Short term haemodynamic effects of converting enzyme inhibition before and after eating in patients with moderate heart failure caused by dilated cardiomyopathy: a double blind study

Symptoms of hypertrophic cardiomyopathy, with special emphasis on syncope and postprandial exacerbation of symptoms

We undertook a prospective study of the symptoms of hypertrophic cardiomyopathy with the aim of profiling symptomatic morbidity in detail, determining the prevalence of anxiety and depression, and describing the prevalence and associations of syncope and postprandial symptom exacerbation. A questionnaire was administered to consecutive outpatients; 70 with hypertrophic cardiomyopathy, 43 with coronary artery disease, 32 with idiopathic dilated cardiomyopathy, and to 40 normal subjects. Hypertrophic cardiomyopathy patients underwent exercise testing, echocardiography, and Holter monitoring. Hypertrophic cardiomyopathy patients had a high frequency of cardiac symptoms and, on average, had a level of symptomatic morbidity equivalent to that of chronic stable angina and dilated cardiomyopathy. There was no evidence for an excess of anxiety (14%) or depression (6%) in patients with hypertrophic cardiomyopathy. Syncope and presyncope, especially provoked by exertion or posture change, were characteristic and common symptoms in hypertrophic cardiomyopathy. A history of syncope was associated with an abnormal blood pressure response to exercise in over 50% of cases that may be the mechanism of syncope in some. Postprandial exacerbation of symptoms occurred in over one-third of hypertrophic cardiomyopathy patients, half of coronary disease patients, and infrequently in dilated cardiomyopathy. Hypertrophic cardiomyopathy patients with postprandial symptoms had a greater frequency of angina, were more symptomatic, and had a reduced exercise capacity, suggesting that postprandial symptoms are a marker for more severe disease.

Cardiovascular and hormonal responses to a meal in hypertrophic cardiomyopathy: a comparison of patients with and without postprandial exacerbation of symptoms

Some patients with hypertrophic cardiomyopathy experience postprandial exacerbation of symptoms. The aim of this study was to determine whether the hemodynamic and/or hormonal responses to a meal differ between patients with and without postprandial symptoms. Ten hypertrophic cardiomyopathy patients with postprandial symptoms, 10 patients without postprandial symptoms, and 10 normal subjects ate a 740 Kcal meal, following which heart rate, blood pressure, and echocardiographic and gastrointestinal hormone changes were compared among the three groups. Heart rate increased (p < 0.001) and diastolic blood pressure fell (p < 0.001) to a similar degree in the three groups. Left ventricular outflow tract velocity increased (p < 0.01) and some patients had substantial increases in outflow tract pressure gradient; however, this was independent of the presence or absence of postprandial symptoms. The atrial contribution to filling increased in normal subjects and in both groups of hypertrophic cardiomyopathy patients. There was no significant difference in the gastrointestinal hormone changes in the three groups. In summary, there is no evidence for a distinctive hemodynamic or hormonal response to food in hypertrophic cardiomyopathy patients with postprandial symptoms. These symptoms more likely reflect differences in underlying cardiac disease characteristics and severity.

Short-term effects of eating on vasoactive hormones and haemodynamics in patients with heart failure

OBJECTIVES

To investigate if eating can influence the measurements of vasoactive hormones or their relationship to important haemodynamic variables.

DESIGN

Haemodynamic variables and plasma concentrations of atrial natriuretic peptide (ANP), arginine vasopressin and angiotensin enzyme (ACE) activity were measured. During the 24-h study period the patients ate ordinary hospital meals and thus were studied both in the absorptive and post-absorptive phases.

SETTING

Two university hospitals in Sweden participated in the study.

SUBJECTS

Ten patients with heart failure, due to ischaemic heart disease.

INTERVENTION

Eating.

MAIN OUTCOME MEASURES

Change in haemodynamic variables and plasma concentrations of vasoactive hormones related to eating.

RESULTS

After a meal (absorptive phase) pulmonary capillary wedge pressure and plasma concentrations of ANP were significantly lower compared to the postabsorptive phase, 13 +/- 1.7 vs. 16 +/- 1.9 mmHg and 57 +/- 9.5 vs. 72 +/- 12.2 pmol l-1, respectively. The relationship between ANP and its main predictor, pulmonary capillary wedge pressure, was not altered during the study period. Plasma concentration of arginine vasopressin, ACE activity and mean right atrial pressure decreased with time and the cardiac index increased with time over the study period.

