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.

An echocardiographic study of localized subaortic hypertrophy

A prospective echocardiographic investigation was undertaken to determine the prevalence and significance of localized subaortic hypertrophy in 1000 consecutive patients presenting for a routine echocardiographic examination. Localized septal hypertrophy was diagnosed when the subaortic septum was hypertrophied (greater than 1.4 cm) and was 50% thicker than the mid-point of the septum. Patients with hypertrophic cardiomyopathy and fixed subvalvular aortic stenosis were excluded. Eight cases of localized subaortic hypertrophy were identified. In 7 the appearances of the left side of the interventricular septum were similar with an apparently sigmoid shape (reversed S on its side) and in 1 with associated mitral stenosis the septum was a tapered wedge. All patients with localized subaortic hypertrophy had left ventricular hypertrophy (left ventricular mass or posterior wall thickness greater than 2 SD from normal) with a normal size cavity due to aortic valve disease (2 patients were also hypertensive). Of the 180 patients with aortic valve disease, localized subaortic hypertrophy was found in 10% of those with left ventricular hypertrophy and 33% of those with asymmetrical septal hypertrophy (septum to posterior wall ratio of greater than 1.5:1). There was no evidence of subaortic stenosis by pulsed and continuous wave doppler echocardiography (8 cases) and cardiac catheterization (6 cases). The aetiology of this discrete localized muscular bulge is unclear but is presumably due to change in shape of the septum with left ventricular hypertrophy. However, this finding has important implications as a cause of asymmetrical septal hypertrophy and because of the possible false diagnosis of subvalvular stenosis and its effect on ultrasound measurements.

The distribution of left ventricular hypertrophy in hypertrophic cardiomyopathy: comparison to athletes and hypertensives

Cross-sectional echocardiography was performed in 134 patients with hypertrophic cardiomyopathy and 75 with secondary left ventricular hypertrophy (57 hypertensives and 18 athletes) to determine the diagnostic sensitivity and specificity and predictive value of the pattern of left ventricular hypertrophy. Myocardial wall thickness was assessed in the anterior and posterior septum, free wall and posterior wall in both the upper and lower left ventricle. All patients had at least one region exceeding 2 SD from normal (greater than 1.4 cm). Asymmetrical septal hypertrophy) septum to posterior wall ratio greater than or equal to 1.5:1 in the upper or lower left ventricle) was found in 75 patients with hypertrophic cardiomyopathy (56%), 11 hypertensives (18%) and 4 (22%) athletes. This pattern was more common in patients with primary compared to secondary left ventricular hypertrophy (P less than 0.01). Distal ventricular hypertrophy was only seen in patients with hypertrophic cardiomyopathy (10%). Symmetrical left ventricular hypertrophy was demonstrated in 45 patients with hypertrophic cardiomyopathy (34%), 50 hypertensives (82%) and 14 athletes (78%). This pattern was significantly more common in patients with secondary left ventricular hypertrophy (P less than 0.01). Amongst those with symmetrical hypertrophy, patients with hypertrophic cardiomyopathy had more severe hypertrophy while the athletes had larger left ventricular cavity size. Asymmetrical septal hypertrophy was the most sensitive (56%) and distal ventricular (100%) the most specific pattern for the diagnosis of hypertrophic cardiomyopathy with a predictive value of 83 and 100% respectively. Symmetrical left ventricular hypertrophy was 81% sensitive and 66% specific with a predictive value of 58% for the diagnosis of secondary hypertrophy.(ABSTRACT TRUNCATED AT 250 WORDS)

Is cardiac ultrasound mandatory in patients with transient ischaemic attacks?

