Gender differences in response to cold pressor test assessed with velocity-encoded cardiovascular magnetic resonance of the coronary sinus

Background

Gender-specific differences in cardiovascular risk are well known, and current evidence supports an existing role of endothelium in these differences. The purpose of this study was to assess non invasively coronary endothelial function in male and female young volunteers by myocardial blood flow (MBF) measurement using coronary sinus (CS) flow quantification by velocity encoded cine cardiovascular magnetic resonance (CMR) at rest and during cold pressor test (CPT).

Methods

Twenty-four healthy volunteers (12 men, 12 women) underwent CMR in a 3 Tesla MR imager. Coronary sinus flow was measured at rest and during CPT using non breath-hold velocity encoded phase contrast cine-CMR. Myocardial function and morphology were acquired using a cine steady-state free precession sequence.

Results

At baseline, mean MBF was 0.63 ± 0.23 mL·g^-1·min^-1 in men and 0.79 ± 0.21 mL·g^-1·min^-1 in women. During CPT, the rate pressure product in men significantly increased by 49 ± 36% (p < 0.0001) and in women by 52 ± 22% (p < 0.0001). MBF increased significantly in both men and women by 0.22 ± 0.19 mL·g^-1·min^-1 (p = 0.0022) and by 0.73 ± 0.43 mL·g^-1·min^-1 (p = 0.0001), respectively. The increase in MBF was significantly higher in women than in men (p = 0.0012).

Conclusion

CMR coronary sinus flow quantification for measuring myocardial blood flow revealed a higher response of MBF to CPT in women than in men. This finding may reflect gender differences in endothelial-dependent vasodilatation in these young subjects. This non invasive rest/stress protocol may become helpful to study endothelial function in normal physiology and in physiopathology.     

Utility of the cold pressor test to predict future cardiovascular events

Introduction: The cold pressor test (CPT) is a common and extensively validated test, which induces systemic stress involving immersion of an individual’s hand in ice water (normally temperature between 0 and 5 degrees Celsius) for a period of time. CPT has been used in various fields, like examining effects of stress on memory, decision-making, pain and cardiovascular health.

Areas covered: In terms of cardiovascular health, current research is mainly interested in predicting the occurrence of cardiovascular (CV) events. The objective of this review is to give an overview of the history and methodology of the CPT, and clinical utility in possibly predicting CV events in CAD and other atherosclerotic diseases. Secondly, we will discuss possible future applications of the CPT in clinical care.

Expert opinion: An important issue to address is the fact that the physiology of the CPT is not fully understood at this moment. As pointed out multiple mechanisms might be responsible for contributing to either coronary vasodilatation or coronary vasoconstriction. Regarding the physiological mechanism of the CPT and its effect on the measurements of the carotid artery reactivity even less is known.     

Inhibitory effects of neuropeptide Y on splanchnic glycogenosis and renin release in humans

Summary. Neuropeptide Y (NPY) is stored in sympathetic nerves and NPY levels increase several times during exercise. NPY administration during prolonged exercise causes reduced splanchnic glucose production. To elucidate the effects of NPY on adrenaline (Adr)-stimulated splanchnic glycogenolysis these substances were infused to seven healthy subjects in the post-absorptive state. Blood samples were drawn from an arterial and a central hepatic vein catheter for determination of splanchnic blood flow, exchanges of metabolites and arterial levels of NPY, catecholamines, insulin, glucagon and renin in the basal state and during 20 min Adr infusion (0–1-0-3 nmol kg^-1 min^-1). After basal values were reached a 60 min NPY infusion was initiated. At 40 min of NPY infusion the Adr infusion was repeated. Adr alone increased splanchnic blood flow (41%, P < 0–01), arterial glucose concentration (29%, P < 0–001) and splanchnic glucose production (102%, P < 0–01). During the NPY infusion both splanchnic blood flow and arterial glucose fell (P < 0–05). Although the combined NPY and Adr infusion caused the same proportional increases in splanchnic blood flow, arterial glucose and splanchnic glucose production as with Adr alone the absolute values were lower (all P < 0–05). Arterial insulin as well as Adr and noradrenaline increased with the combined NPY-and Adr infusion as with Adr alone. Arterial plasma renin activity was 12% lower with the combined NPY and Adr-infusion compared to Adr infusion alone. These results indicate further an inhibitory effect of NPY on splanchnic glycogenolysis and suggest that NPY inhibits Adr-stimulated renin release.,     

Effects of pharmacological adrenergic and vagal modulation on fractal heart rate dynamics

