Clinical and Research Considerations
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Radionuclear Measurement of Peripheral Hemodynamics In
RadionuclearMeasurementof Peripheral Hemodynamics in Selection of Vasodilators for Treatment of Heart Failure Yasuhiro Todo, Mitsumasa Ohyanagi, Ryu Fujisue, and Tadaaki Iwasaki Hyogo College ofMedicine, Nishinomiya, Japan Inorder to select the optimal vasodilator for the treatment of patients with congestive heart failure (CHF), the acute effects of three vasodilators (isosorbide dinitrate (ISDN) 5 mg, nifedipine 10 mg, and prazosin 1 mg) on peripheral capacitance and resistance vessels (CV and RV)were evaluated by a newly devised radionuclear technique (Study 1).Thirty-six @ patients with chronic CHF were dividedinto Group A (ejectionfraction (EF) 35%, n = 20, mean EF: 47.2 ±6.5%) and B (EF < 35%, n = 16, mean EF: 24.8 ±7.1%). ISDNproduced the strongest CVdilatation(25% in both groups). Nifedipinereduced RVtone in Groups A and B (14% and 27%, respectively),and CVtone in Group A (6%). Prazosin had the most prominent effects on both vessels in Group B. From these results, it appeared: (a) ISDN is indicated for the cases with increased CV tone, (b) nifedipine is suitable for those with @ increased RV tone, (C)in cases of increased tone in both vessels, nifedipine (when EF 35%) or prazosin (when EF < 35%) is optimal.To evaluate the validityof this assignment, 49 subjects with CHF were divided into Group 1 (n = 16, increased CV tone), Group 2 (n = 17, increased RV tone), and Group 3 (n = 16, increased CV and RV tone) in Study 2. In Group 1, the changes of all indexes were not significantly different between the subjects treated with optimal drug based on the assignment (subgroup P) and those with a non-optimaldrug (subgroup N)after 2 wk of therapy. -
Blood Vessels: Part A
Chapter 19 The Cardiovascular System: Blood Vessels: Part A Blood Vessels • Delivery system of dynamic structures that begins and ends at heart – Arteries: carry blood away from heart; oxygenated except for pulmonary circulation and umbilical vessels of fetus – Capillaries: contact tissue cells; directly serve cellular needs – Veins: carry blood toward heart Structure of Blood Vessel Walls • Lumen – Central blood-containing space • Three wall layers in arteries and veins – Tunica intima, tunica media, and tunica externa • Capillaries – Endothelium with sparse basal lamina Tunics • Tunica intima – Endothelium lines lumen of all vessels • Continuous with endocardium • Slick surface reduces friction – Subendothelial layer in vessels larger than 1 mm; connective tissue basement membrane Tunics • Tunica media – Smooth muscle and sheets of elastin – Sympathetic vasomotor nerve fibers control vasoconstriction and vasodilation of vessels • Influence blood flow and blood pressure Tunics • Tunica externa (tunica adventitia) – Collagen fibers protect and reinforce; anchor to surrounding structures – Contains nerve fibers, lymphatic vessels – Vasa vasorum of larger vessels nourishes external layer Blood Vessels • Vessels vary in length, diameter, wall thickness, tissue makeup • See figure 19.2 for interaction with lymphatic vessels Arterial System: Elastic Arteries • Large thick-walled arteries with elastin in all three tunics • Aorta and its major branches • Large lumen offers low resistance • Inactive in vasoconstriction • Act as pressure reservoirs—expand -
Central Venous Pressure: Uses and Limitations
Central Venous Pressure: Uses and Limitations T. Smith, R. M. Grounds, and A. Rhodes Introduction A key component of the management of the critically ill patient is the optimization of cardiovascular function, including the provision of an adequate circulating volume and the titration of cardiac preload to improve cardiac output. In spite of the appearance of several newer monitoring technologies, central venous pressure (CVP) monitoring remains in common use [1] as an index of circulatory filling and of cardiac preload. In this chapter we will discuss the uses and limitations of this monitor in the critically ill patient. Defining Central Venous Pressure What is the Central Venous Pressure? Central venous pressure is the intravascular pressure in the great thoracic veins, measured relative to atmospheric pressure. It is conventionally measured at the junction of the superior vena cava and the right atrium and provides an estimate of the right atrial pressure. The Central Venous Pressure Waveform The normal CVP exhibits a complex waveform as illustrated in Figure 1. The waveform is described in terms of its components, three ascending ‘waves’ and two descents. The a-wave corresponds to atrial contraction and the x descent to atrial relaxation. The c wave, which punctuates the x descent, is caused by the closure of the tricuspid valve at the start of ventricular systole and the bulging of its leaflets back into the atrium. The v wave is due to continued venous return in the presence of a closed tricuspid valve. The y descent occurs at the end of ventricular systole when the tricuspid valve opens and blood once again flows from the atrium into the ventricle. -