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Prevalence and clinical significance of aortic valve prolapse

The prevalence and clinical significance of aortic valve prolapse were determined prospectively in 2000 consecutive patients undergoing routine clinical cross sectional echocardiography. Two hundred and twelve patients were excluded because the aortic cusps were not adequately visualised. Aortic valve prolapse was defined as downward displacement of cuspal material below a line joining the points of attachment of the aortic valve leaflets. Twenty four cases of aortic valve prolapse (1.2%) were identified. The patients were aged 12-64 years and nine were women. All had underlying valvar heart disease and the commonest lesion (in 11 cases) was prolapse of the larger cusp in bicuspid valves. Aortic valve prolapse was seen in four patients with mitral valve prolapse (two with severe regurgitation), one of whom had marfanoid aortic root dilatation. The remaining examples of aortic prolapse were seen in patients with various disorders including one with pulmonary atresia, two with aortic root disease (one with dissection and one with idiopathic dilatation), and one case of severe mitral regurgitation. Valves destroyed by infective endocarditis were seen in two cases. Aortic valve prolapse may be detected in various cardiac disorders and does not imply the presence of aortic regurgitation, but when bicuspid aortic valves are present it may well be important in producing such regurgitation. Although aortic valve prolapse may be associated with severe forms of mitral valve prolapse, these patients rarely have aortic regurgitation.

Longitudinal changes in left ventricular diastolic function in hypertrophic cardiomyopathy

Digitised M-mode echocardiography was used to study the changes in left ventricular diastolic function over a 3-year period in 11 patients with hypertrophic cardiomyopathy an 14 normals. Compared to normal, in hypertrophic cardiomyopathy, isovolumic relaxation was prolonged (P less than 0.001) and mitral valve opening delayed relative to minimum dimension (P less than 0.001). There was a wide range of values for the peak rates of dimension increase and wall thinning, and although the means were normal, 6 and 8 patients respectively were outside the normal range. There were no significant mean changes in function during the 3.4 +/- 0.3 years of follow-up, but, in 3 patients, marked alterations in relaxation were observed. They showed a gross reduction in the delay in mitral valve opening (125 to 55 125 to 35 and 110 to 75 msec). There was little overall change in isovolumic relaxation in two, but in one patient it reduced from 95 to 50 msec. In most patients with hypertrophic cardiomyopathy, relaxation and diastolic function appear to remain stable over a period of 3 years, and none had an apparent deterioration. Some patients may have an apparently spontaneous "improvement" in function similar in extent to that described due to the therapeutic action of calcium antagonists.

Relation between electrocardiographic repolarisation changes and mechanical events in left ventricular hypertrophy

The relation between ventricular function and the presence of electrocardiographic "strain" in patients with left ventricular hypertrophy was examined using digitised M mode echocardiography and 12 lead electrocardiograms in 64 patients with pressure overload, 21 with hypertrophic cardiomyopathy, and 14 athletes. Although all had increased left ventricular mass, those with strain had a prolonged interval from minimum cavity dimension to mitral valve opening and a reduced rate of early diastolic posterior wall thinning and dimension increase compared with those with normal ST segments and T waves. Both groups had normal systolic function (fractional shortening and peak velocity of circumferential fibre shortening), and the time between the termination of the T wave and minimum dimension was similar. In athletes, however, electromechanical systole was shorter than normal, and the end of the T wave and minimum cavity dimension were synchronous. It is concluded that abnormal electrical recovery in left ventricular hypertrophy is closely related to impaired early relaxation and may be dissociated from impaired systolic function, cavity dimension, interventricular conduction delay, and the presence of increased mass alone. The normal relation between electrical and mechanical systole is preserved even when the polarity of repolarisation is reversed.

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.

Physiological left ventricular hypertrophy

Echocardiograms were recorded in 154 active athletes (from various sports) and 21 ex-athletes and compared with those in 40 normal control subjects (non-athletes). Diastolic cavity dimension and posterior wall and septal thickness were measured and left ventricular mass and the ratio of posterior wall thickness to cavity radius and of septum to posterior wall thickness calculated. As a group athletes had a significantly increased diastolic cavity dimension, posterior wall and septal thickness, and left ventricular mass. The ratio of posterior wall thickness to cavity radius was distributed as a single continuous variable with a significantly increased mean, and there was no separate subgroup of shot putters or weight lifters with inappropriate hypertrophy. The mean ratio of septum to posterior wall thickness was normal, but there was a wide range of values up to 2.1:1. Ex-athletes had entirely normal left ventricular dimensions and wall thickness. When athletes are categorised by their standard of competition national standard competitors had a significantly increased posterior wall and septal thickness and left ventricular mass compared with university and non-competitive sportsmen. In conclusion, strenuous activity results in left ventricular hypertrophy which is appropriate to the body size of the athlete and the degree of activity but not to its type.

