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2.
Rev Assoc Med Bras (1992) ; 70(4): e20231359, 2024.
Article in English | MEDLINE | ID: mdl-38716945

ABSTRACT

OBJECTIVE: The aim of this study was to evaluate the relationship between uterine leiomyoma and fragmented QRS, a non-invasive indicator of cardiovascular risk and myocardial ischemia, in women with uterine leiomyoma. METHODS: In this prospective case-control study, a total of 47 patients diagnosed with uterine leiomyoma (case group) and 47 healthy individuals without uterine leiomyoma (control group) who had undergone bilateral tubal ligation surgery were included. Various demographic, clinical, and laboratory parameters and the presence of fragmented QRS were recorded. RESULTS: The leiomyoma group showed significantly higher body mass index (27.46±2.18 vs. 25.9±2.87 kg/m2, p=0.005) and waist circumference (91.34±9.30 vs. 84.97±9.3 cm, p=0.001) compared with the control group. Uterine volumes were also significantly higher in the leiomyoma group (235.75±323.48 vs. 53.24±12.81 mm3, p<0.001). The presence of fragmented QRS was detected in 18.1% of the patients. Multiple regression analysis identified age, fasting blood glucose value, and the presence of fragmented QRS as independent risk factors for the presence of leiomyoma. CONCLUSION: This study provides valuable insights into the relationship between uterine leiomyoma and fragmented QRS. The presence of fragmented QRS was identified as an independent risk factor for the presence of leiomyoma. Further research is needed to better understand the underlying mechanisms connecting uterine leiomyoma and cardiovascular health.


Subject(s)
Electrocardiography , Leiomyoma , Uterine Neoplasms , Humans , Female , Leiomyoma/physiopathology , Leiomyoma/complications , Prospective Studies , Case-Control Studies , Adult , Uterine Neoplasms/physiopathology , Uterine Neoplasms/complications , Middle Aged , Body Mass Index , Risk Factors , Myocardial Ischemia/physiopathology
3.
Sci Rep ; 14(1): 11249, 2024 05 16.
Article in English | MEDLINE | ID: mdl-38755348

ABSTRACT

This technique-focused observational study explores the impact of a 6-week Nordic Walking (NW) program on physiological and biomechanical aspects in ischemic heart disease (IHD) patients. Twelve male IHD patients (66.2 ± 5.2 years, 12.2 ± 7.5 years of disease duration) were evaluated pre- and post-training for (i) gait parameters, (ii) exercise tolerance using electrocardiographic (ECG) stress test, (iii) a 6-min walk test (6MWT). The NW training, adhering to IHD patient guidelines, involved a 100-m walk at a self-selected, preferred speed without sticks, with classic NW sticks and mechatronic sticks. A mechatronic measuring system, specifically engineered for measuring, diagnosing and monitoring the patient's gait, was integrated into mechatronic sticks. Post-training, significant enhancements were observed in ECG stress test duration, metabolic equivalency, and 6MWT distance, irrespective of the stick type. However, no significant changes were noted in spatiotemporal parameters concerning the measured side, stick utilisation, or type. The results suggest that NW training boosts exercise capacity and refines gait mechanics in male IHD patients. However, the improvement in exercise capacity was not linked to changes in gait mechanics from NW training but rather to the movement during NW gait. Hence, the key to enhancing exercise capacity in IHD patients is the movement during NW gait, not the quality of gait mechanics.