Non-Coding Rnas in the Cardiac Action Potential and Their Impact on Arrhythmogenic Cardiac Diseases
Review Non-Coding RNAs in the Cardiac Action Potential and Their Impact on Arrhythmogenic Cardiac Diseases Estefania Lozano-Velasco 1,2 , Amelia Aranega 1,2 and Diego Franco 1,2,* 1 Cardiovascular Development Group, Department of Experimental Biology, University of Jaén, 23071 Jaén, Spain; [email protected] (E.L.-V.); [email protected] (A.A.) 2 Fundación Medina, 18016 Granada, Spain * Correspondence: [email protected] Abstract: Cardiac arrhythmias are prevalent among humans across all age ranges, affecting millions of people worldwide. While cardiac arrhythmias vary widely in their clinical presentation, they possess shared complex electrophysiologic properties at cellular level that have not been fully studied. Over the last decade, our current understanding of the functional roles of non-coding RNAs have progressively increased. microRNAs represent the most studied type of small ncRNAs and it has been demonstrated that miRNAs play essential roles in multiple biological contexts, including normal development and diseases. In this review, we provide a comprehensive analysis of the functional contribution of non-coding RNAs, primarily microRNAs, to the normal configuration of the cardiac action potential, as well as their association to distinct types of arrhythmogenic cardiac diseases. Keywords: cardiac arrhythmia; microRNAs; lncRNAs; cardiac action potential Citation: Lozano-Velasco, E.; Aranega, A.; Franco, D. Non-Coding RNAs in the Cardiac Action Potential 1. The Electrical Components of the Adult Heart and Their Impact on Arrhythmogenic The adult heart is a four-chambered organ that propels oxygenated blood to the entire Cardiac Diseases. Hearts 2021, 2, body. It is composed of atrial and ventricular chambers, each of them with distinct left and 307–330. -
Relationship Between Vasodilatation and Cerebral Blood Flow Increase in Impaired Hemodynamics: a PET Study with the Acetazolamide Test in Cerebrovascular Disease
CLINICAL INVESTIGATIONS Relationship Between Vasodilatation and Cerebral Blood Flow Increase in Impaired Hemodynamics: A PET Study with the Acetazolamide Test in Cerebrovascular Disease Hidehiko Okazawa, MD, PhD1,2; Hiroshi Yamauchi, MD, PhD1; Hiroshi Toyoda, MD, PhD1,2; Kanji Sugimoto, MS1; Yasuhisa Fujibayashi, PhD2; and Yoshiharu Yonekura, MD, PhD2 1PET Unit, Research Institute, Shiga Medical Center, Moriyama, Japan; and 2Biomedical Imaging Research Center, Fukui Medical University, Fukui, Japan Key Words: acetazolamide; cerebrovascular disease; cerebral The changes in cerebral blood flow (CBF) and arterial-to- blood volume; vasodilatory capacity; cerebral perfusion pressure capillary blood volume (V0) induced by acetazolamide (ACZ) are expected to be parallel each other in the normal circula- J Nucl Med 2003; 44:1875–1883 tion; however, it has not been proven that the same changes in those parameters are observed in patients with cerebro- vascular disease. To investigate the relationship between changes in CBF, vasodilatory capacity, and other hemody- namic parameters, the ACZ test was performed after an The ability of autoregulation to maintain the cerebral 15O-gas PET study. Methods: Twenty-two patients with uni- blood flow (CBF), which resides in the cerebral circulation lateral major cerebral arterial occlusive disease underwent despite transient changes in systemic mean arterial blood 15 PET scans using the H2 O bolus method with the ACZ test pressure, has been shown to occur via the mechanism of 15 after the O-gas steady-state method. CBF and V0 for each arteriolar vasodilatation in the cerebral circulation (1). The subject were calculated using the 3-weighted integral vasodilatory change in the cerebral arteries is assumed for method as well as the nonlinear least-squares fitting method. -
Hemodynamic Effects of Vasodilators and Long-Term Response in Heart Failure
