The variable effects of angiotensin converting enzyme inhibition on myocardial ischaemia in chronic stable angina

The effect of angiotensin converting enzyme inhibition on myocardial ischaemia was studied in 12 normotensive patients with chronic stable angina and exercise induced ST segment depression. The study was randomised, double blind, placebo controlled, and crossover with treatment periods of two weeks. Enalapril was used to inhibit angiotensin converting enzyme. Assessment was by angina diaries and maximum symptom limited treadmill exercise tests. The results for the whole group showed a significant reduction in systolic blood pressure at rest and at peak exercise. Mean total exercise duration was 466 s (95% confidence interval 406 to 525) when the patients were taking placebo and 509 s (436 to 583) when they were taking enalapril. Four patients prolonged their total exercise time (mean 450 to mean 591 s) by more than 20%. Two patients, however, developed ischaemia earlier on exercise and reduced their total exercise duration (mean 490 to mean 390 s). Although angiotensin converting enzyme inhibition tended to reduce myocardial ischaemia in the group as a whole, some patients improved while others deteriorated. Thus the effects of enalapril are variable and this may have important implications when enalapril is used to treat heart failure in patients with underlying severe ischaemic heart disease.

Diurnal variation of pulmonary artery pressure in chronic heart failure

Variation in pulmonary artery pressure has important consequences for the interpretation of isolated pressure measurements in patients with chronic heart failure. To investigate the nature of diurnal variation in pulmonary artery pressure in chronic heart failure, eight angina-free men (aged 50-72 years) with treated chronic heart failure caused by ischaemic heart disease underwent continuous ambulatory pulmonary artery pressure recording by a transducer tipped catheter. The mean (1 SD) daytime pulmonary artery pressure was 29.6 (5.0) mm Hg systolic and 13.7 (5.6) mm Hg diastolic. The mean change in pressure from day to night was +5.1 (3.2) mm Hg systolic and +3.8 (1.7) mm Hg diastolic; and the mean change from standing to lying +9.3 (2.3) mm Hg systolic and +6.4 (2.1) mm Hg diastolic. In six of the eight patients there was considerable rise in pulmonary artery pressure at night, but in the two patients with the most severe symptoms there was no nocturnal rise. In patients with chronic heart failure, nocturnal pulmonary artery pressure is not determined by postural change alone. But interpretation of isolated pulmonary artery pressure measurements must take the posture of the patient into account.

Unpredictable zero drift in intravascular micromanometer tipped catheters during long term pulmonary artery pressure recording: implications for catheter design

Zero drift may be a cause of imprecision when micromanometer tipped catheters are used for intravascular pressure measurement over long periods of time. Drift of only a few mm Hg may represent a significant error when accurate recording of low vascular pressures is required. To overcome this problem a micromanometer tipped catheter has been modified so that it can be calibrated easily while it is in the circulation. Laboratory testing has demonstrated that when zero drift occurs this intravascular "reference calibration" is a valid linear function of true zero (r = 0.999). As the sensitivity of the catheter is unaffected by zero drift, it is possible to measure pressure accurately by compensating for this zero drift. During dynamic testing of two catheters, there was a mean net drift over 24 h of -0.54 mm Hg. Clinical evaluation of the catheter was undertaken in the human pulmonary circulation in eight patients (two for 48 h, five for 24 h and one for 8 h). In contrast to the laboratory findings, over the first 4 h after catheterisation there was a phase of rapid zero drift: the net drift was -1.9 (SD 3.3) mm Hg with a range of drift of 5.5 (7.4) mm Hg. Subsequently there was gradual drift: the net drift between 4 and 24 h was -0.44 (2.1) mm Hg with a range of drift of 2.8(1.0) mm Hg; and the net drift between 24 and 48 h was 3.7(2.1) mm Hg with a range of drift of 4.1(1.9) mm Hg. During long term intravascular pressure measurement with micromanometer tipped catheters, zero drift may occur unpredictably and should be quantified.

Digital and palmar dermatoglyphics in dementia of the Alzheimer type

Digital and palmar dermatoglyphics were examined in 29 men and 27 women with dementia of the Alzheimer type (DAT) and 112 age-, sex-, and racial group-matched controls. Female patients had significantly (p less than 0.05) more accessory triradii and complete Sydney creases than controls; no dermatoglyphic differences were detected in the males. Separating the patients by age of onset prior to or after age 65 years did not help differentiate patients from controls by dermatoglyphic profile. This study failed to confirm either the previously reported dermatoglyphic differences between DAT patients and controls or the reported similarity of the dermatoglyphic pattern of DAT to that of Down syndrome patients.

Perforation thresholds and safety factors in in vivo coronary laser angioplasty

Laser angioplasty can cause early (acute perforation) or late (stenosis or aneurysm) complications. To find how much intravascular laser energy can be delivered via a 100 microns core optical fibre passed down a balloon angioplasty catheter without causing angiographic abnormalities up to 10 days later, argon laser energy was delivered percutaneously under radiographic screening to the coronary circulation of 12 normal closed chest dogs. With the balloon inflated, sequential laser pulses were delivered to the same site. Angiograms were recorded before, immediately, and again at one week, after laser delivery. There were two laser-induced perforations (both fatal). Mechanical perforation with the 100 microns fibre occurred four times, but there were no haemodynamic sequelae. To find the acute perforation threshold of similar sized arteries to energy delivered via the bare 100 microns core fibre, the tip of which was held in contact with the luminal surface, 32 argon laser pulses were delivered transluminally in vivo to separate sites in normal rabbit iliac and canine coronary arteries. The acute perforation threshold with energy delivered via the angioplasty catheter lay between 6 and 10 J and that without the balloon angioplasty catheter lay between 3 and 4 J. After delivery of up to 6 J via a balloon angioplasty catheter, there were no angiographic abnormalities at one week. Fibre optic transluminal delivery of laser energy may improve the primary success rate of, and perhaps widen the indications for, coronary angioplasty.

