Relation of low diastolic blood pressure to coronary heart disease death in presence of myocardial infarction: the Framingham Study.

OBJECTIVE--To examine the hypothesis that a J curve relation between blood pressure and death from coronary heart disease is confined to high risk subjects with myocardial infarction. DESIGN--Cohort longitudinal epidemiological study with biennial examinations since 1950. SETTING--Framingham, Massachusetts, USA. SUBJECTS--5209 subjects in the Framingham study cohort followed up by a person examination approach. MAIN OUTCOME MEASURES--Coronary heart disease deaths and non-cardiovascular disease deaths in men and women with or without myocardial infarction relative to blood pressure. RESULTS--Among subjects without myocardial infarction non-cardiovascular disease deaths were twice to three times as common as coronary heart disease deaths. Furthermore, there was no significant relation between non-cardiovascular disease death and diastolic or systolic blood pressure. Also coronary heart disease deaths were linearly related to diastolic and systolic blood pressures. Among high risk patients (that is, people with myocardial infarction but free of congestive heart failure) death from coronary heart disease was more common than non-cardiovascular disease death. There was a significant U shaped relation between coronary heart disease death and diastolic blood pressure. Although there was an apparent U shaped relation between coronary heart disease death and systolic blood pressure, it did not attain statistical significance when controlling for age and change in systolic blood pressure from the pre-myocardial infarction level. None of the above conclusions changed when adjustments were made for risk factors such as serum cholesterol concentration, antihypertensive treatment, and left ventricular function. The U shaped relation between diastolic blood pressure and high risk subjects existed for both those given antihypertensive treatment and those not. CONCLUSIONS--These data suggest that an age and sex independent U curve relation exists for diastolic blood pressure and coronary heart disease deaths in patients with myocardial infarction but not for low risk subjects without myocardial infarction. The relation seems to be independent of left ventricular function and antihypertensive treatment.     

Control of blood pressure and risk of first acute myocardial infarction: Skaraborg hypertension project.

OBJECTIVE--To analyse the relation between treated blood pressure and concomitant risk factor and morbidity from acute myocardial infarction. DESIGN--Prospective longitudinal study. Treated blood pressures and other variables were used to predict acute myocardial infarction. SETTING--Primary health care in Skaraborg, Sweden. SUBJECTS--1121 men and 1453 women aged 40-69 years at registration at outpatient clinics, 1977-81, with no evidence of previous myocardial infarction were followed up for an average of 7.4 years. Subjects were undergoing treatment with drugs to lower blood pressure or had blood pressure that exceeded the systolic or diastolic limits, or both, for diagnosis (> 170/> 105 mm Hg (patients aged 40-60 years) and > 180/> 110 mm Hg (older than 60 years)) on three different occasions, or both. MAIN OUTCOME MEASURES--First validated event of fatal or non-fatal acute myocardial infarction. RESULTS--In men but not in women there was a negative relation between treated diastolic blood pressure and risk of acute myocardial infarction. Left ventricular hypertrophy and smoking were contributory risk factors in both sexes, as was serum cholesterol concentration in men. In men with normal electrocardiograms (n = 345) risk increased with increasing diastolic blood pressure (P = 0.047), whereas the opposite was found in men with electrocardiograms suggesting ischaemia or hypertrophy, or both (n = 499, P = 0.009). In those with a reading of 95-99 mm Hg the relative risk was 0.30 (P = 0.034); at > or = 100 mm Hg it was 0.37 (P = 0.027). No similar relations were seen in women or for systolic blood pressure. CONCLUSION--It may be hazardous to lower diastolic blood pressure below 95 mm Hg in hypertensive men with possible ischaemia or hypertrophy, or both. Electrocardiographic findings should be considered when treatment goals are decided for men with hypertension.     

A Survey of Cardiac Infarctions: Hospital Experience

A study of patients with cardiac infarction, treated in hospital between 1950 and 1954 and followed up to the present, is reported. One hundred and forty-two patients suffered 169 attacks. In 95 attacks, the patients received anticoagulant therapy, with 15 acute deaths. Fifty-six were not so treated; among these there were 21 deaths. The rate of survival was best in younger patients with their first episode of infarction, without preexisting hypertension, cardiac failure, or systolic blood pressure persistently below 100. Angina preceding infarction disappeared in one-half of the subjects after the episode; half the survivors suffered recurrent myocardial infarction within five years. Moderate hypertension had no effect upon immediate or 10-year survival. No patient received long-term anticoagulant therapy. Of the survivors of acute infarction, 16 died in the first year after the acute attack, nine in the second year, nine in the third, six in the fourth and five in the fifth. At the end of five years, 51 subjects had survived 60 episodes. At the end of 10 years, 43 living patients had sustained 45 myocardial infarctions.     

