Biomedical subjects

R A Foale

Publications and source records attributed to R A Foale.

At least 37 records · Page 2Linked to original sources

PubMed1997

Left ventricular geometry in presenting untreated hypertension.

In order to investigate the spectrum of geometry in our patient population, 63 untreated hypertensives underwent two-dimensional echocardiography. Left ventricular (LV) mass index and relative wall thickness, a measure of wall thickness in relation to cavity size, were calculated from the M-mode strip. In addition, to assess the sphericity of the left ventricle the ratio of LV minor to major hemiaxis was calculated. The subjects comprised 41 men (17 Caucasian, 22 Afro-Caribbean and two Oriental), and 21 women (five Caucasian, 12 Afro-Caribbean and two Oriental). Concentric hypertrophy was present in 46% of subjects, concentric remodelling in 32% of subjects, eccentric hypertrophy in only 6% of subjects and a normal left ventricular shape in 16% of subjects. The degree of sphericity of the left ventricle was similar among the four groups, suggesting that it does not change in uncomplicated hypertension. In contrast to the previously published combined series from Sassari and New York we had a low proportion of patients with either eccentric hypertrophy or normal left ventricular geometry. This is probably due to the high proportion of Afro-Caribbean subjects in our clinic population who are more likely to have left ventricular hypertrophy.

Adult↗

PubMed1996

Left ventricular hypertrophy and QT dispersion in hypertension.

The interlead variation in QT length on a standard electrocardiograph reflects regional repolarization differences in the heart. To investigate the association between this interlead variation (QT dispersion) and left ventricular hypertrophy, we subjected 100 untreated subjects to 12-lead electrocardiography and echocardiography. Additionally, 24 previously untreated subjects underwent a 6-month treatment study with ramipril and felodipine. In the cross-sectional part of the study, QT dispersion corrected for heart rate (QTc dispersion) was significantly correlated with left ventricular mass index (r = .30, P < .01), systolic pressure (r = .30, P < .01), the ratio of peak flow velocity of the early filling wave to peak flow velocity of the atrial wave (E/A ratio) (r = -.22, P = .02), isovolumic relaxation time (r = .31, P < .01), and age (r = .21, P < .04). In the treatment part of the study, lead-adjusted QTc dispersion decreased from 24 to 19 milliseconds after treatment, and after a subsequent 2 weeks of drug washout remained at 19 milliseconds (P < .01). The changes in left ventricular mass index at these stages were 144, 121, and 124 g/m2 (P < .01). Systolic pressure decreased from 175 to 144 mm Hg and increased again to 164 mm Hg after drug washout (P < .01). The E/A ratio (0.97, 1.02, and 1.02; P = 69) and isovolumic relaxation time (111, 112, and 112; P = .97) remained unchanged through the three assessment points. In conclusion, QT dispersion is increased in association with an increased left ventricular mass index in hypertensive individuals. Antihypertensive therapy with ramipril and felodipine reduced both parameters. If an increased QT dispersion is a predictor of sudden death in this group of individuals, then the importance of its reduction is evident.

Adult↗

PubMed1995

Left ventricular diastolic function in hypertension: a 4 year follow-up study.

In order to assess the long term effects of antihypertensive treatment on left ventricular diastolic function, 26 hypertensive patients were followed up for a mean of 4.25 years with two-dimensional and Doppler echocardiography. A significant reduction in left ventricular mass index was first apparent after 9 months of therapy (mean (S.D.) 124 (22) vs. 114 (18) g/m2, P < 0.01), and this was maintained over the 4.25 year period (124 (22) vs. 117 (17) g/m2, p < 0.05). At 9 months there was no change in either isovolumic relaxation time (108 (26) vs. 108 (17) ms, P = N.S.) or left ventricular filling as assessed by peak flow velocity E/A ratio (0.94 (0.22) vs. 0.95 (0.27), P = N.S.). However, after 4.25 years there was a significant improvement in IVRT (108 (26) vs. 83 (11) ms, P < 0.01) with a trend towards an improved peak flow velocity E/A ratio, although this did not reach statistical significance (0.95 (0.27) vs. 1.02 (0.26), P = N.S.). Of the 14 patients who had an abnormal isovolumic relaxation time at baseline, 12 normalised and 2 improved. These findings suggest that left ventricular diastolic dysfunction in hypertension may be reversed by prolonged antihypertensive treatment.

