Effect of transmural versus nontransmural myocardial infarction on inducibility of ventricular arrhythmias during sympathetic stimulation in dogs

Herre, John M.; Wetstein, Lewis; Lin, Yuh‐Lin; Mills, A. Scott; Dae, Michael W.; Thames, Marc D.

doi:10.1016/0735-1097(88)90110-6

Cited by 56 publications

(19 citation statements)

References 24 publications

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“…Efferent as well as afferent phenomena are affected during ischaemia and necrosis, according to the kind of hypoperfusion: transmural or sub-endocardial (BARBER et al, 1983;HERRE et al, 1988). There is no objection, from our point of view, to accepting the results in the sense that HRV analysis in the frequency domain has the sensitivity to detect well-known physiopathological phenomena, such as ischaemia and/or cardiac necrosis, over neurovegetative heart regulation.…”

Section: Discussionmentioning

confidence: 75%

Wavelet transform analysis of heart rate variability during myocardial ischaemia

Gamero

Vila

Palácios

2002

Med. Biol. Eng. Comput.

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Analysis of heart rate variability (HRV) is a valuable, non-invasive method for quantifying autonomic cardiac control in humans. Frequency-domain analysis of HRV involving myocardial ischaemic episodes should take into account its non-stationary behaviour. The wavelet transform is an alternative tool for the analysis of non-stationary signals. Fourteen patients have been analysed, ranging from 40 to 64 years old and selected from the European Electrocardiographic ST-T Database (ESDB). These records contain 33 ST episodes, according to the notation of the ESDB, with durations of between 40s and 12 min. A method for analysing HRV signals using the wavelet transform was applied to obtain a time-scale representation for very low-frequency (VLF), low-frequency (LF) and high-frequency (HF) bands using the orthogonal multiresolution pyramidal algorithm. The design and implementation using fast algorithms included a specially adapted decomposition quadrature mirror filter bank for the frequency bands of interest. Comparing a normality zone against the ischaemic episode in the same record, increases in LF (0.0112 +/- 0.0101 against 0.0175 +/- 0.0208 s2 Hz(-1); p<0.1) and HF (0.0011 +/- 0.0008 against 0.00 17 +/- 0.0020 s2 Hz(-1); p<0.05) were obtained. The possibility of using these indexes to develop an ischaemic-episode classifier was also tested. Results suggest that wavelet analysis provides useful information for the assessment of dynamic changes and patterns of HRV during myocardial ischaemia.

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Section: Discussionmentioning

confidence: 75%

Wavelet transform analysis of heart rate variability during myocardial ischaemia

Gamero

Vila

Palácios

2002

Med. Biol. Eng. Comput.

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“…This partial denervation may produce imbalanced sympathetic innervation, which may predispose the heart to arrhythmia. 123 Interestingly, nontransmural infarction is associated with myocardial denervation as an area of reduced MIBG uptake both in experimental and clinical studies. 112.124 Nontransmural infarction largely involves the subendocardium with the preserved subepicardial layer where the sympathetic nerve trunks are located.…”

Section: Evaluation Of Adrenergic Neuron Functionmentioning

confidence: 99%

Recent advances in nuclear cardiology in the study of coronary artery disease

et al. 1997

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A variety of new radiopharmaceutical agents have been introduced to probe myocardial function in vivo. This review will introduce these new techniques which have recently been available in Japan. Tc-99m perfusion imaging agents provide excellent myocardial perfusion images which may enhance diagnostic accuracy in the study of coronary artery disease. In addition, greater photon flux from the tracer permits simultaneous assessment of regional perfusion and function with use of first-pass angiography or ECG-gated acquisition. Positron emission tomography enables metabolic assessment in vivo. Preserved FDG uptake indicates ischemic but viable myocardium which is likely to improve regional dysfunction after revascularization. In addition, FDG-PET seems to be valuable for selecting a high risk subgroup. Recently I-123 BMIPP, a branched fatty acid analog, has been clinically available in Japan. Less uptake of BMIPP than thallium is often observed in the ischemic myocardium. Such perfusion metabolic mismatch which seems to be similarly observed in FDG-PET is identified in the stunned or hibernating myocardium with regional dysfunction. Both of them are likely to recover afterwards. Severe ischemia is identified as reduced BMIPP uptake at rest, suggesting its role as an ischemic memory imaging. I-123 MIBG uptake in the myocardium reflects adrenergic neuronal function in vivo. In the study of coronary artery disease, neuronal denervation is often observed around the infarcted myocardium and post ischemic region as well. More importantly, reduced MIBG uptake in these patients can identify high risk for ventricular arrhythmias and assess severity of congestive heart failure. These new techniques will provide insights into new pathological states in the ischemic heart disease and enable to select optimal treatment in these patients.