Radioimmunoassay of serum myoglobin in screening for acute myocardial infarction.

Over an 8-month period 289 patients consecutively admitted to a coronary care unit were studied to assess the value of serum myoglobin determinations by radioimmunoassay in screening for acute myocardial infarction. Of the 289 patients 127 (44%) had an infarction. It was found that when blood sampling was done within 5 to 15 hours after the onset of chest pain this assay had a sensitivity, specificity, and positive and negative predictive values of more than 97%. In this study healthy young adults had a mean serum myoglobin level of 37 +/- 11 (standard deviation) ng/ml, and values above 80 ng/ml were considered positive for acute myocardial infarction. False-positive results can be due to stock, vigorous exercise, skeletal muscle damage and several renal failure, but, except for the last one, these conditions also caused an increase in the serum level of the creatine kinase isoenzyme CK-MB.     

Indicators of acute and persistent renal damage in adult thrombotic microangiopathy

Background

Thrombotic microangiopathies (TMA) in adults such as thrombotic thrombocytopenic purpura (TTP) and hemolytic uremic syndrome (HUS) are life-threatening disorders if untreated. Clinical presentation is highly variable and prognostic factors for clinical course and outcome are not well established.

Methods

We performed a retrospective observational study of 62 patients with TMA, 22 males and 40 females aged 16 to 76 years, treated with plasma exchange at one center to identify clinical risk factors for the development of renal insufficiency.

Results

On admission, 39 of 62 patients (63%) had acute renal failure (ARF) with 32 patients (52%) requiring dialysis treatment. High systolic arterial pressure (SAP, p = 0.009) or mean arterial pressure (MAP, p = 0.027) on admission was associated with acute renal failure. Patients with SAP>140 mmHg on admission had a sevenfold increased risk of severe kidney disease (OR 7.464, CI 2.097–26.565). MAP>100 mmHg indicated a fourfold increased risk for acute renal failure (OR 4.261, CI 1.400–12.972). High SAP, diastolic arterial pressure (DAP), and MAP on admission were also independent risk factors for persistent renal insufficiency with the strongest correlation for high MAP. Moreover, a high C-reactive protein (CRP) level on admission correlated with renal failure in the course of the disease (p = 0.003). At discharge, renal function in 11 of 39 patients (28%) had fully recovered, 14 patients (23%) remained on dialysis, and 14 patients (23%) had non-dialysis-dependent chronic kidney disease. Seven patients (11%) died. We identified an older age as risk factor for death.

Conclusions

High blood pressure as well as high CRP serum levels on admission are associated with renal insufficiency in TMA. High blood pressure on admission is also a strong predictor of sustained renal insufficiency. Thus, adult TMA patients with high blood pressure may require special attention to prevent persistent renal failure.     

