Combined left and right ventricular volume determination by radionuclide angiocardiography using double bolus and equilibrium technique

Pulmonary blood volume and transit time in cirrhosis: relation to lung function

BACKGROUND/AIMS

In cirrhosis a systemic vasodilatation leads to an abnormal distribution of the blood volume with a contracted central blood volume. In addition, the patients have a ventilation/perfusion imbalance with a low diffusing capacity. As the size of the pulmonary blood volume (PBV) has not been determined separately we assessed PBV and pulmonary transit time (PTT) in relation to lung function in patients with cirrhosis and in controls.

METHODS

Pulmonary and cardiac haemodynamics and transit times were determined by radionuclide techniques in 22 patients with alcoholic cirrhosis and in 12 controls. The lung function including diffusing capacity for carbon monoxide (DL, CO) was determined by conventional single breath technique.

RESULTS

In the patients, PTT was shorter, 3.9+/-1.2 vs 5.7+/-1.0 s in the controls, P<0.001, and the PBV was lower, 362+/-151 vs 587+/-263 ml, in the controls, P<0.005. Both PTT and PBV were lowest in patients with advanced disease. DL, CO was reduced in the patients and correlated significantly with PTT (r=0.58, P=0.007) and PBV (r=0.49, P<0.03).

CONCLUSIONS

The results suggest that the reduced PBV contributes to the reduced effective blood volume in cirrhosis. The relation between PBV and PTT and the low diffusing capacity suggests the pulmonary vascular compartment as an important element in the pathophysiology of the lung dysfunction in cirrhosis.

Increased plasma N-terminal pro-B-type natriuretic peptide and markers of inflammation related to atherosclerosis in patients with primary hyperparathyroidism

OBJECTIVE

Increased risk of cardiovascular disease has been reported in patients with primary hyperparathyroidism (PHPT). The aim of this study was to evaluate novel plasma risk markers of cardiovascular disease in patients with PHPT.

DESIGN

PHPT patients were evaluated with a control group. Patients who underwent parathyroidectomy were re-evaluated after 7 and 18 months.

PATIENTS

Forty-five PHPT patients and 40 matched controls participated. Seventeen patients underwent parathyroidectomy.

MEASUREMENTS

Plasma N-terminal pro-B-type natriuretic peptide (NT-proBNP), high-sensitivity C-reactive protein (CRP), interleukin-6 (IL-6) and tumour necrosis factor alpha (TNF-alpha), lipids and blood pressure were measured. In 27 patients a bicycle exercise test and radionuclide angiography were performed, and repeated in those who underwent parathyroidectomy.

RESULTS

Plasma NT-proBNP, CRP and TNF-alpha, but not IL-6, were higher in patients with PHPT than in controls (P < 0.01 and P = 0.17, respectively). In patients with PHPT, NT-proBNP correlated with systolic blood pressure, left ventricular end-diastolic volume, and peak oxygen uptake (all P < 0.01). Log CRP correlated with systolic and diastolic blood pressure (both P < 0.05) and log IL-6 (P < 0.01). No significant correlations were observed between PTH or calcium and risk markers of cardiovascular disease. No decrease in NT-proBNP, markers of inflammation or blood pressure was observed after parathyroidectomy.

CONCLUSIONS

Our data suggest that hypertension or other factors, rather than plasma calcium or PTH, could explain the increased levels of the inflammatory markers and NT-proBNP in PHPT. We therefore suggest that aggressive treatment of hypertension should be initiated in patients with PHPT to try to reduce the increased cardiovascular mortality described in PHPT. Further prospective studies are needed to validate the suggestion that increased levels of NT-proBNP and inflammatory markers also represent strong prognostic markers of cardiovascular disease in patients with PHPT.

Predictors of sudden death and death from pump failure in congestive heart failure are different. Analysis of 24 h Holter monitoring, clinical variables, blood chemistry, exercise test and radionuclide angiography

One hundred and ninety consecutive patients discharged with congestive heart failure were examined with clinical evaluation, blood chemistry, 24 h Holter monitoring, exercise test and radionuclide angiography. Median left ventricular ejection fraction was 0.30, 46% were in New York Heart Association class II and 44% in III. Total mortality after 1 year was 21%, after 2 years 32%. Of 60 deaths, 33% were sudden and 49% due to pump failure. Multivariate analyses identified totally different risk factors for sudden death: ventricular tachycardia, s-sodium < or = 137 mmol/l, s-magnesium < or = 0.80 mmol/l, s-creatinine > 121 mumol/l, and maximal change in heart rate during exercise < or = 35 min-1, and for death from progressive pump failure: New York Heart Association class III + IV, delta heart rate over 24 h < or = 50 min-1, low ejection fraction, high resting p-noradrenaline, s-urea > 7.6 mmol/l, s-potassium < 3.5 mmol/l, and maximal exercise duration < or = 4 min. In conclusion, this study demonstrated different risk factors for sudden death and for death from progressive pump failure.