Adult↗

PubMed1995

The effects of antihypertensive therapy on carotid vascular structure in man.

OBJECTIVE: An increased carotid intima-media thickness (IMT) has been found to be associated with a number of cardiovascular risk factors such as age, hypertension, cigarette smoking, hypercholesterolaemia and left ventricular hypertrophy. Our objective was to assess whether carotid intima-media thickness in hypertensive patients could be reduced by antihypertensive therapy. METHODS: 13 hypertensive patients, 10 previously untreated, were examined using carotid ultrasonography and echocardiography at baseline and then at 8 weeks and 39 weeks after commencement of antihypertensive therapy with ramipril and the second-line addition of felodipine. RESULTS: By the end of the study significant regression of IMT (0.1(0.05-0.16) mm, F-value 10.2, P < 0.01) and left ventricular mass index had occurred (25(10.7-39.3) g/m2, F-value 9.7, P < 0.01). The reduction in IMT was significantly related to the reduction in mean arterial pressure, r = 0.55, P = 0.05). CONCLUSION: Antihypertensive therapy with ramipril and felodipine causes regression of IMT in hypertensive patients, probably chiefly through blood pressure reduction. Large prospective studies are required to assess whether a reduction in IMT results in a reduction in morbidity and mortality.

Adult↗

PubMed1995

Left ventricular structure and function in previously untreated hypertensive patients: the importance of blood pressure, the nocturnal blood pressure dip and heart rate.

BACKGROUND: Cardiac assessment is an important part of risk stratification in hypertensive patients. Left ventricular hypertrophy in particular is a powerful predictor of subsequent cardiovascular morbidity and mortality. Previous studies assessing haemodynamic factors that may be responsible for cardiac changes in hypertensive patients have been performed in those previously treated for hypertension. To investigate more fully these haemodynamic relationships, a large group of previously untreated patients were studied. METHODS: Ninety-eight previously untreated hypertensive patients underwent electrocardiography, two-dimensional and Doppler echocardiography, 24 h ambulatory blood pressure monitoring and exercise stress testing. RESULTS: The left ventricular mass index (LVMI) was more closely related to mean 24 h than to clinic blood pressures (24 h systolic r = 0.48, P < 0.01; 24 h diastolic r = 0.49, P < 0.01; clinic systolic r = 0.28, P < 0.01; clinic diastolic r = 0.31, P < 0.01). In addition, the systolic nocturnal blood pressure dip was found to be inversely related to LVMI in men (r = -0.32, P < 0.01). Of the indices of left ventricular diastolic function, age (r = -0.64, P < 0.01), heart rate (r = -0.25, P = 0.02) and LVMI (r = -0.22, P = 0.02) were independently related to the E-A ratio. Age (r = 0.40, P < 0.01), blood pressure (systolic r = 0.39, P < 0.01; diastolic r = 0.43, P < 0.01), the nocturnal blood pressure dip (systolic r = -0.38, P < 0.01, diastolic r = -0.31, P < 0.01) and LVMI (r = 0.37, P < 0.01) were independently related to the isovolumic relaxation time. CONCLUSIONS: Blood pressure was the only independent determinant of LVMI; nocturnal blood pressure may be particularly important in men. Age and both haemodynamic and structural factors are independent determinants of parameters of left ventricular diastolic function in hypertensive patients.

Blood Pressure↗

PubMed1995

Ventricular arrhythmias in hypertension: in which patients do they occur?