血清Trx1、FGL2与急性心肌梗死后心力衰竭患者预后的关系

摘要 目的：探讨血清硫氧还蛋白1（Trx1）、纤维蛋白原样蛋白2（FGL2）与急性心肌梗死后心力衰竭患者预后的关系。方法：选择2019年10月至2020年5月我院收治的158例急性心肌梗死后心力衰竭患者作为观察组,并根据心功能Killip分级分为Ⅱ级组54例、Ⅲ级组57例、Ⅳ级组47例。另选择同期我院收治的102例急性心肌梗死患者作为对照组。入院后采用酶联免疫吸附法（ELISA）检测所有患者血清Trx1、FGL2水平;观察组患者出院后随访2年,并根据是否出现主要不良心血管事件（MACE）将患者分为预后不良组和预后良好组。采用多因素Logistic回归分析影响急性心肌梗死后心力衰竭患者预后的相关因素,采用受试者工作特征（ROC）曲线评估血清Trx1、FGL2对急性心肌梗死后心力衰竭患者预后的预测价值。结果：观察组血清FGL2水平明显高于对照组,血清Trx1水平明显低于对照组（P<0.05）;心功能Killip分级Ⅳ级组患者血清Trx1水平明显低于Ⅱ级组、Ⅲ级组（P<0.05）,血清FGL2水平明显高于Ⅱ级组、Ⅲ级组（P<0.05）。预后不良组患者血清Trx1、LVEF均明显低于预后良好组,而年龄、血清FGL2及血尿酸、血肌酐、N末端B型利钠肽原（NT-proBNP）均明显高于预后良好组（P<0.05）,两组心功能Killip分级比例比较差异有统计学意义（P<0.05）。多因素Logistic回归分析显示,年龄（较高）、心功能Killip分级为Ⅳ级、Trx1下降、FGL2升高均是影响急性心肌梗死后心力衰竭患者预后的危险因素（P<0.05）。ROC曲线结果显示,血清Trx1、FGL2预测急性心肌梗死后心力衰竭患者预后的曲线下面积分别为0.807、0.811,两者联合检测预测急性心肌梗死后心力衰竭患者预后的曲线下面积为0.889。结论：急性心肌梗死后心力衰竭患者血清中Trx1水平降低,FGL2水平升高,且血清Trx1、FGL2水平与患者心功能分级及预后密切相关,可作为评估急性心肌梗死后心力衰竭患者预后的辅助性指标。     

Pregnancy and the Nephrotic Syndrome

Nineteen patients with nephrotic syndrome, 13 with histological diagnosis, were studied throughout 31 pregnancies. Eight were diagnosed for the first time during pregnancy.Antenatal problems due to severe oedema, urinary tract infection, and refractory orthochromic anaemia were encountered. Eight patients were hypertensive at booking, and in two of these pregnancy was terminated; three others had a significant increase in blood pressure. In 12 of the remaining pregnancies a rise in blood pressure of 20 mm. Hg or more occurred towards term.There were 29 live births (including one set of twins), one stillbirth due to a cord accident, and one neonatal death. The infant birth weight, apart from being affected by hypertension, was related to the maternal serum albumin level.The patients have been under observation for up to 20 years. Fifteen have not shown any deterioration of renal function during the prolonged period of observation. One developed oliguric renal failure immediately post partum and three others died, two, four, and 12 years after their pregnancies.     

Acute Renal Failure and Open Heart Surgery

A retrospective study of 428 open heart operations showed the incidence of mild and severe renal failure to be 26% and 4·7% respectively. The mortality rate was 38% in the mild cases and 70% in the severe cases. Only half of the patients whose death was associated with renal failure showed macroscopic or microscopic renal lesions at necropsy. The patients who developed renal impairment had significantly higher mean preoperative blood urea (40 mg/100 ml) than the non-renal-failure cases (33 mg/100 ml). Periods of perfusion over 60 minutes, mean perfusion pressures below 80 mm Hg, and multiple valve replacement operations also increased the incidence of renal failure. There was no statistical correlation between the age of individual patients, the degree of cooling, and postoperative blood urea values. There was no evidence to suggest that frusemide or mannitol separately or together influenced the development of renal failure. Peritoneal dialysis was preferred for initial treatment of patients with severe renal failure, and haemodialysis was required only in special cases.     

Reduction in mortality after myocardial infarction with long-term beta-adrenoceptor blockade. Multicentre international study: supplementary report.

In a controlled multicentre trial carried out to assess the value of long-term practolol treatment after myocardial infarction the provisional results showed a significant reduction in mortality, though some of the data were lacking. These have now been included and the results updated. The final figures for all deaths were 78 in the placebo group of 1533 patients and 48 in the practolol group of 1520 patients. The reduction in mortality (38%) was significant at the 1% level. The figures for non-fatal reinfarction (97 in the placebo group, and 75 in the practolol group) were not significantly different. Patients with pre-entry anterior infarction, and especially those with a diastolic blood pressure equal to or below the mean (78 mm Hg) at entry to the trial, were at high risk but benefited particularly well from beta-adrenoceptor blockade. After pre-entry inferior infarction the percentage reduction in deaths occurring within two hours after symptoms of a new event was similar to that after anterior infarction, but the incidence of death more than two hours after the event was greater in the practolol-treated group. Thus the difference between groups in total deaths after pretrial inferior infarction was marginal. Until the results of further trials are reported long-term beta-adrenoceptor blockade (possibly up to two years) is recommended after uncomplicated anterior myocardial infarction.     

