The patient with acute cardiovascular problems
Ian Peate, Helen Dutton in Acute Nursing Care, 2014
Neural mechanisms of blood pressure regulation lie predominately within the pons and medulla of the brain. The cardiovascular centre (CVC) controls both vessel tone, through the vasomotor centre, and heart rate, through the cardiac centre. Changes in the internal environment are detected by sensors which communicate with the cardiovascular centre via neural pathways. The cardiovascular centre responds by activation or inhibition of the sympathetic and parasympathetic branches of the autonomic nervous system, to maintain homeostasis. (The autonomic nervous system is explained in more detail in Chapter 9.) Sensor mechanisms include baroreceptors, which are sensitive to stretch and are situated in the walls of the aortic arch and bifurcation of the common carotid arteries, in an ideal position to detect pressure changes. Information from the baroreceptors is transmitted via the carotid sinus and vagus nerves to the CVC and a falling mean arterial pressure will reduce the information flow. A corresponding increase in sympathetic outflow from the CVC causes vasoconstriction via stimulation of alpha adrenergic receptors in the systemic vasculature and an increase in heart rate and contractility via beta adrenergic
The patient with acute cardiovascular problems
Peate Ian, Dutton Helen in Acute Nursing Care, 2020
Neural mechanisms of blood pressure regulation lie predominately within the pons and medulla of the brain. The cardiovascular centre (CVC) controls both vessel tone through the vasomotor centre and heart rate through the cardiac centre. Changes in the internal environment are detected by sensors, which communicate with the cardiovascular centre via neural pathways. The cardiovascular centre responds by activation or inhibition of the sympathetic and parasympathetic branches of the autonomic nervous system to maintain homeostasis. The autonomic nervous system is explained in more detail in Chapter 9. Sensor mechanisms include baroreceptors, which are sensitive to stretch and are situated in the walls of the aortic arch, and bifurcation of the common carotid arteries, in an ideal position to detect pressure changes. Information from the baroreceptors is transmitted via the carotid sinus and vagus nerves to the CVC, and a falling mean arterial pressure will reduce the information flow. A corresponding increase in sympathetic outflow from the CVC causes vasoconstriction via stimulation of alpha-adrenergic receptors in the systemic vasculature and an increase in heart rate and contractility via beta-adrenergic receptor stimulation in the heart. These responses will cause an increase in cardiac output and blood pressure (see Figure 6.9).
Management problems
Brian J Pollard, Gareth Kitchen in Handbook of Clinical Anaesthesia, 2017
The nature of the response suggests that they cause a steadily increasing intracellular calcium ion concentration. Calcium, at concentrations lower than those required to activate the contractile apparatus, has other important intracellular functions namely regulation of phosphorylation, and hence activity, of various enzymes, including those of the glycolytic pathway. As intracellular calcium rises, increased carbon dioxide and lactate production occur. In the spontaneously breathing patient there is an increase in respiratory rate and end-tidal carbon dioxide; if a circle system is in use, the soda lime will be rapidly exhausted. Simultaneously, or shortly following, a tachycardia develops secondary to the effects of acidaemia on the midbrain cardiovascular centre. The blood pressure may rise or fall, presumably due to a predominant effect of local metabolites on vascular smooth muscle. An increase in oxygen consumption occurs leading to a fall in the SaO2. Arterial blood gases show acidaemia, hypercarbia, a base deficit and usually mild hypoxaemia.