Subject(s)
Exercise Tolerance , Gait , Myocardial Ischemia , Walking , Humans , Male , Myocardial Ischemia/physiopathology , Myocardial Ischemia/rehabilitation , Gait/physiology , Aged , Walking/physiology , Exercise Tolerance/physiology , Middle Aged , Exercise Therapy/methods , Electrocardiography , Walk Test , Exercise Test
4.
BMC Cardiovasc Disord ; 24(1): 254, 2024 May 16.
Article in English | MEDLINE | ID: mdl-38750460

ABSTRACT

INTRODUCTION: The aim of this study is to analyze the diagnostic value of global longitudinal strain (GLS) in detecting inducible myocardial ischemia in patients with chest pain undergoing treadmill contrast-enhanced stress echocardiography (SE). METHODS: We retrospectively enrolled all patients who underwent invasive coronary angiography after treadmill contrast-enhanced SE. Rest and peak-stress myocardial GLS, segmental LS, and LS of 4-chamber (CH), 2-CH, and 3-CH views were reported. Luminal stenosis of more than 70% or fractional flow reserve (FFR) of < 0.8 was considered significant. RESULTS: In total 33 patients were included in the final analysis, among whom sixteen patients (48.4%) had significant coronary artery stenosis. Averaged GLS, 3-CH, and 4-CH LS were significantly lower in patients with critical coronary artery stenosis compared to those without significant stenosis (-17.1 ± 7.1 vs. -24.2 ± 7.2, p = 0.041), (-18.2 ± 8.9 vs. -24.6 ± 8.2, p = 0.045) and (-14.8 ± 6.2 vs. -22.8 ± 7.8, p = 0.009), respectively. Receiver operating characteristic (ROC) analysis of ischemic and non-ischemic segments demonstrated that a cut-off value of -20% of stress LS had 71% sensitivity and 60% specificity for ruling out inducible myocardial ischemia (Area under the curve was AUC = 0.72, P < 0.0001). CONCLUSION: Myocardial LS measured with treadmill contrast-enhanced stress echocardiography demonstrates potential value in identifying patients with inducible myocardial ischemia.


Subject(s)
Contrast Media , Coronary Angiography , Coronary Stenosis , Echocardiography, Stress , Predictive Value of Tests , Humans , Male , Female , Echocardiography, Stress/methods , Retrospective Studies , Middle Aged , Aged , Contrast Media/administration & dosage , Coronary Stenosis/physiopathology , Coronary Stenosis/diagnostic imaging , Reproducibility of Results , Myocardial Contraction , Ventricular Function, Left , Myocardial Ischemia/physiopathology , Myocardial Ischemia/diagnostic imaging , Fractional Flow Reserve, Myocardial
5.
Sci Rep ; 14(1): 10685, 2024 05 09.
Article in English | MEDLINE | ID: mdl-38724607

ABSTRACT

This study aims to measure myocardial blood flow (MBF) using dynamic CT- myocardial perfusion imaging (CT-MPI) combined with mental stressors in patients with obstructive coronary artery disease (OCAD) and in patients with anxiety and no obstructive coronary artery disease (ANOCAD). A total of 30 patients with OCAD with 30 patients with ANOCAD were included in this analysis. Using the 17-segment model, the rest and stress phase MBF of major coronary arteries in participants were recorded respectively. Compared with ANOCAD patients, OCAD patients were more likely to have localized reduction of MBF (p < 0.05). For patients with ANOCAD, both global MBF and MBF of the main coronary arteries in the stress phase were lower than those in the rest phase (all p < 0.05), but there was no significant difference in MBF among the main coronary arteries in the rest or stress phase (p = 0.25, p = 0.15). For patients with OCAD, the MBF of the target area was lower than that of the non-target area in both the rest and stress phase, and the MBF of the target area in the stress phase was lower than that in the rest phase (all p < 0.05). However, there was no significant difference in MBF between the rest or stress phase in the non-target area (p = 0.73). Under mental stress, the decrease in MBF in ANOCAD patients was diffuse, while the decrease in MBF in OCAD patients was localized. Dynamic CT-MPI combined with mental stressors can be used to detect MBF changes in anxiety patients.