急性心肌梗死患者冠状动脉病变严重性与脉压和脉压指数的关系

目的:探讨急性心肌梗死(AMI)患者冠状动脉病变严重程度与脉压和脉压指数的关系.方法:对185例AMI患者进行冠状动脉造影术,冠状动脉病变严重程度用冠状动脉病变支数和Gensini积分来表示,并测定收缩压(SBP)和舒张压(DBP)并计算脉压(PP)及脉压指数(PPI).结果:与脉压＜65mmHg的患者相比,脉压≥65mmHg的患者冠状动脉3支血管病变的患病率和Gensini积分显著增高(P＜0.01).与PPI＜0.500的患者相比,PPI≥0.500的患者冠状动脉3支血管病变的患病率和Gensini积分亦显著增高(P＜0.01).结论:PP和PPI与AMI患者冠状动脉病变程度密切相关,在临床上具有指导作用.     

Hospital Admissions for Hypertensive Crisis in the Emergency Departments: A Large Multicenter Italian Study

Epidemiological data on the impact of hypertensive crises (emergencies and urgencies) on referral to the Emergency Departments (EDs) are lacking, in spite of the evidence that they may be life-threatening conditions. We performed a multicenter study to identify all patients aged 18 years and over who were admitted to 10 Italian EDs during 2009 for hypertensive crises (systolic blood pressure ≥220 mmHg and/or diastolic blood pressure ≥120 mmHg). We classified patients as affected by either hypertensive emergencies or hypertensive urgencies depending on the presence or the absence of progressive target organ damage, respectively. Logistic regression analysis was then performed to assess variables independently associated with hypertensive emergencies with respect to hypertensive urgencies. Of 333,407 patients admitted to the EDs over the one-year period, 1,546 had hypertensive crises (4.6/1,000, 95% CI 4.4–4.9), and 23% of them had unknown hypertension. Hypertensive emergencies (n = 391, 25.3% of hypertensive crises) were acute pulmonary edema (30.9%), stroke (22.0%,), myocardial infarction (17.9%), acute aortic dissection (7.9%), acute renal failure (5.9%) and hypertensive encephalopathy (4.9%). Men had higher frequency than women of unknown hypertension (27.9% vs 18.5%, p<0.001). Even among known hypertensive patients, a larger proportion of men than women reported not taking anti-hypertensive drug (12.6% among men and 9.4% among women (p<0.001). Compared to women of similar age, men had higher likelihood of having hypertensive emergencies than urgencies (OR = 1.34, 95% CI 1.06–1.70), independently of presenting symptoms, creatinine, smoking habit and known hypertension. This study shows that hypertensive crises involved almost 5 out of 1,000 patients-year admitted to EDs. Sex differences in frequencies of unknown hypertension, compliance to treatment and risk of hypertensive emergencies might have implications for public health programs.     

Prognosis of patients with "chest pain ?cause".

All 662 patients admitted to the two coronary care units in Nottingham during 12 consecutive months were followed up prospectively for one year. At the time of discharge from hospital they were categorised according to set criteria into the following diagnostic groups: definite, probable, or possible myocardial infarction; ischaemia heart disease without infarction; chest pain ?cause; and other diagnoses. Eighty-nine patients (13% of admissions) were categorised as having chest pain ?cause. No deaths occurred among these patients during the observation period, although two were readmitted with myocardial infarction. Patients with chest pain ?cause had few problems during the year after admission, and at the end of that time 75% were in their original employment. Patients admitted with ischaemic heart disease had a similar death rate (between six weeks and one year after admission) to those with myocardial infarction, and only 36% were in their original employment one year after admission. Chest pain ?cause is a clinically useful diagnostic category to which patients may be allocated after only simple investigations.     

A comparison of aspirin and anticoagulation following thrombolysis for myocardial infarction (the AFTER study): a multicentre unblinded randomised clinical trial.