Relation of regional echo amplitude to left ventricular function and the electrocardiogram in left ventricular hypertrophy

In order to determine the relation between three manifestations of left ventricular hypertrophy--ST-T wave changes on the electrocardiogram, diastolic disturbances, and increased myocardial echo intensity--M mode and cross sectional echocardiograms were recorded in 12 normal subjects, 15 athletes, 16 patients with hypertrophic cardiomyopathy, and 42 patients with secondary left ventricular hypertrophy due to aortic stenosis (20), severe essential hypertension (8), coarctation (7), or subaortic stenosis (7). M mode echocardiograms were digitised and cross sectional echocardiograms were analysed for regional echo intensity. In patients with hypertrophy regional echo amplitude was significantly increased in mid and basal septum and posterior left ventricular wall. Patients with increased echo amplitude in any region showed a higher incidence of ST-T wave abnormalities than those without and of diastolic abnormalities--including prolongation of isovolumic relaxation time, delay in mitral valve opening with respect to minimum cavity dimension, and a reduction in peak rate of posterior wall thinning and dimension increase. There was a significant rank order correlation between median pixel count and these diastolic abnormalities. No significant differences were demonstrable in these relations between the diagnostic groups. By contrast, electrocardiographic findings, diastolic function, and pixel count were uniformly normal in athletes, although the increase in left ventricular mass was similar to that in the patients. Thus an increase in left ventricular mass alone is not responsible for repolarisation or wall motion abnormalities occurring in pathological left ventricular hypertrophy. These latter changes are, however, strongly associated with the change in myocardial properties detected as an increase in echo intensity and may be due to increased interstitial fibrosis.

Diagnosis of broad complex tachycardias with ambulatory monitoring of atrial electrography

Simultaneous 24 hour ambulatory monitoring of the surface electrocardiogram and the intra-atrial electrocardiogram was evaluated in eight patients with broad complex tachycardia. The technique using a J shaped atrial pacing wire permitted a distinction between ventricular tachycardia and supraventricular tachycardia in all eight patients. Formal electrophysiological testing would still be required, however, in patients in whom diagnostic doubt remained.

Left ventricular hypertrophy. Relation of structure to diastolic function in hypertension

Digitised M mode echocardiography was used to determine the relation between the degree of left ventricular hypertrophy and abnormalities of isovolumic relaxation and diastolic function. Fifty six patients with varying severity of non-malignant systemic hypertension without evidence of ischaemic heart disease, left ventricular dilation, or clinical heart failure were studied. In addition, 10 athletes with hypertrophy and 20 normal subjects were studied. Athletes and patients with moderate (systolic blood pressure 175 to 200 mm Hg) and severe hypertension (greater than 200 mm Hg) had a significant increase in left ventricular mass. Cavity dimensions were normal in hypertensive patients and increased in athletes. Systolic function was normal in all groups. Regardless of the degree of hypertrophy patients with hypertension had a prolonged isovolumic relaxation period and delayed mitral valve opening. Patients with hypertrophy also had a reduced rate and prolonged duration of rapid early diastolic dimension increase and posterior wall thinning. Athletes, however, who had an equivalent degree of hypertrophy to patients with moderate or severe hypertension had entirely normal function. Measurements of diastolic function were significantly correlated with wall thickness and left ventricular mass. These indices of hypertrophy, particularly posterior wall thickness and the sum of posterior wall and septal thickness, were positively correlated with the duration of isovolumic relaxation and delay in mitral opening and negatively with the peak rate of early diastolic dimension increase and wall thinning. Thus in hypertensive patients with non-dilated left ventricular hypertrophy there appears to be a relation between the degree of wall thickening and abnormalities of diastolic function.