OBJECTIVE: It has been suggested that the increased incidence of sudden death in hypertensive patients, particularly those with left ventricular hypertrophy, may be casually related to the increased number and complexity of ventricular arrhythmias that have been demonstrated in these patients. The objective of the present study was to assess some of the factors which might be responsible for these arrhythmias. SUBJECTS AND METHODS: One hundred and three untreated subjects were divided into four groups on the basis of blood pressure and echocardiographic measurements: hypertensive patients with left ventricular hypertrophy (n = 38), hypertensive patients without left ventricular hypertrophy (n = 16), patients with borderline or white-coat hypertension (n = 26) and normotensive subjects (n = 23). Each subject underwent two-dimensional and Doppler echocardiography, 12-lead electrocardiogram examination, 12-lead electrocardiogram exercise stress testing, 24-h ambulatory blood pressure monitoring and 24-h Holter monitoring. A further 17 hypertensive patients with left ventricular hypertrophy who were on long-term antihypertensive therapy were also investigated in the same manner and compared with untreated hypertensive patients with left ventricular hypertrophy who were matched for age, sex and race. RESULTS: Untreated hypertensive patients, even with left ventricular hypertrophy, had a low prevalence of frequent or complex arrhythmias (seven out of 80 patients with Lown score 2+). In contrast, hypertensive patients with left ventricular hypertrophy on long-term antihypertensive therapy had a significantly greater prevalence of complex arrhythmias than untreated patients with left ventricular hypertrophy (eight out of 17 treated patients compared with two out of 17 untreated patients with Lown score 2+). CONCLUSIONS: Hypertensive patients with left ventricular hypertrophy who had received long-term antihypertensive therapy were found to have a high prevalence of complex ventricular arrhythmias, which was in contrast to untreated hypertensive patients, even those with left ventricular hypertrophy. This may reflect the consequences on the left ventricle of long-term antihypertensive treatment. If complex ventricular arrhythmias are implicated in the excess of sudden deaths in hypertensive patients, this might be an important factor.

Adult↗

PubMed1994

Comparison of exercise echocardiography with an exercise score to diagnose coronary artery disease in women.

This study compares the accuracy of the routine exercise electrocardiogram, exercise score, and exercise echocardiography for the diagnosis of coronary artery disease (CAD) in women. Seventy women with a pretest probability of 53 +/- 30% for CAD were stressed using a maximal symptom-limited bicycle exercise protocol. Significant ST-segment change was defined by a depression of > 0.1 mV 0.06 second after the J point. The exercise score was calculated from ST response, heart rate, and workload using an equation derived from a multivariate model. A positive stress echocardiogram was defined by development of a new or worsening wall motion abnormality. The results were compared with the presence or absence of significant (> 50% diameter) stenoses at angiography. Exercise echocardiography identified 29 of the 33 patients (88%) with CAD, compared with 22 (67%) using ST analysis alone, and 20 (61%) using the exercise score (both p < 0.05 vs exercise echocardiography). The specificity of exercise echocardiography (84%) and the multivariate score (73%) were comparable, and exceeded that of the ST analysis (51%) in 37 patients without CAD (p < 0.01). The accuracy of exercise echocardiography (86%) exceeded that of the exercise score (67%, p = 0.01) and ST analysis (59%, p < 0.01). Among all 70 patients, an intermediate (20% to 80%) probability of coronary disease was identified in 21 patients on the basis of exercise echocardiography, in 38 based on the multivariate score, and in 38 based on the ST analysis alone. Exercise echocardiography is more sensitive than the exercise score, and more sensitive and specific than ST-segment analysis for the diagnosis of CAD in women.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗

PubMed1994

Racial differences in cardiac structure and function in essential hypertension.

OBJECTIVE: To assess racial differences in cardiac structure and function in patients presenting with previously untreated hypertension. DESIGN: Untreated black patients with hypertension were compared with untreated white patients matched for age and sex. Both groups had similar body mass indices, blood pressures, and reported duration of hypertension. SETTING: Cardiovascular risk factor clinic for outpatients. SUBJECTS: 36 men and 22 women with untreated essential hypertension. MAIN OUTCOME MEASURES: Variables of heart structure and function on cross sectional and Doppler echocardiography. RESULTS: The black patients had a significantly greater interventricular septal thickness (mean 1.23 (95% confidence interval 1.14 to 1.33) v 1.09 (1.02 to 1.16) cm; P = 0.02) and posterior wall thickness (mean 1.14 (1.07 to 1.22) v 0.96 (0.88 to 1.03) cm; P = 0.001) than the white patients, although left ventricular internal diameter was not significantly different (mean 4.90 (4.68 to 5.12) v 4.82 (4.64 to 5.01) cm; P = 0.59). This resulted in a significantly greater left ventricular mass index (mean 151 (137 to 164) v 120 (107 to 133) g/m2; P = 0.001) and relative wall thickness (mean 0.47 (0.43 to 0.51) v 0.40 (0.37 to 0.42) cm; P = 0.004) in the black patients. Comparison of Doppler measures of left ventricular diastolic function showed a significantly longer isovolumic relaxation time in black patients (mean 107 (98 to 116) v 92 (83 to 101) ms; P = 0.02) compared with white patients, although peak early to atrial filling ratios were similar in both groups (mean 1.14 (0.95 to 1.32) v 1.04 (0.94 to 1.15); P = 0.37). CONCLUSION: Among previously untreated hypertensive patients, black subjects compared with white subjects have significantly higher left ventricular mass index and relative wall thickness, as well as more impairment of left ventricular function during diastole.