OBJECTIVE: To compare aspirin with anticoagulation with regard to risk of cardiac death and reinfarction in patients who received anistreplase thrombolysis for myocardial infarction. DESIGN: A multicentre unblinded randomised clinical trial. SETTING: 38 hospitals in six countries. SUBJECTS: 1036 patients who had been treated with anistreplase for myocardial infarction were randomly assigned to either aspirin (150 mg daily) or anticoagulation (intravenous heparin followed by warfarin or other oral anticoagulant). The trial was stopped earlier than originally intended because of the slowing rate of recruitment. MAIN OUTCOME MEASURE: Cardiac death or recurrent myocardial infarction at 30 days. RESULTS: After 30 days cardiac death or reinfarction, occurred in 11.0% (57/517) of the patients treated with anticoagulation and 11.2% (58/519) of the patients treated with aspirin (odds ratio 1.02, 95% confidence interval 0.69 to 1.50, P = 0.92). Corresponding findings at three months were 13.2% (68/517) and 12.1% (63/519) (0.91, 0.63 to 1.32, P = 0.67). Patients receiving anticoagulation were more likely than patients receiving aspirin to have had severe bleeding or a stroke by three months (3.9% v 1.7% (0.44, 0.20 to 0.97, P = 0.04)). CONCLUSION: No evidence of a difference in the incidence of cardiac events was found between the two treatment groups, though the trial is too small to claim treatment equivalence confidently. A higher incidence of severe bleeding events and strokes was detected in the group receiving anticoagulation, suggesting that aspirin may be the drug of choice for most patients in this context.     

Intravenous diazoxide in treatment of hypertension associated with recent myocardial infarction

Twenty patients with blood pressure over 180/110 mm Hg one hour after admission to a coronary care unit with recent acute myocardial infarction were given intravenous diazoxide in a bolus of 300 mg. The average blood pressure before diazoxide was 194/122 mm Hg. Blood pressure fell considerably in all patients, though six patients required two injections. The average fall was 58 mm Hg systolic and 40 mm Hg diastolic. No patient became severely hypotensive. The heart rate increased by an average of 10 beats/min. In nine patients the electrocardiographic changes immediately after the administration of diazoxide suggested an increase in myocardial injury. Though none of the patients seemed to deteriorate clinically from the diazoxide the electrocardiographic changes suggested that the use of intravenous diazoxide to lower blood pressure in patients with acute myocardial infarction might possibly be deleterious.     

Renal failure induces telomere shortening in the rat heart

BackgroundRenal failure aggravates pathological cardiac remodelling induced by myocardial infarction (MI). Cardiac remodelling is associated with telomere shortening, a marker for biological ageing. We investigated whether mild and severe renal failure shorten cardiac telomeres and excessively shorten telomeres after MI. MethodsRats were subjected to sham, unilateral (UNX) or 5/6th nephrectomy (5/6NX) to induce none, mild or severe renal failure. MI was induced by left coronary artery ligation. Renal function parameters and blood pressure were measured. DNA was isolated from non-infarcted cardiac tissue. Telomere length was assessed by quantitative polymerase chain reaction (PCR). ResultsProteinuria was unchanged in UNX and MI compared with control, but strongly increased in 5/6NX, UNX+MI and 5/6NX+MI. Serum creatinine levels were increased fourfold in 5/6NX and tenfold in 5/6NX+MI. 5/6NX and groups with both renal failure and MI showed an approximate 20% reduction of telomere length, similar to the MI group. No excess telomere shortening was observed in hearts from rats with renal ablation after MI. ConclusionSevere renal failure, but not mild renal failure, leads to shortening of cardiac telomeres to a similar extent as found after MI. Renal failure did not induce excessive telomere shortening after MI. (Neth Heart J 2009;17:190–4.)     

慢性阻塞性肺疾病合并心力衰竭患者的预后影响因素分析

目的:探讨慢性阻塞性肺疾病合并心力衰竭患者的预后影响因素。方法:选取我院自2007年12月-2012年12月收住入院的慢性阻塞性肺疾病患者352例,其中合并心力衰竭患者124例,随访1年两组的结局事件发生率及相关预后。结果:年龄、糖尿病、脑卒中病史、肿瘤、合并CHF均为COPD患者死亡的危险因素(P0.05)。与未合并CHF组比较,合并CHF组患者的死亡、因COPD再次入院、脑梗死或心肌梗死的危险性增高(P0.05)。结论:CHF是COPD的常见合并症,是COPD患者死亡或相关心血管疾病的危险因素,临床需密切关注。     

Blood level of free serotonin, catecholamines and the renin-angiotensin-aldosterone system in patients with primary hypertension]

Two subgroups of patients were selected out of those dialysed for chronic renal failure. Group A included patients without arterial hypertension before dialysis, and group B patients with arterial hypertension before dialysis. Blood endogenous digoxin-like substance (DLS) has been assayed. Its blood levels were not increased in hypertensive patients either before or after dialysis. No correlation was found between DLS and mean arterial pressure in the whole group of patients with chronic renal failure. The obtained results do not suggest that arterial blood pressure in patients with chronic renal failure is related to the presence of DLS in the blood.     