Smoking, catecholamines, and the ischemic myocardium

Catecholamine stimulation increases the heart rate and the force of cardiac contraction. Cardiac output then increases, with a decrease occurring in total peripheral resistance due to smooth muscle dilation in the vascular beds of the muscle and heart, though there is constriction of the skin and viscera; this leads to a net decrease in total peripheral resistance. Consequently, systolic pressure rises and diastolic pressure falls. The net effect is to increase myocardial oxygen demand. Smoking stimulates catecholamine secretion and may therefore be expected to have detrimental effects in patients with angina. In a double-blind study of ten patients with stable angina pectoris treated with nifedipine, propranolol, and atenolol, smoking was found to have direct and adverse effects on the heart and to interfere with the efficacy of all three antianginal drugs, but with that of nifedipine the most. Differences between the two beta blockers may be related, at least in part, to the known different metabolic pathways of these drugs.

Effects of intracoronary isosorbide dinitrate during acute myocardial ischaemia: a study during angioplasty

The effects of isosorbide dinitrate on acute myocardial ischaemia were studied in 19 patients during coronary angioplasty. The duration of balloon inflation to the onset of ST segment depression was increased by the administration of intracoronary isosorbide dinitrate from (mean +/- SEM) 13 +/- 2 to 20 +/- 2 s (48%) (P less than 0.01) and the duration to 1 mm ST segment depression increased form 23 +/- 2 to 29 +/- 3 s (28%) (P less than 0.01). Systolic blood pressure fell from 118 +/- 3 to 111 +/- 4 mmHg but there was no change in intracoronary distal occlusion pressure. Thus during coronary occlusion isosorbide dinitrate prolongs the time to the onset of myocardial ischaemia.

Treatment of angina pectoris with nifedipine: a double blind comparison of nifedipine and slow-release nifedipine alone and in combination with atenolol

The relative efficacy of nifedipine and slow-release nifedipine (Adalat Retard) in the treatment of stable exertional angina pectoris was evaluated in a double blind randomised crossover study in eight patients on no concomitant antianginal treatment and in 10 patients who were additionally on atenolol. Patients were assessed by angina diaries and exercise testing. Slow-release nifedipine was as effective as nifedipine in the treatment of these patients, both alone and in combination with atenolol.

Haemodynamic changes during silent myocardial ischaemia

The haemodynamic significance of asymptomatic ST segment depression has been assessed in patients with coronary artery disease by direct measurement of left ventricular end-diastolic pressure (LVEDP) or pulmonary artery end-diastolic pressure (PADP). Both techniques have demonstrated a rise in pressure during such episodes of ST segment depression recorded in the Coronary Care Unit, cardiac catheter and exercise laboratories or during ambulant activity. Thus silent or asymptomatic ST segment depression is associated with similar haemodynamic changes to that seen during angina pectoris and has considerable therapeutic implications.

Toe and plantar dermatoglyphics in adult American Caucasians

The scarcity of information on control data of toe and plantar dermatoglyphics led us to undertake this study of adult American Caucasians. Toe and sole prints of 168 male and 83 female participants of the Baltimore Longitudinal Study of Aging were analyzed. Toe pattern frequencies demonstrate that fibular loops are the most prevalent pattern on the toes in both males and females. Pattern distribution by digit shows that arches are most often located on the fifth toe while whorls are found with greatest frequency on the third toe. Plantar pattern frequencies indicate that the most common pattern found in the hallucal area is the distal loop. Open fields are frequently found in the II and IV interdigital areas while distal loops are prevalent in the III area. These results are compared to the finger and palmar patterns of the same individuals. The distribution of patterns on the toes and fingers of the same individuals appear to be quite different. Population comparisons did not demonstrate a clear racial difference in the toe pattern frequencies or in the plantar areas.

Hypertension and the ischaemic myocardium

Hypertension and ischaemic heart disease often co-exist. Recent studies, using ambulatory ST-segment and haemodynamic monitoring, have shown that myocardial ischaemia may not necessarily be accompanied by angina pectoris. Unless transient myocardial ischaemia is actively sought it may, therefore, be missed and this may have important prognostic and therapeutic implications. Studies investigating the use of beta-blockers, calcium antagonists and nitrates in angina pectoris have shown that these agents have an equal effect on painless as opposed to painful myocardial ischaemia. While there are no currently completed studies demonstrating the prognostic implication of silent ischaemia in stable angina, it is well known that approximately one-quarter of all myocardial infarctions occur without chest pain. Recent investigation in unstable angina showed that silent ischaemia was an important predictor of future coronary events.

Choice of therapy in chronic ischemic heart disease

The choice of therapy in chronic ischemic heart disease depends on identifying the underlying mechanism. Ambulatory monitoring provides a means of identifying those patients in whom increased myocardial oxygen demand is the most important mechanism and who will respond to a beta blocker. In contrast, those patients with coronary spasm are best treated with a calcium antagonist. The history of angina pectoris and the time of onset may, in itself, be misleading. Detailed ambulatory monitoring studies show that nocturnal angina is frequently due to increased myocardial oxygen demand and in such circumstances should be treated by careful control of the heart rate using a beta blocker without intrinsic sympathomimetic activity. Other factors that will influence the choice of medical therapy must be considered. Smoking is particularly important because it not only acts detrimentally in terms of increased myocardial oxygen demand, but may also interfere with the metabolism of those antianginal agents that are metabolized in the liver. The importance of silent myocardial ischemia has been emphasized recently, and studies using ambulatory pulmonary artery monitoring have shown that silent ischemic episodes have the same significance in terms of hemodynamic effects as painful ischemic episodes. The therapeutic and prognostic implications of these findings need to be explored.

