Transoesophageal echocardiography

Transoesophageal echocardiography gives unparalleled views of the posterior structures of the heart. It is the investigation of choice for the diagnosis of acute dissection of the aorta, in patients with endocarditis, management of the hypotensive patient in the intensive care unit, and in the search for a potential cardiac source of thromboembolism. However, it is a semi-invasive procedure, and proper training is required to carry it out safely, to ensure that maximum information is obtained at the time of examination, and to avoid diagnostic pitfalls.

Diastolic dysfunction and natriuretic peptides in systolic heart failure. Higher ANP and BNP levels are associated with the restrictive filling pattern

BACKGROUND

Left ventricular diastolic dysfunction is common in patients with systolic heart failure and the restrictive type of filling pattern appears to be associated with increased cardiac mortality. Both artrial and brain (or ventricular) natriuretic peptides are also proven markers of the severity of heart failure. The aim of this study was to determine in a large cohort of patients with systolic heart failure whether diastolic abnormalities, and in particular the restrictive filling pattern of transmitral flow velocity, correlate with plasma atrial and brain natriuretic peptide levels.

METHODS

Sixty-eight consecutive patients with symptomatic systolic heart failure (ejection fraction < 0.5) underwent two-dimensional Doppler echocardiography of left ventricular systolic and diastolic function, together with measurement of atrial and brain natriuretic peptides.

RESULTS

The restrictive filling pattern was present in 62%, the abnormal relaxation pattern in 31% and only 7% were normal. Atrial and brain natriuretic peptide (ANP/BNP) levels were significantly higher in the restrictive compared to the abnormal relaxation group (ANP: 202.2 +/- 31.7 vs 102.5 +/- 22.1 pg.ml-1, P = 0.012; BNP: 277.8 +/- 27.7 vs 162.4 +/- 21.9 pg.ml-1, P = 0.002). In addition, a restrictive filling pattern was associated with lower ejection fractions (P = 0.026), higher pulmonary artery systolic pressure (P < 0.001), larger left atrial size (P = 0.044), and were more likely to be in New York Heart Association class III or IV than those with an abnormal relaxation pattern (P = 0.007). Both atrial and brain natriuretic peptides correlated inversely with ejection fraction (P < 0.001), fractional shortening (P < 0.001), and positively with pulmonary artery pressure (P = 0.004 and 0.001 respectively). There were no significant correlations between single diastolic parameters and atrial or brain natriuretic peptide levels for the total patient group except between mitral peak A wave velocity and brain natriuretic peptides (r = -0.3, P = 0.01). For those with abnormal relaxation pattern mitral, valve E-wave deceleration time correlated significantly with both atrial and brain natriuretic peptide levels (P < 0.01).

CONCLUSIONS

This study confirms that the restrictive filling pattern of transmitral flow velocity is a marker of more severe heart failure, as indicated by its association with higher atrial and brain natriuretic peptide levels, lower ejection fraction and higher pulmonary artery pressure. Thus, this easily obtained Doppler-derived marker of diastolic dysfunction is useful for identifying those patients with more severe heart failure.

Hyperhomocysteinaemia, Helicobacter pylori, and coronary heart disease

Hyperhomocysteinaemia and Helicobacter pylori infection have recently been implicated in the pathogenesis of coronary artery disease. These two risk factors, though they seem unrelated, could be linked by a deficiency of vitamins and folate caused by chronic gastritis in H pylori infection. This nutritional defect could lead to failure of methylation by 5-methyl-tetrahydrofolic acid and thus exacerbate the accumulation of homocysteine in susceptible patients. Homocysteine is toxic to endothelial cells and results in coronary artery disease.

Dilated cardiomyopathy in Noonan's syndrome

Hypertrophic cardiomyopathy, with myocardial fibre disarray, may occur in 20-25% of cases with Noonan's syndrome. However, dilated cardiomyopathy has not previously been reported. We describe a patient with Noonan's syndrome who presented with typical features of dilated cardiomyopathy with biventricular enlargement and left ventricular ejection fraction of 0.16. Endomyocardial biopsy showed focal interstitial fibrosis and fibre hypertrophy but no disarray. This is the first report in the world literature of an association between Noonan's syndrome and dilated cardiomyopathy. It is possible that this linkage with dilated rather than hypertrophic cardiomyopathy is more common in the Chinese.

