzak ◽  
Tomasz M. Książczyk ◽  
Elżbieta Górska ◽  
Łukasz A. Małek ◽  
Bożena Werner

Galectin-3 (G3) is a biomarker known as an inflammatory state exponent. The aim of this paper was to analyze the G3 in adolescents with ventricular arrhythmia (VES) in order to evaluate its impact on myocardial tissue preservation. The study group (SG) consisted of 25 VES adolescents. The control group (CG) was 21 healthy children. G3 was assessed in the SG and CG. In the SG electrocardiography, Holter monitoring, echocardiography and CMR were performed. The G3 in SG was 13.45 ± 11.4 ng/mL and in CG 7.2 ± 2.0 ng/mL, p < 0.001. Moderate positive correlation between the G3 and z-score of the left ventricular diameter (r = 0.47, p = 0.041) and moderate negative correlation between the G3 and the left ventricular ejection fraction in cardiac magnetic resonance (CMR EF) (−0.49, p = 0.032) were found. According to the multiple linear regression analysis, CMR EF and VES were independent predictors for G3 elevation. Conclusion: Galectin-3 plasma concentration is elevated and correlates with the chosen left ventricular dysfunction parameters in adolescents suffering from ventricular arrhythmia. Further investigation is necessary to establish if elevated G3 is a useful biomarker for screening young individuals with ventricular arrhythmia who are at risk of structural cardiovascular pathology.


Cardiology ◽  
2016 ◽  
Vol 135 (4) ◽  
pp. 221-227 ◽  
Author(s):  
Shao-Ling Yang ◽  
Ke-Qiang Tang ◽  
Jun-Jia Tao ◽  
Ai-Hong Wan ◽  
Yan-Duan Lin ◽  
...  

Objectives: We aimed to evaluate whether ultrasound (US) and microbubble-mediated delivery of Cluster of Differentiation 151 (CD151) could enhance the therapeutic effects of CD151 on myocardial infarction (MI). Methods: A rabbit model of MI was established by a modified Fujita method. Then, 50 MI rabbits were randomly divided into 5 groups, including G1 (CD151 plasmid and physiological saline in the presence of US); G2 (CD151 and Sonovue in the presence of US); G3 (CD151 and Sonovue in the absence of US); G4 (Sonovue in the absence of US), and a control group (physiological saline in the absence of US). After 14 days of treatment, the expression of CD151 was detected by Western blot. Besides, vessel density of peri-infarcted myocardium was measured by immunohistochemistry, and cardiac function was analyzed by echocardiography. Results: The rabbit model of MI was established successfully. CD151 injection increased the expression of CD151 and microvessel density in the myocardium of MI rabbits. Heart function was significantly improved by CD151, which exhibited increased left ventricular ejection fraction, left ventricular fractional shortening and a reduced Tei index. Besides, US Sonovue significantly increased the expression efficiency of CD151. Conclusion: US microbubble was an effective vector for CD151 delivery. CD151 might be an effective therapeutic target for MI.


2014 ◽  
Vol 9 ◽  
pp. IMI.S13939 ◽  
Author(s):  
Bandi Hari Krishna ◽  
Pravati Pal ◽  
G. K. Pal ◽  
J. Balachander ◽  
E. Jayasettiaseelon ◽  
...  

Aims The purpose of this study was to evaluate whether yoga training in addition to standard medical therapy can improve cardiac function and reduce N terminal pro B-type natriuretic peptide (NT pro BNP) in heart failure (HF). Methods 130 patients were recruited and randomized into two groups: Control Group (CG) ( n = 65), Yoga Group (YG). In YG, 44 patients and in CG, 48 patients completed the study. Cardiac function using left ventricular ejection fraction (LVEF), myocardial performance index (Tei index), and NT pro BNP, a biomarker of HF, was assessed at baseline and after 12 weeks. Result Improvement in LVEF, Tei index, and NT pro BNP were statistically significant in both the groups. Furthermore, when the changes in before and after 12 weeks were in percentage, LVEF increased 36.88% in the YG and 16.9% in the CG, Tei index was reduced 27.87% in the YG and 2.79% in the CG, NT pro BNP was reduced 63.75% in the YG and 10.77% in the CG. The between group comparisons from pre to post 12 weeks were significant for YG improvements (LVEF, P < 0.01, Tei index, P < 0.01, NT pro BNP, P < 0.01). Conclusion These results indicate that the addition of yoga therapy to standard medical therapy for HF patients has a markedly better effect on cardiac function and reduced myocardial stress measured using NT pro BNP in patients with stable HF.


Circulation ◽  
2007 ◽  
Vol 116 (suppl_16) ◽  
Author(s):  
Marcus Sandri ◽  
Stephan Gielen ◽  
Norman Mangner ◽  
Volker Adams ◽  
Sandra Erbs ◽  
...  

Background: The concept of ventricular-arterial coupling implies that LV-function is determined by the three factors left ventricular diastolic, left ventricular systolic and arterial elastance. We have previously documented an improvement in endothelial function and systolic LV-function in patients with chronic heart failure (CHF) after 6 months of exercise training (ET). It remains, however, unclear, how shorter ET periods may affect endothelial, systolic and diastolic ventricular function as echocardiographic parameters related to ventricular arterial coupling in patients with CHF. METHODS: In this ongoing study we randomised 43 patients with stable CHF (age 60.3 ± 2.9 years, EF 27.4 ± 1.7%, VO 2 max 14.7 ± 4.3ml/kg*min) to a training or a control group (C). Patients in the training group exercised 4 times daily at 70% of the individual heart rate reserve for 4 weeks under supervision. At baseline and after 4 weeks the E/A ratio and septal/lateral E’/A’ velocities were determined by echocardiography with tissue Doppler. Exercise capacity was measured by ergospirometry and flow-mediated dilatation (FMD) was assessed by high-resolution radial ultrasound. RESULTS: After only 4 weeks of ET oxygen uptake at peak exercise increased from 14.9 ± 3.3 to 18.1 ± 4.7 ml/min/kg, (p<0.01 vs. C) in training subjects. Left ventricular ejection fraction improved from 26.8 ± 4.6 to 33.1 ± 5.5% (p<0.05 vs. C) in patients of the training group while it remained unchanged in the control group. E/A-ratio mended from 0.63 ± 0.12 to 0.81 ± 0.22 (p<0.01 vs. C) in training patients. Septal E’ velocities increased from 5.5 ± 0.5 to 7.8 ± 1.4 cm/s in training patients (p<0.05 vs. C). FMD of the radial artery improved from 8.2 ± 2.1 to 15.2 ± 3.8% (p<0.01 vs. C) as a result of ET. CONCLUSIONS: Only 4 weeks of endurance training are highly effective with significantly improved FMD accompanied by an emended systolic and diastolic LV-function. We hypothesise that the improvement in LV-EF in training patients may be caused by a corrected ventricular-arterial coupling: ventricular diastolic relaxation and effective endothelial function are ameliorated resulting in an augmentation of stroke volume.


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