Prognostic value of plasma catecholamines, plasma renin activity, and plasma atrial natriuretic peptide at rest and during exercise in congestive heart failure: comparison with clinical evaluation, ejection fraction, and exercise capacity

Survival in congestive heart failure is related to plasma catecholamines and atrial natriuretic peptide at rest, but the prognostic importance of changes during exercise is unknown. The aim of this study was to evaluate the prognostic value of catecholamines and atrial natriuretic peptide at rest and during maximal exercise in congestive heart failure, and to compare it to clinical and exercise test variables and left ventricular ejection fraction. One hundred ninety consecutive patients (136 men and 54 women; median age, 66 years; range, 42-75 years) with clinically stable congestive heart failure were included. Sixteen patients were in New York Heart Association class I, 87 in class II, 83 in class III, and 4 in class IV. Left ventricular ejection fraction was 0.30 (range, 0.06-0.74). Total survival after 1 year was 79%, after 2 years, it was 68%. Prognostic variables at univariate analysis were: plasma noradrenaline at rest (P < .0001), plasma adrenaline at rest (P = .049), and atrial natriuretic peptide at rest (P = .016). During exercise, plasma catecholamines and plasma atrial natriuretic peptide increased significantly; the change, however, was not related to survival. Six variables carried significant, independent prognostic information in a multivariate analysis: left ventricular ejection fraction (P = .03), plasma noradrenaline at rest (P = .009), New York Heart Association class III + IV (P = .005), increase in heart rate during exercise < or = 35 min-1 (P < .0001), serum creatinine > 121 mumol/L (P = .004), and serum urea > 7.6 mmol/L (P = .007). Patients with congestive heart failure have a poor survival despite intensive medical treatment. Plasma catecholamines and plasma atrial natriuretic peptide are elevated at rest and rises further during exercise; the increase, however, is not related to mortality. Plasma noradrenaline at rest contributes with further prognostic information despite knowledge of clinical and exercise variables and was the only neurohormonal variable with independent, significant prognostic information on survival.

Dependency of blood pressure upon cardiac filling in patients with severe postural hypotension

Autonomic denervation of the vascular bed results theoretically in a stronger dependency of blood pressure upon intravascular volume, and the study described aimed at an investigation of the relation between cardiac filling and arterial blood pressure in patients with severe postural hypotension. Seven patients were studied during head-up tilt at three different tilt angles using intra-arterial blood pressure recordings and estimates of left ventricular volumes by radioisotope ventriculography. Blood pressure fell dramatically during head-up tilt due to reductions in cardiac output unopposed by vasoconstriction. The reduction in cardiac output resulted from reductions in left ventricular end-diastolic volumes with unchanged left ventricular ejection fractions and only moderate increments in heart rate. The study was demonstrated that blood pressure is strongly dependent upon cardiac filling in severe autonomic dysfunction, and that volume expansion is an important measure against postural hypotension.

Cardiac contractility, central haemodynamics and blood pressure regulation during semistarvation

Eight obese patients were studied before and after 2 weeks of treatment by a very-low-calorie diet (VLCD). Cardiac output and central blood volume (pulmonary blood volume and left atrial volume) were determined by indicator dilution (125I-albumin) and radionuclide angiocardiography (first pass and equilibrium technique by [99Tcm]red blood cells). Cardiac output decreased concomitantly with the reduction in oxygen uptake as the calculated systemic arteriovenous difference of oxygen was unaltered. There were no significant decreases in left ventricular contractility indices, i.e. the ejection fraction, the peak ejection rate and changes in end-systolic volume. Also the diastolic function evaluated by the peak filling rate remained normal. Furthermore, no sign of backward failure could be demonstrated since the central blood volume was not significantly increased. Both systolic and diastolic blood pressure (BP) declined. The fall in BP was caused by the reduction in cardiac output as the total peripheral resistance was unchanged. Finally, the decline in total blood volume was not significant. These findings together with a reduction in heart rate indicated that a reduced sympathetic tone via increased capacitance of the venous bed was the main operator of a reduced venous return. Thus, the haemodynamic alterations in obese patients during short-term semistarvation may be caused by the fall in oxygen uptake and produced mainly by changes in the sympathetic tone.