Breakdown of short‐term fractal‐like behaviour of HR indicates an increased risk for adverse cardiovascular events and mortality, but the pathophysiological background for altered fractal HR dynamics is not known. Our aim was to study the effects of pharmacological modulation of autonomic function on fractal correlation properties of heart rate (HR) variability in healthy subjects. Short‐term fractal scaling exponent (α₁) along with spectral components of HR variability were analysed during the following pharmacological interventions in healthy subjects: (i) noradrenaline (NE) infusion (n=22), (ii) NE infusion after phentolamine (PHE) (n=8), (iii) combined NE + adrenaline (EPI) infusion (n=12), (iv) vagal blockade with high dose of atropine (n=10), (v) and vagal activation by low dose of atropine (n=10). Then α₁ decreased progressively during the incremental doses of NE (from 0·85 ± 0·250 to 0.55 ± 0·23, P<0·0001). NE also decreased the average HR (P<0·001) and increased the high frequency spectral power (P<0·001). Vagal blockade with atropine increased the α₁ value (from 0·82 ± 0·22 to 1·24 ± 0·41, P<0·05). Combined NE + EPI infusion and vagal activation with a low dose atropine did not result in any changes in α₁, and α‐adrenergic blockade by PHE did not completely reverse the effects of NE on α₁. Increased levels of circulating NE result in reduction of short‐term correlation properties of HR dynamics. The results suggest that coactivation of cardiac vagal outflow at the time of high levels of a circulating sympathetic transmitter explains the breakdown of fractal‐like behaviour of human HR dynamics.     

Increased circulating endothelins are not of cardiopulmonary origin in heart failure patients

Objective. Plasma concentrations of endothelin‐1 and big‐endothelin are increased in heart failure patients. However, the precise contribution of endothelin secretion from the cardiopulmonary system remains unresolved. The aim of this study was to investigate whether the cardiopulmonary system contributes to the circulating endothelin‐1 and big‐endothelin concentrations in heart failure patients. Material and methods. Blood samples were obtained at right heart catheterization from different cardiovascular regions including the coronary sinus in chronic heart failure patients (n?=?12) and from age‐matched control subjects (n?=?12). Results. The peripheral plasma concentrations of endothelin‐1 were almost 3‐fold higher in heart failure patients compared with the control subjects (1.25?pmol/l, 0.30–8.20?pmol/l (median, range) versus 0.46?pmol/l, 0.10–0.88?pmol/l, p<0.01). However, the endothelin‐1 concentration was ～25% lower in plasma samples from the coronary sinus than in plasma from the inferior caval vein (p<0.05) in the heart failure patients. There were no differences in big‐endothelin concentrations between any of the cardiovascular regions. Conclusions. In heart failure patients, increased plasma concentrations of endothelin‐1 and big‐endothelin mainly reflect an increased secretion from the peripheral endothelium.     

冷加压实验超声心动图及冠脉血流显像技术评价冠脉微循环内皮功能

目的应用冷加压实验超声心动图及冠脉血流显像技术评价冠状动脉造影结果正常的冠心病高危人群的微循环内皮功能。方法冠脉造影结果正常受检者40例,分为无冠心病危险因素的对照组20例和冠心病高危人群组20例。分别于静息状态下、冷加压实验后、舌下含服硝酸甘油后测量冠状动脉左主干内径并计算其内径变化率;测量冠状动脉左前降支舒张期峰值血流速度,并计算其流速变化率,比较两组干预状态下的内径变化率和流速变化率。结果静息状态下两组冠脉内径及峰值流速基础值之间均无统计学差异（P〉0．05）。冷加压实验后,冠心病高危人群组冠脉内径扩张率（4．53±2．65）％、流速增加率（23．64±5．72）％,低于对照组的（11．37±3．29）％及（43．76±4．28）％（P〈0．05）。含服硝酸甘油后,两组内径变化率和流速变化率之间无统计学差异（P〉0．05）。结论冠心病高危人群在冠脉造影结果正常时可能已合并冠状动脉微循环内皮功能损伤,冷加压实验超声心动图评价冠状动脉微循环内皮功能有一定可行性。     

Haemodynamic and renal effects of urodilatin bolus injections in patients with congestive heart failure