Subject(s)
Anxiety , Myocardial Ischemia , Myocardial Perfusion Imaging , Stress, Psychological , Tomography, X-Ray Computed , Humans , Male , Female , Myocardial Perfusion Imaging/methods , Middle Aged , Stress, Psychological/diagnostic imaging , Stress, Psychological/physiopathology , Anxiety/diagnostic imaging , Anxiety/physiopathology , Myocardial Ischemia/diagnostic imaging , Myocardial Ischemia/physiopathology , Myocardial Ischemia/psychology , Aged , Tomography, X-Ray Computed/methods , Coronary Artery Disease/diagnostic imaging , Coronary Artery Disease/physiopathology , Coronary Artery Disease/psychology , Coronary Circulation , Coronary Vessels/diagnostic imaging , Coronary Vessels/physiopathology
6.
Med Sci Monit ; 30: e943122, 2024 May 27.
Article in English | MEDLINE | ID: mdl-38801723

ABSTRACT

BACKGROUND Multi-vessel coronary artery disease (MVD) represents a severe type of coronary artery disease (CAD). Ischemic mitral regurgitation (IMR) is a common mechanical complication in patients with CAD. This study aimed to retrospectively investigate the efficacy of percutaneous coronary intervention (PCI) on moderate/severe IMR in patients with MVD. MATERIAL AND METHODS Clinical data were collected from 15 patients who underwent successful treatment for MVD combined with moderate/severe IMR through the PCI procedure and achieved complete revascularization between January 2014 and December 2022. Cardiac structural and functional parameters were assessed through echocardiographic evaluations. Color flow recordings of MR jets were obtained through an enlarged view of the 4-chamber cut, and the diagnosis of MR was categorized into mild (<4 cm²), moderate (4-8 cm²), and severe (>8 cm²), based on the MR area. RESULTS The common features of the selected cases were advanced age, low body weight, and renal insufficiency. Cardiac echocardiography revealed an augmentation in the left atrial anteroposterior diameter and left ventricular internal diameter at end-systole after PCI, while the left ventricle internal diameter in diastole, left ventricular ejection fraction, and left ventricular fractional shortening were comparable to preoperative values. All patients had moderate/severe MR preoperatively, and MR improved at 1 month (2.73±0.69) and 12 months (2.26±0.58) after PCI. CONCLUSIONS In cases of MVD accompanied by moderate/severe IMR, undergoing PCI can spare certain elderly patients with low body weight and renal insufficiency from high-risk surgery, alleviating the severity of MR without undergoing mitral valve intervention.


Subject(s)
Coronary Artery Disease , Echocardiography , Mitral Valve Insufficiency , Percutaneous Coronary Intervention , Humans , Mitral Valve Insufficiency/surgery , Mitral Valve Insufficiency/physiopathology , Male , Female , Percutaneous Coronary Intervention/methods , Coronary Artery Disease/surgery , Coronary Artery Disease/complications , Coronary Artery Disease/physiopathology , Aged , Middle Aged , Retrospective Studies , Treatment Outcome , Myocardial Ischemia/complications , Myocardial Ischemia/surgery , Myocardial Ischemia/physiopathology
7.
Medicina (Kaunas) ; 60(4)2024 Apr 19.
Article in English | MEDLINE | ID: mdl-38674313