Medical treatment of patients with severe exertional and rest angina: double blind comparison of beta blocker, calcium antagonist, and nitrate

The role of medical treatment of patients who had resting nocturnal angina as well as exertional angina was investigate. The effects of atenolol 100 mg a day, nifedipine 20 mg three times a day, and isosorbide mononitrate 40 mg twice a day were investigated in a double blind, triple dummy randomised study. Nine patients with coronary artery disease, early positive exercise tests, and transient daytime and nocturnal ambulatory ST segment changes were initially assessed off all antianginal medication. They were then treated with each drug for three five day periods. Angina diaries were reviewed and maximal treadmill exercise tests and 48 hour ambulatory ST segment monitoring were performed at the end of each treatment period. Resting and exercise heart rate and blood pressure were significantly lower on atenolol than on either isosorbide mononitrate or nifedipine. The duration of exercise to 1 mm ST segment depression was significantly greater on atenolol than on isosorbide mononitrate. Only one patient had an improvement in exercise tolerance on nifedipine that was greater than the improvement on atenolol; this patient had single vessel disease. The total number and duration of episodes of ST segment change during ambulatory monitoring were significantly lower with atenolol than on either isosorbide mononitrate or nifedipine. Nocturnal ST segment changes were abolished in six patients on atenolol, in six patients on nifedipine, and in five patients on isosorbide mononitrate. When nocturnal ST segment changes occurred, their frequency was reduced with all three drugs. Pain was abolished in four patients on atenolol and pain relief was significantly better on atenolol than on isosorbide mononitrate. There was no significant difference in pain relief between isosorbide mononitrate and nifedipine. Thus beta receptor blockade with atenolol was the most effective means of reducing myocardial ischaemia both during exercise and at rest at night without causing deterioration in any patient. Nocturnal myocardial ischaemia in patients with severe coronary artery disease can be effectively treated with beta receptor antagonists and vasodilators.

Diurnal variation in left ventricular function: a study of patients with myocardial ischaemia, syndrome X, and of normal controls

Angina can occur in the early morning. The mechanism of this is unclear and both haemodynamic changes and coronary artery spasm may be important. The purpose of this study was to investigate the diurnal variation in pulmonary artery diastolic pressure (an indirect measure of left ventricular filling pressure) in six normal subjects, 18 patients with coronary artery disease, five with variant angina, and six with syndrome X. A transducer tipped catheter and a simple recording system were used to record ambulatory pulmonary artery diastolic pressure for 24 hours. Variation in pulmonary artery diastolic pressure was related to the timing of episodes of ST segment depression and elevation by simultaneously recording a frequency modulated electrocardiogram. Episodes of ST segment change occurred predominantly in the early morning (midnight to 6 am) in variant angina (eight out of 14 episodes) whereas in syndrome X all episodes were recorded during the day. In coronary artery disease both painful and painless episodes were distributed throughout the day, with 10 out of 67 episodes occurring between midnight and 6 am. A similar diurnal variation in pulmonary artery diastolic pressure was seen in the groups--that is, values were low during the day and higher at night, with the maximum values between midnight and 6 am. The 24 hour median pulmonary artery diastolic pressure was higher in patients with coronary artery disease than in the control group and those with syndrome X. The finding that pulmonary artery diastolic pressure, and therefore left ventricular end diastolic pressure, is greatest in the early morning may represent the background haemodynamic state in which other factors lead to myocardial ischaemia during these hours.

Should we treat silent ischaemic?

24-hour ambulatory monitoring of the ST segment in patients with angina has shown that ST segment depression may be accompanied by angina pectoris, but it occurs equally often without any symptoms. Approximately half of all episodes of ST segment depression are accompanied by chest pain. Doubt has been expressed as to the significance of ST segment changes that occur in the absence of chest pain, but haemodynamic studies and nuclear imaging have shown that such changes are accompanied by alterations in left ventricular filling pressure. Ambulatory pulmonary artery monitoring has also shown that silent ST segment depression is accompanied by a significant increase in pulmonary artery diastolic pressure, and this does not differ from painful episodes of ST segment depression. Studies using ambulatory monitoring have shown that antianginal drugs are capable of reducing the frequency of ST segment depression accompanied by pain. We have recently performed studies investigating the use of antianginal medications; i.e. beta-blocking drugs with and without sympathomimetic activity, alpha-beta-blocking drugs, calcium antagonists and nitrates in the treatment of both painful and painless ST segment depression. These studies have shown that the effect of these drugs on painless episodes is similar to their effect on painful episodes of myocardial ischaemia. Although the prognostic implications of silent ischaemia and the importance of these therapeutic findings are unknown, it is well known that approximately one-quarter of all myocardial infarctions occur without chest pain. Moreover, recent investigations in unstable angina show that silent myocardial ischaemia is an important predictor of future coronary events.

The haemodynamic significance of asymptomatic ST segment depression assessed by ambulatory pulmonary artery pressure monitoring

A transducer-tipped catheter with simultaneous frequency modulated electrocardiograms and a miniaturised tape recorder was used to record ambulatory pulmonary artery pressure for 24-48 hours in 19 men (mean age 57.7) with clinical and angiographic evidence of coronary artery disease. Sixty seven episodes of ST segment depression (greater than 1 mm) were recorded. Thirty five were accompanied by pain of which six occurred at night; in 34 pulmonary artery diastolic pressure rose significantly. In all but two of the 32 episodes of painless ST segment depression (four of which were at night) there was a significant rise in pulmonary artery diastolic pressure. No such rise was found in six normal subjects during exertion. ST segment changes tended to occur before (24 episodes) or at the same time (27 episodes) as changes in pulmonary artery diastolic pressure. ST segment depression followed an increase in pulmonary artery diastolic pressure in only 13 episodes. The times to maximum ST depression and maximum pulmonary artery diastolic pressure rise were similar. Painful and painless ST segment depression could not be distinguished on the basis of the configuration of the ST segment or in terms of the changes in the pulmonary artery diastolic pressure.