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“…Because the residual neural integrity at the infarcted site is one of the determinants of the response to electrical induction of ventricular arrhythmias (11), only rats with the infarcted area of the LV totally replaced by scar tissue were included. The protocol for pacing and the arrhythmia scoring system used were as previously described (23).…”

Section: Animalsmentioning

confidence: 99%

Effect of pravastatin on sympathetic reinnervation in postinfarcted rats

Lee¹,

Lin²,

Chang³

2007

American Journal of Physiology-Heart and Circulatory Physiology

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Lee TM, Lin MS, Chang NC. Effect of pravastatin on sympathetic reinnervation in postinfarcted rats. Am J Physiol Heart Circ Physiol 293: H3617-H3626, 2007. First published September 21, 2007; doi:10.1152/ajpheart.00875.2007.-We assessed whether pravastatin attenuates cardiac sympathetic reinnervation after myocardial infarction through the activation of ATP-sensitive K ϩ (KATP) channels. Epidemiological studies have shown that men treated with statins appear to have a lower incidence of sudden death than men without statins. However, the specific factor for this has remained disappointingly elusive. Twenty-four hours after ligation of the anterior descending artery, male Wistar rats were randomized to groups treated with either vehicle, nicorandil (a specific mitochondrial KATP channel agonist), pinacidil (a nonspecific KATP channel agonist), pravastatin, glibenclamide (a KATP channel blocker), or a combination of nicorandil and glibenclamide, pinacidil and glibenclamide, or pravastatin and glibenclamide for 4 wk. Myocardial norepinephrine levels revealed a significant elevation in vehicle-treated rats at the remote zone compared with sham-operated rats (2.54 Ϯ 0.17 vs. 1.26 Ϯ 0.36 g/g protein, P Ͻ 0.0001), consistent with excessive sympathetic reinnervation after infarction. Immunohistochemical analysis for tyrosine hydroxylase, growth-associated factor 43, and neurofilament also confirmed the change of myocardial norepinephrine. This was paralleled by a significant upregulation of tyrosine hydroxylase protein expression and mRNA in vehicle-treated rats, which was reduced after the administration of either nicorandil, pinacidil, or pravastatin. Arrhythmic scores during programmed stimulation in vehicle-treated rats were significantly higher than those treated with pravastatin. In contrast, the beneficial effects of pravastatin were reversed by the addition of glibenclamide, implicating KATP channels as the relevant target. The sympathetic reinnervation after infarction is modulated by the activation of K ATP channels. Chronic use of pravastatin after infarction, resulting in attenuated sympathetic reinnervation by the activation of K ATP channels, may modify the arrhythomogenic response to programmed electrical stimulation.immunohistochemistry; ion channels; myocardial infarction; norepinephrine; polymerase chain reaction PHARMACOLOGICAL ACTIONS of 3-hydroxy-3-methyglutaryl-CoA reductase inhibitors, commonly referred to as "statins," are not merely due to blockade of cholesterol synthesis. Statins possess important adjunctive properties that may confer additional benefits beyond changes in plasma cholesterol concentrations (25). Epidemiological studies have shown that men treated with statin administration appear to have a lower incidence of sudden death than men without statins (40). Patterson et al. (35) have shown that statins improved baroreflex sensitivity, a predictor of sudden cardiac death. There is evidence that many effects of statins are the result of reduced synthesis of isoprenoid intermediates ...

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Effect of transmural versus nontransmural myocardial infarction on inducibility of ventricular arrhythmias during sympathetic stimulation in dogs

Cited by 56 publications

References 24 publications

Wavelet transform analysis of heart rate variability during myocardial ischaemia

Wavelet transform analysis of heart rate variability during myocardial ischaemia

Recent advances in nuclear cardiology in the study of coronary artery disease

Effect of pravastatin on sympathetic reinnervation in postinfarcted rats

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