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Biomedical subjects

F Aguirre

Publications and source records attributed to F Aguirre.

At least 19 recordsLinked to original sources
PubMed1992

Angiographic identification of malpositioned balloon catheters during mitral valvuloplasty.

The positioning of balloon catheters for the percutaneous mitral valvuloplasty technique is critical to ensure an adequate result and minimize complications. Passage of two balloon catheters in parallel through a thickened atrial septum and maintenance of satisfactory positioning in the left ventricle can be difficult. We describe unsuspected malpositioning of the balloons in two patients documented angiographically in our laboratory. Recognizing and avoiding these positions will reduce the potential for serious complications.

Adult↗
PubMed1992

Interpretation of cardiac pathophysiology from pressure waveform analysis: pericardial compressive hemodynamics, Part II.

Constrictive physiology characteristically alters atrial and ventricular waveforms. Normal pressure and flow responses to inspiration are blocked or reversed. The impairment of early diastolic filling is the common feature of restrictive myocardial, as well as diseased pericardial, processes. Low pressure tamponade can limit cardiac output, but may be difficult to detect by clinical signs alone. Examination of the pressure waveforms may provide clues to the diagnosis of constrictive physiology in these patients.

Blood Pressure↗
PubMed1992

Interpretation of cardiac pathophysiology from pressure waveform analysis: coronary hemodynamics, Part III: Coronary hyperemia.

Basal patterns (systolic/diastolic components) of coronary flow velocity as previously described are generally maintained during hyperemia and can be easily recorded in the catheterization laboratory during pharmacologic stimulation. The interpretation of the clinical significance of coronary vasodilatory reserve may be complicated by both coronary and myocardial diseases. Distal coronary artery hyperemic responses measured with ultrasound Doppler-tipped guidewires will provide new information on traditional observations of coronary physiology in humans.

Adenosine↗
PubMed1992

Interpretation of cardiac pathophysiology from pressure waveform analysis: mitral valve gradients: Part I.

The mitral valve gradient is dependent on the precise measurement of left atrial (or pulmonary capillary wedge) and left ventricular pressures. Artifacts involving either pressure measurement will produce inaccuracies which may have clinical significance. Several methods and formulas using both invasive and noninvasive techniques should verify clinical findings and confirm the severity of mitral valve disease prior to definite therapy. The changes in mitral valve gradients after balloon catheter valvuloplasty will be discussed in part II of this hemodynamic rounds.

Blood Flow Velocity↗
PubMed1992

The usefulness of a tracking catheter in complex coronary angioplasty.

Complex lesion angioplasty, such as chronic total occlusions, coronary vessels with right angle take-offs, tortuous vessels, and tortuous internal mammary artery or saphenous vein grafts is a continuing challenge. The complex problems have been successfully managed with novel guiding catheter shapes and ultralow profile balloons. However, on occasion steerable guidewire placement remains extremely difficult, despite significantly improved means of intracoronary manipulations.

Aged↗
PubMed1992

The effect of ergonovine on coronary vasodilatory reserve in patients with angiographically normal coronary arteries.

Ergonovine produces physiologic coronary artery narrowing in many patients without focal coronary spasm. The effect of ergonovine-induced coronary vasoconstriction on coronary vasodilatory reserve is unknown. Therefore we studied 10 patients with atypical chest pain and angiographically normal coronary arteries. The heart rate and blood pressure were recorded continuously and coronary Doppler flow velocity was measured continuously with a 20 MHz Doppler-tipped catheter. Ergonovine caused diffuse narrowing of the vessels in all patients, with a 12% +/- 5% change in diameter of the left anterior descending coronary artery (p less than 0.001). There was a significant change in systolic (17% +/- 12% change; p less than 0.05) and mean arterial pressure (13% +/- 13% change; p less than 0.05), with no significant change in mean coronary flow velocity with ergonovine. Ergonovine also did not attenuate the maximal hyperemic response with papaverine. Thus despite an increase in myocardial demand and a decrease in caliber of conductance coronary vessels, the coronary autoregulatory flow responses were intact after the administration of ergonovine.

Angina Pectoris, Variant↗
PubMed1992

The effects of ionic and nonionic radiographic contrast media on coronary hyperemia in patients during coronary angiography.