The haemodynamic response to myocardial ischaemia in ambulant patients with variant angina

The haemodynamic response to myocardial ischaemia in patients with variant angina during ambulatory activity is unknown. Ambulatory pulmonary artery pressure monitoring with a transducer tipped catheter and simultaneous frequency modulated electrocardiograms was used to assess changes in left ventricular function in five male patients (mean age 51.8 years) during variant angina; four patients had coronary artery stenosis and one had normal coronary arteries. Two hundred and seventy hours of ambulatory recordings were analysed. Twenty episodes (12 painful, 8 silent) of ST segment change greater than 1 mm occurred. Episodes tended to occur more frequently in the early morning hours. Six episodes of painful ST elevation were associated with a rise in pulmonary artery diastolic pressure. In the remaining episodes ST segment elevation was of shorter duration and there was no rise in pulmonary artery diastolic pressure. Pain was usually a late feature. Silent ST segment elevation occurred at rest and pulmonary artery diastolic pressure increased in all but one episode. Silent exertional ST segment depression was associated with a greater increase in pulmonary artery diastolic pressure than that seen during ST segment elevation. ST segment depression preceded or followed ST segment elevation in two episodes. The onset of ST segment elevation nearly always preceded the onset of a rise in pulmonary artery diastolic pressure. Ergometrine maleate provocation produced a rise in pulmonary artery diastolic pressure in three patients. In one there was no response to 1000 micrograms but spontaneous episodes of ST segment elevation were recorded during ambulatory monitoring. Treadmill exercise resulted in both ST segment elevation and depression with a similar haemodynamic response during both types of electrocardiographic change. When there is important coronary artery disease in two or more vessels ST segment changes may occur in different territories during treadmill exercise and during spontaneous episodes. Ambulatory pulmonary artery diastolic pressure monitoring is a useful technique for the investigation of variant angina.

The incidence and morphology of ischaemic ventricular tachycardia

Ventricular arrhythmias are a frequent cause of sudden death in patients with coronary artery disease. The incidence and relationship of ventricular tachycardia to periods of myocardial ischaemia in these patients has not been fully investigated. Ambulatory ST-segment monitoring was performed in 100 consecutive patients with chest pain, of whom 74 had significant coronary artery disease. Recordings were analysed for ST-segment changes and episodes of ventricular tachycardia (greater than 3 beats, rate greater than 100 beats min-1). None of the 26 patients with normal coronary arteries, one of the 22 patients (4.5%) with single vessel disease, one of the 22 patients (4.5%) with double vessel disease and four of the 30 patients (13%) with triple vessel disease, had episodes of non-sustained ventricular tachycardia. Four of these six patients had episodes of reversible ST-segment change but ventricular tachycardia was related to these episodes in only two patients. These two patients had multiple episodes of tachycardia which occurred after the onset of ST-segment change and terminated before the ST-segment returned to baseline; they occurred in clusters with a mean of 12 episodes in each cluster. ST-segment change did not follow episodes of ventricular tachycardia in any patient. The number of ventricular complexes in each episode varied between three and 24 beats and were uniform in three of the six patients. The mean heart rate before the onset of tachycardia was 79 +/- 8 beats per minute and the rate of tachycardia had a mean of 170 +/- 34 beats a minute. Less than 10% of the episodes had a prematurity index of less than 1.(ABSTRACT TRUNCATED AT 250 WORDS)

Magnetic resonance assessment of aortic and mitral regurgitation

Magnetic resonance imaging provides an accurate method for the measurement of left and right ventricular volume. The ratio of left ventricular stroke volume to right ventricular stroke volume was calculated from contiguous transverse magnetic resonance images and was used to measure the severity of regurgitation in 18 patients with aortic regurgitation and 10 with mitral regurgitation. Cardiac anatomy was well demonstrated, allowing an assessment of relative chamber volumes and associated abnormalities, although valve abnormality was not well seen. There was a weak correlation between magnetic resonance measurements of left ventricular end diastolic volume and stroke volume ratio. The stroke volume ratio differed significantly in four groups with increasing angiographic severity of regurgitation, and all but the group with trivial regurgitation differed significantly from normal. There was good correlation between magnetic resonance and radionuclide measurements of left ventricular ejection fraction and stroke volume ratio, although the stroke volume ratio was consistently overestimated by radionuclide ventriculography. Correlation was less good for the right ventricular ejection fraction, which was underestimated by radionuclide ventriculography. It is concluded that magnetic resonance imaging provides valuable information in patients with valvar regurgitation, and serves as a suitable standard by which to judge conventional techniques.

Value of the bipolar lead CM5 in electrocardiography

Only bipolar lead recording are available during ambulatory monitoring. Their sensitivity in detecting ST segment changes in relation to standard electrocardiographic leads is not known. The magnitude and direction of ST segment changes in the bipolar lead CM5 were compared with those in standard electrocardiographic leads in patients during exercise testing and percutaneous transluminal coronary angioplasty. Thirty patients with coronary artery disease were studied during exercise tests in which ST segment depression (greater than 0.5 mm) occurred in one or more standard electrocardiographic leads and 13 patients were studied during angioplasty that resulted in ST segment change in one or more leads (I, II, III, V2, V5, and CM5). Lead CM5 was the most sensitive lead (93%) during exercise testing and also showed the greatest magnitude of ST segment change below the isoelectric line in 93% of the patients. Only two patients, one with ST segment elevation in inferior leads and one with changes restricted to septal leads, had no ST segment depression in lead CM5. When ST segment shift from the baseline electrocardiogram was measured the magnitude of depression was greatest in lead CM5 in only 63% of the patients. During angioplasty of the left anterior descending coronary artery, lead CM5 showed ST segment depression in seven patients, ST segment elevation in two, and a biphasic response in one. Two of the three patients with balloon inflation in right coronary artery developed ST segment elevation in lead CM5. Thus lead CM5 is a reliable lead for detecting subendocardial ischaemia experienced during everyday activities in anginal patients. During total occlusion of coronary arteries (as in variant angina or myocardial infarction) lead CM5 commonly shows ST segment depression and changes due to right coronary artery occlusion may not be detected.