Left ventricular function in patients with ankylosing spondylitis and Reiter's disease

We have studied left ventricular function by non-invasive methods in 28 patients with ankylosing spondylitis and 14 with Reiter's disease and compared them with 42 normal subjects. A dilated and poorly contracting left ventricle with abnormal systolic time intervals were found in five (18%) of those with ankylosing spondylitis and two (14%) with Reiter's disease. Our results suggest that the high cardiovascular morbidity and mortality in these diseases may be due to abnormality of the myocardium in the absence of valve disease.

A prospective study of heart disease in diabetes mellitus

Six hundred and twenty-five patients with diabetes mellitus were studied by standardised clinical methods, resting and exercise electrocardiography (ECG) and digitised echocardiography to determine the prevalence of coronary and non-coronary heart disease. Clinical evidence of coronary artery disease (angina and infarction) was present in 110 (18 per cent) normotensive patients. Hypertension (blood pressure greater than 165/95 mmHg) was present in 172 (27 per cent) of whom 32 had cardiac symptoms. Heart failure or left ventricular dilatation was seen in 18 of whom 11 had either hypertension or coronary artery disease and six asymptomatic patients had unexplained ventricular hypertrophy. Echocardiograms in 245 of 290 asymptomatic patients with normal ECG showed that relaxation was prolonged (p less than 0.001) and mitral valve opening delayed (p less than 0.001) from normal especially in those with severe microangiopathy (proliferative retinopathy and/or heavy proteinuria). The peak rates of cavity dimension increase and posterior wall thinning were reduced from normal (both p less than 0.001) and patients with severe microangiopathy had the most marked changes. Redivision of these 245 diabetics by abnormalities of left ventricular function showed that 147 had normal function in whom only one of 23 (random 15 per cent sample) had a positive exercise ECG. Prolonged relaxation or delayed mitral valve opening alone (a nonspecific abnormality) was present in 41 and only three of 28 had a positive exercise ECG. Thirty-one had delayed mitral valve opening with inco-ordinate relaxation (abnormalities very suggestive of coronary artery disease) of whom 20 of 29 had a positive exercise ECG. Twenty-six had delayed mitral valve opening with slow cavity dimension increase or wall thinning (without hypertrophy) of whom 21 of 25 had a negative exercise ECG. This is a relatively specific abnormality similar to that found in left ventricular hypertrophy. Coronary artery disease is common in symptomatic and asymptomatic forms in diabetes mellitus. Non-coronary left ventricular diseases, such as dilation and hypertrophy, are probably no more common in diabetics than non-diabetics. A small number of diabetics with severe microangiopathy had abnormal relaxation and reduced peak rate of dimension increase or wall thinning which may represent left ventricular disease due to microangiopathy.

Hypertrophic cardiomyopathy: a common disease with a good prognosis. Five year experience of a district general hospital

The manifestations and workload in a district general hospital cardiac unit of 39 unselected cases of hypertrophic cardiomyopathy over a five year period are reported. The "typical" form with asymmetrical septal hypertrophy and a gradient was found in only one third of patients, serious ventricular arrhythmias were probably no more common than in the general population, and no deaths occurred during a relatively short follow up (mean 3.1 years). It is concluded that although hypertrophic cardiomyopathy occupies a not insignificant proportion of cardiac workload, unselected cases presenting to a district general hospital represent a relatively mild disease without a grave prognosis.