ABSTRACT

Background and Objectives: The combination of aortic valve stenosis (AS) and ischemic heart disease (IHD) is quite common and is associated with myocardial fibrosis (MF). The purpose of this study was to evaluate the association between the histologically verified left ventricular (LV) MF and its geometry and function in isolated AS and AS within IHD groups. Materials and Methods: In a single-center, prospective trial, 116 patients underwent aortic valve replacement (AVR) with/without concomitant surgery. The study population was divided into groups of isolated AS with/without IHD. Echocardiography was used, and LV measurements and aortic valve parameters were obtained from all patients. Myocardial tissue was procured from all study patients undergoing elective surgery. Results: There were no statistical differences between isolated AS and AS+IHD groups in LV parameters or systolic and diastolic functions during the study periods. The collagen volume fraction was significantly different between the isolated AS and AS+IHD groups and was 7.3 ± 5.6 and 8.3 ± 6.4, respectively. Correlations between MF and left ventricular end-diastolic diameter (LVEDD) (r = 0.59, p = < 0.001), left ventricular mass (LVM) (r = 0.42, p = 0.011), left ventricular ejection fraction (LVEF) (r = -0.67, p < 0.001) and an efficient orifice area (EOA) (r = 0.371, p = 0.028) were detected in isolated AS during the preoperative period; the same was observed for LVEDD (r = 0.45, p = 0.002), LVM (r = 0.36, p = 0.026), LVEF (r = -0.35, p = 0.026) and aortic annulus (r = 0.43, p = 0.018) in the early postoperative period; and LVEDD (r = 0.35, p ≤ 0.05), LVM (r = 0.43, p = 0.007) and EOA (r = 0.496, p = 0.003) in the follow-up period. In the group of AS and IHD, correlations were found only with LV posterior wall thickness (r = 0.322, p = 0.022) in the follow-up period. Conclusions: Histological MF in AS was correlated with LVM and LVEDD in all study periods. No correlations between MF and LV parameters were found in aortic stenosis in the ischemic heart disease group across all study periods.


Subject(s)
Aortic Valve Stenosis , Echocardiography , Fibrosis , Heart Ventricles , Humans , Aortic Valve Stenosis/physiopathology , Aortic Valve Stenosis/surgery , Aortic Valve Stenosis/complications , Male , Female , Middle Aged , Prospective Studies , Aged , Heart Ventricles/physiopathology , Heart Ventricles/diagnostic imaging , Heart Ventricles/pathology , Echocardiography/methods , Myocardium/pathology , Ventricular Function, Left/physiology , Myocardial Ischemia/physiopathology , Myocardial Ischemia/complications
9.
Biomed Phys Eng Express ; 10(4)2024 May 07.
Article in English | MEDLINE | ID: mdl-38640907

ABSTRACT

Cardiac electrical changes associated with ischemic heart disease (IHD) are subtle and could be detected even in rest condition in magnetocardiography (MCG) which measures weak cardiac magnetic fields. Cardiac features that are derived from MCG recorded from multiple locations on the chest of subjects and some conventional time domain indices are widely used in Machine learning (ML) classifiers to objectively distinguish IHD and control subjects. Most of the earlier studies have employed features that are derived from signal-averaged cardiac beats and have ignored inter-beat information. The present study demonstrates the utility of beat-by-beat features to be useful in classifying IHD subjects (n = 23) and healthy controls (n = 75) in 37-channel MCG data taken under rest condition of subjects. The study reveals the importance of three features (out of eight measured features) namely, the field map angle (FMA) computed from magnetic field map, beat-by-beat variations of alpha angle in the ST-T region and T wave magnitude variations in yielding a better classification accuracy (92.7 %) against that achieved by conventional features (81 %). Further, beat-by-beat features are also found to augment the accuracy in classifying myocardial infarction (MI) Versus control subjects in two public ECG databases (92 % from 88 % and 94 % from 77 %). These demonstrations summarily suggest the importance of beat-by-beat features in clinical diagnosis of ischemia.


Subject(s)
Machine Learning , Magnetocardiography , Myocardial Ischemia , Humans , Magnetocardiography/methods , Myocardial Ischemia/physiopathology , Myocardial Ischemia/diagnosis , Male , Female , Middle Aged , Adult , Case-Control Studies , Signal Processing, Computer-Assisted , Algorithms , Electrocardiography/methods , Aged , Heart Rate/physiology , Heart/physiopathology , Reproducibility of Results
10.
J Echocardiogr ; 22(2): 71-78, 2024 Jun.
Article in English | MEDLINE | ID: mdl-38615090