Adult↗

PubMed1993

Atenolol versus the fixed combination of atenolol and nifedipine in stable angina pectoris.

One hundred and fourteen patients (94 male) with chronic stable angina who had a positive exercise test after 4 weeks on atenolol alone were randomized to receive either atenolol alone or the fixed combination of atenolol and nifedipine slow release formulation for 4 weeks in a double-blind cross-over manner. Exercise stress testing (Bruce protocol) at the end of each treatment period demonstrated that the time to the onset of pain and occurrence of 1 mm ST segment depression improved significantly (P < 0.05 and P < 0.001 respectively) whilst on the fixed combination compared to atenolol alone. In order to achieve sufficient sensitivity in the analysis of the exercise times, novel statistical methods based on survival analysis were used. Maximum ST segment depression was 0.13 mm less (P < 0.04) while on the fixed combination. The incidence of withdrawals and adverse effects was similar on both treatments.

Adult↗

PubMed1993

Effects of supplemental oxygen on cardiac rhythm during upper gastrointestinal endoscopy: a randomised controlled double blind trial.

To investigate the effects of supplemental oxygen on cardiac rhythm during gastroscopy, 103 patients aged over 60 were randomised to receive either supplemental oxygen or air at 2 litres/minute during the procedure. Pulse rate, blood pressure, oxygen saturation, and a Holter cardiac trace were monitored before, during, and for one hour after the gastroscopy. A wide range of electrocardiographic abnormalities were recorded in both oxygen and air groups, of which ventricular and supraventricular ectopic beats were the most common. There were no significant differences in the rate of occurrence of any clinically important cardiac abnormality either between the oxygen and air groups or between the three monitored periods before, during, and after gastroscopy. There were significantly fewer patients, however, with supraventricular extra systoles when oxygen was given during gastroscopy (p < 0.05). Although supplemental oxygen during gastroscopy significantly improved oxygen saturation (p < 0.001; 95% confidence intervals for the difference between the means: 2.9 to 4.7), there was no correlation between oxygen saturation and any electrocardiographic changes. It is concluded that electrocardiographic abnormalities are common in patients over 60, but this study found no evidence that they are induced by gastroscopy. Supplemental oxygen increases oxygen saturation but does not reduce the incidence of clinically important cardiac arrhythmias.

Aged↗

PubMed1992

Sustained-release verapamil and nifedipine in exercise-induced angina pectoris.

In a randomised, double-blind, crossover study of oral sustained-release verapamil 360 mg o.d. ('SR-verapamil') and oral nifedipine 20 mg t.d.s. in 19 patients with chronic stable angina pectoris, significantly greater improvement from baseline was seen with SR-verapamil than with nifedipine. Mean exercise duration was 380 +/- 108 s with SR-verapamil and 343 +/- 130 s with nifedipine (P less than 0.05); mean time to onset of angina was 326 +/- 79 s with SR-verapamil and 239 +/- 79 s with nifedipine (P less than 0.01); median time to 1 mm ST depression was 252 s (range 114-579) with SR-verapamil and 182 s (range 84-582) with nifedipine (P less than 0.01); mean ST depression at maximum exercise was 1.65 +/- 0.56 mm with SR-verapamil and 2.17 +/- 0.98 mm with nifedipine (P less than 0.05). Ambulatory ECG recordings indicated a trend in favour of SR-verapamil (median ST-time integral 0.00 [range 0-24.16] mm h-1 with SR-verapamil, 1.15 [range 0-12.50] mm h-1 with nifedipine, not significant). Median glyceryl trinitrate consumption was significantly lower (P less than 0.05) with SR-verapamil (0.21; range 0-1.25 per day) than with nifedipine (0.31; range 0-1.32 per day), but there was no significant difference between angina attack frequency. Adverse events were reported by two patients with SR-verapamil and nine with nifedipine. Once-daily sustained-release verapamil 360 mg has a significantly better effect on exercise tolerance than nifedipine 20 mg t.d.s. and also appears to be better-tolerated.

