Localisation of atrial natriuretic peptide immunoreactivity in the ventricular myocardium and conduction system of the human fetal and adult heart.Wharton, J; Anderson, R H; Springall, D; Power, R F; Rose, M; Smith, A; Espejo, R; Khaghani, A; Wallwork, J; Yacoub, M H
doi: 10.1136/hrt.60.4.267pmid: 2973340
Atrial natriuretic peptide immunoreactivity was found in ventricular and atrial tissues with specific antisera raised to the amino and carboxy terminal regions of the precursor molecule. In 13 developing human hearts (7-24 weeks' gestation) the immunoreactivity was concentrated in the atrial myocardium and ventricular conduction system but it was also detected in the early fetal ventricular myocardium. Immunoreactivity in five normal adults was largely confined to the atrial myocardium although it was also found in the ventricular conduction tissues of hearts removed from 10 patients who were undergoing cardiac transplantation. The ventricular conduction system is an extra-atrial site for the synthesis of atrial natriuretic peptide. In the failing heart this synthesis may be further supplemented by expression of the gene in the ventricular myocardium. It is possible that ventricular production of the peptide contributes to the raised circulating concentrations of atrial natriuretic peptide immunoreactivity found in severe congestive heart disease, particularly in patients with dilated cardiomyopathy.
Electrocardiographic prediction of coronary artery patency after thrombolytic treatment in acute myocardial infarction: use of the ST segment as a non-invasive marker.Hogg, K J; Hornung, R S; Howie, C A; Hockings, N; Dunn, F G; Hillis, W S
doi: 10.1136/hrt.60.4.275pmid: 3190955
The predictive value of the measurement of changes in ST segment elevation was assessed as a non-invasive marker of coronary artery reperfusion after thrombolytic treatment. Forty five patients with acute myocardial infarction (23 anterior, 22 inferior) of less than six hours' duration were given thrombolytic treatment by either the intravenous (n = 28) or the intracoronary route (n = 17). A proportional value for the shift in ST segment, termed the fractional change, was calculated both from 12 lead electrocardiograms and from the Holter tape for each patient. Coronary artery patency in an initial group of 22 patients (training group) was associated with a fractional change value of greater than or equal to 0.5 (100% specific, 88% sensitive by Holter analysis; 100% specific, 94% sensitive by 12 lead electrocardiogram). This rule performed well when it was applied to a test group of 17 patients (100% specific, 93% sensitive by Holter analysis; and 67% specific, 93% sensitive by 12 lead electrocardiogram). Linear discriminant analysis was then used to determine which features gave the best separation of those in whom there was reperfusion and those in whom there was not. This gave 100% specificity and 100% sensitivity when applied to the training group for either the 12 lead electrocardiogram or Holter monitoring. When it was applied to the test group, the sensitivity was maintained at 100%, but the specificity dropped to 33% irrespective of whether the basis of the test was Holter monitoring or the 12 lead electrocardiogram. These results suggest that a fractional change of >/= 0.5 calculated from a single lead showing myocardial injury is a useful non-invasive marker of reperfusion. The technique can be applied to either 12 lead electrocardiograms or Holter monitoring. The use of a more complex classification increased the sensitivity of the test at the expense of its specificity.
Short term reproducibility of exercise testing in patients with ST segment elevation and different responses to the dipyridamole test.Picano, E; Masini, M; Lattanzi, F; Klassen, G A; Distante, A; Levantesi, D; Marraccini, P; L'Abbate, A
doi: 10.1136/hrt.60.4.281pmid: 3190956
The short term reproducibility of exercise testing in 25 patients who had exercise induced ST segment elevation without baseline regional asynergy or a previous myocardial infarction, who had different responses to the dipyridamole test, was assessed. The patients performed a dipyridamole echocardiography test and a second exercise stress test. All underwent coronary arteriography. Seventeen patients had transient regional asynergy after dipyridamole (group 1) and either ST segment elevation (14 patients) or depression (three patients); a second group of eight had no asynergy and no electrocardiographic changes (group 2). The repeated exercise stress test was positive in 16 of the 17 patients of group 1 (11 with ST elevation and five with ST depression) and in two patients of group 2 (both had ST depression and one had coronary artery disease). The dipyridamole echocardiography test was positive in 17 of the 19 patients with coronary artery disease and was negative in all six patients without coronary artery disease. The repeated exercise stress test was positive in 17 of the 19 patients with coronary artery disease and in one patient without. The dipyridamole echocardiography test and a repeated exercise stress test, but not a single exercise stress test, identified coronary artery disease causing exercise induced ST segment elevation.