Effect of training on left ventricular structure and function. An echocardiographic study

To study the cardiac effects of running, 15 healthy non-athletic male volunteers underwent a moderate training schedule for six weeks; thereafter five continued to run at a similar intensity for a further six weeks and 10 stopped. Left ventricular wall thickness and dimension, relaxation, and diastolic function were studied by digitised echocardiography at entry and at two, four, and six weeks, and again at 12 weeks. Significant increases in running ability and maximum oxygen consumption were observed. Maximum oxygen consumption was unchanged in those who continued to run but a reduction was noted in those who stopped. No significant changes in left ventricular dimensions were observed, but the thickness of the posterior wall and the septum increased during six weeks' running. Left ventricular mass (cube volume formula) increased significantly during the first six weeks. Comparison of those who continued to train and those who stopped showed that the former had no change in mass, whereas in the latter mass returned towards pre-exercise values. Systolic function (fractional shortening) was unchanged throughout the study. In addition, no abnormalities of relaxation or diastolic function were detected. Exercise induced left ventricular hypertrophy may develop rapidly during training and the increased myocardial mass resulting from six or 12 weeks' running is not associated with impaired relaxation and diastolic function as found in pathological forms of hypertrophy.

A comparison of the effects of intermittent and continuous nasogastric feeding on the oxygen consumption and nitrogen balance of patients after major head and neck surgery

Ten patients were fed by nasogastric tube for 5 days after major surgery of the head and neck. Five were fed by continuous infusion 24 h/day using an enteral nutrition pump and five were fed comparable quantities by 2-h bolus administration between 0600 and 2200 h. Those fed by bolus had lower resting oxygen consumption on the 4th and 5th postoperative days and better cumulative nitrogen balance over the 5 days than the continuously fed group. It appears that metabolically it may be better to use an intermittent feeding regimen than a continuous one when feeding patients postoperatively via a nasogastric tube.

Cross sectional echocardiographic assessment of the aortic root and coronary ostial stenosis in familial hypercholesterolaemia

Aortic root abnormalities (atherosclerotic thickening and obstruction) seen at necropsy may readily be detected by aortography in familial hypercholesterolaemia. We studied 35 patients with familial types IIa and IIb hyperlipoproteinaemia including three homozygotes and 32 heterozygotes. Two homozygotes showed abnormal bright echoes (atheroma) encircling the proximal aortic root, which interfered with full excursion of the aortic cusps. One homozygote showed the typical echocardiographic features of supravalvular aortic stenosis at the superior border of the sinus of Valsava with normal aortic cusps. Cardiac catheterisation showed valvular gradients of 15 and 80 mm Hg in two homozygotes and a supravalvular gradient of 40 mm Hg in the third. Left coronary artery ostial stenosis was identified by echocardiography in all three homozygotes. Echocardiographic measurements of the aortic root in the 32 heterozygotes were similar to the control group, but 10 patients showed abnormal bright echoes within the aortic cusps and four had supravalvular changes similar to, but less severe than, the homozygotes. In one severely heterozygote supravalvular atheroma prevented full aortic cusp excursion, and this finding was confirmed during coronary artery bypass surgery.

Myocarditis in siblings leading to chronic heart failure

Two brothers, aged 7 and 9, presented 4 years apart with progressive heart failure following a probable viral infection. Electrocardiograms of both showed widespread precordial Q waves. Cardiac catheterization in each case revealed almost equal right atrial, right ventricular and pulmonary artery pressures and poorer contraction of the right than left ventricle. High neutralizing antibody titres to Coxsackie B4 virus were found in the siblings and their mother. Widespread post-myocarditic scarring of both ventricles was found at autopsy on the elder brother. These findings provide further evidence that Coxsackie myocarditis accounts for some cases of dilated cardiomyopathy and suggest that familial factors may be important.