Amyotrophic lateral sclerosis and parkinsonism-dementia on Guam: a 25-year prospective case-control study

Familial and genetic studies of high-incidence amyotrophic lateral sclerosis and parkinsonism-dementia among the Chamorro people of Guam were initiated in 1958 with the establishment of a prospective case-control registry. The major objective of this registry was to determine if first-degree relatives and spouses of patients with amyotrophic lateral sclerosis or parkinsonism-dementia had an increased risk of developing disease compared with relatives of nonaffected controls individually matched for age, sex, and village. At the time of its closing in 1963, the registry included 126 patients (77 with amyotrophic lateral sclerosis, 42 with parkinsonism-dementia, and seven with both amyotrophic lateral sclerosis and parkinsonism-dementia) and an equal number of controls; 994 living first-degree relatives (parents, siblings, and offspring) of patients and 1,218 of controls; and 88 living spouses of patients and 101 of controls. The present analysis of the 25-year follow-up study (1958-1983) demonstrated a significantly increased risk of developing amyotrophic lateral sclerosis or parkinsonism-dementia among parents, siblings, and spouses of patients, but not among relatives of controls. Offspring of both patients and controls showed no significantly increased risk of developing disease. The increased risk among spouses of patients and the lack of increase among their offspring, together with recent histochemical findings, support the contention that exogenous factors are strong contributors to the etiology of amyotrophic lateral sclerosis and parkinsonism-dementia. The present results also demonstrate a declining incidence of both diseases.

Longitudinal study of bone loss in the second metacarpal

This longitudinal study was undertaken to ascertain the rate of bone loss and to identify aging, cohort and/or time effects on bone loss in male participants of the Baltimore Longitudinal Study of Aging. Hand-wrist radiographs were obtained from 1958-1981 and were evaluated for total width, medullary width, and length of the second metacarpal. Data were analyzed using an age-time matrix with 8-year intervals for three epochs and nine age groups. The bone measurements were analyzed in three perspectives (cross-sectional, longitudinal and time-series). The results demonstrate that there is both a cross-sectional and longitudinal loss of cortical bone with age in the second metacarpal. Furthermore, the results show that males lose approximately 14% of their cortical bone, at a rate of about 2% per decade, over the adult lifespan. The majority of this loss occurs between the ages of 45 and 69 and is due primarily to aging and is not an artifact of cohort differences or secular change.

Assessment of regional left ventricular function by magnetic resonance

The ability of magnetic resonance to determine regional left ventricular function was investigated in 18 patients--13 with coronary artery disease (nine with previous infarction), one with congestive cardiomyopathy, one with mitral stenosis, one with an atrial septal defect, and two without detectable cardiac abnormality. Coronal magnetic resonance images were acquired through the aortic valve and sagittal images were acquired in the plane of widest diameter of the left ventricle seen in the coronal image, both at end diastole and end systole. Regional wall motion assessed by magnetic resonance was compared with the results of anteroposterior and left lateral x ray ventriculograms by two independent observers. The left ventricular wall was divided into three segments in each plane and the motion of the segments was classified as normal, hypokinetic, akinetic, or dyskinetic. Muscle thickness was measured in each segment of the magnetic resonance images and was considered to be abnormal if in the systolic images it was less than 75% of that in neighbouring segments or if it failed to increase by at least 25% between diastole and systole. Wall motion assessments by the two methods agreed in 68 of 105 segments analysed, but differed by one class in 32 segments and by two classes in five segments. The differences can be explained by the conditions under which the investigations were performed and by the disparity between a tomographic section and an x ray projection. Magnetic resonance showed 25 segments to have abnormal wall thickness. Only one patient with infarction did not have an area of wall thinning and no patient without infarction had an area of thinning. It is concluded that magnetic resonance allows an accurate non-invasive assessment of left ventricular wall motion and thickness.

Syndrome X: the haemodynamic significance of ST segment depression

The relation between chest pain, ST segment depression, and changes in left ventricular function was assessed in six patients with angina, a positive exercise test, and normal coronary arteries as assessed by arteriography (syndrome X). In the six patients with syndrome X and in six controls there was no significant rise in pulmonary artery diastolic pressure during treadmill exercise, although there was ST segment depression (range 1-4.5 mm) in the patients with syndrome X. In 19 patients with coronary artery disease, however, the pulmonary artery diastolic pressure increased by a median 5 mm Hg (range 0-13.6 mm Hg) on treadmill exercise. In only one patient with coronary artery disease, who showed 1 mm ST segment depression, was there no rise in pulmonary artery diastolic pressure. During ambulatory monitoring in patients with syndrome X there were 12 episodes of ST segment depression (greater than 1 mm) (4 painful, 8 painless) in which there was no change in pulmonary artery diastolic pressure. In the patients with coronary artery disease there were 29 episodes of angina during ambulatory monitoring and during all of them pulmonary artery diastolic pressure rose by a median 7.5 mm Hg (range 1.8-19.7 mm Hg). Unlike the haemodynamic changes that usually occur during myocardial ischaemia in coronary artery disease, chest pain and ST segment changes in patients with syndrome X are not associated with impaired left ventricular function as assessed by ambulatory pulmonary artery pressure monitoring.