The purpose of this study was to compare the differential effects of ionic, high-osmolar meglumine diatrizoate; ionic, low-osmolar ioxaglate meglumine; and nonionic, low-osmolar iohexol (all radiographic contrast agents) on coronary blood flow velocity and hyperemic responses during diagnostic coronary angiography. Coronary flow velocity and arterial pressure were measured at baseline and during maximal hyperemia after contrast media were randomly injected (4 to 6 ml into left coronary artery) in 22 patients with the use of a Judkins-style 20 MHz Doppler-tipped angiographic catheter. Contrast media-induced hyperemic responses were compared to those induced with intracoronary nitroglycerin (200 micrograms) and papaverine (10 mg). There were no significant differences in systolic, diastolic, or mean arterial pressure measurements among the three contrast agents. The increase in mean coronary flow velocity during hyperemia was 118 +/- 93%, 133 +/- 73%, and 136 +/- 86% for iohexol, ioxaglate meglumine, and diatrizoate, respectively (p = NS among agents vs 264 +/- 109% for papaverine; p less than 0.05 for all). Coronary vasodilatory reserve (calculated as the ratio of hyperemic to basal mean flow velocity) was also similar among agents. It was comparable to the coronary vasodilatory reserve with nitroglycerin (2.1 +/- 1.0 to 2.2 +/- 1.1) and significantly less than that with papaverine (3.3 +/- 2.2, p less than 0.05). These data indicate that the clinical advantages of nonionic or low-osmolar contrast media are not mechanistically related to significant attenuation of the coronary hyperemic response.

Blood Flow Velocity↗
PubMed1992

Variability in the quantitation of mitral regurgitation by Doppler color flow mapping: comparison of transthoracic and transesophageal studies.

OBJECTIVES: This study was designed to assess the most accurate and reproducible methods to quantitate mitral regurgitation by color flow transthoracic and transesophageal echocardiography. BACKGROUND: Quantitative measurements of mitral regurgitant jets have resulted in an intraobserver and interobserver variability of up to 20%. Few data are available evaluating the various techniques by which mitral regurgitant jets are quantitated. METHODS: Forty patients who underwent cardiac catheterization and both transesophageal and transthoracic echocardiography within 1 week were studied. Two boundaries of the color regurgitant jet area were identified and quantitated: 1) the central aliased core of the regurgitant jet with the mosaic pattern excluding any swirling low velocity flow; and 2) the largest definable area of the regurgitant flow, including low velocity flow considered to be part of the regurgitant jet. RESULTS: The total regurgitant areas obtained by transthoracic and transesophageal studies did not differ (5.7 +/- 4.6 vs. 5.7 +/- 3.7 cm2; p = NS). However, the transesophageal mosaics were significantly larger than those obtained by transthoracic echocardiography (3.6 +/- 3.1 vs. 2.8 +/- 3.4 cm2; p less than 0.01). In transthoracic studies observer variability was higher when the mosaic aspect of the regurgitant jet rather than the total regurgitant area was measured (24 +/- 20 vs. 16 +/- 11%; p less than 0.05). In contrast, in transesophageal studies variability was lower when the mosaic area rather than the total regurgitant area was measured (11 +/- 12% vs. 18 +/- 18%; p less than 0.05). The best correlations with left ventriculography were obtained by using the absolute total regurgitant area (r = 0.72) for transthoracic studies and the mosaic area of the jets (r = 0.87) for transesophageal studies. CONCLUSIONS: Doppler color flow jet areas correlate closely with angiographic results in the evaluation of mitral regurgitation. The total regurgitant area (including the surrounding swirling flow) in transthoracic studies and the aliased core of the regurgitant jet (mosaic) in transesophageal studies appear to be the most accurate and reproducible measurements for evaluating mitral regurgitation.

Cardiac Catheterization↗
PubMed1992

Heparin-induced prolongation of partial thromboplastin time after thrombolysis: relation to coronary artery patency. HART Investigators.

Having previously shown in the Heparin Aspirin Reperfusion Trial that the empiric use of early intravenous heparin after recombinant tissue-type plasminogen activator (rt-PA) is an important component in the overall treatment strategy, we examine in this report the specific relation between the degree of prolongation of activated partial thromboplastin time and coronary artery patency. To evaluate the hypothesis that arterial patency after administration of rt-PA for acute myocardial infarction is sustained by effective anticoagulation, activated partial thromboplastin time of heparin recipients was determined 8 and 12 h after the start of thrombolysis. Mean activated partial thromboplastin time was higher among patients with an open infarct-related artery than in those with a closed artery (81 +/- 4 vs. 54 +/- 9 s, p less than 0.02). Only 45% of patients with values less than 45 s at both 8 and 12 h had Thrombolysis in Myocardial Infarction (TIMI) flow grade 2 or 3 in the infarct-related artery at 18 h. In contrast, 88% of patients with activated partial thromboplastin time greater than 45 s and 95% of those with values greater than 60 s had an open infarct-related artery at 18 h (p = 0.003 and 0.0006, respectively). Among patients with an initially patent infarct-related artery who underwent repeat angiography at 7 days, activated partial thromboplastin time was similar in those with a persistently patent artery and those with late reocclusion. Excessive anticoagulation did not appear to increase hemorrhagic risk except that access site-related hemorrhage was more common in patients with activated partial thromboplastin time greater than 100 s at 8 h.(ABSTRACT TRUNCATED AT 250 WORDS)

Aspirin↗