A prospective randomized comparison of the accuracy of computer-assisted versus GUSTO nomogram--directed heparin therapy.

Failure to adequately anticoagulate the blood of patients receiving recombinant tissue plasminogen activator (TPA) leads to greater rates of rethrombosis. In a multicentered, randomized trial in 51 patients we compared the ability to achieve and maintain therapeutic anticoagulation by use of computer-assisted heparin therapy or the GUSTO (Global Utilization of Streptokinase and TPA for Occluded Coronary Arteries) heparin nomogram guidelines in patients with myocardial infarction treated with recombinant TPA. Heparin therapy was initiated with either computer-generated starting doses or GUSTO guideline starting doses.

Normal electrophysiological findings in a patient with symptomatic intermittent advanced atrioventricular block.

This report describes an otherwise healthy young woman who presented with syncope during episodes of advanced atrioventricular (AV) block. The His bundle recordings during normal sinus rhythm and atrial and ventricular pacing were normal. Carotid sinus massage produced no abnormality.

Can the human right ventricle create a negative diastolic pressure suggestive of suction?

Pressure in the right ventricle (RV) as well as the right atrium (RA) and pulmonary artery (PA) were measured in 80 patients with catheter-tip micromanometers and evaluated to determine if the pressures are compatible with the concept of RV diastolic suction. In 40 patients with normal PA pressure, minimal RV diastolic pressure that occurred during early filling, was negative (-2 +/- 0.3 mm Hg) (mean +/- SEM).

Effect of chronic pressure overload on the maximal rate of pressure fall of the right ventricle.

The maximal rate of fall in right ventricular pressure (negative dp/dt) was evaluated in 34 patients. Eight had normal pulmonary arterial pressure. Seventeen had pulmonary arterial hypertension, and nine had pulmonary arterial hypertension with right ventricular failure.

Effect of turbulent blood flow on systolic pressure contour in the ventricles and great vessels: significance related to anacrotic and bisferious pulses.

The effect of turbulent blood flow on the contour of systolic pressure in the left and right ventricles and great vessels was investigated in 64 patients undergoing diagnostic cardiac catheterization. Intracardiac pressure and sound were recorded using a catheter-tip micromanometer. Measurements were made in normal subjects and patients with a variety of disorders including aortic stenosis, hypertrophic obstructive cardiomyopathy, coarctation of the aorta and atrial septal defect.

Negative intraventricular diastolic pressure in patients with mitral stenosis: evidence of left ventricular diastolic suction.

Left ventricular diastolic pressure was evaluated in 15 patients with mitral stenosis and 16 patients with no significant heart disease to determine if a stenotic mitral valve can cause the left ventricle to produce a negative diastolic pressure, indicative of ventricular diastolic suction. The minimal level of diastolic pressure in patients with mitral stenosis ranged between 6 and -7 mm Hg; in normal subjects it did not fall below 0. The average value of minimal diastolic pressure in patients with mitral stenosis (-2 +/- 1 mm Hg [mean +/- standard error of the mean]) was significantly lower than in patients without significant heart disease (5 +/- 1 mm Hg) (p less than 0.

Orifice-view aortography in patients with congenitally deformed aortic valves: determination of aortic valve area.

Orifice-view aortography is a contrast cineaortographic technique that allows en face viewing of the aortic valve. In this projection the anatomic configuration of the aortic valve is identified, and it is possible to planimeterize the visualized aortic valve opening and accurately determine the orifice area. Fifteen individuals with congenitally deformed aortic valves with gradients ranging from trivial (< 10 mm Hg) to surgically significant (6E 60 mm Hg) were subjected to aortic orifice area measurement by orifice-view aortography, and the area was compared with the peak systolic gradient and valve area.

Mid-systolic closure of the aortic valve in hypertrophic obstructive cardiomyopathy: a pressure-related phenomenon induced by turbulent blood flow.

The purpose of this study was to determine whether mid-systolic closure and opening of the aortic valve in patients with hypertrophic obstructive cardiomyopathy (HOCM) may reflect dynamic changes of pressure induced by turbulent blood flow in the aorta and left ventricular outflow tract. Five patients with HOCM who had echocardiographic evidence of mid-systolic closure of the aortic valve and two patients with HOCM who did not have transient mid-systolic closure of the aortic valve were studied. In patients in whom mid-systolic closure was present, a transient mid-systolic drop of pressure was present in the left ventricular outflow tract, distal to the dynamic intraventricular obstruction, 17 +/- 3 mm Hg (mean +/- SEM) and in the root of the aorta, 16 +/- 4 mm Hg.

Intracardiac sound as a diagnostic adjunct in subaortic stenosis.

The purpose of this investigation is to demonstrate the potential diagnostic value of intracardiac sound recordings in patients with subaortic stenosis. Intracardiac pressure and sound were measured in 10 patients with various types of subaortic obstructions using a catheter-tip micromanometer. Seven patients had idiopathic hypertrophic subaortic stenosis (IHSS), 2 had a subvalvular membrane, and 1 had a subvalvular tunnel.

Performance of the failing and nonfailing right ventricle of patients with pulmonary hypertension.

Hemodynamic performance of the right ventricle was measured in 34 patients: 17 with pulmonary hypertension, 9 with pulmonary hypertension and right ventricular failure and 8 control subjects. Among the patients with pulmonary hypertension who did not have right ventricular failure, right ventricular maximal isovolumic rate of development of ventricular pressure (dP/dt) was significantly elevated (P less than 0.001), whereas maximal 1/P dP/dt and maximal velocity of contractile element shortening (Vmax) were comparable with values observed in control subjects.

Diagnostic value of visualization of the right ventricle using thallium-201 myocardial imaging.

The diagnostic significance of visualizing the right ventricle on thallium-201 myocardial perfusion scans (T-scan) at rest was studied in 53 patients. In 33 patients the right ventricle was visualized clearly on the T-scan (group A). Hemodynamic evidence of right ventricular hypertension with systolic pressure greater than or equal to 30 mmHg was present in 28 of 33 (85%) of these patients.