Adult↗

PubMed1992

Myocardial dysfunction in treated adult hypopituitarism: a possible explanation for increased cardiovascular mortality.

OBJECTIVE: To assess cardiac structure and function in patients with treated hypopituitarism and to determine their relation to the degree of growth hormone deficiency and body composition pattern. DESIGN: 26 patients with treated hypopituitarism were studied by cross sectional and Doppler echocardiography and by exercise testing. The results were analysed and their relation to the degree of growth hormone deficiency and body composition determined. SETTING: All tests were performed in the department of cardiology and the unit of metabolic medicine at a tertiary referral centre. PATIENTS: Patients with hypopituitarism referred for endocrine assessment. MAIN OUTCOME MEASURES: Left ventricular mass, left ventricular diastolic function, and exercise capacity in patients with hypopituitarism and their relation to growth hormone deficiency. RESULTS: Mean (SD) serum concentration of insulin-like growth factor 1 (IGE-1), a measure of growth hormone deficiency, was 82.4 (45) micrograms/l. Lean body mass calculated by measuring total body potassium was 50 (9) kg. All patients had a normal left ventricular mass index and a normal left ventricular ejection fraction. Eight patients had abnormal left ventricular diastolic function. There was a significant correlation between IGF-1 and left ventricular mass (r = 0.45, p less than 0.02). Lean body mass was also significantly correlated with left ventricular mass (r = 0.78, p less than 0.0001) and left ventricular diastolic function (r = -0.63, p less than 0.01). The mean exercise duration was 8.6 (3.6) minutes. There was a significant correlation between serum IGF-1 and the rate-pressure product on exercise (r = 0.47, p less than 0.01). Seven patients had planar ST segment depression greater than 0.1 mV during exercise testing. In five of these patients there was rapid resolution of ST segment depression immediately after exercise. Two patients developed considerable ST segment depression, and subsequent coronary angiography showed normal coronary arteries. Exercise-induced ST segment depression was not related to the severity or duration of growth hormone deficiency or serum cholesterol concentration. CONCLUSIONS: This study suggests that left ventricular mass and the rate-pressure product are related to the degree of growth hormone deficiency, that left ventricular diastolic dysfunction is frequently seen in hypopituitarism, and that these patients may have ischaemic-like ST segment changes during exercise testing. These findings may explain the increased cardiovascular mortality in patients with hypopituitarism and may also have implications for growth hormone replacement therapy in adults.

Adult↗

PubMed1992

Metabolic changes and vascular risk factors in hypopituitarism.

Adults with hypopituitarism die prematurely, and the excess mortality is from vascular disease. On echocardiography we have demonstrated abnormalities of myocardial diastolic function in hypopituitary adults, indicating possible early ischaemic change. Peripheral arterial disease is evident on ultrasonography. Vascular risk factors have also been examined. Impaired glucose tolerance and unrecognized diabetes are common in hypopituitary adults. Total cholesterol levels are elevated, particularly in hypopituitary women. The role of growth hormone (GH) deficiency in the vascular disease and in the vascular-risk-factor abnormalities is unknown at present. Prolonged GH therapy causes a decrease in the levels of fasting total cholesterol, without any adverse effects on glucose homeostasis. GH therapy trials in adults will clarify the role of GH in the excess vascular risk of hypopituitarism. Prolonged GH therapy will be necessary for the vascular effects to be defined.

Adult↗

PubMed1991

Impaired left ventricular filling during ST-segment depression provoked by dipyridamole infusion in patients with syndrome X.

The left ventricular filling and regional wall motion patterns were compared in 6 normal subjects, 20 patients with coronary artery disease, and 10 patients with syndrome X by means of Doppler and two-dimensional echocardiography during high-dose (0.9 mg/kg body weight in 10 min) dipyridamole infusion. During the procedure none of the normal subjects had chest pain or significant ST depression (greater than 0.1 mV) whereas 10 of 20 patients with coronary artery disease had ST depression, 3 with chest pain. Six patients with syndrome X had ST depression, 5 with chest pain. Regional wall motion abnormalities were identified in 6 patients with coronary artery disease who had ST depression but none were detected in normals or in patients with syndrome X. Compared with normals (-2.1 +/- 3.5%) there was a significant difference in percentage decrease in the peak early filling velocity in patients with coronary artery disease and ST depression (-10.3 +/- 6.2%; p less than 0.01) and in patients with syndrome X and ST depression (-9.4 +/- 6.9%; p less than 0.05). These findings indicate that, in the presence of dipyridamole-induced ST depression, patients with syndrome X have an abnormal left ventricular filling pattern similar to that observed in patients with coronary artery disease. This suggests that myocardial ischemia occurs in patients with syndrome X but the absence of regional wall motion abnormality suggests that it is diffuse.