ABSTRACT

Echocardiography has been used clinically to assess regional myocardial wall motion for the diagnosis of acute myocardial ischemia or stress-induced ischemia, but it is often difficult to distinguish hypokinetic motion from normal motion. Myocardial wall motion is affected by loading conditions as well as intrinsic contractility, making it challenging to define a normal range of wall motion. Therefore, hypokinesis is usually diagnosed by comparing target areas with other areas of myocardium considered normal (relative hypokinesis). Myocardial strain analysis by tissue Doppler echocardiography and speckle-tracking echocardiography has enabled objective and quantitative evaluation of regional myocardial wall motion. Peak systolic strain decreases during acute ischemia, but subtle and invisible myocardial motion, such as early systolic lengthening (ESL) and postsystolic shortening (PSS), also occurs, and the analysis of these subtle motions can improve the diagnostic accuracy of ischemia. However, the diagnosis of ischemic myocardium by strain analysis is not widely performed in clinical practice at this time due to several limitations. This article reviews the features of myocardial motion during acute ischemia, the mechanisms of ESL and PSS, the diagnosis of ischemic myocardium using strain analysis, and current approaches and future challenges to overcome the limitations in the detection of relative hypokinesis. This article also explains the use of ESL and PSS to detect myocardial ischemic memory that remains after brief ischemia.


Subject(s)
Echocardiography , Myocardial Contraction , Myocardial Ischemia , Humans , Myocardial Ischemia/physiopathology , Myocardial Ischemia/diagnostic imaging , Myocardial Ischemia/diagnosis , Myocardial Contraction/physiology , Echocardiography/methods , Acute Disease , Systole
15.
J Appl Physiol (1985) ; 136(5): 1157-1169, 2024 May 01.
Article in English | MEDLINE | ID: mdl-38511210

ABSTRACT

The coronary sinus reducer (CSR) is an emerging medical device for treating patients with refractory angina, often associated with myocardial ischemia. Patients implanted with CSR have shown positive outcomes, but the underlying mechanisms are unclear. This study sought to understand the mechanisms of CSR by investigating its effects on coronary microcirculation hemodynamics that may help explain the therapy's efficacy. We applied a validated computer model of the coronary microcirculation to investigate how CSR affects hemodynamics under different degrees of coronary artery stenosis. With moderate coronary stenosis, an increase in capillary transit time (CTT) [up to 69% with near-complete coronary sinus (CS) occlusion] is the key change associated with CSR. Because capillaries in the microcirculation can still receive oxygenated blood from the upstream artery with moderate stenosis, the increase in CTT allows more time for the exchange of gases and nutrients, aiding tissue oxygenation. With severe coronary stenosis; however, the redistribution of blood draining from the nonischemic region to the ischemic region (up to 96% with near-complete CS occlusion) and the reduction in capillary flow heterogeneity are the key changes associated with CSR. Because blood draining from the nonischemic region is not completely devoid of O2, the redistribution of blood to the capillaries in the ischemic region by CSR is beneficial especially when little or no oxygenated blood reaches these capillaries. This simulation study provides insights into the mechanisms of CSR in improving clinical symptoms. The mechanisms differ with the severity of the upstream stenosis.NEW & NOTEWORTHY Emerging coronary venous retroperfusion treatments, particularly coronary sinus reducer (CSR) for refractory angina linked to myocardial ischemia, show promise; however, their mechanisms of action are not well understood. We find that CSR's effectiveness varies with the severity of coronary stenosis. In moderate stenosis, CSR improves tissue oxygenation by increasing capillary transit time, whereas in severe stenosis, it redistributes blood from nonischemic to ischemic regions and reduces capillary flow heterogeneity.


Subject(s)
Computer Simulation , Coronary Circulation , Coronary Sinus , Hemodynamics , Microcirculation , Myocardial Ischemia , Humans , Coronary Sinus/physiopathology , Myocardial Ischemia/physiopathology , Myocardial Ischemia/metabolism , Coronary Circulation/physiology , Hemodynamics/physiology , Microcirculation/physiology , Coronary Stenosis/physiopathology , Models, Cardiovascular
16.
Am J Physiol Regul Integr Comp Physiol ; 326(6): R484-R498, 2024 Jun 01.
Article in English | MEDLINE | ID: mdl-38406842