CONCLUSIONS

A meal may significantly influence plasma concentrations of ANP. Studies on vasodilator treatment and its interactions with ANP should take account of these basal fluctuations. The present data confirm previous reports on haemodynamic improvement during the first 24 h of supine cardiac catheterization in patients with heart failure, and add new information about decreasing concentrations of arginine vasopressin and ACE.

Acute haemodynamic effects and pharmacokinetics of ramipril in patients with heart failure. A placebo controlled three-dose study

The aim of the present study was primarily to evaluate the haemodynamic effects of the ACE-inhibitor ramipril which is active via its metabolite ramiprilat. Ramipril 1.25, 2.5 and 5 mg and placebo was administered orally to 4 groups of 12 patients with heart failure (NYHA III) in a double-blind randomised, parallel study. Haemodynamics were monitored for 24 h and blood was sampled and urine collected for up to 96 h. In the placebo-treated group the cardiac index (CI) was significantly increased (15.8%) and right atrial pressure decreased (26.6%). Ramipril 1.25 mg had insignificant haemodynamic effects compared to placebo and the 2.5 mg dose had significant effects on some haemodynamic variables. Ramipril 5 mg had pronounced and sustained effects on pulmonary artery pressure, which fell by 43.7%, and pulmonary capillary wedge pressure (PCWP; -59.1%); systemic vascular resistance was also decreased 21%. A significant effect on CI was only seen after 2.5 mg ramipril (+7.4%). The mean maximal degree of ACE inhibition was 73.2, 90.4 and 98.5%, respectively, after the three doses of ramipril. Complete inhibition of ACE-activity was seen at a mean plasma concentration of ramiprilat of 4.7 ng.ml-1. The degree of inhibition declined with a half life of about 75 h. There was a significant relation between the degree of ACE-inhibition and change in PCWP but not with the change in SVR. Ramipril was mainly eliminated in the form of ramiprilat and inactive metabolites.

Effects of a meal on hemodynamic function at rest and during exercise in patients with hypertrophic cardiomyopathy

Many patients with hypertrophic cardiomyopathy experience postprandial exacerbation of their symptoms. The vasodilation associated with eating may be deleterious in hypertrophic cardiomyopathy, especially during exercise. To examine the hemodynamic effects of a meal in hypertrophic cardiomyopathy, 11 patients were studied with invasive hemodynamic monitoring during exercise testing in the fasting state and 45 min after a 740 kcal (3,100 J) meal. The meal induced a decrease in systemic vascular resistance index at rest (mean +/- SD, -17 +/- 14%), increases in mean right atrial (31 +/- 21%), mean pulmonary artery (14 +/- 14%) and mean pulmonary capillary wedge (17 +/- 14%) pressures and an increase in cardiac index (18 +/- 10%) due to an increased heart rate without any significant change in stroke volume. During postprandial exercise, heart rate, rate-pressure product, cardiac index and cardiac filling pressures were higher than during fasting exercise and one patient had a decrease in exercise blood pressure compared with the fasting test. Five patients with postprandial exacerbation of symptoms in everyday life had a lesser increase in systemic arterial pressure and stroke volume during both exercise tests and a smaller increase in cardiac index after the meal than did the six patients without postprandial symptom exacerbation, suggesting more severe cardiac disease. It is concluded that patients with hypertrophic cardiomyopathy have an abnormal hemodynamic response to food, in which stroke volume fails to increase and pulmonary capillary wedge and pulmonary artery pressures increase. These adverse changes persist during postprandial exercise and may predispose to exertional collapse in certain patients.

Tissue and plasma angiotensin converting enzyme and the response to ACE inhibitor drugs

1. There is a body of circumstantial and direct evidence supporting the existence and functional importance of a tissue based RAS at a variety of sites. 2. The relation between circulatory and tissue based systems is complex. The relative importance of the two in determining haemodynamic effects is unknown. 3. Despite the wide range of ACE inhibitors already available, it remains unclear whether there are genuine differences related to tissue specificity. 4. Pathological states such as chronic cardiac failure need to be explored with regard to the contribution of tissue based ACE activities in generating acute and chronic haemodynamic responses to ACE inhibitors. 5. The role of tissue vs plasma ACE activity may be clarified by study of the relation between drug concentration and haemodynamic effect, provided that the temporal dissociation is examined and linked to circulating and tissue based changes in ACE activity, angiotensin peptides and sympathetic hormones.