[Intracoronary blood flow velocity during angioplasty. Functional guide and indicator of the success of dilatation]

In order to assess the value of a new Doppler-fitted dilatation catheter, changes in blood flow velocities in the coronary arteries were recorded at various stages of transluminal angioplasty in 15 patients with isolated proximal coronary stenosis. A pulsed Doppler probe (emission frequency 20 MHz, recurrence frequency 62.5 MHz) attached to the distal end of the balloon catheter was used to measure blood flow velocities with a Doppler frequency/velocity relationship of about 3.75 cm/s per KHz. During each angioplasty the balloon was inflated 4 times on average, with successive increases of pressure from 7 to 12 atmospheres. Flow velocities were measured before and after each inflation and also when maximum hyperaemia occurred after temporary occlusion by the inflated balloon. Computer-assisted analysis of the coronary stenosis was carried out before and after the procedure. Patient's mean age was 53 years. Angioplasty was performed in the anterior interventricular artery (12 cases), the circumflex artery (2 cases) or the right coronary artery (1 case). Anatomical success was assessed by an increase of minimum luminal section area from 1.3 +/- 0.0 to 3.0 +/- 1.2 mm2. Functional success was assessed by a progressive and significant increase of the velocities measured during the first 3 dilatations. No further increase of velocity was observed between the last 2 inflations. Coronary reserve at the end of angioplasty was 2.1, corresponding to the theoretical value calculated taking into account the residual stenosis and the presence of the catheter in situ.(ABSTRACT TRUNCATED AT 250 WORDS)

Does the quantitative assessment of coronary artery dimensions predict the physiologic significance of a coronary stenosis?

To study the relationship between the quantitatively assessed coronary artery dimensions and the regional coronary flow reserve as measured by digital subtraction cineangiography, we investigated 17 coronary arteries with a single discrete proximal stenosis and 12 normal coronary arteries before and after intracoronary administration of papaverine. Coronary flow reserve was found to be curvilinearly related to minimal luminal cross-sectional area (r = .92, SEE = 0.73) and to percentage area stenosis (r = .92, SEE = 0.74). Normal coronary arteries had a coronary flow reserve of 5.0 (+/- 0.8 [SD]), which differed significantly from the coronary flow reserve of the coronary arteries with obstructive disease, in which values ranging from 0.5 to 3.9 were found. Coronary arteries with a percentage area stenosis between 50% and 70% and a minimal luminal cross-sectional area between 2 and 4.5 mm2 differed significantly (p = .001), with respect to the coronary flow reserve, from coronary arteries with a percentage area stenosis in excess of 70% and a minimal luminal cross-sectional area less than 2 mm2. With the use of hemodynamic equations that describe the pressure loss over a stenosis, a theoretical pressure-flow relationship can be inferred that characterizes the severity of the stenosis. Based on this theoretical pressure-flow relationship, coronary arteries that have a limited coronary flow reserve and critical stenosis (distal coronary perfusion pressure below 40 mm Hg at coronary flow of 3 ml/sec) can be identified with high sensitivity (83%) and specificity (82%). Thus, in coronary artery disease the consequent reduction in coronary flow reserve can be predicted with reasonable accuracy by quantitative assessment of coronary artery dimensions.

Diabetes insipidus associated with dysplastic pancytopenia

This case report describes a 60-year-old man who presented with a three-year history of generalized malaise, decreased libido, polyuria, and polydipsia. He had been previously investigated for pancytopenia, and found to have a hypoplastic bone marrow. A diagnosis of central diabetes insipidus was established; the patient was also found to have a number of other defects in his hypothalamic-pituitary function. Hematologic studies again revealed peripheral pancytopenia associated with a hypoplastic megaloblastic bone marrow. Computed axial and nuclear magnetic resonance tomography failed to establish the nature of the morphologic lesion in the hypothalamus. A possible relationship between the hematologic and endocrine disturbance is discussed.

Diagnosis of tricuspid regurgitation: comparison of jugular venous and liver pulse tracings with combined two-dimensional and Doppler-echocardiography

The clinical diagnosis of tricuspid regurgitation is difficult in patients after mitral valve replacement. We therefore studied the value of the jugular venous pulse tracing, liver pulse tracing and right atrial size estimated from a two-dimensional echocardiogram for diagnosing tricuspid regurgitation in 57 patients with a Björk-Shiley prosthesis in the mitral position and compared them with Doppler echocardiography. Liver pulse tracings have a higher diagnostic yield than jugular venous tracings which often have carotid pulse artifacts. The liver pulse has a sensitivity of 0.91, a specificity of 0.80. Right atrial dilatation has a sensitivity of only 0.50, but a specificity of 0.88. Likelihood ratios calculated on the basis of the combination of these two methods allow an accurate prediction of the presence or absence of tricuspid regurgitation.

Echocardiographic demonstration of free wall vegetative endocarditis complicated by a pulmonary embolism in a patient with ventricular septal defect

A defect in the muscular part of the interventricular septum in a 19 year old man was complicated by infective endocarditis caused by Staphylococcus aureus. The lesion was a large right ventricular free wall vegetation which embolised to the lungs. The vegetation was displayed by cross sectional echocardiography, which also confirmed the clinical diagnosis of ventricular septal defect. This case confirms the concept that the jet stream causes endocarditis at its point of impact. After six weeks' treatment with antibiotics the ventricular septal defect was repaired at operation.

Papaverine: the ideal coronary vasodilator for investigating coronary flow reserve? A study of timing, magnitude, reproducibility, and safety of the coronary hyperemic response after intracoronary papaverine

A potent, short-acting vasodilator that induces a maximal hyperemic response of the coronary vascular bed is needed to determine coronary flow reserve. In 12 patients, we measured coronary sinus blood flow by thermodilution over a period of 2 min during which a bolus of 10 mg papaverine was given into the left main coronary artery. This was repeated after 5 min to assess the reproducibility of the changes. The maximal hyperemic response lasted from 24 until 37 sec after papaverine administration. There was no significant difference between the two consecutive hyperemic responses (Student's t-test for paired observations). The mean difference between first and second hyperemic responses at 30 sec was 7.0% (SD +/- 6.2%). In conclusion, 10 mg of intracoronary papaverine is a short-lasting and reproducible means of inducing a maximal hyperemic response in the coronary vascular bed and therefore appears to be the ideal agent for investigating coronary flow reserve.