无创机械通气治疗急性心肌梗死低氧血症的护理体会

目的:探讨Bi PAP无创呼吸机辅助呼吸治疗急性心肌梗死低氧血症的临床疗效和护理措施。方法:选取我院2013年8月至2014年12月抢救中心急性心肌梗死伴低氧血症患者,在常规治疗及高流量吸氧后,末梢血氧饱和度(SPO2)90%者40例,采用无创呼吸机辅助治疗并加强护理,观察治疗后血气指标SPO2、Pa O2和Pa CO2的变化。结果:所有患者在无创通气30 min后SPO2均升至90%以上,而PO2升至正常低限,1 h后Pa O2恢复正常。结论:无创呼吸机辅助治疗是治疗急性心肌梗死低氧血症的有效方法。     

Predictive value of circulating miR-328 and miR-134 for acute myocardial infarction

MicroRNA (miRNAs) is demonstrated to be present in the blood of humans and has been increasingly suggested as a novel biomarker for various pathological processes in the heart, including myocardial infarction, myocardial remodeling and progression to heart failure. In this study, we aim to evaluate the diagnostic and prognostic value of circulating miR-328 and miR-134 in patients with acute myocardial infarction (AMI). Circulating levels of miR-328 and miR-134 were detected by quantitative real-time PCR in plasma samples from 359 AMI patients and 30 healthy volunteers. Concentrations of high-sensitivity cardiac troponin T (hs-cTnT) were measured using electrochemiluminescence-based methods. MiRNAs were assessed for discrimination of a clinical diagnosis of AMI and for association with primary clinical endpoint defined as a composite of cardiogenic death and development of heart failure within 6 months after infarction. Results showed that levels of plasma miR-328 and miR-134 were significantly higher in AMI patients than in healthy controls. Receiver operating characteristic curve analyses showed significant diagnostic value of miR-328 and miR-134 for AMI. However, neither of them was superior to hs-cTnT for the diagnosis. Additionally, increased miRNA levels were strongly associated with increased risk of mortality or heart failure within 6 months for miR-328 (OR 7.35, 95 % confidence interval 1.07–17.83, P < 0.001) and miR-134 (OR 2.28, 95 % confidence interval 1.03–11.32 P < 0.001). In conclusion, circulating miR-328 and miR-134 could be potential indicators for AMI, and the miRNA levels are associated with increased risk of mortality or development of heart failure.     

Role of exercise testing early after myocardial infarction in identifying candidates for coronary surgery.

It has been suggested that ST depression in lead V5 or equivalent on early exercise testing after acute myocardial infarction predicts a high risk of death. To evaluate exercise testing and radionuclide ventriculography in this context 103 consecutive patients with myocardial infarction who were able to undertake a limited exercise test before discharge from hospital were exercised and underwent gated blood pool scanning. No serious complications resulted from exercise testing. Twenty nine patients developed ST depression in lead V5, 19 had exertional hypotension, 31 developed a heart rate of greater than or equal to 130 beats/min, and 15 had complex ventricular arrhythmias. Death during the first year after discharge from hospital was associated with exertional hypotension (p less than 0.001) and a heart rate on exercise testing of greater than or equal to 130 beats/min (p less than 0.05); these two variables identified all nine deaths. Inability to complete the exercise protocol for any reason was also predictive of death (p less than 0.01). Ventricular arrhythmias and ST depression in lead V5 induced by exercise were not significantly associated with an increased risk of death. The mean (SD) radionuclide ejection fraction in the patients who died was 29 (16%) compared with 43 (11)% in the patients who survived (p less than 0.001). ST changes on exercise testing after myocardial infarction appear to be less predictive of later complications than haemodynamic signs, which may indicate left ventricular damage rather than ischaemia.