Hyperhomocysteinaemia and premature coronary artery disease in the Chinese

OBJECTIVES

To examine the prevalence of hyperhomocysteinaemia and compare it with the classic risk factors and vitamin status in Hong Kong Chinese patients with premature atherosclerotic coronary artery disease.

DESIGN

Case-control study.

SETTING

General hospital and community.

SUBJECTS

Forty five patients (39 males) with significant coronary artery disease confirmed by angiography (32 post myocardial infarction) and 23 healthy volunteers (17 male), all aged less than 55 years.

INTERVENTION

Standardised methionine-loading test.

MAIN OUTCOME MEASURES

Coronary artery disease, risk factors.

RESULTS

More patients than controls had fasting hyperhomocysteinaemia (10/45 v 2/23, P = 0.122), post-methionine hyperhomocysteinaemia (17/45 v 1/23, P = 0.008), and an abnormal response to methionine (15/45 v 1/23, P = 0.015). A history of smoking was more frequent in patients (3/23 v 25/45, P = 0.002). Sixteen of 17 patients with hyperhomocysteinaemia but only nine of 28 with normohomocysteinaemia were smokers (P = 0.0002). Fasting plasma cholesterol concentrations (mean (SD)) were higher in hyperhomocysteinaemic patients (6.41 (1.58) mmol/l) than in controls (5.53 (0.90) mmol/l) (P = 0.042). Serum vitamin B-12 was not reduced and serum folate was higher in hyperhomocysteinaemic patients (35 (4) nmol/l) than normohomocysteinaemic patients (26 (9) nmol/l) (P = 0.009).

CONCLUSIONS

Although the prevalence of hyperhomocysteinaemia in Hong Kong Chinese is similar to that in white subjects, hyperhomocysteinaemia is not an independent risk factor for coronary artery disease and is associated with smoking. This may be of some consequence in view of the change to a more Western diet with more animal protein, and therefore methionine, coupled with a high frequency of cigarette smokers in this region. The causes of the hyperhomocysteinaemia are multifactorial but in this pilot study a deficiency of folate and/or vitamin B-12 did not seem to be one of them.

The effect of transcutaneous electrical nerve stimulation on coronary and systemic haemodynamics in syndrome X

BACKGROUND

Neurostimulation techniques have been shown to be beneficial in patients with angina and syndrome X but the mechanism remains unclear. We examined the effect of transcutaneous electrical nerve stimulation (TENS) on coronary artery blood flow in a group of patients with syndrome X.

METHODS

Coronary blood flows were measured in 11 patients with angiographically normal coronary arteries, positive results from exercise tests and angina (syndrome X) using intracoronary Doppler catheters combined with quantitative coronary angiography.

RESULTS

The mean coronary flow velocity did not increase in any patient during TENS therapy; in fact, there was a fall from 5.2 +/- 2.8 to 4.3 +/- 1.9 cm/s (P = 0.02) and the coronary blood flow index fell from 47 +/- 22 to 38 +/- 16 cm/s per mm2 (P = 0.007). This was associated with a fall in the rate x pressure product from 0.92 +/- 0.22 to 0.83 +/- 0.18 mmHg/min (P = 0.038). The coronary vascular resistance rose from 2.4 +/- 1.1 to 3.0 +/- 1.6 mmHg/cm per s per mm2 (P = 0.041). There were no major changes in the epicardial coronary artery diameter during TENS and there was no significant effect on the response to the cold-pressor test.

CONCLUSIONS

In this group of patients with syndrome X, TENS produced a small but significant fall in coronary artery blood flow associated with a reduction in the rate x pressure product. TENS had no significant effect on coronary vasomotion during sympathetic stimulation by the cold-pressor test. Thus, TENS is unlikely to have a direct effect on coronary artery vasomotion or haemodynamics in syndrome X but reduces the rate x pressure product and thus myocardial oxygen consumption.