ABSTRACT

Salmonid fish include some of the most valued cultured fish species worldwide. Unlike most other fish, the hearts of salmonids, including Atlantic salmon and rainbow trout, have a well-developed coronary circulation. Consequently, their hearts' reliance on oxygenation through coronary arteries leaves them prone to coronary lesions, believed to precipitate myocardial ischemia. Here, we mimicked such coronary lesions by subjecting groups of juvenile rainbow trout to coronary ligation, assessing histomorphological myocardial changes associated with ischemia and scarring in the context of cardiac arrhythmias using electrocardiography (ECG). Notable ECG changes resembling myocardial ischemia-like ECG in humans, such as atrioventricular blocks and abnormal ventricular depolarization (prolonged and fragmented QRS complex), as well as repolarization (long QT interval) patterns, were observed during the acute phase of myocardial ischemia. A remarkable 100% survival rate was observed among juvenile trout subjected to coronary ligation after 24 wk. Recovery from coronary ligation occurred through adaptive ventricular remodeling, coupled with a fast cardiac revascularization response. These findings carry significant implications for understanding the mechanisms governing cardiac health in salmonid fish, a family particularly susceptible to cardiac diseases. Furthermore, our results provide valuable insights into comparative studies on the evolution, pathophysiology, and ontogeny of vertebrate cardiac repair and restoration.NEW & NOTEWORTHY Juvenile rainbow trout exhibit a remarkable capacity to recover from cardiac injury caused by myocardial ischemia. Recovery from cardiac damage occurs through adaptive ventricular remodeling, coupled with a rapid cardiac revascularization response. These findings carry significant implications for understanding the mechanisms governing cardiac health within salmonid fishes, which are particularly susceptible to cardiac diseases.


Subject(s)
Myocardial Ischemia , Oncorhynchus mykiss , Animals , Myocardial Ischemia/physiopathology , Heart Failure/physiopathology , Ventricular Remodeling , Electrocardiography , Fish Diseases/physiopathology , Fish Diseases/pathology , Time Factors
17.
Eur J Heart Fail ; 26(3): 598-609, 2024 Mar.
Article in English | MEDLINE | ID: mdl-38247182

ABSTRACT

AIMS: Cardiac involvement is the main driver of clinical outcomes in systemic amyloidosis and preliminary studies support the hypothesis that myocardial ischaemia contributes to cellular damage. The aims of this study were to assess the presence and mechanisms of myocardial ischaemia using cardiovascular magnetic resonance (CMR) with multiparametric mapping and histopathological assessment. METHODS AND RESULTS: Ninety-three patients with cardiac amyloidosis (CA) (light-chain amyloidosis n = 42, transthyretin amyloidosis n = 51) and 97 without CA (three-vessel coronary disease [3VD] n = 47, unobstructed coronary arteries n = 26, healthy volunteers [HV] n = 24) underwent quantitative stress perfusion CMR with myocardial blood flow (MBF) mapping. Twenty-four myocardial biopsies and three explanted hearts with CA were analysed histopathologically. Stress MBF was severely reduced in patients with CA with lower values than patients with 3VD, unobstructed coronary arteries and HV (CA: 1.04 ± 0.51 ml/min/g, 3VD: 1.35 ± 0.50 ml/min/g, unobstructed coronary arteries: 2.92 ± 0.52 ml/min/g, HV: 2.91 ± 0.73 ml/min/g; CA vs. 3VD p = 0.011, CA vs. unobstructed coronary arteries p < 0.001, CA vs. HV p < 0.001). Myocardial perfusion abnormalities correlated with amyloid burden, systolic and diastolic function, structural parameters and blood biomarkers (p < 0.05). Biopsies demonstrated abnormal vascular endothelial growth factor staining in cardiomyocytes and endothelial cells, which may be related to hypoxia conditions. Amyloid infiltration in intramural arteries was associated with severe lumen reduction and severe reduction in capillary density. CONCLUSION: Cardiac amyloidosis is associated with severe inducible myocardial ischaemia demonstrable by histology and CMR stress perfusion mapping. Histological evaluation indicates a complex pathophysiology, where in addition to systolic and diastolic dysfunction, amyloid infiltration of the epicardial arteries and disruption and rarefaction of the capillaries play a role in contributing to myocardial ischaemia.


