Changes in abdominal aortic diameter in response to the cold pressor test and nitroglycerin: a new noninvasive model for the assessment of endothelial-dependent and endothelial-independent vascular relaxation.

Coronary vascular responses to the cold pressor test (CPT) have been shown to parallel changes caused by infusion of acetylcholine. Whereas the CPT is a method of assessing endothelial-dependent vasodilation, nitroglycerin produces endothelial-independent vasodilation. We performed histological studies on autopsy specimens of abdominal aorta and demonstrated that it is predominantly muscular artery.

Usefulness of transthoracic echocardiography in demonstrating coronary blood flow after coronary artery bypass grafting.

In this pilot study, we used transthoracic echocardiography to measure coronary sinus blood flow in 15 patients before and after coronary artery bypass grafting. Coronary sinus blood flow before and after revascularization was 274 +/- 95 and 451 +/- 102 ml/min, respectively (p <0.001).

Usefulness of the response of flow velocity in the left anterior descending coronary artery to the cold pressor test for evaluating endothelium-dependent vascular relaxation in the coronary microvasculature by transesophageal echocardiography in subjects with angiographically normal coronary arteries.

Measurement of flow velocity in the left anterior descending coronary artery by transesophageal echocardiography in subjects without risk factors for coronary artery disease (group 1) and in subjects with normal coronary arteries but conditions associated with endothelial dysfunction (group 2) revealed that there was a significantly impaired coronary flow velocity response to the cold pressor test in group 2 subjects. Thus, transesophageal echocardiography provides a minimally invasive tool for the functional assessment of endothelium and can be valuable in evaluating endothelial dysfunction and recovery in a variety of disease states.

Noninvasive cardiac output monitoring during exercise stress test.

A computerized continuous wave Doppler instrument was used to monitor changes in cardiac output during symptom limited supine bicycle exercise in 41 individuals. Eight (19%) had technically unsatisfactory Doppler signals. Of the remaining 33 patients, 21 had clinical and 18 had angiographic evidence of coronary artery disease (group 1) and 12 age-matched asymptomatic subjects served as controls (group 2).

2-D echocardiographic analysis of interventricular septal motion: concept of an anterior and posterior part to the septum.

2-D echocardiography was performed in 50 patients with transmural anteroseptal (group 1) or inferior myocardial infarction (group 2). Twenty-four patients with myocardial infarction had diagnostic coronary arteriography. Twenty-five normal subjects served as controls.

Thyrotropin secretion in thyrotoxic and thyroxine-treated patients: assessment by a sensitive immunoenzymometric assay.

A new TSH immunoenzymometric assay was found to be capable of discriminating between the serum TSH values of normal subjects [2.28 +/- 1.02 (+/-SD); range, 0.

Studies on the diurnal pattern of serum 3,5,3'-triiodothyronine.

Seventeen subjects, including 12 mildly obese women, were investigated to determine the presence of a diurnal variation in serum T3 levels. A subset of 8 subjects was studied after fasting for 6 days, while another subset of 5 subjects was studied 2 days after receiving 3 mg T4, orally, to suppress TSH secretion. To negate the influence of hemoconcentration produced by ambulation, serum T3 to T4 ratios (nanograms per microgram) rather than total T3 values were used for analysis.

Differentiation between acute and healed myocardial infarction by signal averaging and color encoding two-dimensional echocardiography.

To evaluate the ability of a system developed in our laboratory to differentiate between acute and healed myocardial infarction (MI), gated 2-dimensional echocardiography was performed in 10 patients with recent MI (within 48 hours) and 10 patients with healed MI (later than 4 weeks). The 2-dimensional echocardiographic images were digitized using a Datacube VG-120 videoframe digitizer and each digitized videoframe (320 X 240 matrix) was transmitted using a high-speed serial data link to a second computer and stored on floppy disc. Five gated video frames of each patient were time-averaged to give a smoothed digitized image.

Identification of the increased frequency of cardiovascular abnormalities associated with mitral valve prolapse by two-dimensional echocardiography.

Two-dimensional echocardiography (2-D echo) was performed in 86 consecutive patients with mitral valve prolapse (MVP) and in 25 normal subjects. In normal subjects, mitral leaflet thickness was 3.5 +/- 0.

Determination of cardiac output by transcutaneous continuous-wave ultrasonic Doppler computer.

To evaluate the accuracy of a new, portable, continuous-wave Doppler computer (Ultracom) in measuring cardiac output (CO), simultaneous thermodilution CO and Doppler CO were measured in triplicate in 39 selected patients. Technically adequate Doppler CO studies were obtained in 36 patients. Aortic root diameter was measured by echocardiography and the cross-sectional area was calculated.

Application of 2-dimensional contrast studies during pericardiocentesis.

Two-dimensional echocardiographic contrast studies were performed in 16 patients with pericardial effusion. A 4-chamber view was obtained by positioning the transducer at the apex. The exploratory needle was visualized in 9 patients.

Clinical implications of large vegetations in infectious endocarditis.

Thirty-four patients with clinical infectious endocarditis were examined by M-mode and two-dimensional (2D) echocardiography. Vegetations were identified in 16 patients (47%) by M-mode and in 27 patients (87%) by 2D echocardiography. Vegetations identified by 2D echocardiography were categorized as small (less than 5 mm), medium (5 to 9 mm), or large (greater than or equal to 10 mm).

Left ventricular asynergy in acute myocarditis. Simulation of acute myocardial infarction.

Recent studies have demonstrated the usefulness of two-dimensional echocardiography in the detection of regional wall abnormalities in acute myocardial infarction. We describe two patients with acute myocarditis who had acute chest pain simulating acute myocardial infarction. Two-dimensional echocardiography initially demonstrated regional wall motion abnormalities that disappeared within a few days.

Mitral valve aneurysm: clinical features, echocardiographic-pathologic correlations.

Aneurysm of the mitral valve occurs most commonly in association with infective endocarditis of the aortic valve. The probable mechanism of its formation is destruction of the aortic valve which results in a regurgitant jet that strikes the anterior leaflet of the mitral valve, creating a secondary site of infection leading to the development of an aneurysm. Perforation of these aneurysms may occur, resulting in mitral regurgitation and pulmonary edema from a ventricle already volume overloaded from aortic regurgitation.

A case of insulinoma with peripheral neuropathy.

A 25-year-old woman with chronic neuropsychiatric symptoms, peripheral neuropathy and hypoglycaemia was found to have an islet cell adenoma in the pancreas. Her neuropsychiatric symptoms disappeared following its removal and she partially recovered from her peripheral neuropathy.

Value of two-dimensional echocardiography in detecting tricuspid stenosis.

We reviewed the M-mode and two-dimensional echocardiograms of 100 consecutive patients with rheumatic heart disease. All were subsequently studied by cardiac catheterization and angiography. In four patients, cardiac catheterization showed tricuspid stenosis (average mean diastolic gradient 6.

A preliminary report of an out-patient systems study in Sri Lanka.

Out-patient medical clinics in Sri Lanka often have long queues of patients waiting to see a doctor partly due to a shortage of doctors. To apply operational research techniques to optimize the functioning of the clinic, an initial step is to determine the distributional pattern of patient arrival times and the doctors' service times. The results showed that the arrival times of patients were time dependent.