Value of a bipolar modified inferior lead in detection of inferior myocardial ischaemia.Jespersen, C M; Rasmussen, V
doi: 10.1136/hrt.60.4.287pmid: 3190957
Only bipolar leads are normally available for ambulatory monitoring. Bipolar precordial leads are reliable for detecting left coronary artery insufficiency, but may not detect changes caused by right coronary artery insufficiency. The magnitude and polarity of ST segment changes in a bipolar modified inferior lead and in CM5 were compared with those in standard electrocardiographic leads in 10 consecutive patients with acute myocardial infarction (eight inferior and two anteroseptal). The polarity of the ST segment in the modified orthogonal y lead was the same as that in aVF in all eight patients with inferior myocardial infarction and in six the size of the ST segment shift was identical in the two leads as well. In two patients the ST segment shift was larger in the modified orthogonal y lead than in aVF. In one of the two patients with anteroseptal myocardial infarction the polarity of the ST segment shift was the same in the modified orthogonal y lead and aVF. In the other patient it was slightly different. The CM5 lead did not reliably detect inferior myocardial ischaemia. A modified orthogonal y lead is suitable for the detection of inferior myocardial ischaemia.
Effect of hyaluronidase on mortality and morbidity in patients with early peaking of plasma creatine kinase MB and non-transmural ischaemia. Multicentre investigation for the limitation of infarct size (MILIS).Roberts, R; Braunwald, E; Muller, J E; Croft, C; Gold, H K; Hartwell, T D; Jaffe, A S; Mullin, S M; Parker, C; Passamani, E R
doi: 10.1136/hrt.60.4.290pmid: 3056476
A multicentred, randomised, blind study was started in 1978 to compare propranolol or hyaluronidase with placebo in patients with acute myocardial infarction admitted within 18 hours of onset of symptoms. Patients were randomised to group A and received hyaluronidase, propranolol, or placebo, or, if propranolol was contraindicated, to group B and received hyaluronidase or placebo. Hyaluronidase (500 U/kg given every six hours for 48 hours) had no effect on mortality or infarct size in the overall population. Because spontaneous reperfusion was more common in patients with early peaking of plasma creatine kinase MB or non-transmural electrocardiographic changes or both, the results were reanalysed for two subgroups: those in whom plasma creatine kinase peaked less than 15 hours after the onset of symptoms (early peak, n = 184) and those with a peak greater than 15 h after the onset of symptoms (late peak, n = 546). The distribution of time to peak activity of creatine kinase MB was similar in the hyaluronidase and placebo groups. In the early peak patients who were given hyaluronidase (groups A and B) total mortality and cardiac-specific four year mortality were significantly lower. This was most pronounced in group B in which the total mortality was 45% and cardiovascular mortality was 47% less than in the placebo group. Similarly, mortality from cardiovascular disease in patients (groups A and B) with nontransmural ischaemia (ST-T changes) given hyaluronidase was significantly lower, with group B showing a 50% reduction. In the subsets of patients with late peaking of creatine kinase MB or those presenting with transmural electrocardiographic changes there was no difference in total mortality or deaths from cardiac disease between those given hyaluronidase and those given placebo. Hyaluronidase was associated with improved survival in patients with early peaking of plasma creatine kinase MB, suggesting the possibility of salvage of myocardium in patients who have early spontaneous reperfusion and possibly after therapeutic reperfusion.
Percutaneous balloon dilatation of the mitral valve: an analysis of echocardiographic variables related to outcome and the mechanism of dilatation.Wilkins, G T; Weyman, A E; Abascal, V M; Block, P C; Palacios, I F
doi: 10.1136/hrt.60.4.299pmid: 3190958
Twenty two patients (four men, 18 women, mean age 56 years, range 21 to 88 years) with a history of rheumatic mitral stenosis were studied by cross sectional echocardiography before and after balloon dilatation of the mitral valve. The appearance of the mitral valve on the pre-dilatation echocardiogram was scored for leaflet mobility, leaflet thickening, subvalvar thickening, and calcification. Mitral valve area, left atrial volume, transmitral pressure difference, pulmonary artery pressure, cardiac output, cardiac rhythm, New York Heart Association functional class, age, and sex were also studied. Because there was some increase in valve area in almost all patients the results were classified as optimal or suboptimal (final valve area less than 1.0 cm2, final left atrial pressure greater than 10 mm Hg, or final valve area less than 25% greater than the initial area). The best multiple logistic regression fit was found with the total echocardiographic score alone. A high score (advanced leaflet deformity) was associated with a suboptimal outcome while a low score (a mobile valve with limited thickening) was associated with an optimal outcome. No other haemodynamic or clinical variables emerged as predictors of outcome in this analysis. Examination of pre-dilatation and post-dilatation echocardiograms showed that balloon dilatation reliably resulted in cleavage of the commissural plane and thus an increase in valve area.
