Biomedical subjects
Publications and source records attributed to F Aguirre.
Congenital anomalies are unusual in adults, but characteristic hemodynamic data facilitate precise diagnoses. A complete evaluation, including assessment for intracardiac shunts, is usually indicated in patients prior to major surgical procedures or electrophysiologic interventions.
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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.
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.
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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.
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)
Eighty consecutive patients who underwent both left ventriculography and single-plane transesophageal echocardiography with Doppler color flow mapping were studied to compare the two techniques in the assessment of mitral regurgitation. Only the mosaic aspect of the regurgitant jet was included in the measurements. Values for inter- and intraobserver variability for the maximal regurgitant area measurements were 10 +/- 9% and 9 +/- 8%, respectively. The best correlation between angiography and Doppler color flow imaging was obtained with the maximal regurgitant area (r = 0.90). A maximal regurgitant area less than 3 cm2 predicted mild mitral regurgitation with a sensitivity of 96%, specificity of 100% and a predictive accuracy of 98%, whereas a maximal regurgitant area greater than 6 cm2 predicted severe mitral regurgitation with a sensitivity of 91%, a specificity of 100% and a predictive accuracy of 98%. A strong, although inferior, correlation was found for the maximal regurgitant area/left atrial area ratio (r = 0.81). A ratio less than 20% predicted mild mitral regurgitation with 94% accuracy, whereas a ratio greater than 35% predicted severe mitral regurgitation with 85% accuracy. Thus, single-plane transesophageal echocardiography with Doppler color flow mapping is an exquisitely sensitive technique for the diagnosis of mitral regurgitation. Minimal degrees of mitral regurgitation can be detected in approximately 62% of patients in whom no mitral regurgitation is detected by angiography. The mosaic maximal regurgitant area is a simple and easily obtainable Doppler echocardiographic index that provides an accurate estimation of mitral regurgitation severity.
To assess the outcome of percutaneous transluminal coronary angioplasty (PTCA) in patients with severe left ventricular (LV) dysfunction and to determine the predictors of mortality, 73 patients with LV ejection fraction less than or equal to 40% who underwent initial PTCA were analyzed. The majority of patients had prior (greater than 1 week) myocardial infarction (62 patients, 85%). Congestive heart failure and unstable angina were present in 24 (45%) and 49 (67%) patients, respectively. Multivessel coronary artery disease was present in 60 (83%). The LV ejection fraction ranged from 14 to 40% (mean 34%). Intraaortic balloon pump (15%) and percutaneous cardiopulmonary bypass support (4%) was used infrequently. Angiographic success was obtained in 109 of 128 lesions (85%) attempted. Complete revascularization was obtained in 16 of 60 patients with clinical success. Procedure-related mortality was 5% (4 patients). All patients were followed from greater than or equal to 6 to less than or equal to 71 months (average 26). The estimated survival was 79 +/- 5%, 74 +/- 6%, 66 +/- 7% and 57 +/- 8% at 1, 2, 3 and 4 years, respectively. A Cox regression analysis revealed that the presence of congestive heart failure, a lower LV ejection fraction and a higher myocardial jeopardy score for contractile myocardium were independent predictors of survival after PTCA in patients with LV dysfunction. In conclusion, a high-risk subset can be identified among patients with severe LV dysfunction who undergo PTCA.