JACC Vol. 3, No.6 1521 June 1984:1521-30 REPORTS ON THERAPY Hemodynamic Effects of Vasodilators and Long-Term Response in Heart Failure JOSEPH A. FRANCIOSA, MD, FACC, W. BRUCE DUNKMAN, MD, FACC,* CHERYL L. LEDDY, MD* Philadelphia, Pennsylvania and Little Rock, Arkansas Hemodynamic responses to vasodilators are commonly ml/min per kg (p < 0.01), and exercise duration also assessed when starting long-term vasodilator treatment increased by 1.8 ± 3.5 minutes (p < 0.01). Changes in in patients with chronic left ventricular failure, although maximal oxygen uptake, however, did not correlate with the relation between short- and long-term responses is short-term changes in pulmonary wedge pressure (cor• not established. Thus, short- and long-term hemody• relation coefficient [r] = - 0.14), cardiac index (r = namic responses to placebo and vasodilators (isosorbide - 0.01) or systemic vascular resistance (r = - 0.20). dinitrate, minoxidil and enalapril or captopril) were Long-term hemodynamic changes also failed to correlate measured and long-term clinical efficacy was assessed with changes in exercise capacity. Baseline hemody• by changes in exercise capacity after 1 to 5 months of namics, cardiac dimensions and left ventricular ejection vasodilator administration (plus digitalis and diuretic fraction before vasodilator administration all failed to agents) in 46 patients with New York Heart Association correlate with baseline exercise capacity or with long• fun~tional class II to IV heart failure caused by cardio• term changes in exercise capacity. myopathy. There were no significant changes in hemo• Thus, hemodynamic measurements at initiation or dynamics or exercise capacity during placebo treatment. -
Effects of Vasodilation and Arterial Resistance on Cardiac Output Aliya Siddiqui Department of Biotechnology, Chaitanya P.G
& Experim l e ca n i t in a l l C Aliya, J Clinic Experiment Cardiol 2011, 2:11 C f a Journal of Clinical & Experimental o r d l DOI: 10.4172/2155-9880.1000170 i a o n l o r g u y o J Cardiology ISSN: 2155-9880 Review Article Open Access Effects of Vasodilation and Arterial Resistance on Cardiac Output Aliya Siddiqui Department of Biotechnology, Chaitanya P.G. College, Kakatiya University, Warangal, India Abstract Heart is one of the most important organs present in human body which pumps blood throughout the body using blood vessels. With each heartbeat, blood is sent throughout the body, carrying oxygen and nutrients to all the cells in body. The cardiac cycle is the sequence of events that occurs when the heart beats. Blood pressure is maximum during systole, when the heart is pushing and minimum during diastole, when the heart is relaxed. Vasodilation caused by relaxation of smooth muscle cells in arteries causes an increase in blood flow. When blood vessels dilate, the blood flow is increased due to a decrease in vascular resistance. Therefore, dilation of arteries and arterioles leads to an immediate decrease in arterial blood pressure and heart rate. Cardiac output is the amount of blood ejected by the left ventricle in one minute. Cardiac output (CO) is the volume of blood being pumped by the heart, by left ventricle in the time interval of one minute. The effects of vasodilation, how the blood quantity increases and decreases along with the blood flow and the arterial blood flow and resistance on cardiac output is discussed in this reviewArticle. -
Comparison of Gated Myocardial Perfusion SPECT, Echocardiography and Equilibrium Radionuclide Ventriculography in the Evaluation of Left Ventricle Contractility
Türk Kardiyol Dern Arş - Arch Turk Soc Cardiol 2014;42(4):349-357 doi: 10.5543/tkda.2014.74150 349 Comparison of gated myocardial perfusion SPECT, echocardiography and equilibrium radionuclide ventriculography in the evaluation of left ventricle contractility Sol ventrikül kontraktil fonksiyonlarının değerlendirilmesinde equilibrium radyonüklid ventrikülografi, ekokardiyografi ve miyokart perfüzyon gated SPECT görüntülemenin karşılaştırılması Filiz Hatipoğlu, M.D., Zeynep Burak, M.D.,# Özgür Ömür, M.D.# Department of Nuclear Medicine, Afyon Kocatepe University Faculty of Medicine, Afyonkarahisar; #Department of Nuclear Medicine, Ege University Faculty of Medicine, Izmir ABSTRACT ÖZET Objectives: In this study, we investigated the reliability of Amaç: Çalışmamızda, sol ventrikül (SV) fonksiyonlarının gated myocardial perfusion single-photon emission comput- değerlendirilmesinde ‘miyokart perfüzyon gated SPECT’ erized tomography (GSPECT) for the evaluation of left ven- (GSPECT) yönteminin güvenilirliği araştırıldı, GSPECT ile tricle (LV) function. We compared left ventricle ejection frac- hesaplanan sol ventrikül ejeksiyon fraksiyonu (SVEF) orta- tion (LVEF) calculated with GSPECT with the values derived laması planar ‘equilibrium gated radyonüklid ventrikülografi’ from planar equilibrium-gated radionuclide ventriculography (ERVG) ve ekokardiyografi (EKO) ile elde edilen değerlerle (ERVG) and echocardiography (ECHO). karşılaştırıldı. Study design: Forty-eight patients with suspected coronary Çalışma planı: Koroner arter hastalığı (KAH) şüphesi -