Impact of changes in respiratory frequency and posture on power spectral analysis of heart rate and systolic blood pressure variability in normal subjects and patients with heart failure

1. Autonomic dysfunction is a major feature of congestive cardiac failure and may have an important role in determining progression and prognosis. The low-frequency/high-frequency ratio derived from power spectral analysis of heart rate variability has been proposed as a non-invasive method to assess sympatho-vagal balance. However, the effects of different respiratory rates or posture are rarely accounted for, but may be relevant in patients with heart failure in whom clinical improvement is accompanied by a fall in respiratory rate and an increased proportion of the day in the upright position. 2. We have assessed the effect of controlled respiration at different rates (10, 15, 20 breaths/min or 0.17, 0.25 and 0.33 Hz), while supine and standing, on power spectral analysis of heart rate and blood pressure variability in 11 patients with heart failure and 10 normal subjects. 3. Heart rate variance and low-frequency power (normalized units) were reduced in patients with heart failure (absent in six). During controlled breathing while supine, the power of the high-frequency component was significantly greater at 10 breaths/min than at 20 breaths/min in patients with heart failure, whether expressed in absolute units (P = 0.005) or percentage of total power (P = 0.03). 4. On standing, controlled breathing in patients with heart failure produced less change in high-frequency power (P = 0.054), but the low-frequency/high-frequency ratio at lower respiratory rates was reduced (P = 0.05). In normal subjects, as expected, respiratory rate had a highly significant effect on high-frequency power. Also, in normal subjects there was the expected increase in heart rate low-frequency power (P = 0.04) moving from supine to standing with an increase in the low-frequency/high-frequency ratio (P = 0.003), while in the patients with heart failure this was absent, reflecting blunted cardiovascular reflexes. 5. Systolic blood pressure low- and high-frequency components and their ratio were significantly affected by respiration (P < 0.03) and change in posture (P < 0.03) in both patients with heart failure and normal subjects, with a significant increase in the low-frequency/high-frequency ratio (P = 0.03) on standing in patients with heart failure, indicating that autonomic modulation of blood pressure is still operating in heart failure. 6. Thus, respiratory rate and changes in posture have a significant effect on measurements derived from spectral analysis of heart rate and blood pressure variability. Studies that use power spectral analysis as a measure of sympatho-vagal balance should control for these variables.

Lack of association between insertion/deletion polymorphism of the angiotensin-converting enzyme gene and end-stage heart failure due to ischemic or idiopathic dilate cardiomyopathy in the Chinese

Homozygosity for the deletion allele of the angiotensin-converting enzyme gene (DD) has been associated with a variety of cardiovascular diseases, including ischemic and idiopathic dilated cardiomyopathy, in Caucasians. In this study of 104 Chinese patients with end-stage heart failure due to idiopathic dilated or ischemic cardiomyopathy, the DD genotype frequency was low (12% and 11%, respectively) and was not seen more often than in a control group of 183 subjects without cardiac disease (13%). Therefore, in the Chinese, the DD genotype is less common than in Caucasians and does not appear to be associated with the development of either ischemic or idiopathic dilated cardiomyopathy.

Right ventricular diastolic dysfunction in heart failure

BACKGROUND

Left ventricular (LV) diastolic dysfunction is common in heart failure and is an important predictor of prognosis and mortality. Less attention has been paid to right ventricular (RV) diastolic function. In this study, we compared RV diastolic function in a large cohort of patients with heart failure (HF) with two groups: patients with pulmonary hypertension and normal LV function (the PHT group) and normal subjects.

METHODS AND RESULTS

Transtricuspid and pulmonary artery flow were assessed by two-dimensional Doppler echocardiography at maximum inspiration and expiration in 185 subjects: 114 symptomatic HF patients (ejection fraction < 0.5), 31 PHT patients (pulmonary artery systolic pressure > 40 mm Hg), and 40 normal subjects. A subset was matched for age and heart rate. The results showed a high prevalence of RV diastolic abnormalities: HF patients had lower tricuspid E-A ratios, lower peak E-wave velocity, and prolonged RV isovolumic relaxation time (all P< .0001). Tricuspid E-wave deceleration time was significantly shorter only in those who had an LV restrictive filling pattern. The PHT group had similar findings. Compared with a normal range, more than half of the patients had lower tricuspid E-A ratios (HF, 55%; PHT, 69%), and 61% of HF and 58% of PHT patients had a prolonged RV isovolumic relaxation time. In the PHT group, RV diastolic parameters (E-wave deceleration time, E-A ratio, and isovolumic relaxation time) correlated significantly with pulmonary artery systolic pressure (P< .05). In the HF group, however, only tricuspid E-wave deceleration time correlated significantly with pulmonary artery systolic pressure, and HF patients with normal pulmonary artery systolic pressures had significantly lower tricuspid E-A ratios and prolonged RV isovolumic relaxation times compared with normal subjects. A close correlation existed between individual RV and LV diastolic parameters, suggesting that LV diastolic dysfunction may directly affect RV function, but there was no relation between LV size or systolic function and RV diastolic dysfunction.