With the reduction in profile of balloon dilation catheters, until recently, it has been the internal dimensions and performance of the guiding catheter that has mandated the use of 7, 8 or 9 French (F) systems for the performance of percutaneous transluminal coronary angioplasty (PTCA). A new 5F catheter design (Sherwood Medical Co., St. Louis, MO) provided a large inner lumen (0.4") permitting use of 0.20-0.22" fixed-wire PTCA balloon catheters with good coronary visualization. Potential advantages include reduced coronary artery ostial trauma and catheter induced damping and enhanced patient comfort. We report our initial experience in 14 patients undergoing PTCA with a 5 and 6F guide/fixed-wire system. Mean age was 63 +/- 10 (43-78 years). PTCA indications: Cardiogenic shock (1), post-myocardial infarction angina pectoris (2), grade III angina (5) and unstable angina pectoris (6). Vessel attempted: Left anterior descending (3), circumflex (4), obtuse marginal (2), diagonal (1), right coronary artery (3), and internal thoracic artery (1). Twelve patients had femoral approach; two brachial approach. The USCI Probe (USCI Division, Billerica, MA) was used in 8 lesions and SCIMED ACE (SCIMED Life Systems, Maplegrove, MN) catheter in 7 lesions. Successful 5 or 6F guide/fixed-wire dilations reduced the stenosis (77 +/- 14 to 37 +/- 30%) and were successfully performed in 79% (11/14). One 5F patient required 8F guiding catheter and was dilated with 2.0 fixed-wire balloon. A second failed 5F PTCA could not be dilated with any larger conventional system. A third total occlusion could not be crossed with a guidewire or fixed wire balloon. No patient had a complication.(ABSTRACT TRUNCATED AT 250 WORDS)
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To assess the use of adenosine as an alternative agent for determination of coronary vasodilator reserve, hemodynamics and coronary blood flow velocity were measured at rest and during peak hyperemic responses to continuous intravenous adenosine infusion (50, 100 and 150 micrograms/kg per min for 3 min) and intracoronary papaverine (10 mg) in 34 patients (17 without [group 1] and 17 with [group 2] significant left coronary artery disease), and in 17 patients (11 without and 6 with left coronary artery disease) after low dose (2.5 mg) intravenous bolus injection of adenosine. The maximal adenosine dose did not change mean arterial pressure (-10 +/- 14% and -6 +/- 12% for groups 1 and 2, respectively) but increased the heart rate (15 +/- 18% and 13 +/- 16, respectively). For continuous adenosine infusions, mean coronary flow velocity increased 64 +/- 104%, 122 +/- 94% and 198 +/- 59% and 15 +/- 51%, 110 +/- 95% and 109 +/- 86% in groups 1 and 2, respectively for each of the three doses. Mean coronary flow velocity increased significantly after 100 and 150 micrograms/kg of adenosine and 10 mg of intracoronary papaverine (48 +/- 25, 52 +/- 19 and 54 +/- 21 cm/s, respectively; all p less than 0.05 vs. baseline) and was significantly higher than in group 2 (37 +/- 24, 32 +/- 16, 41 +/- 23 cm/s; all p less than 0.05 vs. group 1). The coronary vasodilator reserve ratio (calculated as the ratio of hyperemic to basal mean flow velocity) for adenosine and papaverine was 2.94 +/- 1.50 and 2.94 +/- 1.00, respectively, in group 1 and was significantly and similarly reduced in group 2 (2.16 +/- 0.81 and 2.38 +/- 0.78, respectively; both p less than 0.05 vs. group 1). Low dose bolus injection of adenosine increased mean velocity equivalently to that after continuous infusion of 100 micrograms/kg, but less than after papaverine. There was a strong correlation between adenosine infusion and papaverine for both mean coronary flow velocity and coronary vasodilator reserve ratio (r2 = 0.871 and 0.325; SEE = 0.068 and 0.189, respectively; both p less than 0.0005). No patient had significant arrhythmias or prolongation of the corrected QT (QTc) interval with adenosine, but papaverine increased the QT (QTc) interval from 445 +/- 44 to 501 +/- 43 ms (p less than 0.001 vs. both maximal adenosine and baseline) and produced nonsustained ventricular tachycardia in one patient.(ABSTRACT TRUNCATED AT 400 WORDS)
It is often difficult to delineate the true course of anomalous coronary arteries by angiography because it only provides a 2-dimensional view of a complex 3-dimensional structure. The purpose of this study was to confirm morphologically the radiographic appearance of anomalous coronary arteries and to construct a protocol for rapid determination of their true course. Twenty-one adults who had anomalous origin of coronary arteries without other evidence of congenital heart disease were reviewed. Using an anatomically correct model of the heart, solder wire was placed in the pathologically described anomalous positions and radiographed. With this model the pathologically described courses could be easily recognized and separated radiographically. These courses were confirmed in the operating room in 2 patients and a rare anomaly of posterior origin of a coronary artery was also confirmed by autopsy.