Showing papers by "John G.F. Cleland published in 1987"

Mortality in heart failure: clinical variables of prognostic value.

Abstract: One hundred and fifty two patients with chronic heart failure caused primarily by left ventricular dysfunction were followed prospectively in an open study for a mean period of 21 months. The effects of several clinical variables on subsequent outcome were examined, including the effects of treatment, which was determined by the clinician caring for the patient and was not randomly allocated. In order of importance, frequent ventricular extrasystoles, non-treatment with amiodarone, low mean arterial pressure, and a diagnosis of coronary artery disease were associated with a poor prognosis, with each of these variables providing extra predictive information independently of the others. Initial serum potassium concentration and treadmill exercise time also carried further weak but independent prognostic information. Neither treatment with angiotensin converting enzyme inhibitors nor digoxin appeared to affect outcome. Left ventricular function (as reflected by M mode echocardiography) and the dose of diuretic also failed to predict outcome. There did, however, appear to be a reduction in the frequency of sudden death when angiotension converting enzyme inhibitors were given. Further studies are required to confirm the adverse prognostic significance of ventricular arrhythmias in patients with heart failure and the possible benefit associated with amiodarone treatment.

Relation of arrhythmias and electrolyte abnormalities to survival in patients with severe chronic heart failure.

Abstract: To investigate the determinants of mortality in patients with chronic congestive heart failure, we prospectively evaluated 84 patients with this disorder who underwent detailed biochemical, clinical, and functional tests at the time of initial evaluation and were then followed for 12 to 52 months (mean 31). During this period of follow-up, 58% of the patients died, of whom 71% died suddenly. The most important pretreatment predictor of mortality in these patients was the frequency of ventricular extrasystoles, followed by echocardiographic fractional shortening, a diagnosis of coronary artery disease, and duration of treadmill exercise. The finding of hypokalemia and hyponatremia in these patients at the time of entry into the study was associated with a poor prognosis by univariate analytical methods, but these electrolyte abnormalities did not provide independent prognostic information. The presence of ventricular arrhythmias was related to the severity of left ventricular dysfunction, exercise intolerance, and neurohormonal activation, suggesting that such arrhythmias are multifactorial in origin and may not simply be related to electrolyte abnormalities.

Clinical, haemodynamic, and antiarrhythmic effects of long term treatment with amiodarone of patients in heart failure.

Abstract: Twenty two patients with heart failure were studied in a double blind crossover trial to compare amiodarone (200 mg/day) with placebo. Each agent was given for three months. Extrasystoles and complex ventricular arrhythmias were common during ambulatory electrocardiographic monitoring and during exercise testing at entry to the study. Breathlessness and tiredness as assessed by visual analogue scores and duration of treadmill exercise did not become worse during amiodarone treatment. During the placebo and amiodarone phases of the study left ventricular ejection fraction and cardiac index determined by first pass radionuclide ventriculography were similar, both at rest and during upright bicycle exercise. Exercise induced ventricular tachycardia was abolished and simple and complex ventricular arrhythmias observed on 24 hour ambulatory monitoring were greatly diminished during amiodarone treatment. Three patients died, all suddenly, during the placebo phase. In two patients amiodarone was withdrawn after a further myocardial infarction in one and a worsening of symptoms of ventricular arrhythmia in the other. In contrast with other antiarrhythmic agents amiodarone is effective in suppressing ventricular arrhythmias in heart failure without causing adverse haemodynamic effects. Because frequent ventricular arrhythmias are known to be associated with a poor prognosis in heart failure, these data suggest that amiodarone may improve the poor prognosis in patients with heart failure.

Plasma atrial natriuretic peptide concentrations during exercise in sodium replete and deplete normal man.