CONCLUSIONS

RV diastolic function is frequently abnormal in HF patients, and this is not related to elevated pulmonary artery systolic pressure alone, although high pulmonary artery pressure by itself also is associated with impaired RV diastolic function. Assessment of the role of right ventricular diastolic function in determining the symptoms and prognosis of heart failure is warranted.

Autoimmunity to alpha myosin in a subset of patients with idiopathic dilated cardiomyopathy

OBJECTIVE

To use an enzyme linked immunoassay (ELISA) technique to assess frequency and disease specificity of anti-alpha-myosin antibodies in patients with dilated cardiomyopathy and their relatives.

METHODS

Evaluation was performed on sera (dilution 1/320) from 123 consecutive patients with dilated cardiomyopathy (WHO criteria) (age 42 (SD 14) years), 252 of their relatives (35 (17) years), 203 healthy controls (45 (16) years), and 92 patients with ischaemic heart disease (63 (11) years).

RESULTS

Abnormal antibody levels were commoner in patients with dilated cardiomyopathy (25, 20%) than in ischaemic heart disease (4, 4%), or normal controls (4, 2%, P = 0.001). Forty one (16%) of the relatives had abnormal results compared to the controls (4, 2%, P < 0.001) and antibodies were detected in 20 (38%) of pedigrees. Relatives from non-familial kindreds had higher antibody levels than those with familial disease (P << 0.001), and higher antibody levels were identified in 53 relatives of probands who had abnormal results compared to 116 relatives for whom the proband had a normal result (0.37 (SEM 0.02) v 0.22 (0.01); P < 0.001).

CONCLUSIONS

The finding of anti-alpha-myosin antibodies in 20% of patients with dilated cardiomyopathy, in 16% of their asymptomatic relatives, and in 38% of families (particularly those with non-familial disease and where proband also had an abnormal result) provides additional evidence for autoimmunity against alpha myosin in a subset of patients.

Effect of low dose beta blockers on atrial and ventricular (B type) natriuretic factor in heart failure: a double blind, randomised comparison of metoprolol and a third generation vasodilating beta blocker

OBJECTIVES

This study examines the acute effects of two differing beta adrenergic blocking agents (metoprolol and a third generation vasodilating beta blocker) on plasma concentrations of atrial natriuretic factor (ANF), brain (ventricular) natriuretic factor (BNF), and haemodynamic variables in patients with heart failure.

SETTING

University teaching hospital.

METHODS

20 patients with impaired left ventricular systolic function [ejection fraction 32 (SEM 2.3)%] were randomised in a double blind manner to receive either oral metoprolol 6.25 mg twice daily or celiprolol 25 mg daily. Haemodynamic variables were evaluated by Swan-Ganz pulmonary artery catheter over 24 hours. ANF and BNF concentrations were measured at baseline, 5 h, and 24 h by radioimmunoassay.

RESULTS

At baseline ANF and BNF concentrations were considerably raised compared to the normal range. Treatment with metoprolol caused ANF to rise further to 147% of the basal level at 5 h (P = 0.017) and 112% at 24 h (P = 0.029). This was associated with a small but non-significant rise in pulmonary capillary wedge pressure. Cardiac output and systemic vascular resistance were unchanged at 24 h. In contrast, after celiprolol ANF fell to 90% of basal levels at 5 h and to 74% of basal level at 24 h (P = 0.019), associated with a small but non-significant fall in pulmonary capillary wedge pressure [-3.3 (2.7) mm Hg] and systemic vascular resistance, and rise in cardiac output from 3.2 (0.2) to 4.0 (0.4) l/min (P = 0.04). BNF concentrations rose to 112% of baseline at 5 h (P = 0.09) after metoprolol but fell slightly, to 91% of baseline values, after celiprolol (NS).

CONCLUSIONS

Metoprolol, even in very low doses (6.25 mg), produced a rise in ANF and BNF, although minimal haemodynamic changes were detected. In contrast, a vasodilating beta blocker was associated with a significant fall in ANF and BNF and a small rise in cardiac output. This study confirms both the advantages of vasodilating beta blockers over metoprolol for initial treatment of heart failure and the usefulness of ANF and BNF measurements for the assessment of drug effects in heart failure compared to traditional haemodynamic measurements.

