Electrophysiologic effects of salbutamol, a beta2-selective agonist.

Introduction: A positive chronotropic effect of beta2 stimulation is well known. Case reports of ventricular arrhythmias during beta2-inhalation therapy have been published. The aim of this study was to asses the overall electrophysiologic effects of the beta2-agonist salbutamol.

Electrophysiologic effects of mental stress in healthy subjects: a comparison with epinephrine infusion.

Mental stress has been associated with serious cardiac arrhythmias, including ventricular tachycardia and ventricular fibrillation. The purpose of this study was to assess cardiac electrophysiologic effects of mental stress and compare them with those of epinephrine infusion. Ten healthy male volunteers participated.

Pulmonary embolism: a follow-up study of the relation between the degree of right ventricle overload and the extent of perfusion defects.

Objectives: To describe the course of changes in perfusion lung scintigraphy (LS) after acute pulmonary embolism (PE) and test the hypothesis that patients with persistent pulmonary hypertension (PH)/right ventricle (RV) dysfunction after acute PE can be differentiated from those without through larger perfusion defects (PDf) on LS. Design. Prospective, one-year follow-up study with repeated LS and echocardiography-Doppler investigations.

Pulmonary embolism: one-year follow-up with echocardiography doppler and five-year survival analysis.

Background: The long-term prognosis for patients with pulmonary embolism (PE) is dependent on the underlying disease, degree of pulmonary hypertension (PH), and degree of right ventricular (RV) dysfunction. A precise description of the time course of pulmonary artery pressure (PAsP)/RV function is therefore of importance for the early identification of persistent PH/RV dysfunction in patients treated for acute PE. Other objectives were to identify variables associated with persistent PH/RV dysfunction and to analyze the 5-year survival rate for patients alive 1 month after inclusion.

Pulmonary embolism: relation between the degree of right ventricle overload and the extent of perfusion defects.

Background: Inasmuch as the presence of right ventricle (RV) overload in patients with pulmonary embolism (PE) is associated with a bad prognosis, evaluation of RV function in PE is of importance. This study was done to establish if the degree of RV overload can be predicted from the extent of perfusion defects (PDf).

Methods: One hundred twenty-one consecutive patients with PE diagnosed by lung scintigraphy (LS) were examined by echocardiography Doppler (ED) immediately after diagnosis.

Echocardiography Doppler in pulmonary embolism: right ventricular dysfunction as a predictor of mortality rate.

To test the hypothesis that right ventricular (RV) systolic dysfunction at the time of diagnosis of pulmonary embolism (PE) is a predictor of mortality rate, 126 consecutive patients with PE were examined with echocardiography Doppler (ED) on the day of diagnosis. RV function was assessed by evaluation of wall motion on a four-point scale. The material was divided into two groups: group A (n = 56) with normal or slightly reduced RV function and group B (n = 70) with moderately or severely reduced RV function.

Long-term effects of dual chamber pacing in patients with hypertrophic cardiomyopathy without outflow tract obstruction at rest.

Background: Atrioventricular-synchronous pacing is beneficial in patients with hypertrophic obstructive cardiomyopathy. The effects of pacing in patients without significant left ventricular outflow tract obstruction at rest are, however, less well explored. This study compares the long-term outcome of pacing patients with and without significant left ventricular outflow tract obstruction at rest.

High incidence of scintigraphic myocardial uptake defects at rest and during exercise in male elite runners.

Objective: To evaluate the usefulness of myocardial perfusion scintigraphy (MIBI-SPECT) as a diagnostic tool in well trained men.

Design: The study was prospective, involving 2 d stress-rest myocardial scintigraphy (MIBI-SPECT), polar map reconstruction with and without uniform attenuation correction, and comparison with a healthy male group (local Swedish) and with a commonly used reference group (American, Emory University Hospital).

Setting: University Hospital, Stockholm, Sweden.

Cardiac function in primary hyperparathyroidism before and after operation. An echocardiographic study.

Objective: To identify possible causes for the increased cardiovascular morbidity and mortality seen in patients with primary hyperparathyroidism.

Design: Prospective, blind study.

Setting: University hospital, Sweden.

Magnetic resonance imaging as an aid to the diagnosis and treatment evaluation of suspected myocardial sarcoidosis in a fighter pilot.

We present a case of possible myocardial sarcoidosis suspected by the presence of multiorgan sarcoidosis along with cardiac dysrhythmia. The diagnosis of a highly probable sarcoid infiltrate was made by magnetic resonance imaging, depicting a high intensity mass in the ventricular septum. Following corticosteroid treatment the mass disappeared, and remains absent after 3 years followup.

Ventilation-perfusion relationships and central haemodynamics in patients with cirrhosis. Effects of a somatostatin analogue.

The ventilation-perfusion relationships of the lung (VA/Q) and central haemodynamics were studied in seven patients with cirrhosis before and 30 min after a bolus injection of a somatostatin analogue, octreotide (Sandostatin, 50 micrograms i.v.), to elucidate the role of this substance in the hepatopulmonary syndrome.