Nocturnal angina: precipitating factors in patients with coronary artery disease and those with variant angina

Factors precipitating nocturnal myocardial ischaemia were investigated in 10 patients with frequent daytime and nocturnal angina pectoris. Eight patients had fixed obstructive coronary artery disease or a low exercise threshold or both before the onset of ischaemia. Two patients had variant angina with normal coronary arteries and negative exercise tests. During sleep the electrocardiogram, electroencephalogram, electro-oculogram, electromyogram, chest wall movements, nasal airflow, and oxygen saturation were continuously measured. Forty two episodes of transient ST segment depression were recorded in the eight patients with coronary artery disease and 26 episodes of ST segment depression and elevation in the two patients with variant angina and normal coronary arteries. All episodes of ST segment depression in the former group of patients were preceded by an increase in heart rate as a result of arousal and lightening of sleep, bodily movements, rapid eye movement sleep, or sleep apnoea (one episode). In contrast, in the variant angina group no increase in heart rate, arousal, or apnoea preceded 23 of the 26 episodes of ST segment change. Thus increase in myocardial oxygen demand was important in precipitating nocturnal angina in patients with coronary artery disease and reduced coronary reserve. In the patients with coronary spasm these factors did not often precede the onset of nocturnal myocardial ischaemia.

Incidence of spasm at the site of previous successful transluminal coronary angioplasty: effect of ergometrine maleate in consecutive patients

The incidence of coronary artery spasm at the site of previous successful angioplasty and its importance in leading to subsequent restenosis or recurrence of symptoms are unknown. Fourteen consecutive patients with single vessel coronary artery disease who had undergone successful percutaneous transluminal angioplasty were studied. All patients were given ergometrine maleate (ergonovine maleate) intravenously during repeat cardiac catheterisation six weeks to three months after angioplasty. Five patients demonstrated excessive luminal reduction (spasm) at the site of previous angioplasty that led to luminal stenoses ranging from 50% to 79%. Two of these patients developed chest pain and ST segment changes during ergometrine maleate provocation and they also showed maximal vasoconstriction. The remaining nine patients did not develop important luminal change at the site of angioplasty after ergometrine maleate. Ergometrine maleate administration resulted in less than or equal to 20% reduction in lumen diameter of adjacent apparently normal sections of the coronary arteries in all but two patients. At the site of previous angioplasty in the five patients with spasm, however, the lumen was constricted by a mean (SD) of 51 (12)%, whereas in the nine patients not demonstrating spasm mean reduction was 12 (7)%. Thus hypersensitivity to ergometrine maleate at the site of previous successful angioplasty was demonstrated in over a third of consecutive patients with single vessel coronary artery disease. The importance of this finding to long term results of coronary angioplasty needs to be investigated further.

Haemodynamic response to myocardial ischaemia during unrestricted activity, exercise testing, and atrial pacing assessed by ambulatory pulmonary artery pressure monitoring

Ambulatory pulmonary artery pressure monitoring by means of a transducer tipped catheter with a simultaneous frequency modulated electrocardiogram and a miniaturised tape recorder was used to study the haemodynamic implications of ST segment depression in patients with coronary artery disease. Nineteen male patients (mean (SD) age 58 (11) years) with clinical and angiographic evidence of coronary artery disease were studied together with six controls. Changes in the ST segment and pulmonary artery diastolic pressure during treadmill exercise, atrial pacing, and unrestricted ambulant activity were analysed. During exercise, pulmonary artery diastolic pressure rose significantly in patients with coronary artery disease but not in the controls. One patient with ST depression greater than 1 mm did not have a rise in pulmonary artery diastolic pressure on exercise; two had a rise in pulmonary artery diastolic pressure with no ST segment change despite severe angina. The pulmonary artery diastolic pressure tended to rise before or simultaneously with the onset of ST segment depression. The haemodynamic response to atrial pacing was similar in normal controls and patients with coronary artery disease. During ambulatory monitoring there were 29 episodes of ST segment depression all of which were associated with a rise in pulmonary artery diastolic pressure and chest pain. The onset of ST segment depression occurred before a rise in pulmonary artery diastolic pressure in 11 episodes, was simultaneous with it in 11, and followed it in seven episodes. During exercise and ambulatory monitoring there was a correlation between the magnitude of ST segment depression and the rise in pulmonary artery diastolic pressure. Pain was a late feature during exercise, atrial pacing, and anginal episodes. This technique for the first time allows the relation between ST segment changes and haemodynamic alterations in left ventricular function to be assessed in ambulant patients with coronary artery disease.

Optical transmission of normal and atheromatous arterial wall: a spectral analysis

In laser angioplasty one of the factors influencing the immediate damage (and therefore the risk of acute arterial perforation) is the optical absorption characteristics of the target tissue. In an attempt to evaluate the differences in optical absorptive properties, the transmission spectrograms of samples of normal and atheromatous human postmortem aortic wall were measured over the visible spectrum. Optical transmission varied inversely with sample thickness and directly with wavelength through both normal and atheromatous samples. Over the whole visible spectrum atheromatous tissue transmitted less per unit thickness than normal tissue. This differential effect was, however, most pronounced at 500 nm, where atheromatous tissue transmitted light 5-10 times less strongly than normal aortic wall. Such wavelength dependent differential optical absorption could provide a means for the selective photovaporisation of atheroma in laser angioplasty.