The aetiology of heart failure in the Chinese population of Hong Kong--a prospective study of 730 consecutive patients

Heart failure is a common and serious condition in many parts of the world and is a frequent cause for hospital admission in the Chinese population of Hong Kong. There is no published information on the epidemiology of heart failure in this community or from mainland China. Therefore, a prospective study of consecutive patients admitted with the clinical diagnosis of heart failure has been carried out to identify the main risk factors or possible causes, and other clinical data. Seven-hundred thirty consecutive patients with cardiac failure were identified and studied. Standard clinical criteria were used for diagnosis and identification of the main or most likely aetiologies and echocardiography was done in 30%. The data analysis of the 730 patients showed the following. The majority were females (56%) and the prevalence of heart failure increased with age (mean age 73.5 +/- 11.7 years) with 76% of the women > 70 years old. In contrast, the men were younger with 40% < 70 years old. The main identifiable risk factors were hypertension (37%), ischemic heart disease (31%), valvular heart disease (15%), cor pulmonale (27%), idiopathic dilated cardiomyopathy (4%), and miscellaneous (10%). In women, hypertension was the commonest cause at all ages but in men aged < 70 years ischemic heart disease was equal in frequency to hypertension (36% and 35%, respectively). Twenty-one percent had diabetes compared to a community rate of 10% for this age group (odds ratio 2.25, P < 0.0001). There was considerable overlap between diabetes, hypertension and ischemic heart disease. The estimated incidence rate was 3.8/1000 women and 3.0/1000 men aged > 45 years old.(ABSTRACT TRUNCATED AT 250 WORDS)

Dual chamber pacing: how many patients remain in DDD mode over the long term?

OBJECTIVE

DDD pacing is better than VVI pacing in complete heart block and sick sinus syndrome but is more expensive and demanding. In addition, some patients have to be programmed out of DDD mode and this may have an important impact on the cost-effectiveness of DDD pacing. The purpose of this study was to determine how many patients remain in DDD mode over the long term (up to 10 years).

DESIGN

A retrospective analysis of the outcome over 10 years of consecutive patients who had their pacemakers programmed initially in DDD mode.

SETTING

A district general hospital.

PATIENTS

249 patients with DDD pacemakers. Sixty two patients (24.9%) had predominantly sick sinus syndrome and 180 (72.3%) had predominantly atrioventricular conduction disease. Mean (range) complete follow up for this group of patients was 32 months (1-10 years).

RESULTS

Cumulative survival of DDD mode was 83.5% at 60 months. Atrial fibrillation was the commonest reason for abandonment of DDD pacing. Atrial fibrillation developed in 30 patients (12%), with atrial flutter in three (1.2%). Loss of atrial sensing or pacing, pacemaker mediated tachycardia, and various other reasons accounted for reprogramming out of DDD mode in eight patients (3.2%). Overall, an atrial pacing mode was maintained in 91% and VVI pacing was needed in only 9%.

CONCLUSIONS

With careful use of programming facilities and appropriate secondary intervention, most patients with dual chamber pacemakers can be maintained successfully in DDD or an alternative atrial pacing mode until elective replacement, although atrial arrhythmia remains a significant problem. There are no good reasons, other than cost, for not using dual chamber pacing routinely as suggested by recent guidelines and this policy can be achieved successfully in a district general hospital pacing centre.

The effect of transcutaneous electrical nerve stimulation (TENS) on autonomic cardiovascular reflexes

Transcutaneous electrical nerve stimulation (TENS) has been shown to have an anti-ischaemic effect in patients with angina and peripheral vascular disease that appears to be additional to any analgesic action. The mechanism for this anti-ischaemic effect is not known but it is possible that TENS interferes with the autonomic responses to ischaemia. To determine if TENS has any direct action on autonomic reflexes we have assessed the effect of high frequency TENS on a variety of standard tests of autonomic cardiovascular reflexes in 10 normal subjects. Tests were done on four consecutive days at the same time and TENS therapy or placebo was randomly allocated on 2 days each. Results of the tests were assessed by one person 'blinded' to the randomization order. These showed that TENS was associated with a significant reduction in the rise of the diastolic blood pressure (21.8 +/- 2.3 v. 17.6 +/- 17 mmHg; p < 0.05) during isometric exercise, using sustained Handgrip. There was no significant effect discernible on the changes of heart rate and blood pressure during the Valsalva manoeuvre, cold face stimulus or head-up tilt. Transcutaneous electrical nerve stimulation appears, therefore, to have a mild inhibitory action on those reflexes mediated predominantly by the sympathetic nervous system and this is more apparent when the stimulation may be greater, as during isometric exercise.