Prediction parameters of left ventricular diastolic dysfunction improvement in patients after acute coronary syndrome
Published in Acta Clinica Belgica, 2023
Marija Bjelobrk, Tatjana Miljković, Aleksandra Ilić, Aleksandra Milovančev, Snežana Tadić, Snežana Bjelić, Dragana Dabović, Milenko Čanković, Vladimir Ivanović, Andrej Preveden, Dejana Popović
The study was designed as non-randomized and conducted during two years in which period a total of 85 subjects were included. We prospectively enrolled patients 4–6 weeks after ACS, including both ST elevation myocardial infarction (STEMI) and non-ST elevation myocardial infarction (NSTEMI), as well as non-stable angina pectoris (APNS) distinguished following the recommendations to the relevant guidelines [5,6]. Exclusion criteria included patients <18 and >75 years old, chronic heart failure (HF) with left ventricular ejection fraction <45%, uncontrolled hypertension, anaemia, inability to exercise, or patients who were not motivated to exercise, hemodynamically significant valvular disorders, advanced chronic pulmonary diseases (forced vital capacity (FVC) and/or forced expiratory volume in the first second (FEV1) <80% of the predicted value for the observed age), uncontrolled supraventricular or ventricular rhythm disorders, and myocardial ischemia induced by exercise. The study was conducted at a tertiary care cardiovascular centre, Institute of Cardiovascular Diseases Vojvodina (ICVDV), Division of Cardiology, which is relevant for a population of around 2,000,000 patients. Before the beginning and at the end of the study, all patients underwent clinical evaluation, detailed echocardiography (ECHO), and cardiopulmonary exercise test (CPET). All patients provided written informed consent prior to enrolment, approved by the local Ethical Committee.
Contemporary Impact of circadian symptom-onset patterns of acute ST-Segment elevation myocardial infarction on long-term outcomes after primary percutaneous coronary intervention
Published in Annals of Medicine, 2021
Hui Peng, Zhijun Sun, Beibing Di, Xiaosong Ding, Hui Chen, Hongwei Li
Patient demographic information, medical history, cardiovascular risk factors, laboratory assessments, medical therapy at discharge, and revascularization procedures were collected and recorded in the Cardiovascular Centre Beijing Friendship Hospital Database Bank. Patients were categorized by standard 6-h intervals over 24 h according to the time-of-day at symptom onset: 0:00–5:59 (night, group1), 6:00–11:59 (morning, group2), 12:00–17:59 (afternoon, group 3), and 18:00–23:59 (evening, group4) [3]. As shown in Figure 1, 91 were excluded for (1) no PPCI performed; (2) time of symptom onset unknown; (3) a previous episode of MI; (4) ischaemic time more than 12 h; (5) antegrade or retrograde collateral flow presence; (6) TIMI <3 flow after PPCI. Finally, 1099 patients were included in this analysis. After discharge, all patients were followed up until June 2020.
Association of anthropometric and body composition parameters with the presence of hypertension in the Central European population: results from KardioVize 2030 study
Published in Acta Cardiologica, 2023
Robert Prosecky, Sarka Kunzova, Petra Kovacovicova, Maria Skladana, Pavel Homolka, Ondrej Sochor, Peter Kruzliak, Laura Kate Gadanec, Ladislav Soukup, Jan Novak
Our study is supported by similar studies, such as Hürr et al. [21], who use similar-sized cohort (n = 2034) and demonstrated the association of obesity (defined using BMI and ECW) and the categories of hypotensive, normotensive and hypertensive individuals. ECW content had the highest effect on the SBP, while no effect on DBP, similarly our spatial thin-plate models showed a correlation to BMI and ECW (Figure 2). Similar results were also obtained by Seo et al. [22] who studied the effect of body water parameters obtained by the bioimpedance method and their effect on blood pressure values. They used non-randomized adult population of patients visiting the Cardiovascular Centre Outpatient Hypertension Clinic and Health Examination Centre of Korea University, Guro Hospital in Seol, Korea. Altogether they enrolled 2934 individuals and observed increased values of ECW between normotensive and hypertensive women, but not in men. When they adjusted the values of ECW to BMI, the difference became apparent even in men and for every decrease by 1 standard deviation there was a reduced risk of hypertension by 30% in women and 28% in men. Within our study we observed smaller differences; however, we used a different methodology (changes induced by 1 l vs. 1 standard deviation change). In contrast to Seo et al. we did not exclude individuals with apparent lower limb oedemas. Moreover, unlike Seo et al. we decided to adjust ECW values to BSA, not BMI, as BMI itself already contains the “weight” of the water in it, thus BSA seems more suitable for adjustments to us.
Related Knowledge Centers
- Brainstem
- Exercise
- Heart Rate
- Nervous System
- Vagal Tone
- Medulla Oblongata
- Endocrine System
- Brain
- Major Trauma
- Acid–Base Homeostasis