Subject(s)
Amyloidosis , Cardiomyopathies , Coronary Circulation , Humans , Male , Female , Middle Aged , Coronary Circulation/physiology , Aged , Cardiomyopathies/physiopathology , Cardiomyopathies/diagnosis , Amyloidosis/physiopathology , Magnetic Resonance Imaging, Cine/methods , Myocardium/pathology , Immunoglobulin Light-chain Amyloidosis/physiopathology , Immunoglobulin Light-chain Amyloidosis/complications , Myocardial Ischemia/physiopathology , Myocardial Ischemia/diagnosis , Amyloid Neuropathies, Familial/physiopathology , Amyloid Neuropathies, Familial/complications , Myocardial Perfusion Imaging/methods , Coronary Vessels/physiopathology , Coronary Vessels/diagnostic imaging , Coronary Vessels/pathology , Biopsy
18.
Eur J Nucl Med Mol Imaging ; 51(6): 1612-1621, 2024 May.
Article in English | MEDLINE | ID: mdl-38191816

ABSTRACT

PURPOSE: We evaluated the impact on cardiovascular outcome of coronary revascularization-induced changes in ischemic total perfusion defect (ITPD) and myocardial flow reserve (MFR) as assessed by 82Rb positron emission tomography (PET)/computed tomography (CT) imaging. METHODS: The study included 102 patients referred to 82Rb PET/CT myocardial perfusion imaging before and after coronary revascularization. All patients were followed for the occurrence of cardiovascular events (cardiac death, nonfatal myocardial infarction, repeated revascularization, and heart failure) after the second imaging study. RESULTS: During a median follow-up of 20 months, 21 events occurred. The clinical characteristics were comparable between patients with and without events. In the overall study population, after revascularization, there was a significant reduction (P < 0.001) of ITPD, while hyperemic myocardial blood flow (MBF) (P < 0.01) and MFR (P < 0.05) significantly improved. Event rate was higher in patients with ITPD (P < 0.005) or MFR (P < 0.001) worsening compared to those with unchanged or improved ITPD or MFR. At Cox univariable analysis, ITPD and MFR worsening resulted in predictors of events (both P < 0.05). Patients with worsening of both ITPD and MFR had the worst event-free survival (log-rank 32.9, P for trend < 0.001). CONCLUSIONS: In patients with stable CAD, worsening of ITPD and MFR after revascularization procedures is associated with higher risk of cardiovascular events. Follow-up MPI with 82Rb PET/CT may improve risk stratification in patients submitted to coronary revascularization.


Subject(s)
Myocardial Perfusion Imaging , Myocardial Revascularization , Positron Emission Tomography Computed Tomography , Humans , Male , Female , Middle Aged , Aged , Fractional Flow Reserve, Myocardial , Myocardial Ischemia/diagnostic imaging , Myocardial Ischemia/physiopathology , Rubidium Radioisotopes , Treatment Outcome
19.
Can J Physiol Pharmacol ; 102(5): 331-341, 2024 May 01.
Article in English | MEDLINE | ID: mdl-38118123