Abstract: 1 To explore the effects of exercise on plasma atrial natriuretic peptide (ANP) concentrations, eight normotensive volunteers performed maximal treadmill exercise in sodium replete and deplete states 2 Baseline immunoreactive plasma ANP concentrations were significantly lower during sodium depletion During exercise plasma ANP rose in all subjects on both occasions Plasma peptide responses were attenuated by sodium depletion with peak exercise levels only double baseline values, in contrast to the threefold increase in ANP concentrations observed when subjects were sodium replete 3 Plasma renin and aldosterone concentrations also rose with exercise In contrast to changes in plasma ANP, the responses of both were enhanced by sodium depletion

Total body electrolyte composition in patients with heart failure: a comparison with normal subjects and patients with untreated hypertension.

Abstract: Total body elemental composition was measured in 40 patients with well documented heart failure who were oedema-free on digoxin and diuretics. The results were compared with values for 20 patients with untreated essential hypertension matched for height, weight, age, and sex. Total body potassium alone was also measured in 20 normal subjects also matched for anthropomorphic measurements. Patients with hypertension had a very similar total body potassium content to that of normal subjects, but patients with heart failure had significantly reduced total body potassium. This could not be explained by muscle wasting because total body nitrogen, largely present in muscle tissue, was well maintained. When total body potassium was expressed as a ratio of potassium to nitrogen mass a consistent depletion of potassium was revealed in the group with heart failure. Potassium depletion was poorly related to diuretic dose, severity of heart failure, age, or renal function. Activation of the renin-angiotensin-aldosterone system was, however, related to hypokalaemia and potassium depletion. Such patients also had significantly lower concentrations of serum sodium and blood pressure. Serum potassium was related directly to total body potassium. Despite the absence of clinically apparent oedema total body chlorine was not consistently increased in heart failure, but the calculated extracellular fluid volume remained expanded in the heart failure group. Total body sodium was significantly increased in patients with heart failure, but less than half of this increase could be accounted for by extracellular fluid volume expansion. Potassium depletion in heart failure may account in part for the high frequency of arrhythmias and sudden death in this condition.

Cardiovascular effects of training for a marathon run in unfit middle aged men

Abstract: The effects of a 30 week exercise programme on serum lipid values, blood pressure, and cardiac function were assessed in a group of sedentary men aged 35-50 training for their first marathon. Mean serum cholesterol concentration (n = 33) fell by 12% from 6.54 (SE 0.18) to 5.76 (0.15) mmol/l (mean fall 0.78 mmol/l; 95% confidence interval 0.52 to 1.04 mmol/l), serum triglyceride concentration (n = 33) by 22% from 1.56 (0.17) to 1.21 (0.09) mmol/l (mean fall 0.34 mmol/l; 95% confidence interval 0.12 to 0.56 mmol/l), and mean blood pressure (n = 27) by 10% from 102 (2) to 92 (2) mm Hg (mean fall 10 mm Hg; 95% confidence interval 7 to 13 mm Hg). These changes were not explained by changes in body composition. Peak exercise left ventricular end diastolic volume (n = 16) increased with training; as a result of this and an increased exercise left ventricular ejection fraction peak exercise cardiac output increased from 19.9 (1.2) to 23.1 (3.0) l/min (mean rise 3.2 l/min; 95% confidence interval 1.5 to 5.0 l/min). Maximum oxygen consumption increased from 33.9 (1.6) to 39.0 (1.3) ml/kg/min (mean rise 5.0 ml/kg/min; 95% confidence interval 1.8 to 8.2 ml/kg/min). This study showed favourable effects on coronary risk factors and cardiac function and supports the place of regular exercise in coronary prevention programmes.

Ventricular arrhythmias during exercise in patients with heart failure: the effect of amiodarone.

Abstract: In a group of 62 patients with chronic heart failure 29% developed ventricular tachycardia during exercise testing. The two-year survival of this group was only 22%, compared to 55% in those not demonstrating ventricular tachycardia (P less than 0.01). In a double-blind cross-over study against placebo, with three-month treatment periods, amiodarone, in a dose of 200 mg day-1, was found effectively to suppress ventricular arrhythmias during exercise and in the immediate post-exercise period. Exercise performance was not impaired. Amiodarone may be useful in preventing life-threatening arrhythmias in patients with heart failure.