Urodilatin (ANF(95-126)) is an analogue of the atrial natriuretic factor (ANF(99-126)), which has been isolated from human urine. Recently we have shown in healthy volunteers, that intravenous bolus injections of synthetic urodilatin produce more pronounced reductions of pulmonary arterial pressure than ANF(99-126). To compare haemodynamic and renal effects of synthetic urodilatin with those of ANF(99-126) in congestive heart failure (CHF), 12 patients (66.3 +/- 1.4 years) received either two high dose intravenous bolus injections of 4 micrograms kg-1 bw Urodilatin (URO) at a 30 min interval (n = 6) or the same doses of ANF(99-126) (n = 6). Prior to i.v. URO, no URO immunoreactivity was found in human plasma (specific RIA, no crossreactivity to ANF). Similar to ANF, the increase in diuresis (1.4 +/- 0.7 to 3.7 +/- 1.6 ml min-1) and natriuresis (169 +/- 114 to 430 +/- 197 mumol min-1) was moderate after URO in CHF. During the 90 min study period, mean plasma cyclic GMP levels increased much more after URO (by 53.4 +/- 15.1 nM) than after ANF (by 13.1 +/- 3.0 nM; P = 0.04). In contrast to ANF, i.v. bolus injections of URO produced sustained haemodynamic effects in CHF lasting up to 90 min: The average (0-90 min) reduction of systemic vascular resistance was more pronounced after URO (-578 +/- 148) than after ANF (-204 +/- 65 dyn*s*cm-5, P = 0.04).(ABSTRACT TRUNCATED AT 250 WORDS)     

Haemodynamic effects of depot zinc protamine glucagon in heart failure (author's transl)]

In contrast to intravenously-administered crystallene glucagon, which acts for 20 minutes only, the depot form, zinc protamine glucagon, shows a prolonged haemodynamic action. Fourteen patients with pre-existing heart failure received a single dose of 20 mg Zn protamine glucagon intramuscularly. The stroke volume and cardiac output were increased, whereas the mean and end-diastolic pulmonary pressure were decreased, indicating a positive inotropic action of the administered drug. Heart rate and mean arterial pressure remained almost unchanged. The haemodynamic changes started 60 minutes after intramuscular administration of the drug, reached a maximum effect at 3 hours and started to decrease after the fourth hour. Zn protamine glucagon can, therefore, be considered a beneficial drug in the treatment of digitalis-resistant heart failure on the basis of its long duration of action and easy route of administration.     

Improved extraction of ePTFE and medical adhesive modified defibrillation leads from the coronary sinus and great cardiac vein

BACKGROUND: Permanent leads with shocking coils for defibrillation therapy are sometimes implanted in the coronary sinus (CS) and great cardiac vein (GCV). These shocking coils, as documented by pathologic examination of animal investigations, often become tightly encapsulated by fibrosis and can be very difficult to remove. METHODS: One of three configurations of the Guidant model 7109 Perimeter coronary sinus shocking lead was implanted into the distal portion of the GCV of 24 sheep for up to 14 months. Group 1 had unmodified coils (control), group 2 had coils backfilled with medical adhesive (MA), and Group 3 had coils coated with expanded polytetrafluoroethylene (ePTFE). Eighteen leads, three from each group at 6 and 14 months were transvenously extracted from the left jugular vein. The remaining six animals were not subject to extraction. All animals were euthanized for pathological and microscopic examination. RESULTS: All six of the control, three of the MA, and one of the ePTFE leads required the use of an electrosurgical dissection sheath (EDS) for extraction. Five control, two MA, and none of the ePTFE leads had significant fibrotic attachments to the shocking coils. Significant trauma was observed at necropsy for those leads requiring the use of the EDS for extraction. CONCLUSIONS: Tissue ingrowth is a major impediment to the removal of defibrillation leads implanted in the CS and GCV of sheep. Reduction of tissue ingrowth by coating the shocking coils with ePTFE or by backfilling with MA facilitates transvenous lead removal with reduced tissue trauma.     

Prevalence of anemia in heart failure and its effects on prognosis

Anemia is common in heart failure patients but its prevalence varies widely according to various sources. There is no agreement regarding the definition of anemia to be used and several risk factors have been found to be associated with higher prevalence of anemia in heart failure patients. The prevalence of anemia depends on its definition and the clinical characteristics of the patients included in the studies. Anemia is associated with adverse prognosis in the general population, in patients with end-stage renal disease, chronic diseases, coronary artery disease and also in patients with heart failure; however, despite all the information available, the issue of whether anemia is an independent predictor of mortality and the nature of the risk between anemia and mortality in heart failure patients are not yet fully understood.     