Effect of beta-receptor blockade on splanchnic and muscle metabolism during prolonged exercise in men.

The importance of beta-receptor stimulation for the metabolism and circulation in the liver and exercising muscle was studied in six men during 3 h of leg exercise at 50% of maximum oxygen uptake. At 160 min of exercise, 0.15 mg propranolol/kg body wt was given intravenously.

Effect of vasoactive intestinal polypeptide (VIP) on pulmonary ventilation-perfusion relationships and central haemodynamics in healthy subjects.

Ventilation-perfusion relationships of the lung (VA/Q) and central haemodynamics were studied in nine healthy subjects before and during 30 min of vasoactive intestinal polypeptide (VIP) infusion (20 ng kg.min-1). During the infusion, arterial concentrations of VIP rose from 16.

Comparison of clinical and echocardiographic determinations of left ventricular dimension during weaning from cardiopulmonary bypass.

Twenty patients (age 45 to 78 years) were studied with ethical committee approval and informed patient consent during coronary artery bypass grafting. Transesophageal echocardiography (TEE) was used to validate a clinical measure of preload: inspection of the line of contact between the heart (acute margin) and the diaphragm. Immediately before going on cardiopulmonary bypass (CPB), with the cannulas and stay sutures in place, a small mark was made with the cautery on the diaphragm at the line of contact.

Effects of low-dose adenosine on myocardial performance after coronary artery bypass surgery.

The effect of a non-hypotensive dose of adenosine infusion on myocardial performance after coronary artery bypass surgery was examined. Upon arrival at the intensive care unit, 16 patients (14 males, 2 females; mean age 64.5, range 46-71) were randomized to a blinded infusion of either low-dose adenosine (n = 8) or placebo (n = 8).

The hemodynamic importance of atrial systole: a function of the kinetic energy of blood flow?

The relative importance of atrial systole on left ventricular filling was investigated at rest and during exercise in 25 patients with dual chamber pacemakers. The mean blood flow velocity over the mitral valve, the velocities of the rapid filling phase (E), the active filling phase (A), and the E/A ratio were determined by pulsed Doppler-echocardiography. The patients were first examined at rest during AV sequential pacing (DVI) at 70 and 104 beats/min.

Left ventricular filling as assessed by pulsed Doppler echocardiography after coronary artery bypass grafting.

Diastolic filling of the left ventricle, as assessed by transesophageal pulsed Doppler echocardiography during and in the early phase following coronary artery bypass grafting, was investigated in nine patients without valvular disease or left ventricular hypertrophy. The ratio between the maximal heights of the early diastolic flow-velocity peak and the late (atrial) diastolic flow-velocity peak, the E:A ratio, and also the deceleration time of the early peak were calculated as indices of left ventricular filling. The E:A ratio decreased from 1.

Increased lipolytic sensitivity to catecholamines in diabetic patients with severe autonomic neuropathy.

Lipolytic sensitivity to catecholamines was studied in gluteal adipocytes from diabetic subjects with severe (n = 3), mild (n = 6) or no autonomic neuropathy (n = 8). Two of the three patients with severe autonomic neuropathy had a completely abolished plasma epinephrine response to insulin-induced hypoglycaemia, whereas the third patient showed a reduced and delayed plasma epinephrine response. Lipolytic sensitivity to isoprenaline (P less than 0.

Adipose tissue and skeletal muscle blood flow during mental stress.

Mental stress [a modified Stroop color word conflict test (CWT)] increased adipose tissue blood flow (ATBF; 133Xe clearance) by 70% and reduced adipose tissue vascular resistance (ATR) by 25% in healthy male volunteers. The vasculatures of adipose tissue (abdomen as well as thigh), skeletal muscle of the calf (133Xe clearance), and the entire calf (venous occlusion plethysmography) responded similarly. Arterial epinephrine (Epi) and glycerol levels were approximately doubled by stress.

Cardiovascular and sympathoadrenal responses to mental stress: influence of beta-blockade.

Cardiovascular, sympathoadrenal, and subjective responses to mental stress induced by a color-word conflict test (CWT) were studied in 30 healthy males before and after intravenous administration of either placebo, beta 1-blockade by metoprolol (0.15 mg/kg), or nonselective beta-blockade by propranolol (0.15 mg/kg).

Disposal of lactate during and after strenuous exercise in humans.

Heavy dynamic exercise using both arm and leg muscles was performed to exhaustion by seven well-trained subjects. The aerobic and anaerobic energy utilization was determined and/or calculated. O2 uptake during exercise and during 1 h of recovery was measured as well as splanchnic and muscle metabolite exchange.

Effect of beta 1-selective and non-selective beta-blockade on work capacity and muscle metabolism.

Six well-trained men were studied while performing a maximal bicycle exercise. The seven experiments included in this study were randomized in a double-blind cross-over fashion. On each occasion the subjects were given either placebo or 40, 80, or 160 mg propranolol (non-selective blockade) or 25,50, or 100 mg atenolol (beta 1-selective blockade).