Aged↗

PubMed1991

Endocarditis due to Salmonella Dublinae.

We describe, to the best of our knowledge, the first reported case of endocarditis due to Salmonella Dublinae, which occurred in a patient with surgically corrected congenital heart disease. The diagnosis was established from positive blood cultures and echocardiography, and the patient was treated by intravenous antibiotic therapy with clinical success at six months follow up. The diagnosis and its implications for management are discussed, together with a review of previously reported cases of endocarditis caused by the Salmonella group of organisms.

Adult↗

PubMed1991

The effects of blood pressure reduction on abnormal left ventricular diastolic function in hypertensive patients.

To investigate whether reduction in blood pressure has a beneficial effect on left ventricular diastolic function, we investigated 20 hypertensive patients with evidence of diastolic dysfunction at baseline and at 3 and 6 months after initiation of captopril therapy. Two-dimensional echocardiography was used to determine left ventricular mass index and Doppler ultrasound to assess diastolic function. Fifteen of the 20 patients had a significant reduction in blood pressure at 3 and 6 months and left ventricular mass index remained unchanged during the study period. Despite reduction in blood pressure, no difference in isovolumic relaxation time, early and atrial filling velocities or their ratio was observed. Our results suggest that a direct relationship between blood pressure and left ventricular diastolic function does not exist and that other factors such as alterations in muscle or collagen composition of the left ventricle may be more important in determining abnormal diastolic function in hypertension.

Adult↗

PubMed1991

Impending paradoxical embolism: a rare but important diagnosis.

A man aged 50 presented with a history of a cerebrovascular accident and arterial embolism at two discrete peripheral sites. Echocardiography showed thrombus trapped in an interatrial site and impending paradoxical embolism was diagnosed. Treatment with heparin was started and the potentially embolic intracardiac material was removed at open heart surgery. The patient was treated with warfarin and made a good recovery. This is only the third case report of impending paradoxical embolism diagnosed in life.

Echocardiography↗

PubMed1991

Characteristics of left ventricular filling in coronary artery disease and myocardial ischaemia after dipyridamole provocation.

Doppler echocardiographic measurement of transmitral filling velocities seems to be a sensitive marker for resting left ventricular diastolic abnormalities in patients with coronary artery disease. The behaviour of these filling velocities during induced myocardial ischaemia, however, has not been fully studied. Left ventricular filling was assessed by pulsed Doppler ultrasound in 21 patients with angina pectoris and coronary artery disease and in five controls (patients with chest pain but without myocardial ischaemia). High dose dipyridamole infusion (0.9 mg/kg over 10 minutes) was used to provoke myocardial ischaemia, which was assessed by symptoms and electrocardiographic ST segment change. Doppler indices of diastolic filling were measured and the results expressed as percentage change from baseline values. Dipyridamole increased the heart rate and reduced systolic blood pressure equally in both groups. In the controls dipyridamole increased the peak filling velocities of both the early and atrial filling waves. In the 12 patients with coronary artery disease who did not develop evidence of myocardial ischaemia, the effect on left ventricular filling velocity resembled that in the controls though the time to peak change was delayed. Six of the nine patients with dipyridamole induced myocardial ischaemia had a significantly reduced maximum changes in early (+30% v +18%) and atrial (-0.2% v +33%) filling velocities compared with the controls. The remaining three patients had a decrease in early filling velocity (-20%) with an associated increase in atrial peak filling velocity (+21%). Dipyridamole increased diastolic filling velocities in the controls. In patients with coronary artery disease there was a variable change in diastolic filling indices which may be attributed either to the degree of myocardial ischaemia or to the different haemodynamic changes occurring during myocardial ischaemia.

Adult↗