Dependency levels of elderly people in institutional care in Canterbury

All elderly persons in long term or social relief institutional care in the Canterbury area were assessed using a rating scale which assessed self care, continence, orientation and social integration. There was no difference in dependency in residents in homes provided by religious and welfare organisations compared with residents in homes provided by the private sector. Organisations providing a comprehensive service with flats, residential and hospital sections had lower dependency residents in the residential care section than institutions that provide home care alone. Public hospital long stay patients were significantly more dependent than private sector long stay patients. Of all subjects in residential homes and long term hospitals in Canterbury 49.3% were essentially independent in the dimensions assessed. This study adds further data concerning patterns of dependency of elderly subjects in institutional care.

Continuous ambulatory pulmonary artery pressure monitoring. A new method using a transducer tipped catheter and a simple recording system

A transducer tipped catheter and simple recording system were used for the continuous measurement of ambulatory pulmonary artery pressure. The pulmonary artery pressure was recorded on a miniaturised tape recorder and replayed via an optical writer. Pulmonary arterial systolic and diastolic pressures can be analysed on a beat to beat basis. Continuous ambulatory monitoring was performed for a total 288 hours in 13 patients who were undergoing routine investigation for coronary artery disease. There was less than 1% zero drift and 0.25% linearity error per full scale pressure. The frequency response of the entire system was flat to 8 Hz with a linear phase delay. The transducer tipped catheter and a conventional fluid-filled system were used to measure left ventricular and pulmonary artery end diastolic pressures in eight patients. The correlation between the results obtained by the two methods was excellent. This method could be used at any centre equipped for ambulatory electrocardiographic monitoring.

Comparison of the ST/heart rate slope with the modified Bruce exercise test in the detection of coronary artery disease

The rate of depression of the ST segment with increasing heart rate (HR) during exercise has been claimed to predict the extent of coronary artery disease (CAD). To determine whether the maximal ST/HR slope is better than the Bruce treadmill exercise test for predicting the presence of CAD, the maximal ST segment/HR slope was calculated in 81 patients and compared with the results of a standard 12-lead exercise test. In 21 patients (26%), the ST/HR slope could not be calculated. In 60 patients with ST/HR slope values, the extent of CAD was predicted in 24 patients (40%). The sensitivity and specificity of the ST/HR slope in predicting the presence of CAD in the 60 patients with slope values were 91% and 27%, respectively. The sensitivity and specificity of the modified Bruce treadmill exercise test in the 81 patients were 81% and 64%, respectively. Thus, the use of the ST/HR slope does not provide additional information that cannot be obtained using the standard Bruce exercise test.

Importance of "reciprocal" electrocardiographic changes during occlusion of left anterior descending coronary artery. Studies during percutaneous transluminal coronary angioplasty

ST-segment depression remote from the region of acute myocardial infarction was investigated in three groups of patients undergoing left anterior descending coronary angioplasty. Ten patients had single-vessel disease, nine concomitant stenoses in one or more other major coronary arteries, and two myocardial infarction after occlusion during angioplasty. Continuous surface electrocardiograms were recorded from leads I, II, III, v2, and v5, before, during, and after coronary angioplasty and ST-segment changes were measured to 0.1 mm. All ten patients with single-vessel disease had ST-segment elevation in lead v2 and nine also had changes in lead III. All nine patients with multivessel disease had ST-segment changes in lead v2; eight of them had concomitant changes in lead III. Both patients with myocardial infarction had elevation in lead v2 and depression in lead III. ST-segment changes began simultaneously in all leads where they occurred. Most (70%) patients with single-vessel disease who had inferior ST-segment depression had a right-dominant coronary circulation. Therefore, the presence of inferior ST-segment depression during left anterior descending coronary artery occlusion does not indicate the presence or absence of multivessel disease. Furthermore, it is unlikely that this change always represents ischaemia remote from the site of infarction; it is merely an electrical phenomenon.

Effects of myocardial revascularisation in patients with effort angina and those with effort and nocturnal angina

The effects of coronary artery bypass graft operation were studied in 32 patients with daytime ambulatory ST segment changes and 14 patients with daytime and nocturnal angina and ST segment changes. Patients had ambulatory ST segment monitoring and exercise testing before and after operation and coronary arteriography was repeated in 34 patients after operation. Before operation, patients with daytime and nocturnal ischaemia tended to have more severe coronary artery disease, lower exercise tolerance, and more frequent ambulatory ST segment changes than those who had daytime ST segment changes only. After operation chest pain recurred in 22% of patients and ST segment depression during exercise testing or ambulatory ST segment monitoring recurred in 37% of the patients and was significantly more frequent in those with nocturnal ischaemia than in those with daytime ischaemia. Graft patency rates were similar in patients with and those without recurrence of ischaemia. After operation the frequency and magnitude of ST segment changes and exercise duration were improved in patients with preoperative daytime angina and also in those with daytime and nocturnal angina. The improvement was more pronounced in the latter groups. Thus, absence of postoperative angina is not a reliable indicator of the absence of reversible myocardial ischaemia. After revascularisation, patients with rest and nocturnal angina can expect relief from ischaemia, and if this recurs postoperatively, the threshold is improved and pain usually occurs only on exertion.