Clinical Characteristics and Prognosis Of
Lyu et al. BMC Cardiovascular Disorders (2019) 19:209 https://doi.org/10.1186/s12872-019-1177-1 RESEARCH ARTICLE Open Access Clinical characteristics and prognosis of heart failure with mid-range ejection fraction: insights from a multi-centre registry study in China Lyu Siqi, Yu Litian* , Tan Huiqiong, Liu Shaoshuai, Liu Xiaoning, Guo Xiao and Zhu Jun Abstract Background: Heart failure (HF) with mid-range ejection fraction (EF) (HFmrEF) has attracted increasing attention in recent years. However, the understanding of HFmrEF remains limited, especially among Asian patients. Therefore, analysis of a Chinese HF registry was undertaken to explore the clinical characteristics and prognosis of HFmrEF. Methods: A total of 755 HF patients from a multi-centre registry were classified into three groups based on EF measured by echocardiogram at recruitment: HF with reduced EF (HFrEF) (n = 211), HFmrEF (n = 201), and HF with preserved EF (HFpEF) (n = 343). Clinical data were carefully collected and analyzed at baseline. The primary endpoint was all-cause mortality and cardiovascular mortality while the secondary endpoints included hospitalization due to HF and major adverse cardiac events (MACE) during 1-year follow-up. Cox regression and Logistic regression were performed to identify the association between the three EF strata and 1-year outcomes. Results: The prevalence of HFmrEF was 26.6% in the observed HF patients. Most of the clinical characteristics of HFmrEF were intermediate between HFrEF and HFpEF. But a significantly higher ratio of prior myocardial infarction (p = 0.002), ischemic heart disease etiology (p = 0.004), antiplatelet drug use (p = 0.009), angioplasty or stent implantation (p = 0.003) were observed in patients with HFmrEF patients than those with HFpEF and HFrEF. -
Medical Management of Advanced Heart Failure
CLINICAL CARDIOLOGY CLINICIAN’S CORNER Medical Management of Advanced Heart Failure Anju Nohria, MD Context Advanced heart failure, defined as persistence of limiting symptoms de- Eldrin Lewis, MD spite therapy with agents of proven efficacy, accounts for the majority of morbidity and mortality in heart failure. Lynne Warner Stevenson, MD Objective To review current medical therapy for advanced heart failure. EART FAILURE HAS EMERGED AS Data Sources We searched MEDLINE for all articles containing the term advanced a major health challenge, in- heart failure that were published between 1980 and 2001; EMBASE was searched from creasing in prevalence as age- 1987-1999, Best Evidence from 1991-1998, and Evidence-Based Medicine from 1995- adjusted rates of myocardial 1999. The Cochrane Library also was searched for critical reviews and meta-analyses Hinfarction and stroke decline.1 Affect- of congestive heart failure. ing 4 to 5 million people in the United Study Selection Randomized controlled trials of therapy for 150 patients or more States with more than 2 million hospi- were included if advanced heart failure was represented. Other common clinical situ- talizations each year, heart failure alone ations were addressed from smaller trials as available, trials of milder heart failure, con- accounts for 2% to 3% of the national sensus guidelines, and both published and personal clinical experience. health care budget. Developments her- Data Extraction Data quality was determined by publication in peer-reviewed lit- alded in the news media increase pub- erature or inclusion in professional society guidelines. lic expectations but focus on decreas- Data Synthesis A primary focus for care of advanced heart failure is ongoing iden- ing disease progression in mild to tification and treatment of the elevated filling pressures that cause disabling symp- moderate stages2,3 or supporting the cir- toms. -
The Evolution of Heart Failure with Reduced Ejection Fraction Pharmacotherapy: What Do We Have and Where Are We Going?