Longitudinal study of ventricular function after the Mustard operation for transposition of the great arteries: a long term follow up.Wong, K Y; Venables, A W; Kelly, M J; Kalff, V
doi: 10.1136/hrt.60.4.316pmid: 3190960
An earlier study of 25 patients who were investigated by radionuclide angiography after a Mustard procedure showed that they had had evidence of right and left ventricular dysfunction at rest and with exercise. Twenty one (mean age 17.0 years (range 13.7-20.6) 11 female patients) of the original 25 patients were followed up a mean of 4.3 years later (mean 14.6 years (range 12.5-16.0) after the procedure). The group means for resting right and left ventricular ejection fraction and exercise response were not significantly different from those reported five years before. Individual changes in values were within the normal variation seen in serial studies. This long term longitudinal follow up of patients after the Mustard operation showed that although some patients still had right and left ventricular dysfunction, resting ventricular function and exercise response remained stable over a five year period. This preservation of cardiac function may contribute to the long term survival of patients after the Mustard procedure.
Left ventricular function in double inlet left ventricle before the Fontan operation: comparison with tricuspid atresia.Redington, A N; Knight, B; Oldershaw, P J; Shinebourne, E A; Rigby, M L
doi: 10.1136/hrt.60.4.324pmid: 3190961
Fourteen patients with double inlet left ventricle and nine patients with tricuspid atresia had biplane left ventricular angiography with simultaneous measurement of left ventricular pressure by micromanometer. Age distribution, haemodynamic function, and previous palliative operation were similar in the two groups. Left ventricular volumes were calculated frame by frame throughout the cardiac cycle by Simpson's rule. The end diastolic volume index was similar in the two groups, but the ejection fraction was significantly lower in tricuspid atresia. Left ventricular peak filling and emptying rates were also lower in tricuspid atresia, although heart rates in the two groups were similar. End diastolic shape index was significantly higher in patients with tricuspid atresia, indicating a more globular shape, and changed less during systole, suggesting differences in the mechanism of ejection between the two groups. Analysis of pressure-volume loops showed normal phase relations between pressure and volume, but systolic stroke work was reduced in tricuspid atresia and correlated with stroke volume and shape change. Left ventricular function was impaired in patients with tricuspid atresia when compared with those with double inlet left ventricle and this finding may reflect structural differences caused by the absence of one atrioventricular connection.
Relation between histological findings on early repeat right ventricular biopsy and ventricular function in patients with myocarditis.Dec, G W; Fallon, J T; Southern, J F; Palacios, I F
doi: 10.1136/hrt.60.4.332pmid: 3190962
Histological findings on repeat endomyocardial biopsy and changes in left ventricular ejection fraction early during immunosuppressive treatment were studied in 20 patients with documented myocarditis. All patients presented with heart failure of less than six months' duration and a left ventricular ejection fraction of less than or equal to 0.40. Repeat biopsy and assessment of ventricular function were performed at a mean (SEM) of 79 (17) days after the initial biopsy. At repeat biopsy eight patients had evidence of ongoing myocarditis and 12 showed resolved myocarditis. In eight (66%) of the 12 patients with resolved myocarditis ventricular function had improved significantly. Left ventricular ejection fraction also improved significantly in four of eight patients during treatment despite ongoing myocardial inflammation. Regardless of the histological findings on repeat biopsy, early improvement in ejection fraction was associated with an excellent long term prognosis--that is 83% survived for at least three years. Histological resolution of myocarditis during immunosuppressive treatment is not a prerequisite for improvement in ventricular function; and changes in left ventricular ejection fraction during the first three months of treatment are predictive of clinical outcome.