Impaired responses of plasma catecholamines to exercise in diabetic patients with abnormal heart rate reactions to tilt

Summary. The plasma catecholamine response to a standardized bicycle exercise test was evaluated in 24 insulin-dependent diabetic (IDDM) patients in whom the heart rate reactions to deep breathing (E/I ratio) and to tilt, the immediate acceleration and the transient deceleration (acceleration and brake indices), had been assessed as tests of autonomic neuropathy. Patients with an abnormal acceleration index (n= 8) showed, compared with non-diabetic (n= 18) controls who had participated in previous studies, an impaired increment in noradrenaline during exercise (80% of maximal working capacity) (MWC) (12·38 ± 1·46 nmol l^-1 vs. 18·74 ± 1·45 nmol I^-1; P<0·01) and adrenaline (50% of MWC: 0·25 ± 0·04 nmol I^-1 vs. 0·54 ± 0·08 nmol I^I–1; P<0·05). Similarly, patients with an isolated abnormal brake index (n= 6), i.e. with a normal acceleration index and a normal E/I ratio, showed compared with controls an impaired increment in noradrenaline (9·53 ± 1·66 nmol I^-1 vs. 18·74 ± 1·45 nmol I^-1; P<0·01) and adrenaline (1·41 ± 0·22 nmol I^-1 vs. 2·92 ± 0·51 nmol I^-1; P<0·05) during 80% of MWC. IDDM patients with abnormal heart rate reactions to tilt, an abnormal acceleration index or an abnormal brake index show impaired catecholamine responses to exercise, which can be demonstrated also in patients without signs of parasympathetic neuropathy.     

Vasopressin antagonists in the management of heart failure

Vasopressin antagonists have been studied in a variety of clinical settings, including patients with acute and chronic heart failure. The clinical trials published to date have sought to describe the clinical and physiologic effects of these agents in an effort to prove clinical efficacy and safety. A variety of agents with varying effects on V2 and V1a vasopressin receptor subtype have been studied. They have been shown to reduce bodyweight and improve serum sodium without worsening renal function. They may also decrease the need for loop diuretic use and may be particularly useful in patients with hyponatremia in the setting of volume overload. Further studies are underway that are powered to assess for morbidity and mortality benefits. The beneficial effects have been well documented but, until outcomes are understood more fully, the use of these agents should be limited to currently approved indications. In the USA, this includes only the treatment of euvolemic hyponatremia.     

冠心病合并心力衰竭患者上肢浅静脉血栓发生率横断面调查及影响因素分析

目的调查冠心病(CHD)合并心力衰竭(HF)患者上肢浅静脉血栓(SVT)的发生率,并分析其影响因素。方法选取我院2017年1月至2020年2月收治的743例CHD合并HF患者作为研究对象,收集患者的一般资料及临床资料。统计CHD合并HF患者上肢SVT的发生率,并采用单因素与多因素分析影响CHD合并HF患者上肢SVT发生的因素。结果743例CHD合并HF患者经彩色多普勒超声诊断确诊SVT 376例,确诊率为50.61%(376/743),其中不完全阻塞315例(83.78%),完全阻塞61例(16.22%)。二元Logistic回归分析显示,年龄、静脉给药途径、单次留置针留置时间、LDL和ATⅡ是CHD合并HF患者上肢SVT发生的危险因素,SVT预防性护理是CHD合并HF患者上肢SVT发生的保护因素(P<0.05)。结论CHD合并HF患者上肢SVT的发生率较高,且影响因素较多,治疗过程中应重视对高龄、留置针穿刺、高LDL和高ATⅡ水平患者的筛查与护理,严格按照相关指南与规范控制留置针留置时长,以减少上肢SVT的发生。     

Comparison of atrial pacing and the cold pressor test in patients with angina pectoris

A haemodynamic and myocardial metabolic study was performed to compare effects of maximal atrial pacing and the cold pressor test (CPT) in patients with angina pectoris. Twelve patients (group I) had angiographically severe coronary artery disease, while 16 patients (group II) had normal coronary angiograms. At maximal pacing, angina developed in all patients in group I, and myocardial lactate production was found in eight of 12 patients. In group II, 12 out of 16 patients experienced chest pain, but only two patients had myocardial lactate production. Neither angina nor myocardial lactate production was present in any patient in either group during CPT. Coronary sinus flow increased and coronary vascular resistance decreased significantly in both groups at maximal pacing (P less than 0.001). At CPT, coronary flow decreased (P less than 0.05) and coronary resistance increased (P less than 0.001) in group I, while individual response was more variable in group II. In conclusion, maximal pacing was a more effective method of provocation of angina pectoris than CPT. The reactions of coronary sinus flow and coronary vascular resistance were different in group I than in group II. However, because of the variability of response in patients with normal coronary arteries, CPT cannot be used to distinguish patients with coronary artery disease from patients with no such disease.     