ABSTRACT

Extracellular potassium concentration might modify electrophysiological properties in the border zone of ischemic myocardium. We evaluated the depolarization and repolarization characteristics across the ischemic-normal border under [K+] variation. Sixty-four-lead epicardial mapping was performed in 26 rats ([K+] 2.3-6.4 mM) in a model of acute ischemia/reperfusion. The animals with [K+] < 4.7 mM (low-normal potassium) had an ischemic zone with ST-segment elevation and activation delay, a border zone with ST-segment elevation and no activation delay, and a normal zone without electrophysiological abnormalities. The animals with [K+] >4.7 mM (normal-high potassium) had only the ischemic and normal zones and no transitional area. Activation-repolarization intervals and local conduction velocities were inversely associated with [K+] in linear regression analysis with adjustment for the zone of myocardium. The reperfusion extrasystolic burden (ESB) was greater in the low-normal as compared to normal-high potassium animals. Ventricular tachycardia/fibrillation incidence did not differ between the groups. In patch-clamp experiments, hypoxia shortened action potential duration at 5.4 mM but not at 1.3 mM of [K+]. IK(ATP) current was lower at 1.3 mM than at 5.4 mM of [K+]. We conclude that the border zone formation in low-normal [K+] was associated with attenuation of IK(ATP) response to hypoxia and increased reperfusion ESB.


Subject(s)
Action Potentials , Myocardial Ischemia , Potassium , Animals , Potassium/blood , Potassium/metabolism , Male , Rats , Myocardial Ischemia/physiopathology , Myocardial Ischemia/blood , Myocardial Ischemia/metabolism , Action Potentials/physiology , Myocardial Reperfusion Injury/blood , Myocardial Reperfusion Injury/physiopathology , Myocardial Reperfusion Injury/metabolism , Rats, Wistar
20.
Heart Rhythm ; 21(5): 610-619, 2024 May.
Article in English | MEDLINE | ID: mdl-38160759

ABSTRACT

BACKGROUND: Neural remodeling in the left stellate ganglion (LSG), as mediated by neuroimmune reactions, promotes cardiac sympathetic nerve activity (SNA) and thus increases the incidence of ventricular arrhythmias (VAs). Interleukin-6 (IL-6) is an important factor of the neuroimmune interaction. OBJECTIVE: The present study explored the effects of IL-6 on LSG hyperactivity and the incidence of VAs. METHODS: Eighteen beagles were randomly allocated to a control group (saline with myocardial infarction [MI], n = 6), adeno-associated virus (AAV) group (AAV with MI, n = 6), and IL-6 group (overexpression of IL-6 via AAV vector with MI, n = 6). Ambulatory electrocardiography was performed before and 30 days after AAV microinjection into the LSG. LSG function and ventricular electrophysiology were assessed at 31 days after surgery, and a canine MI model was established. Samples of the LSG were collected for immunofluorescence staining and molecular biological evaluation. Blood samples and 24-hour Holter data were obtained from 24 patients with acute MI on the day after they underwent percutaneous coronary intervention to assess the correlation between IL-6 levels and SNA. RESULTS: IL-6 overexpression increased cardiac SNA and worsened postinfarction VAs. Furthermore, sustained IL-6 overexpression enhanced LSG function, promoted expression of nerve growth factor, c-fos, and fos B in the LSG, and activated the signal transducer and activator of transcription 3/regulator of G protein signalling 4 signaling pathway. Clinical sample analysis revealed a correlation between serum IL-6 levels and heart rate variability frequency domain index as well as T-wave alternans. CONCLUSION: IL-6 levels are correlated with cardiac SNA. Chronic overexpression of IL-6 mediates LSG neural remodeling through the signal transducer and activator of transcription 3/regulator of G protein signalling 4 signaling pathway, elevating the risk of VA after MI.


Subject(s)
Disease Models, Animal , Interleukin-6 , Stellate Ganglion , Animals , Dogs , Interleukin-6/metabolism , Stellate Ganglion/metabolism , Arrhythmias, Cardiac/etiology , Male , Electrocardiography, Ambulatory/methods , Myocardial Ischemia/metabolism , Myocardial Ischemia/physiopathology , Sympathetic Nervous System/physiopathology , Sympathetic Nervous System/metabolism , Neuroimmunomodulation/physiology , Humans , Tachycardia, Ventricular/etiology , Tachycardia, Ventricular/physiopathology , Tachycardia, Ventricular/metabolism , Tachycardia, Ventricular/therapy
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