Sustained-release isradipine compared with spirapril in the treatment of elderly patients with isolated systolic hypertension

The benefits of treating isolated systolic hypertension (ISH) have been established, but the most appropriate choice of drug is still uncertain. For this reason, a sustained-release formulation of isradipine was compared with spirapril in a double-blind randomized study in elderly Chinese patients with ISH. The dosage was titrated if necessary after 4 weeks of treatment. The reduction in systolic/diastolic blood pressure after 8 weeks was similar for both treatments--20/10 mm Hg with isradipine versus 24/6 mm Hg with spirapril--measured in the supine position. There were no orthostatic symptoms and both treatments were well tolerated.

Spinal electrical stimulation for intractable angina--long-term clinical outcome and safety

Spinal cord electrical stimulation is an alternative therapy for patients with chronic pain syndromes including angina. Although it has been shown to produce symptomatic relief and reduce ischaemia, doubts remain about its long-term safety. We report here for the first time the results of a follow-up study over a period of 62 months, mean 45 months (range 21-62), of 23 patients who had stimulator units implanted for intractable angina unresponsive to standard therapy. Symptomatic improvement was good and persisted in the majority with a mean (SD) change of NYHA grade from 3.1 (0.8) pre-operatively to 2.0 (0.9) (P < 0.01) immediately after operation and 2.1 (1.07) at the latest follow-up. GTN consumption fell markedly. Mean (SEM) treadmill exercise time increased from 407 (45) s with the stimulator off to 499 (46) s with the stimulator on (P < 0.01). Forty-eight hour ST segment monitoring in those with bipolar leads showed a reduction of total number and duration of ischaemic episodes. There were three deaths, none of which were sudden or unexplained and this mortality rate is acceptable for such a group of patients. Two patients had a myocardial infarction, which was associated with typical pain and not masked by the treatment. Complications related to earlier lead designs were frequent. This study confirms that spinal electrical stimulation is an effective and safe form of alternative therapy for the occasional patient whose angina is unresponsive to standard therapies.

Effects of spinal cord stimulation on myocardial ischaemia during daily life in patients with severe coronary artery disease. A prospective ambulatory electrocardiographic study

BACKGROUND

Spinal cord stimulation (SCS) may be a useful additional therapy for pain in patients with therapeutically refractory angina pectoris. But doubts remain about whether it also relieves ischaemia.

METHODS

Indices of ischaemia were studied with and without SCS in 10 patients with otherwise intractable angina and evidence of myocardial ischaemia on 48 h ambulatory electrocardiographic (ECG) recording. Primary end points assessed by 48 h ECG recordings were total ischaemic burden, number of ischaemic episodes, and duration of ischaemic episodes. In addition, symptoms were assessed by a diary of glyceryl trinitrate intake and angina attacks.

RESULTS

During SCS the total ischaemic burden of the entire group was significantly reduced from a median of 27.9 (1.9-278.2) before SCS to 0 (0-70.2) mm x min with SCS (p < 0.03). In six out of the 10 patients there was no myocardial ischaemia during 48 h ambulatory ECG monitoring with SCS. The number of ischaemic episodes was reduced from a median of 3 (1-15) before SCS to 0 (0-9) with SCS (p < 0.04). The duration of ischaemic episodes decreased from a median of 20.6 (1.7-155.4) min before SCS to 0 (0-48.3) min with SCS (p < 0.03). This was accompanied by a significant improvement in symptoms with a reduction in daily glyceryl trinitrate intake from a median of 3.0 (0-10) before SCS to 0.3 (0-10) tablets per 48 h (p < 0.02) and a decrease in the frequency of anginal attacks from a median of 5.5 (2-14) before SCS to 1.0 (0-10) per 48 h with SCS (p < 0.03).

CONCLUSIONS

SCS not only reduced symptoms but also myocardial ischaemia. Therefore, SCS appears to be both a safe and an effective therapy for patients with refractory angina.