Distribution of left ventricular hypertrophy in hypertrophic cardiomyopathy: a two-dimensional echocardiographic study

The distribution of left ventricular hypertrophy was assessed by M-mode and two-dimensional echocardiography in 89 patients with hypertrophic cardiomyopathy. Myocardial thickness was measured in the septum and the free and posterior wall in both the proximal and distal left ventricle. All patients had at least one myocardial region that was hypertrophied. The predominant pattern of hypertrophy was defined as symmetric (31%), asymmetric septal (55%) and distal ventricular (14%). The spectrum of wall thickness measurements between patients with symmetric hypertrophy was wide (1.5 to 4.5 cm) and was not related to age. In patients with asymmetric septal hypertrophy, the distribution of hypertrophy conformed to previously described patterns; hypertrophy was localized to the anterior septum (14%) or the anterior and posterior septum (35%) or involved both the septum and the left ventricular free wall (51%). The patients with distal ventricular hypertrophy had marked papillary muscle thickening, and only 1 of 12 patients could be correctly diagnosed using M-mode echocardiography. The proportion of patients with symmetric and distal ventricular hypertrophy was greater than that reported when patients are selected on the basis of M-mode diagnostic criteria. This reflects the limitations of the M-mode technique in the assessment of left ventricular hypertrophy and suggests that the recognition and understanding of hypertrophic cardiomyopathy have been biased by patients with asymmetric septal hypertrophy who previously were most readily identified.

Malignant hypertension: cardiac structure and function at presentation and during therapy

We have studied electrocardiograms, chest radiographs, and digitised apex echocardiograms in 16 patients with malignant hypertension before and after up to six months of antihypertensive treatment and compared them with those of eight patients with severe benign hypertension. Adequate blood pressure reduction was obtained in 14 with resolution of retinopathy, but one patient died and another had poor blood pressure control. Nine had electrocardiographic criteria of left ventricular hypertrophy which did not change with treatment and 10 had lateral ischaemia which resolved in seven. The malignant hypertensives were divided into seven with and nine without a previous hypertensive history. Both groups had normal echocardiographic cavity dimensions, but the former group tended to have hypertrophy (similar to that in benign hypertensives) and the latter did not. After adequate reduction of blood pressure, no change in wall and septal thickness occurred (except in one patient with poor blood pressure control). At entry, malignant hypertensives showed delayed mitral valve opening with significant cavity dimension increase during prolonged isovolumic relaxation, reduced peak rate, and prolonged duration of cavity dimension increase and cavity shape change (inward wall motion) during the upstroke of the apexcardiogram which showed a tall "a" wave. After reduction of blood pressure, though the delay in mitral valve opening persisted, the timing of A2 returned towards normal and the dimension change during the upstroke of the apexcardiogram and the relative height of the "a" wave were reduced but remained significantly different from normal. Some patients without a previous hypertensive history may develop a malignant phase without left ventricular hypertrophy on the electrocardiogram or echocardiogram. They maintain their pump function even with radiological pulmonary oedema, have incoordinate relaxation and contraction, and have abnormal filling. Similar functional abnormalities were found in malignant hypertensives with hypertrophy. Treatment to reduce blood pressure reduces incoordinate contraction, but impaired diastolic function persists as in benign hypertension, suggesting that these abnormalities are the result of altered myocardial properties that may occur without hypertrophy.

Clinical trials of an antiplatelet agent, ticlopidine, in diabetes mellitus

At present there is no simple, reliable and non-invasive method for monitoring progression and improvement in diabetic microangiopathy. However, some diabetic patients with severe microvascular complications show a fairly specific pattern of impaired left ventricular function (abnormal relaxation, cavity filling and wall thinning) and abnormalities of haemorheology (increased viscosity, erythrocyte rigidity and beta-thromboglobulin and decreased threshold for platelet ADP aggregation). A single-blind, 6-months' crossover study of an antiplatelet agent, ticlopidine, was conducted in 20 diabetics with clinical evidence of microvascular disease. Response to therapy was monitored by digitised M-mode echocardiographic analysis of left ventricular diastolic function and haemorheology. All patients had abnormal basal values with no significant change during the 3-month placebo run-in period but, although significant alterations in viscosity, erythrocyte deformability, beta-thromboglobulins and ADP threshold were observed, no change in left ventricular function was detected. It is concluded that, while it may be possible to alter abnormal haemorheology in diabetes, there was no change in one parameter of microvascular end-organ damage.