冷加压试验研究血压及血管反应性对动脉弹性参数的影响

目的 通过冷加压试验观察血压及血管反应性变化对动脉弹性参数测值的影响.方法 应用血管回声跟踪技术(ET)测暈冷加压试验中22名健康青年男性右侧颈总动脉的瞬时波强(WI),记录其中的动脉弹性参数:僵硬度(β)、弹性模量(Ep)、顺应性(AC)、膨大指数(A1)、β值推导的脉搏波传导速度(PWVβ)及WI值推导的脉搏波传导速度(PWV-WI),并与静息状态下的测值进行比较分析.结果 冷加压试验时,心率轻度加快(P相似文献   

Doppler sonographic diagnosis of severe portal vein pulsatility in constrictive pericarditis: Flow normalization after pericardiectomy

This case report describes the noninvasive assessment of hepatic and portal vein hemodynamics in a patient with constrictive pericarditis before and after pericardiectomy. Doppler sonography of the hepatic veins demonstrated a typical W‐shaped pattern with pronounced late diastolic flow reversal that disappeared after surgery. Preoperatively, we observed severe pulsatility of the portal vein with flow reversal in systole; after pericardiectomy, portal venous flow was normal. We concluded that the high right atrial pressure in this patient might have led to increased hepatic venous outflow resistance, with subsequent trans‐sinusoidal shunting between the hepatic artery and portal vein causing severe portal vein pulsatility. After pericardiectomy and a decrease in right atrial pressure, portal vein flow normalized. © 1999 John Wiley & Sons, Inc. J Clin Ultrasound 27:84–88, 1999.     

Transcatheter mapping and ablation of arrhythmias in the coronary sinus

The coronary sinus (CS) is a complex structure of particular interest to cardiac electrophysiologists. It is exploited as an anatomical reference, a site to record left-sided atrial and ventricular signals and for cardiac resynchronization therapy. Perhaps less appreciated, it may itself serve as a substrate for arrhythmias. It is now increasingly recognized that arrhythmias may be targeted by transcatheter ablation within the CS. This review summarizes pertinent anatomic considerations, explores the relationship between the CS and various arrhythmia substrates, elaborates on current indications for intra CS ablation and addresses efficacy and safety concerns associated with transcatheter ablation.     

Combined evaluation of pupillary and cardiovascular responses to cold pressor test in cluster headache patients

Little is known about the structures and mechanisms involved in the pathophysiology of cluster headache (CH). In this study, pupillary and cardiovascular responses to the cold pressor test (CPT) were monitored in CH patients during either an active phase of disease or a remission period in order to evaluate the oculocephalic and cardiovascular functioning of the autonomic nervous system in this form of idiopathic headache. CH patients showed a specific pattern of pupillary response on both sides during both phases of the disease. This response differed from that of controls because of an absent miosis. The pressor response to CPT was more marked in CH patients than in controls. Naloxone pretreatment caused specific and selective changes in both the pupillary and cardiovascular responses of CH patients. These data suggest a systemic sympathetic hyperactivation in response to CPT in CH patients. An oculocephalic sympathetic hypofunction is possibly associated as well as an altered opioid neuromodulation.     

Effect of fosinopril on the rate of neurohumoral and proinflammatory activation in patients with heart failure

The purpose of the study was to examine the effect of fosinopril on the magnitude of neurohumoral and proinflammatory activation in patients with severe heart failure (HF). Twenty-eight patients aged 52-68 years who had Functional Class (FC) III-IV HF that had developed due to coronary heart disease were examined. All the patients were divided into 2 groups (with 14 patients in each group) and they received routine therapy including an angiotensin-converting enzyme inhibitor (ACEI) and a beta-adrenoblocker. Group 1 patients were given the ACEI fosinopril in a dose of 10-20 mg/day, Group 2 patients took captopril in a dose of 50-75 mg/day. The course of therapy was 12 weeks. All the patients underwent echocardiography by the routine procedure. The plasma levels of angiotensin-II, aldosterone, and brain natriuretic peptide (BNUP) were determined by radioimmunoassay. The plasma contents of tumor necrosis factor-alpha (TNF-alpha) and C-reactive protein (C-RP) were verified by enzyme immunoassay. An analysis of the findings indicated that during therapy the FC of HF decreased on the average by 10.9% in Group 1 and by 11. 7% in Group 2 (p = 0.14). With this, fosinopril was superior to captopril not only in its capacity of improving overall left ventricular contractile function, but it was characterized by a more pronounced effect on regression of the plasma pool of C-RP and TNF-alpha. The marked depressive action of the ACEI fosinopril on the plasma pool of products of the renin-angiotensin system, BNUP, and proinflammatory cytokines may be considered to be as a basis for preferably prescribing the agent to patients with severe HF.