Coronary anatomy in patients with various manifestations of three vessel coronary artery disease

The histology of coronary arteries was compared in patients with rest and effort angina. The arteries came from six patients with three vessel disease who died within four weeks of arteriography and ambulatory ST segment monitoring. Sections of all macroscopically visible arteries were taken every 5 mm and examined histologically. Episodes of ST segment depression had occurred on exertion in two patients, during exertion and rest (nocturnal) in two, and two patients had had no episodes of ST segment depression during ambulatory monitoring. Concentric (29%) or eccentric (62%) intimal thickening due to atheroma or fibroelastic tissue was found in 91% of sections. All but two normal intimal sections (1%) were found to be diseased in patients with ambulatory ST segment changes. Eccentric lesions with medial smooth muscle preservation in areas without intimal thickening, where further luminal narrowing could occur due to increases in smooth muscle tone, were found in 15% of sections. But these areas were not found in the proximal 3.5 cm of any of the major coronary arteries of the two patients with rest and effort ischaemia. Spasm could not have caused total occlusion in any of these arteries because the lumen was splinted by the lesion. There was no difference in mean luminal narrowing between patients with exertional and rest ischaemia and exertional ischaemia only (mean 74%), but mean luminal narrowing was lower in patients with no ambulatory episodes of ST segment change (39%). Thus medial smooth muscle spasm was unlikely to have caused occlusion in patients with ambulatory ST segment changes, although it could have altered lumen diameter. There are no histological differences in the coronary arteries of patients with rest or effort induced myocardial ischaemia.

How important is a history of chest pain in determining the degree of ischaemia in patients with angina pectoris?

Since therapeutic decisions in patients with angina pectoris are usually based on the reported frequency of exertional and rest pain the relations between the historical frequency of chest pain and objective evidence of myocardial ischaemia during normal daily activity were investigated in 100 patients by 48 hour ambulatory ST segment monitoring. Of these 100 consecutive patients with chest pain, 91 had typical pain and nine some atypical features. Twenty six patients had normal coronary arteries and 52 of the 74 with significant coronary disease had ambulatory ST segment changes. There was no relation between the frequency of reported exertional or rest pain and (a) the severity of coronary artery disease or (b) the frequency of daytime or nocturnal ST segment changes. Twelve patients had nocturnal ST segment changes but only four complained of nocturnal angina. Most patients had both painful and painless episodes of ST segment changes, but a substantial number had either painless or painful episodes only. These differences were not related to the severity of coronary artery disease. Chest pain after the onset of ST segment change was perceived with wide interpatient and intrapatient variability. Thus the frequency of pain is a poor indicator of the frequency of significant cardiac ischaemia. Individual differences in the perception of pain may be more important.

Morphology of ambulatory ST segment changes in patients with varying severity of coronary artery disease. Investigation of the frequency of nocturnal ischaemia and coronary spasm

The frequency and magnitude of objectively determined myocardial ischaemia during normal daily activities of patients with varying severity of coronary artery disease are unknown. Furthermore, the incidence of nocturnal resting myocardial ischaemia and frequency of coronary spasm in patients with normal coronary arteries and chest pain are also not known. One hundred consecutive patients with chest pain referred for coronary angiography were therefore investigated with exercise testing and ambulatory ST segment monitoring. Fifty two of 74 patients with significant coronary artery disease and six of 26 with no significant coronary narrowing had episodes of ST segment change during 48 hours of ambulatory monitoring. Two patients, one with normal coronary arteries and localised spasm and one with three vessel disease, had episodes of ST segment elevation, whereas all other patients had episodes of ST segment depression. The frequency, duration, and magnitude of ST segment changes were greater in patients with more severe types of coronary artery disease. Thus more than six episodes of ST segment change per day occurred in patients with two or three vessel disease or left main stem stenosis and in the only patient with coronary spasm and normal coronary arteries. Nocturnal ischaemia occurred in 15% of patients with coronary artery disease and was almost an invariable indicator of two or three vessel coronary artery disease or left main stem stenosis. Episodes of ST segment change occurred most commonly during the morning hours and least commonly during the night, in parallel with changes in basal hourly heart rates. The heart rate at the onset of ST segment change tended to be lower in patients with coronary artery disease than in those with normal coronary arteries. The duration of exercise to ST segment depression tended to be shorter in patients with more severe disease, but it could not predict patients with nocturnal myocardial ischaemia, left main stem stenosis, or coronary spasm, whereas ambulatory ST segment monitoring was able to identify most of these patients.

Effects of combined alpha and beta adrenoceptor blockade in patients with angina pectoris. A double blind study comparing labetalol with placebo

The effects of a combined alpha and beta receptor antagonist, labetalol, were investigated in 10 patients with chronic stable angina pectoris. The optimal dose was determined during an initial dose titration study when the patients were treated with 200 mg, 400 mg, and 600 mg (six patients) of labetalol a day. The effective dose was then compared with placebo in a double blind randomised study. The effects of the drug were monitored with angina diaries, treadmill exercise testing, and 48 hour ambulatory electrocardiographic ST segment monitoring. Plasma labetalol concentrations were measured during each treatment period. The mean effective antianginal dose of labetalol was 480 (SD 140) mg/day given by mouth twice a day. There was a dose related reduction in daytime and nocturnal heart rate, the frequency of pain was significantly reduced by 41%, and exercise duration was significantly increased by 44% with labetalol when compared with placebo. The frequency and duration of the episodes of ST segment depression were significantly reduced by 56% and 73% respectively with labetalol. Adverse effects resulted in a reduction of the dose of labetalol in two patients. Thus labetalol is an effective agent in the treatment of angina pectoris.

Detection of arrhythmia: limited usefulness of patient activated recording devices

The findings of 24 hour ambulatory electrocardiography and monitoring with the Cardiomemo, a device recording 32 seconds of electrocardiogram during symptoms, were compared in 20 patients with symptoms suggestive of arrhythmia. Ambulatory electrocardiography showed arrhythmia in seven patients, extrasystoles in six, and normal findings in seven. Nine patients failed to transmit any Cardiomemo recordings, and the Cardiomemo failed to show ventricular and supraventricular tachycardia. It did not show any appreciable arrhythmia in the seven patients with normal 24 hour electrocardiograms. The Cardiomemo does not offer any important advantages over ambulatory electrocardiography, and its relative cheapness is outweighed by the limited number of patients who can use the device in one year. It can, however, reassure anxious patients of the absence of arrhythmia during symptoms.