Pharmacology & Therapeutics 178 (2017) 67–82 Contents lists available at ScienceDirect Pharmacology & Therapeutics journal homepage: www.elsevier.com/locate/pharmthera Associate editor: M. Curtis The evolution of heart failure with reduced ejection fraction pharmacotherapy: What do we have and where are we going? Ahmed Selim, Ronald Zolty, Yiannis S. Chatzizisis ⁎ Division of Cardiovascular Medicine, University of Nebraska Medical Center, Omaha, NE, USA article info abstract Available online 21 March 2017 Cardiovascular diseases represent a leading cause of mortality and increased healthcare expenditure worldwide. Heart failure, which simply describes an inability of the heart to meet the body's needs, is the end point for many Keywords: other cardiovascular conditions. The last three decades have witnessed significant efforts aiming at the discovery Heart failure of treatments to improve the survival and quality of life of patients with heart failure; many were successful, Reduced ejection fraction while others failed. Given that most of the successes in treating heart failure were achieved in patients with re- Pharmacotherapy duced left ventricular ejection fraction (HFrEF), we constructed this review to look at the recent evolution of Novel drugs HFrEF pharmacotherapy. We also explore some of the ongoing clinical trials for new drugs, and investigate poten- tial treatment targets and pathways that might play a role in treating HFrEF in the future. © 2017 Elsevier Inc. All rights reserved. Contents 1. Introduction.............................................. -
Valve Replacement Alexander Zezulkal, John Mackinnon2 and D.G
Postgrad Med J: first published as 10.1136/pgmj.68.797.180 on 1 March 1992. Downloaded from Postgrad Med J (1992) 68, 180 - 185 i) The Fellowship of Postgraduate Medicine, 1992 Hypertension in aortic valve disease and its response to valve replacement Alexander Zezulkal, John Mackinnon2 and D.G. Beevers' 'University Department ofMedicine and 2Department ofCardiology, Dudley Road Hospital, Birmingham BT18 7QH, UK Summary: We have investigated the prevalence ofhypertension and the response ofblood pressure to operation in 87 patients with lone aortic valve disease who underwent aortic valve replacement. In patients with aortic stenosis alone 26% were hypertensive pre-operatively (age and sex adjusted blood pressure > 160 systolic and or > 95 mmHg diastolic) and 24% were hypertensive post-operatively. In those with aortic regurgitation alone, hypertension was present in 65% before and 57% after valve replacement using the same criterion. For combined stenosis and regurgitation, the prevalence was 54% and 62%, respectively. The post-operative increase in systolic pressure in patients with aortic stenosis occurred mainly in those with a history of left ventricular failure. In those with aortic regurgitation or combined stenosis with regurgitation, diastolic pressure rose after valve replacement resulting in a prevalence of diastolic hypertension of 44% and 35%, respectively. Blood pressure changes were not predicted by the type of valve inserted nor its size. Our data show that despite severe symptomatic aortic valve disease, systolic hypertension was common in aortic stenosis and diastolic hypertension was found in aortic regurgitation. This underlines the by copyright. importance of blood pressure monitoring in patients following aortic valve replacement.